Protamine sulphate is a potent base that forms a stable salt complex with heparin, an acidic substance. This complex is inactive and is used to counteract the effects of heparin. Additionally, protamine sulphate can be used to reverse the effects of LMWHs, although it is not as effective, providing only about two-thirds of the relative effect.

Apart from its ability to neutralize heparin, protamine sulphate also possesses a weak intrinsic anticoagulant effect. This is believed to be due to its inhibition of the formation and activity of thromboplastin.

To administer protamine sulphate, it is slowly injected intravenously. The dosage should be adjusted based on the amount of heparin to be neutralized, the time elapsed since heparin administration, and the aPTT. For every 100 IU of heparin, 1 mg of protamine is required for neutralization. However, the maximum adult dose within a 10-minute period should not exceed 50 mg.

It is important to note that protamine sulphate has additional effects on the body. It acts as a depressant on the heart muscle and may lead to bradycardia and hypotension. These effects are caused by complement activation and the release of leukotrienes.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 individuals. It occurs due to a deficiency in Von Willebrand factor (vWF), which plays a crucial role in blood clotting. vWF not only binds to factor VIII to protect it from rapid breakdown, but it is also necessary for proper platelet adhesion. When vWF is lacking, both factor VIII levels and platelet function are affected, leading to prolonged APTT and bleeding time. However, the platelet count and thrombin time remain unaffected.

While some individuals with vWD may not experience any symptoms and are diagnosed incidentally during a clotting profile check, others may present with easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be managed with desmopressin. This medication works by stimulating the release of vWF stored in the Weibel-Palade bodies, which are storage granules found in the endothelial cells lining the blood vessels and heart. By increasing the patient’s own levels of vWF, desmopressin helps improve clotting. In more severe cases, replacement therapy is necessary. This involves infusing cryoprecipitate or Factor VIII concentrate to provide the missing vWF. Replacement therapy is particularly recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

Dabigatran etexilate is a medication that directly inhibits thrombin, a protein involved in blood clotting. It is prescribed to prevent venous thromboembolism in adults who have undergone total hip or knee replacement surgery. It is also approved for the treatment of deep-vein thrombosis and pulmonary embolism, as well as the prevention of recurrent episodes in adults.

The duration of treatment with dabigatran etexilate should be determined by considering the benefits of the medication against the risk of bleeding. For individuals with temporary risk factors such as recent surgery, trauma, or immobilization, a shorter duration of treatment (at least three months) may be appropriate. On the other hand, individuals with permanent risk factors or those with idiopathic deep-vein thrombosis or pulmonary embolism may require a longer duration of treatment.

Dabigatran etexilate is also indicated for the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation who have additional risk factors such as previous stroke or transient ischemic attack, symptomatic heart failure, age 75 years or older, diabetes mellitus, or hypertension.

One of the advantages of dabigatran etexilate is its rapid onset of action. Additionally, routine monitoring of anticoagulant activity is not necessary as traditional tests like INR may not accurately reflect its effects. However, it is important to monitor patients for signs of bleeding or anemia, as hemorrhage is the most common side effect. If severe bleeding occurs, treatment with dabigatran etexilate should be discontinued.

There are certain situations in which dabigatran etexilate should not be used. These include active bleeding, a significant risk of major bleeding (such as recent gastrointestinal ulcer, oesophageal varices, recent brain, spine, or ophthalmic surgery, recent intracranial hemorrhage, malignant neoplasms, or vascular aneurysm), and as an anticoagulant for prosthetic heart valves.

In the UK, idarucizumab is the first approved agent that can reverse the anticoagulant effect of dabigatran etexilate.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 individuals. It occurs due to a deficiency in Von Willebrand factor (vWF), which plays a crucial role in blood clotting. vWF not only binds to factor VIII to protect it from rapid breakdown, but it is also necessary for proper platelet adhesion. When vWF is lacking, both factor VIII levels and platelet function are affected, leading to prolonged APTT and bleeding time. However, the platelet count and thrombin time remain unaffected.

While some individuals with vWD may not experience any symptoms and are diagnosed incidentally during a clotting profile check, others may present with easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be managed with desmopressin. This medication works by stimulating the release of vWF stored in the Weibel-Palade bodies, which are storage granules found in the endothelial cells lining the blood vessels and heart. By increasing the patient’s own levels of vWF, desmopressin helps improve clotting. In more severe cases, replacement therapy is necessary. This involves infusing cryoprecipitate or Factor VIII concentrate to provide the missing vWF. Replacement therapy is particularly recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

In the blood tests, certain findings can support a diagnosis of glandular fever. One of these findings is lymphocytosis, which refers to an increased number of lymphocytes in the blood. Lymphocytes are a type of white blood cell that plays a crucial role in the immune response. In glandular fever, the Epstein-Barr virus (EBV) is the most common cause, and it primarily infects and activates lymphocytes, leading to their increased numbers in the blood.

On the other hand, neutropenia (a decreased number of neutrophils) and neutrophilia (an increased number of neutrophils) are not typically associated with glandular fever. Neutrophils are another type of white blood cell that helps fight off bacterial infections. In glandular fever, the primary involvement is with lymphocytes rather than neutrophils.

Monocytosis, which refers to an increased number of monocytes, can also be seen in glandular fever. Monocytes are another type of white blood cell that plays a role in the immune response. Their increased numbers can be a result of the immune system’s response to the Epstein-Barr virus.

Eosinophilia, an increased number of eosinophils, is not commonly associated with glandular fever. Eosinophils are white blood cells involved in allergic reactions and parasitic infections, and their elevation is more commonly seen in those conditions.

In summary, the presence of lymphocytosis and possibly monocytosis in the blood tests would support a diagnosis of glandular fever, while neutropenia, neutrophilia, and eosinophilia are less likely to be associated with this condition.

Further Reading:

Glandular fever, also known as infectious mononucleosis or mono, is a clinical syndrome characterized by symptoms such as sore throat, fever, and swollen lymph nodes. It is primarily caused by the Epstein-Barr virus (EBV), with other viruses and infections accounting for the remaining cases. Glandular fever is transmitted through infected saliva and primarily affects adolescents and young adults. The incubation period is 4-8 weeks.

The majority of EBV infections are asymptomatic, with over 95% of adults worldwide having evidence of prior infection. Clinical features of glandular fever include fever, sore throat, exudative tonsillitis, lymphadenopathy, and prodromal symptoms such as fatigue and headache. Splenomegaly (enlarged spleen) and hepatomegaly (enlarged liver) may also be present, and a non-pruritic macular rash can sometimes occur.

Glandular fever can lead to complications such as splenic rupture, which increases the risk of rupture in the spleen. Approximately 50% of splenic ruptures associated with glandular fever are spontaneous, while the other 50% follow trauma. Diagnosis of glandular fever involves various investigations, including viral serology for EBV, monospot test, and liver function tests. Additional serology tests may be conducted if EBV testing is negative.

Management of glandular fever involves supportive care and symptomatic relief with simple analgesia. Antiviral medication has not been shown to be beneficial. It is important to identify patients at risk of serious complications, such as airway obstruction, splenic rupture, and dehydration, and provide appropriate management. Patients can be advised to return to normal activities as soon as possible, avoiding heavy lifting and contact sports for the first month to reduce the risk of splenic rupture.

Rare but serious complications associated with glandular fever include hepatitis, upper airway obstruction, cardiac complications, renal complications, neurological complications, haematological complications, chronic fatigue, and an increased risk of lymphoproliferative cancers and multiple sclerosis.

Methaemoglobinaemia is a condition that can be caused by nitrates, including amyl nitrite.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

Blood transfusion is a crucial treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there has been an improvement in safety procedures and a reduction in transfusion use, errors and serious adverse reactions still occur and often go unreported.

Mild allergic reactions during blood transfusion are relatively common and typically occur within a few minutes of starting the transfusion. These reactions happen when patients have antibodies that react with foreign plasma proteins in the transfused blood components. Symptoms of mild allergic reactions include urticaria, Pruritus, and hives.

Anaphylaxis, on the other hand, is much rarer and occurs when an individual has previously been sensitized to an allergen present in the blood. When re-exposed to the allergen, the body releases IgE or IgG antibodies, leading to severe symptoms such as bronchospasm, laryngospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. Anaphylaxis can be fatal.

Mild allergic reactions can be managed by slowing down the transfusion rate and administering antihistamines. If there is no progression after 30 minutes, the transfusion may continue. Patients who have experienced repeated allergic reactions to transfusion should be given pre-treatment with chlorpheniramine. In cases of anaphylaxis, the transfusion should be stopped immediately, and the patient should receive oxygen, adrenaline, corticosteroids, and antihistamines following the ALS protocol.

The table below summarizes the main transfusion reactions and complications, along with their features and management:

Complication | Features | Management
Febrile transfusion reaction | 1 degree rise in temperature, chills, malaise | Supportive care, paracetamol
Acute haemolytic reaction | Fever, chills, pain at transfusion site, nausea, vomiting, dark urine | STOP THE TRANSFUSION, administer IV fluids, diuretics if necessary
Delayed haemolytic reaction | Fever, anaemia, jaundice, haemoglobinuria | Monitor anaemia and renal function, treat as required
Allergic reaction | Urticaria, Pruritus, hives | Symptomatic treatment with ant

Chronic lymphocytic leukaemia (CLL) is the most common type of leukaemia in adults. It occurs when mature lymphocytes multiply uncontrollably. About 95% of cases are of B-cell lineage.

CLL is typically a slow-growing form of leukaemia and is often discovered incidentally during routine blood tests. As the disease progresses, patients may experience swollen lymph nodes, enlarged liver and spleen, anemia, and increased susceptibility to infections.

This condition primarily affects adult men, with over 75% of CLL patients being men over the age of 50.

A blood test for CLL usually reveals an increased number of lymphocytes (typically more than 5 x 109/l, but it can be higher). Advanced stages of the disease may also show normochromic, normocytic anemia. A peripheral blood smear can confirm the presence of lymphocytosis, and smudge cells are often observed.

The Binet system is used to stage CLL, categorizing it as follows:
– Stage A: Hemoglobin (Hb) levels above 10 g/dl, platelet count above 100 x 109/l, involvement of fewer than 3 lymph node areas.
– Stage B: Hb levels above 10 g/dl, platelet count above 100 x 109/l, involvement of more than 3 lymph node areas.
– Stage C: Hb levels below 10 g/dl, platelet count below 100 x 109/l, or both.

Early stages of CLL (Binet stage A and B without active disease) do not require immediate treatment and can be monitored through regular follow-up and blood tests. Patients with more advanced disease have various treatment options available, including monoclonal antibodies (such as rituximab), purine analogues (like fludarabine), and alkylating agents (such as chlorambucil).

Auer rods are small, needle-shaped structures that can be found within the cytoplasm of blast cells. These structures have a distinct eosinophilic appearance. While they are most frequently observed in cases of acute myeloid leukemia, they can also be present in high-grade myelodysplastic syndromes and myeloproliferative disorders.

Transfusion transmitted bacterial infection is a rare complication that can occur during blood transfusion. It is more commonly associated with platelet transfusion, as platelets are stored at room temperature. Additionally, previously frozen components that are thawed using a water bath and red cell components stored for several weeks are also at a higher risk for bacterial infection.

Both Gram-positive and Gram-negative bacteria have been implicated in transfusion-transmitted bacterial infection, but Gram-negative bacteria are known to cause more severe illness and have higher rates of morbidity and mortality. Among the bacterial organisms, Yersinia enterocolitica is the most commonly associated with this type of infection. This particular organism is able to multiply at low temperatures and utilizes iron as a nutrient, making it well-suited for proliferation in blood stores.

The clinical features of transfusion-transmitted bacterial infection typically manifest shortly after the transfusion begins. These features include a high fever, chills and rigors, nausea and vomiting, tachycardia, hypotension, and even circulatory collapse.

If there is suspicion of a transfusion-transmitted bacterial infection, it is crucial to immediately stop the transfusion. Blood cultures and a Gram-stain should be requested to identify the specific bacteria causing the infection. Broad-spectrum antibiotics should be initiated promptly. Furthermore, the blood pack should be returned to the blood bank urgently for culture and Gram-stain analysis.

Protamine sulphate is a potent base that forms a stable salt complex with heparin, an acidic substance. This complex renders heparin inactive, making protamine sulphate a useful tool for neutralizing the effects of heparin. Additionally, protamine sulphate can be used to reverse the effects of LMWHs, although it is not as effective, providing only about two-thirds of the relative effect.

It is important to note that protamine sulphate also possesses its own weak intrinsic anticoagulant effect. This effect is believed to stem from its ability to inhibit the formation and activity of thromboplastin.

When administering protamine sulphate, it is typically done through slow intravenous injection. The dosage should be adjusted based on the amount of heparin that needs to be neutralized, the time that has passed since heparin administration, and the aPTT (activated partial thromboplastin time). As a general guideline, 1 mg of protamine can neutralize 100 IU of heparin. However, it is crucial to adhere to a maximum adult dose of 50 mg within a 10-minute period.

It is worth mentioning that protamine sulphate can have some adverse effects. It acts as a myocardial depressant, potentially leading to bradycardia (slow heart rate) and hypotension (low blood pressure). These effects may arise due to complement activation and leukotriene release.

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, immune dilution, and transfusion errors. While there have been improvements in safety procedures and efforts to minimize the use of transfusion, errors and serious adverse reactions still occur and often go unreported.

One rare complication of blood transfusion is transfusion-associated graft-vs-host disease (TA-GVHD). This condition typically presents with fever, rash, and diarrhea 1-4 weeks after the transfusion. Laboratory findings may show pancytopenia and abnormalities in liver function. Unlike GVHD after marrow transplantation, TA-GVHD leads to severe marrow aplasia with a mortality rate exceeding 90%. Unfortunately, there are currently no effective treatments available for this condition, and survival is rare, with death usually occurring within 1-3 weeks of the first symptoms.

During a blood transfusion, viable T lymphocytes from the donor are transfused into the recipient’s body. In TA-GVHD, these lymphocytes engraft and react against the recipient’s tissues. However, the recipient is unable to reject the donor lymphocytes due to factors such as immunodeficiency, severe immunosuppression, or shared HLA antigens. Supportive management is the only option for TA-GVHD.

The following summarizes the main complications and reactions that can occur during a blood transfusion:

Complication Features Management
Febrile transfusion reaction
– Presents with a 1-degree rise in temperature from baseline, along with chills and malaise.
– Most common reaction, occurring in 1 out of 8 transfusions.
– Usually caused by cytokines from leukocytes in transfused red cell or platelet components.
– Supportive management, with the use of paracetamol for symptom relief.

Acute haemolytic reaction
– Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine.
– Often accompanied by a feeling of ‘impending doom’.
– Most serious type of reaction, often due to ABO incompatibility caused by administration errors.
– Immediate action required: stop the transfusion, administer IV fluids, and consider diuretics if necessary.

Delayed haemolytic reaction
– Typically occurs 4-8 days after a blood transfusion.
– Symptoms include fever, anemia and/or hyperbilirubinemia

Chronic lymphocytic leukaemia (CLL) is the most common form of leukaemia in adults. It occurs when mature lymphocytes multiply uncontrollably. B-cell lineage accounts for about 95% of cases. CLL is typically slow-growing and is often discovered incidentally during routine blood tests. As the disease progresses, patients may experience swollen lymph nodes, enlarged liver and spleen, low red blood cell count, and increased susceptibility to infections. This condition primarily affects adult males, with over 75% of CLL patients being men over the age of 50.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur. One common adverse reaction is febrile transfusion reactions, which present as an unexpected rise in temperature during or after transfusion. This can be caused by cytokine accumulation or recipient antibodies reacting to donor antigens. Treatment for febrile transfusion reactions is supportive, and other potential causes should be ruled out.

Another serious complication is acute haemolytic reaction, which is often caused by ABO incompatibility due to administration errors. This reaction requires the transfusion to be stopped and IV fluids to be administered. Delayed haemolytic reactions can occur several days after a transfusion and may require monitoring and treatment for anaemia and renal function. Allergic reactions, TRALI (Transfusion Related Acute Lung Injury), TACO (Transfusion Associated Circulatory Overload), and GVHD (Graft-vs-Host Disease) are other potential complications that require specific management approaches.

In summary, blood transfusion carries risks and potential complications, but efforts have been made to improve safety procedures. It is important to be aware of these complications and to promptly address any adverse reactions that may occur during or after a transfusion.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur. One common adverse reaction is febrile transfusion reactions, which present as an unexpected rise in temperature during or after transfusion. This can be caused by cytokine accumulation or recipient antibodies reacting to donor antigens. Treatment for febrile transfusion reactions is supportive, and other potential causes should be ruled out.

Another serious complication is acute haemolytic reaction, which is often caused by ABO incompatibility due to administration errors. This reaction requires the transfusion to be stopped and IV fluids to be administered. Delayed haemolytic reactions can occur several days after a transfusion and may require monitoring and treatment for anaemia and renal function. Allergic reactions, TRALI (Transfusion Related Acute Lung Injury), TACO (Transfusion Associated Circulatory Overload), and GVHD (Graft-vs-Host Disease) are other potential complications that require specific management approaches.

In summary, blood transfusion carries risks and potential complications, but efforts have been made to improve safety procedures. It is important to be aware of these complications and to promptly address any adverse reactions that may occur during or after a transfusion.

Transfusion transmitted bacterial infection is a rare complication that can occur during blood transfusion. It is more commonly associated with platelet transfusion, as platelets are stored at room temperature. Additionally, previously frozen components that are thawed using a water bath and red cell components stored for several weeks are also at a higher risk for bacterial infection.

Both Gram-positive and Gram-negative bacteria have been implicated in transfusion-transmitted bacterial infection, but Gram-negative bacteria are known to cause more severe illness and have higher rates of morbidity and mortality. Among the bacterial organisms, Yersinia enterocolitica is the most commonly associated with this type of infection. This particular organism is able to multiply at low temperatures and utilizes iron as a nutrient, making it well-suited for proliferation in blood stores.

The clinical features of transfusion-transmitted bacterial infection typically manifest shortly after the transfusion begins. These features include a high fever, chills and rigors, nausea and vomiting, tachycardia, hypotension, and even circulatory collapse.

If there is suspicion of a transfusion-transmitted bacterial infection, it is crucial to immediately stop the transfusion. Blood cultures and a Gram-stain should be requested to identify the specific bacteria causing the infection. Broad-spectrum antibiotics should be initiated promptly. Furthermore, the blood pack should be returned to the blood bank urgently for culture and Gram-stain analysis.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 individuals. It occurs due to a deficiency in Von Willebrand factor (vWF), which plays a crucial role in blood clotting. vWF not only binds to factor VIII to protect it from rapid breakdown, but it is also necessary for proper platelet adhesion. When vWF is lacking, both factor VIII levels and platelet function are affected, leading to prolonged APTT and bleeding time. However, the platelet count and thrombin time remain unaffected.

While some individuals with vWD may not experience any symptoms and are diagnosed incidentally during a clotting profile check, others may present with easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be managed with desmopressin. This medication works by stimulating the release of vWF stored in the Weibel-Palade bodies, which are storage granules found in the endothelial cells lining the blood vessels and heart. By increasing the patient’s own levels of vWF, desmopressin helps improve clotting. In more severe cases, replacement therapy is necessary. This involves infusing cryoprecipitate or Factor VIII concentrate to provide the missing vWF. Replacement therapy is particularly recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Pernicious anaemia is a condition that affects the stomach and is characterized by the loss of gastric parietal cells and impaired secretion of intrinsic factor (IF). IF is crucial for the absorption of vitamin B12 in the ileum, and as a result, megaloblastic anaemia occurs. This condition is commonly seen in individuals who have undergone gastrectomy.

The clinical manifestations of pernicious anaemia include weight loss, loss of appetite, fatigue, diarrhoea, and a distinct lemon-yellow skin color, which is caused by a combination of haemolytic jaundice and the paleness associated with anaemia. Other symptoms may include glossitis (inflammation of the tongue) and oral ulceration. Neurological symptoms can also occur, such as subacute combined degeneration of the spinal cord and peripheral neuropathy. The earliest sign of central nervous system involvement is often the loss of position and vibratory sense in the extremities.

When investigating pernicious anaemia, certain findings may be observed. These include macrocytic anaemia, neutropaenia, thrombocytopaenia, anisocytosis and poikilocytosis on a blood film, low serum B12 levels, elevated serum bilirubin levels (indicating haemolysis), the presence of intrinsic factor antibodies, and a positive Schilling test.

The treatment for pernicious anaemia involves lifelong supplementation of vitamin B12, typically administered through intramuscular injections.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion usage, errors and adverse reactions still occur.

One serious complication is acute haemolytic transfusion reactions, which happen when incompatible red cells are transfused and react with the patient’s own antibodies. This usually occurs due to human error, such as mislabelling sample tubes or request forms. Symptoms of this reaction include a feeling of impending doom, fever, chills, pain and warmth at the transfusion site, nausea, vomiting, and back, joint, and chest pain. Immediate action should be taken to stop the transfusion, replace the donor blood with normal saline or another suitable crystalloid, and check the blood to confirm the intended recipient. IV diuretics may be administered to increase renal blood flow, and urine output should be maintained.

Another common complication is febrile transfusion reaction, which presents with a 1-degree rise in temperature from baseline, along with chills and malaise. This reaction is usually caused by cytokines from leukocytes in the transfused blood components. Supportive treatment is typically sufficient, and paracetamol can be helpful.

Allergic reactions can also occur, usually due to foreign plasma proteins or anti-IgA. These reactions often present with urticaria, pruritus, and hives, and in severe cases, laryngeal edema or bronchospasm may occur. Symptomatic treatment with antihistamines is usually enough, and there is usually no need to stop the transfusion. However, if anaphylaxis occurs, the transfusion should be stopped, and the patient should be administered adrenaline and treated according to the ALS protocol.

Transfusion-related acute lung injury (TRALI) is a severe complication characterized by non-cardiogenic pulmonary edema within 6 hours of transfusion. It is associated with antibodies in the donor blood reacting with recipient leukocyte antigens. This is the most common cause of death related to transfusion reactions. Treatment involves stopping the transfusion, administering oxygen, and providing aggressive respiratory support in approximately 75% of patients. Diuretic usage should be avoided.

Anaemia of chronic disease is a type of anaemia that can occur in various chronic conditions, such as rheumatoid arthritis, systemic lupus erythematosus, tuberculosis, malignancy, malnutrition, hypothyroidism, hypopituitarism, chronic kidney disease, and chronic liver disease. The underlying mechanisms of this type of anaemia are complex and not fully understood, with multiple contributing factors involved. One important mediator in inflammatory diseases like rheumatoid arthritis is interleukin-6 (IL-6). Increased levels of IL-6 lead to the production of hepcidin, a hormone that regulates iron balance. Hepcidin prevents the release of iron from the reticulo-endothelial system and affects other aspects of iron metabolism.

Anaemia of chronic disease typically presents as a normochromic, normocytic anaemia, although it can also be microcytic. It is characterized by reduced serum iron, reduced transferrin saturation, and reduced total iron-binding capacity (TIBC). However, the serum ferritin levels are usually normal or increased. Distinguishing anaemia of chronic disease from iron-deficiency anaemia can be challenging, but in iron-deficiency anaemia, the TIBC is typically elevated, and serum ferritin is usually low.

Transfusion-related lung injury (TRALI) is responsible for about one-third of all transfusion-related deaths, making it the leading cause. On the other hand, transfusion-associated circulatory overload (TACO) accounts for approximately 20% of these fatalities, making it the second leading cause. TACO occurs when a large volume of blood is rapidly infused, particularly in patients with limited cardiac reserve or chronic anemia. Elderly individuals, infants, and severely anemic patients are especially vulnerable to this reaction.

The typical signs of TACO include acute respiratory distress, rapid heart rate, high blood pressure, the appearance of acute or worsening pulmonary edema on a chest X-ray, and evidence of excessive fluid accumulation. In many cases, simply reducing the transfusion rate, positioning the patient upright, and administering diuretics will be sufficient to manage the condition. However, in more severe cases, it is necessary to halt the transfusion and consider non-invasive ventilation.

Transfusion-related acute lung injury (TRALI) is defined as new acute lung injury (ALI) that occurs during or within six hours of transfusion, not explained by another ALI risk factor. Transfusion of part of one unit of any blood product can cause TRALI.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion usage, errors and adverse reactions still occur.

One serious complication is acute haemolytic transfusion reactions, which happen when incompatible red cells are transfused and react with the patient’s own antibodies. This usually occurs due to human error, such as mislabelling sample tubes or request forms. Symptoms of this reaction include a feeling of impending doom, fever, chills, pain and warmth at the transfusion site, nausea, vomiting, and back, joint, and chest pain. Immediate action should be taken to stop the transfusion, replace the donor blood with normal saline or another suitable crystalloid, and check the blood to confirm the intended recipient. IV diuretics may be administered to increase renal blood flow, and urine output should be maintained.

Another common complication is febrile transfusion reaction, which presents with a 1-degree rise in temperature from baseline, along with chills and malaise. This reaction is usually caused by cytokines from leukocytes in the transfused blood components. Supportive treatment is typically sufficient, and paracetamol can be helpful.

Allergic reactions can also occur, usually due to foreign plasma proteins or anti-IgA. These reactions often present with urticaria, pruritus, and hives, and in severe cases, laryngeal edema or bronchospasm may occur. Symptomatic treatment with antihistamines is usually enough, and there is usually no need to stop the transfusion. However, if anaphylaxis occurs, the transfusion should be stopped, and the patient should be administered adrenaline and treated according to the ALS protocol.

Transfusion-related acute lung injury (TRALI) is a severe complication characterized by non-cardiogenic pulmonary edema within 6 hours of transfusion. It is associated with antibodies in the donor blood reacting with recipient leukocyte antigens. This is the most common cause of death related to transfusion reactions. Treatment involves stopping the transfusion, administering oxygen, and providing aggressive respiratory support in approximately 75% of patients. Diuretic usage should be avoided.

If a patient’s INR reading is above 5, it is necessary to take action. In this case, the patient’s INR is between 5 and 8, but there is no evidence of bleeding. According to the provided table, it is recommended to temporarily stop 1-2 doses of warfarin and closely monitor the INR. While it may be optional to switch antibiotics, it is not a crucial step in this situation.

Further Reading:

Management of High INR with Warfarin

Major Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 5 mg.
– Administer 25-50 u/kg four-factor prothrombin complex concentrate.
– If prothrombin complex concentrate is not available, consider using fresh frozen plasma (FFP).
– Seek medical attention promptly.

INR > 8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR > 8.0 without Bleeding:
– Stop warfarin immediately.
– Administer oral vitamin K 1-5 mg using the intravenous preparation orally.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if any symptoms or concerns arise.

INR 5.0-8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR 5.0-8.0 without Bleeding:
– Withhold 1 or 2 doses of warfarin.
– Reduce subsequent maintenance dose.
– Monitor INR closely and seek medical advice if any concerns arise.

Note: In cases of intracranial hemorrhage, prothrombin complex concentrate should be considered as it is faster acting than fresh frozen plasma (FFP).

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there has been an increased awareness of these risks and improved reporting systems, transfusion errors and serious adverse reactions still occur and may go unreported.

One specific transfusion reaction is transfusion-associated circulatory overload (TACO), which occurs when a large volume of blood is rapidly infused. It is the second leading cause of transfusion-related deaths, accounting for about 20% of fatalities. TACO is more likely to occur in patients with diminished cardiac reserve or chronic anemia, particularly in the elderly, infants, and severely anemic patients.

The typical clinical features of TACO include acute respiratory distress, tachycardia, hypertension, acute or worsening pulmonary edema on chest X-ray, and evidence of positive fluid balance. The B-type natriuretic peptide (BNP) can be a useful diagnostic tool for TACO, with levels usually elevated to at least 1.5 times the pre-transfusion baseline.

In many cases, simply slowing the transfusion rate, placing the patient in an upright position, and administering diuretics can be sufficient for managing TACO. In more severe cases, the transfusion should be stopped, and non-invasive ventilation may be considered.

Blood transfusion is a crucial treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there has been an improvement in safety procedures and a reduction in transfusion use, errors and serious adverse reactions still occur and often go unreported.

Mild allergic reactions during blood transfusion are relatively common and typically occur within a few minutes of starting the transfusion. These reactions happen when patients have antibodies that react with foreign plasma proteins in the transfused blood components. Symptoms of mild allergic reactions include urticaria, Pruritus, and hives.

Anaphylaxis, on the other hand, is much rarer and occurs when an individual has previously been sensitized to an allergen present in the blood. When re-exposed to the allergen, the body releases IgE or IgG antibodies, leading to severe symptoms such as bronchospasm, laryngospasm, abdominal pain, nausea, vomiting, hypotension, shock, and loss of consciousness. Anaphylaxis can be fatal.

Mild allergic reactions can be managed by slowing down the transfusion rate and administering antihistamines. If there is no progression after 30 minutes, the transfusion may continue. Patients who have experienced repeated allergic reactions to transfusion should be given pre-treatment with chlorpheniramine. In cases of anaphylaxis, the transfusion should be stopped immediately, and the patient should receive oxygen, adrenaline, corticosteroids, and antihistamines following the ALS protocol.

The table below summarizes the main transfusion reactions and complications, along with their features and management:

Complication | Features | Management
Febrile transfusion reaction | 1 degree rise in temperature, chills, malaise | Supportive care, paracetamol
Acute haemolytic reaction | Fever, chills, pain at transfusion site, nausea, vomiting, dark urine | STOP THE TRANSFUSION, administer IV fluids, diuretics if necessary
Delayed haemolytic reaction | Fever, anaemia, jaundice, haemoglobinuria | Monitor anaemia and renal function, treat as required
Allergic reaction | Urticaria, Pruritus, hives | Symptomatic treatment with ant

Blood transfusion is a crucial treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur.

Delayed haemolytic transfusion reactions (DHTRs) typically occur 4-8 days after a blood transfusion, but can sometimes manifest up to a month later. The symptoms are similar to acute haemolytic transfusion reactions but are usually less severe. Patients may experience fever, inadequate rise in haemoglobin, jaundice, reticulocytosis, positive antibody screen, and positive Direct Antiglobulin Test (Coombs test). DHTRs are more common in patients with sickle cell disease who have received frequent transfusions.

These reactions are caused by the presence of a low titre antibody that is too weak to be detected during cross-match and unable to cause lysis at the time of transfusion. The severity of DHTRs depends on the immunogenicity or dose of the antigen. Blood group antibodies associated with DHTRs include those of the Kidd, Duffy, Kell, and MNS systems. Most DHTRs have a benign course and do not require treatment. However, severe haemolysis with anaemia and renal failure can occur, so monitoring of haemoglobin levels and renal function is necessary. If an antibody is detected, antigen-negative blood can be requested for future transfusions.

Here is a summary of the main transfusion reactions and complications:

1. Febrile transfusion reaction: Presents with a 1-degree rise in temperature from baseline, along with chills and malaise. It is the most common reaction and is usually caused by cytokines from leukocytes in transfused red cell or platelet components. Supportive treatment with paracetamol is helpful.

2. Acute haemolytic reaction: Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine. It is the most serious type of reaction and often occurs due to ABO incompatibility from administration errors. The transfusion should be stopped, and IV fluids should be administered. Diuretics may be required.

3. Delayed haemolytic reaction: This reaction typically occurs 4-8 days after a blood transfusion and presents with fever, anaemia, jaundice and haemoglobuinuria. Direct antiglobulin (Coombs) test positive. Due to low titre antibody too weak to detect in cross-match and unable to cause lysis at time of transfusion. Most delayed haemolytic reactions have a benign course and require no treatment. Monitor anaemia and renal function and treat as required.

Febrile transfusion reactions, also known as non-haemolytic transfusion reactions, occur when there is an unexpected increase in body temperature (≥ 38ºC or ≥ 1ºC above the baseline, if the baseline is ≥ 37ºC) during or shortly after a blood transfusion. This temperature rise is usually the only symptom, although sometimes it may be accompanied by chills.

Febrile transfusion reactions are the most common type of transfusion reaction, happening in approximately 1 out of every 8 transfusions.

The main cause of febrile transfusion reactions is believed to be the accumulation of cytokines during the storage of blood components, particularly in platelet units. Cytokines are substances released by white blood cells, and the risk of symptoms can be reduced by removing these cells before storage.

In addition to cytokine accumulation, febrile transfusion reactions can also be triggered by recipient antibodies that have been produced as a result of previous transfusions or pregnancies. These antibodies react to specific antigens, such as human leukocyte antigen (HLA), found on the donor’s lymphocytes, granulocytes, or platelets.

Treatment for febrile transfusion reactions is mainly supportive. Other potential causes of fever should be ruled out, and antipyretic medications like paracetamol can be used to reduce the fever. If another cause is suspected, the transfusion should be temporarily stopped, but it can be resumed at a slower rate once other potential causes of fever have been ruled out.

Transfusion transmitted bacterial infection is a rare complication that can occur during blood transfusion. It is more commonly associated with platelet transfusion, as platelets are stored at room temperature. Additionally, previously frozen components that are thawed using a water bath and red cell components stored for several weeks are also at a higher risk for bacterial infection.

Both Gram-positive and Gram-negative bacteria have been implicated in transfusion-transmitted bacterial infection, but Gram-negative bacteria are known to cause more severe illness and have higher rates of morbidity and mortality. Among the bacterial organisms, Yersinia enterocolitica is the most commonly associated with this type of infection. This particular organism is able to multiply at low temperatures and utilizes iron as a nutrient, making it well-suited for proliferation in blood stores.

The clinical features of transfusion-transmitted bacterial infection typically manifest shortly after the transfusion begins. These features include a high fever, chills and rigors, nausea and vomiting, tachycardia, hypotension, and even circulatory collapse.

If there is suspicion of a transfusion-transmitted bacterial infection, it is crucial to immediately stop the transfusion. Blood cultures and a Gram-stain should be requested to identify the specific bacteria causing the infection. Broad-spectrum antibiotics should be initiated promptly. Furthermore, the blood pack should be returned to the blood bank urgently for culture and Gram-stain analysis.

Acute lymphoblastic leukaemia (ALL) is the most common type of leukaemia that occurs in childhood, typically affecting children between the ages of 2 and 5 years. The symptoms of ALL can vary, but many children initially experience an acute illness that may resemble a common cold or viral infection. Other signs of ALL include general weakness and fatigue, as well as muscle, joint, and bone pain. Additionally, children with ALL may have anaemia, unexplained bruising and petechiae, swelling (oedema), enlarged lymph nodes (lymphadenopathy), and an enlarged liver and spleen (hepatosplenomegaly).

In patients with ALL, a complete blood count typically reveals certain characteristics. These include anaemia, which can be either normocytic or macrocytic. Approximately 50% of patients with ALL have a low white blood cell count (leukopaenia), with a white cell count below 4 x 109/l. On the other hand, around 60% of patients have a high white blood cell count (leukocytosis), with a white cell count exceeding 10 x 109/l. In about 25% of cases, there is an extreme elevation in white blood cell count (hyperleukocytosis), with a count surpassing 50 x 109/l. Additionally, patients with ALL often have a low platelet count (thrombocytopaenia).

Anaemia of chronic disease is a type of anaemia that can occur in various chronic conditions, such as rheumatoid arthritis, systemic lupus erythematosus, tuberculosis, malignancy, malnutrition, hypothyroidism, hypopituitarism, chronic kidney disease, and chronic liver disease. The underlying mechanisms of this type of anaemia are complex and not fully understood, with multiple contributing factors involved. One important mediator in inflammatory diseases like rheumatoid arthritis is interleukin-6 (IL-6). Increased levels of IL-6 lead to the production of hepcidin, a hormone that regulates iron balance. Hepcidin prevents the release of iron from the reticulo-endothelial system and affects other aspects of iron metabolism.

Anaemia of chronic disease typically presents as a normochromic, normocytic anaemia, although it can also be microcytic. It is characterized by reduced serum iron, reduced transferrin saturation, and reduced total iron-binding capacity (TIBC). However, the serum ferritin levels are usually normal or increased. Distinguishing anaemia of chronic disease from iron-deficiency anaemia can be challenging, but in iron-deficiency anaemia, the TIBC is typically elevated, and serum ferritin is usually low.

Protamine sulphate is a potent base that forms a stable salt complex with heparin, an acidic substance. This complex renders heparin inactive, making protamine sulphate a useful tool for neutralizing the effects of heparin. Additionally, protamine sulphate can be used to reverse the effects of LMWHs, although it is not as effective, providing only about two-thirds of the relative effect.

It is important to note that protamine sulphate also possesses its own weak intrinsic anticoagulant effect. This effect is believed to stem from its ability to inhibit the formation and activity of thromboplastin.

When administering protamine sulphate, it is typically done through slow intravenous injection. The dosage should be adjusted based on the amount of heparin that needs to be neutralized, the time that has passed since heparin administration, and the aPTT (activated partial thromboplastin time). As a general guideline, 1 mg of protamine can neutralize 100 IU of heparin. However, it is crucial to adhere to a maximum adult dose of 50 mg within a 10-minute period.

It is worth mentioning that protamine sulphate can have some adverse effects. It acts as a myocardial depressant, potentially leading to bradycardia (slow heart rate) and hypotension (low blood pressure). These effects may arise due to complement activation and leukotriene release.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Myelodysplastic syndromes are a group of disorders affecting the haemopoietic stem cell, leading to ineffective production of myeloid blood cells. These conditions typically manifest between the ages of 60 and 75 and are more prevalent in men than women.

The clinical features of myelodysplastic syndromes include tiredness due to anaemia (the most common presentation), easy bruising, and a tendency to bleed. Laboratory findings often reveal anaemia (usually macrocytic or normocytic), neutropenia, thrombocytopenia, and abnormal cell morphology with oddly shaped macrocytes.

Chronic lymphocytic leukaemia (CLL) is the most common form of adult leukaemia, primarily affecting B-lymphocytes. It often presents asymptomatically in patients who undergo routine blood tests revealing elevated white cell counts and lymphocytosis. Men over the age of 50 account for over 75% of CLL cases. Blood films typically show a predominance of mature-looking lymphocytes and smear cells.

Iron deficiency anaemia is characterized by hypochromic microcytic anaemia and a reduced red blood cell count. Peripheral blood smears in iron deficiency anaemia may exhibit poikilocytosis (varying shapes) and anisocytosis (varying sizes). Pencil cells are also observed in this condition.

Vitamin B12 and folate deficiency can also cause macrocytic anaemia. However, the severity of anaemia and macrocytosis would generally need to be much more pronounced to result in neutropenia and thrombocytopenia. Therefore, a myelodysplastic syndrome is more likely in such cases.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Immunoglobulin light chains that are present in the urine are commonly known as Bence-Jones proteins (BJP). These proteins are primarily observed in individuals with multiple myeloma, although they can occasionally be detected in Waldenström macroglobulinemia, although this is a rare occurrence. It is important to note that BJP in the urine is not observed in the other conditions mentioned in this question.

Methaemoglobinaemia is a condition characterized by various symptoms such as headache, anxiety, acidosis, arrhythmia, seizure activity, reduced consciousness or coma. One notable feature is the presence of brown or chocolate coloured blood. It is important to note that the patient is taking chloroquine, which is a known trigger for methaemoglobinaemia. Additionally, despite the condition, the patient’s arterial blood gas analysis shows a normal partial pressure of oxygen.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, immune dilution, and transfusion errors. While there have been improvements in safety procedures and efforts to minimize the use of transfusion, errors and serious adverse reactions still occur and often go unreported.

One rare complication of blood transfusion is transfusion-associated graft-vs-host disease (TA-GVHD). This condition typically presents with fever, rash, and diarrhea 1-4 weeks after the transfusion. Laboratory findings may show pancytopenia and abnormalities in liver function. Unlike GVHD after marrow transplantation, TA-GVHD leads to severe marrow aplasia with a mortality rate exceeding 90%. Unfortunately, there are currently no effective treatments available for this condition, and survival is rare, with death usually occurring within 1-3 weeks of the first symptoms.

During a blood transfusion, viable T lymphocytes from the donor are transfused into the recipient’s body. In TA-GVHD, these lymphocytes engraft and react against the recipient’s tissues. However, the recipient is unable to reject the donor lymphocytes due to factors such as immunodeficiency, severe immunosuppression, or shared HLA antigens. Supportive management is the only option for TA-GVHD.

The following summarizes the main complications and reactions that can occur during a blood transfusion:

Complication Features Management
Febrile transfusion reaction
– Presents with a 1-degree rise in temperature from baseline, along with chills and malaise.
– Most common reaction, occurring in 1 out of 8 transfusions.
– Usually caused by cytokines from leukocytes in transfused red cell or platelet components.
– Supportive management, with the use of paracetamol for symptom relief.

Acute haemolytic reaction
– Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine.
– Often accompanied by a feeling of ‘impending doom’.
– Most serious type of reaction, often due to ABO incompatibility caused by administration errors.
– Immediate action required: stop the transfusion, administer IV fluids, and consider diuretics if necessary.

Delayed haemolytic reaction
– Typically occurs 4-8 days after a blood transfusion.
– Symptoms include fever, anemia and/or hyperbilirubinemia

Glanzmann’s thrombasthenia is an uncommon condition affecting platelets, where they have a deficiency or abnormality in glycoprotein IIb/IIIa. This disorder leads to platelet dysfunction and can result in various complications.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects approximately 1 in 100 people. It occurs due to a deficiency in Von Willebrand factor (vWF), which leads to reduced levels of factor VIII. vWF plays a crucial role in protecting factor VIII from breaking down quickly in the blood. Additionally, it is necessary for proper platelet adhesion, so a deficiency in vWF also results in abnormal platelet function. As a result, both the APTT and bleeding time are prolonged, while the platelet count and thrombin time remain unaffected.

Many individuals with vWD do not experience any symptoms and are diagnosed incidentally during a routine clotting profile check. However, if symptoms do occur, the most common ones include easy bruising, nosebleeds (epistaxis), and heavy menstrual bleeding (menorrhagia). In severe cases, more significant bleeding and joint bleeding (haemarthrosis) can occur.

For mild cases of von Willebrand disease, bleeding can be treated with desmopressin. This medication works by increasing the patient’s own levels of vWF, as it releases vWF stored in the Weibel-Palade bodies found in the endothelial cells. In more severe cases, replacement therapy is necessary, which involves cryoprecipitate infusions or Factor VIII concentrate. Replacement therapy is recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

Congenital afibrinogenaemia is a rare coagulation disorder characterized by a deficiency or malfunction of fibrinogen. This condition leads to a prolongation of the prothrombin time, bleeding time, and APTT. However, it does not affect the platelet count.

Aspirin therapy works by inhibiting platelet cyclo-oxygenase, an essential enzyme in the generation of thromboxane A2 (TXA2). By inhibiting TXA2, aspirin reduces platelet activation and aggregation. Consequently, aspirin therapy prolongs the bleeding time but does not have an impact on the platelet count, prothrombin time, or APTT.

Warfarin, on the other hand, inhibits the synthesis of clotting factors II, VII, IX, and X, as well as protein C and protein S, which are all dependent on vitamin K.

The complete blood count findings indicate a severe case of iron deficiency anemia. The patient’s red blood cells are significantly reduced in number, and there is a noticeable hypochromic microcytic anemia. When examining the peripheral blood smear, variations in shape (poikilocytosis) and size (anisocytosis) can be observed, which are typical of iron deficiency anemia. Pencil cells are commonly seen in this condition. Additionally, it is common for iron deficiency anemia to be accompanied by thrombocytosis, an increase in platelet count.

The CHA2DS2-VASc score is a tool used to predict the likelihood of future stroke in individuals with atrial fibrillation (AF). It is scored on a scale of 0-9, with higher scores indicating a higher risk of stroke. If a male has a score of 1 or more, or if a female has a score of 2 or more, it is recommended to start anticoagulation therapy to prevent future strokes. However, it is important to assess the risk of bleeding before initiating anticoagulation using the HAS-BLED score. The HAS-BLED score does not evaluate the risk of stroke, but rather the risk of bleeding. QRISK3, on the other hand, is a tool used to estimate the risk of cardiovascular disease over a 10-year period and is primarily used to determine the benefits of starting lipid lowering drugs. It is the preferred tool recommended by NICE over the Framingham risk score.

Further Reading:

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting around 5% of patients over the age of 70-75 years and 10% of patients aged 80-85 years. While AF can cause palpitations and inefficient cardiac function, the most important aspect of managing patients with AF is reducing the increased risk of stroke.

AF can be classified as first detected episode, paroxysmal, persistent, or permanent. First detected episode refers to the initial occurrence of AF, regardless of symptoms or duration. Paroxysmal AF occurs when a patient has 2 or more self-terminating episodes lasting less than 7 days. Persistent AF refers to episodes lasting more than 7 days that do not self-terminate. Permanent AF is continuous atrial fibrillation that cannot be cardioverted or if attempts to do so are deemed inappropriate. The treatment goals for permanent AF are rate control and anticoagulation if appropriate.

Symptoms of AF include palpitations, dyspnea, and chest pain. The most common sign is an irregularly irregular pulse. An electrocardiogram (ECG) is essential for diagnosing AF, as other conditions can also cause an irregular pulse.

Managing patients with AF involves two key parts: rate/rhythm control and reducing stroke risk. Rate control involves slowing down the irregular pulse to avoid negative effects on cardiac function. This is typically achieved using beta-blockers or rate-limiting calcium channel blockers. If one drug is not effective, combination therapy may be used. Rhythm control aims to restore and maintain normal sinus rhythm through pharmacological or electrical cardioversion. However, the majority of patients are managed with a rate control strategy.

Reducing stroke risk in patients with AF is crucial. Risk stratifying tools, such as the CHA2DS2-VASc score, are used to determine the most appropriate anticoagulation strategy. Anticoagulation is recommended for patients with a score of 2 or more. Clinicians can choose between warfarin and novel oral anticoagulants (NOACs) for anticoagulation.

Before starting anticoagulation, the patient’s bleeding risk should be assessed using tools like the HAS-BLED score or the ORBIT tool. These tools evaluate factors such as hypertension, abnormal renal or liver function, history of bleeding, age, and use of drugs that predispose to bleeding.

Reed-Sternberg cells are distinctive large cells that are typically observed in Hodgkin lymphoma. These cells are often found to have two nuclei or a nucleus with two lobes. Additionally, they possess noticeable nucleoli that resemble eosinophilic inclusion-like structures, giving them an appearance similar to that of an owl’s eye.

HbAS is known as Sickle cell trait, while HbSS is the genotype for Sickle-cell disease. Sickle-shaped red blood cells have a shorter lifespan of 10-20 days compared to the normal red blood cells that live for 90-120 days. Cholelithiasis, a complication of sickle-cell disease, occurs due to excessive bilirubin production caused by the breakdown of red blood cells. The inheritance pattern of sickle-cell disease is autosomal recessive. The disease is caused by a point mutation in the beta-globin chain of hemoglobin, resulting in the substitution of glutamic acid with valine at the sixth position. Individuals with one normal hemoglobin gene and one sickle gene have the genotype HbAS, which is commonly referred to as Sickle Cell trait.

Haemophilia is a collection of genetic disorders that are inherited and lead to impaired blood clotting. Haemophilia A specifically occurs when there is a deficiency of factor VIII and is typically passed down as a recessive trait on the X chromosome.

The initial signs of haemophilia A usually appear around 6 months of age when infants start crawling, although it can manifest later. Bleeding can occur either spontaneously or as a result of trauma. One key indicator of haemophilia is bleeding into muscles and joints, known as haemarthrosis. While gastrointestinal and cerebral bleeding can also happen, they are less common occurrences.

Based on the symptoms described, the most likely diagnosis from the given options would be Haemophilia A, especially when there is a combination of haemarthrosis and an older brother with the same disorder.

Idiopathic thrombocytopenic purpura (ITP) is a condition where the immune system causes a decrease in platelet count. Antibodies target the glycoprotein IIb-IIIa or Ib complex. Acute ITP is more prevalent in children and affects both sexes equally. Chronic ITP, on the other hand, is more common in young to middle-aged women. Unlike haemophilia, ITP typically presents with symptoms such as nosebleeds, oral bleeding, purpura, or petechiae, rather than haemarthrosis. Additionally, ITP is not an inherited disorder.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited disorder that follows an X-linked recessive pattern. It is characterized by a defect in the G6PD enzyme, which plays a crucial role in red blood cell metabolism. Most individuals with G6PD deficiency do not experience symptoms. However, haemolytic crisis can occur in response to factors like illness (especially infection and diabetic ketoacidosis), certain medications (such as specific antibiotics, antimalarials, sulphonamides, and aspirin), or certain foods (notably fava beans).

Von Willebrand disease (vWD) is the most common hereditary coagulation disorder, affecting approximately 1 in 100 individuals. It arises from a deficiency in Von Willebrand factor (vWF), which leads to reduced levels of factor VIII. vWF is responsible for protecting factor VIII from rapid breakdown in the blood and is also necessary for platelet adhesion.

Transfusion transmitted bacterial infection is a rare complication that can occur during blood transfusion. It is more commonly associated with platelet transfusion, as platelets are stored at room temperature. Additionally, previously frozen components that are thawed using a water bath and red cell components stored for several weeks are also at a higher risk for bacterial infection.

Both Gram-positive and Gram-negative bacteria have been implicated in transfusion-transmitted bacterial infection, but Gram-negative bacteria are known to cause more severe illness and have higher rates of morbidity and mortality. Among the bacterial organisms, Yersinia enterocolitica is the most commonly associated with this type of infection. This particular organism is able to multiply at low temperatures and utilizes iron as a nutrient, making it well-suited for proliferation in blood stores.

The clinical features of transfusion-transmitted bacterial infection typically manifest shortly after the transfusion begins. These features include a high fever, chills and rigors, nausea and vomiting, tachycardia, hypotension, and even circulatory collapse.

If there is suspicion of a transfusion-transmitted bacterial infection, it is crucial to immediately stop the transfusion. Blood cultures and a Gram-stain should be requested to identify the specific bacteria causing the infection. Broad-spectrum antibiotics should be initiated promptly. Furthermore, the blood pack should be returned to the blood bank urgently for culture and Gram-stain analysis.

The most frequently encountered virus transmitted through blood transfusion is parvovirus B19. This particular occurrence happens in roughly 1 out of every 10,000 transfusions.

On the other hand, the transmission of other viruses is extremely uncommon. The likelihood of contracting Hepatitis B through a blood transfusion is estimated to be around 1 in 100,000 to 200,000. Similarly, the chances of acquiring Hepatitis C or HIV through a blood transfusion are even rarer, with the odds being approximately 1 in 1 million for both viruses.

The ‘B’ symptoms associated with Hodgkin’s lymphoma include fever, night sweats, and weight loss. Fever is defined as a body temperature exceeding 38 degrees Celsius. Night sweats refer to excessive sweating during sleep. Weight loss is considered significant if it amounts to more than 10% of a person’s body weight over a period of six months. It is important to note that pain after consuming alcohol is a distinctive sign of Hodgkin’s lymphoma, but it is not classified as a ‘B’ symptom. This symptom is relatively rare, occurring in only 2-3% of individuals diagnosed with Hodgkin’s lymphoma.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur. One common adverse reaction is febrile transfusion reactions, which present as an unexpected rise in temperature during or after transfusion. This can be caused by cytokine accumulation or recipient antibodies reacting to donor antigens. Treatment for febrile transfusion reactions is supportive, and other potential causes should be ruled out.

Another serious complication is acute haemolytic reaction, which is often caused by ABO incompatibility due to administration errors. This reaction requires the transfusion to be stopped and IV fluids to be administered. Delayed haemolytic reactions can occur several days after a transfusion and may require monitoring and treatment for anaemia and renal function. Allergic reactions, TRALI (Transfusion Related Acute Lung Injury), TACO (Transfusion Associated Circulatory Overload), and GVHD (Graft-vs-Host Disease) are other potential complications that require specific management approaches.

In summary, blood transfusion carries risks and potential complications, but efforts have been made to improve safety procedures. It is important to be aware of these complications and to promptly address any adverse reactions that may occur during or after a transfusion.

Aplastic anaemia is a rare and potentially life-threatening condition where the bone marrow fails to produce enough blood cells. This results in a decrease in the number of red blood cells, white blood cells, and platelets in the body, a condition known as pancytopenia. The main cause of aplastic anaemia is damage to the bone marrow and the stem cells that reside there. This damage can be caused by various factors such as autoimmune disorders, certain medications like sulphonamide antibiotics and phenytoin, viral infections like EBV and parvovirus, chemotherapy, radiotherapy, or inherited conditions like Fanconi anaemia. Patients with aplastic anaemia typically experience symptoms such as anaemia, recurrent infections due to a low white blood cell count, and an increased tendency to bleed due to low platelet levels.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Methaemoglobinaemia is a condition characterized by high levels of haemoglobin with iron in the ferric (Fe3+) state. This occurs when haemoglobin is oxidized from Fe2+ to Fe3+. Normally, NADH methaemoglobin reductase, also known as Cytochrome b5 reductase, regulates this process by transferring electrons from NADH to methaemoglobin, converting it back to haemoglobin. However, if there is a congenital or acquired dysfunction in the NADH methaemoglobin reductase enzyme system, it can lead to elevated levels of haemoglobin with iron in the Fe3+ state. Unfortunately, Fe3+ is unable to bind to haemoglobin.

Further Reading:

Methaemoglobinaemia is a condition where haemoglobin is oxidised from Fe2+ to Fe3+. This process is normally regulated by NADH methaemoglobin reductase, which transfers electrons from NADH to methaemoglobin, converting it back to haemoglobin. In healthy individuals, methaemoglobin levels are typically less than 1% of total haemoglobin. However, an increase in methaemoglobin can lead to tissue hypoxia as Fe3+ cannot bind oxygen effectively.

Methaemoglobinaemia can be congenital or acquired. Congenital causes include haemoglobin chain variants (HbM, HbH) and NADH methaemoglobin reductase deficiency. Acquired causes can be due to exposure to certain drugs or chemicals, such as sulphonamides, local anaesthetics (especially prilocaine), nitrates, chloroquine, dapsone, primaquine, and phenytoin. Aniline dyes are also known to cause methaemoglobinaemia.

Clinical features of methaemoglobinaemia include slate grey cyanosis (blue to grey skin coloration), chocolate blood or chocolate cyanosis (brown color of blood), dyspnoea, low SpO2 on pulse oximetry (which often does not improve with supplemental oxygen), and normal PaO2 on arterial blood gas (ABG) but low SaO2. Patients may tolerate hypoxia better than expected. Severe cases can present with acidosis, arrhythmias, seizures, and coma.

Diagnosis of methaemoglobinaemia is made by directly measuring the level of methaemoglobin using a co-oximeter, which is present in most modern blood gas analysers. Other investigations, such as a full blood count (FBC), electrocardiogram (ECG), chest X-ray (CXR), and beta-human chorionic gonadotropin (bHCG) levels (in pregnancy), may be done to assess the extent of the condition and rule out other contributing factors.

Active treatment is required if the methaemoglobin level is above 30% or if it is below 30% but the patient is symptomatic or shows evidence of tissue hypoxia. Treatment involves maintaining the airway and delivering high-flow oxygen, removing the causative agents, treating toxidromes and consider giving IV dextrose 5%.

Multiple myeloma is a cancerous growth of plasma cells, a type of white blood cell responsible for producing antibodies. It is more prevalent in men and typically occurs in individuals over the age of 60.

When a patient over 60 presents with an elevated ESR, unexplained anemia, hypercalcemia, renal impairment, and bone pain, the initial diagnosis is usually multiple myeloma until proven otherwise.

The most common symptoms of multiple myeloma include:

1. Anemia: This is caused by the infiltration of the bone marrow and suppression of blood cell production. It is typically normocytic and normochromic, but can also be macrocytic.

2. Bone pain: Approximately 70% of patients experience bone pain, which commonly affects the spine and ribs. Localized pain and tenderness may indicate a pathological fracture, and vertebral fractures can lead to spinal cord compression.

3. Renal failure: Acute or chronic renal failure occurs in about one-third of patients. This is generally due to the effects of light chains on the tubules.

4. Neurological symptoms: Hypercalcemia can cause weakness, lethargy, and confusion, while hyperviscosity can result in headaches and retinopathy. Amyloid infiltration can lead to peripheral neuropathies, with carpal tunnel syndrome being the most common.

5. Infection: The most common infections seen in multiple myeloma patients are pyelonephritis and pneumonia.

In addition to the routine blood tests already conducted, a suspected diagnosis of multiple myeloma should prompt further investigations, including:

– Plasma viscosity measurement
– Urinary protein electrophoresis to detect Bence-Jones proteins
– Serum electrophoresis to identify the type of paraprotein
– Quantitative immunoglobulin level testing
– Skeletal survey to look for lytic lesions
– Bone marrow aspirate and possibly biopsy

A diagnosis of multiple myeloma is confirmed by the presence of a monoclonal protein in the serum or urine, lytic lesions on X-ray, and an increased number of plasma cells in the bone marrow.

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there has been an increased awareness of these risks and improved reporting systems, transfusion errors and serious adverse reactions still occur and may go unreported.

One specific transfusion reaction is transfusion-associated circulatory overload (TACO), which occurs when a large volume of blood is rapidly infused. It is the second leading cause of transfusion-related deaths, accounting for about 20% of fatalities. TACO is more likely to occur in patients with diminished cardiac reserve or chronic anemia, particularly in the elderly, infants, and severely anemic patients.

The typical clinical features of TACO include acute respiratory distress, tachycardia, hypertension, acute or worsening pulmonary edema on chest X-ray, and evidence of positive fluid balance. The B-type natriuretic peptide (BNP) can be a useful diagnostic tool for TACO, with levels usually elevated to at least 1.5 times the pre-transfusion baseline.

In many cases, simply slowing the transfusion rate, placing the patient in an upright position, and administering diuretics can be sufficient for managing TACO. In more severe cases, the transfusion should be stopped, and non-invasive ventilation may be considered.

The beta thalassaemias are a group of blood disorders that occur when there is an abnormality in the production of the globin chains. These disorders are inherited in an autosomal recessive manner. In individuals with beta thalassaemia trait, there is a slight decrease in the production of beta-globin chains. This condition is most commonly found in people of Mediterranean and Asian descent.

The presentation of beta thalassaemia trait is characterized by a mild form of microcytic hypochromic anaemia. This type of anaemia can be challenging to differentiate from iron deficiency anaemia. However, it can be distinguished from iron deficiency anaemia by the presence of normal iron levels. Another useful marker for diagnosing beta thalassaemia trait is an elevated HbA2 level. A value greater than 3.5% is considered diagnostic for this condition.

When the INR (International Normalized Ratio) is above 8 but there is no sign of bleeding, the usual approach is to stop administering warfarin and instead provide oral vitamin K. If the INR is below 8 and there is no evidence of bleeding, it is appropriate to discontinue warfarin. However, if there is evidence of bleeding or the INR exceeds 8, reversal agents are administered. In cases where the INR is greater than 8 without any bleeding, oral vitamin K is typically prescribed at a dosage of 1-5 mg.

Further Reading:

Management of High INR with Warfarin

Major Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 5 mg.
– Administer 25-50 u/kg four-factor prothrombin complex concentrate.
– If prothrombin complex concentrate is not available, consider using fresh frozen plasma (FFP).
– Seek medical attention promptly.

INR > 8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR > 8.0 without Bleeding:
– Stop warfarin immediately.
– Administer oral vitamin K 1-5 mg using the intravenous preparation orally.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if any symptoms or concerns arise.

INR 5.0-8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR 5.0-8.0 without Bleeding:
– Withhold 1 or 2 doses of warfarin.
– Reduce subsequent maintenance dose.
– Monitor INR closely and seek medical advice if any concerns arise.

Note: In cases of intracranial hemorrhage, prothrombin complex concentrate should be considered as it is faster acting than fresh frozen plasma (FFP).

Chronic myeloid leukaemia (CML) is a type of blood disorder that arises from an abnormal pluripotent haemopoietic stem cell. The majority of CML cases, more than 80%, are caused by a cytogenetic abnormality called the Philadelphia chromosome. This abnormality occurs when there is a reciprocal translocation between the long arms of chromosomes 9 and 22.

CML typically develops slowly over a period of several years, known as the chronic stage. During this stage, patients usually do not experience any symptoms, and it is often discovered incidentally through routine blood tests. Around 90% of CML cases are diagnosed during this stage. In the bone marrow, less than 10% of the white cells are immature blasts.

Symptoms start to appear when the CML cells begin to expand, which is known as the accelerated stage. Approximately 10% of cases are diagnosed during this stage. Between 10 and 30% of the blood cells in the bone marrow are blasts at this point. Common clinical features during this stage include tiredness, fatigue, fever, night sweats, abdominal distension, left upper quadrant pain (splenic infarction), splenomegaly (enlarged spleen), hepatomegaly (enlarged liver), easy bruising, gout (due to rapid cell turnover), and hyperviscosity (which can lead to complications like stroke, priapism, etc.).

In some cases, a small number of patients may present with a blast crisis, also known as the blast stage. During this stage, more than 30% of the blood cells in the bone marrow are immature blast cells. Patients in this stage are generally very ill, experiencing severe constitutional symptoms such as fever, weight loss, and bone pain, as well as infections and bleeding tendencies.

Laboratory findings in CML include a significantly elevated white cell count (often greater than 100 x 109/l), a left shift with an increased number of immature leukocytes, mild to moderate normochromic, normocytic anaemia, variable platelet counts (low, normal, or elevated), presence of the Philadelphia chromosome in more than 80% of cases, and elevated levels of serum uric acid and alkaline phosphatase.

All individuals diagnosed with chronic lymphocytic leukaemia (CLL) experience some level of weakened immune system, although for many, it is not severe enough to have a significant impact on their health. Infections are the leading cause of death for 25-50% of CLL patients, with respiratory tract, skin, and urinary tract bacterial infections being the most prevalent. The primary factor contributing to the weakened immune system in CLL patients is hypogammaglobulinaemia, which is present in approximately 85% of all individuals with this condition.

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, immune dilution, and transfusion errors. While there have been improvements in safety procedures and efforts to minimize the use of transfusion, errors and serious adverse reactions still occur and often go unreported.

One rare complication of blood transfusion is transfusion-associated graft-vs-host disease (TA-GVHD). This condition typically presents with fever, rash, and diarrhea 1-4 weeks after the transfusion. Laboratory findings may show pancytopenia and abnormalities in liver function. Unlike GVHD after marrow transplantation, TA-GVHD leads to severe marrow aplasia with a mortality rate exceeding 90%. Unfortunately, there are currently no effective treatments available for this condition, and survival is rare, with death usually occurring within 1-3 weeks of the first symptoms.

During a blood transfusion, viable T lymphocytes from the donor are transfused into the recipient’s body. In TA-GVHD, these lymphocytes engraft and react against the recipient’s tissues. However, the recipient is unable to reject the donor lymphocytes due to factors such as immunodeficiency, severe immunosuppression, or shared HLA antigens. Supportive management is the only option for TA-GVHD.

The following summarizes the main complications and reactions that can occur during a blood transfusion:

Complication Features Management
Febrile transfusion reaction
– Presents with a 1-degree rise in temperature from baseline, along with chills and malaise.
– Most common reaction, occurring in 1 out of 8 transfusions.
– Usually caused by cytokines from leukocytes in transfused red cell or platelet components.
– Supportive management, with the use of paracetamol for symptom relief.

Acute haemolytic reaction
– Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine.
– Often accompanied by a feeling of ‘impending doom’.
– Most serious type of reaction, often due to ABO incompatibility caused by administration errors.
– Immediate action required: stop the transfusion, administer IV fluids, and consider diuretics if necessary.

Delayed haemolytic reaction
– Typically occurs 4-8 days after a blood transfusion.
– Symptoms include fever, anemia and/or hyperbilirubinemia

Blood transfusion is a crucial treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur.

Delayed haemolytic transfusion reactions (DHTRs) typically occur 4-8 days after a blood transfusion, but can sometimes manifest up to a month later. The symptoms are similar to acute haemolytic transfusion reactions but are usually less severe. Patients may experience fever, inadequate rise in haemoglobin, jaundice, reticulocytosis, positive antibody screen, and positive Direct Antiglobulin Test (Coombs test). DHTRs are more common in patients with sickle cell disease who have received frequent transfusions.

These reactions are caused by the presence of a low titre antibody that is too weak to be detected during cross-match and unable to cause lysis at the time of transfusion. The severity of DHTRs depends on the immunogenicity or dose of the antigen. Blood group antibodies associated with DHTRs include those of the Kidd, Duffy, Kell, and MNS systems. Most DHTRs have a benign course and do not require treatment. However, severe haemolysis with anaemia and renal failure can occur, so monitoring of haemoglobin levels and renal function is necessary. If an antibody is detected, antigen-negative blood can be requested for future transfusions.

Here is a summary of the main transfusion reactions and complications:

1. Febrile transfusion reaction: Presents with a 1-degree rise in temperature from baseline, along with chills and malaise. It is the most common reaction and is usually caused by cytokines from leukocytes in transfused red cell or platelet components. Supportive treatment with paracetamol is helpful.

2. Acute haemolytic reaction: Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine. It is the most serious type of reaction and often occurs due to ABO incompatibility from administration errors. The transfusion should be stopped, and IV fluids should be administered. Diuretics may be required.

3. Delayed haemolytic reaction: This reaction typically occurs 4-8 days after a blood transfusion and presents with fever, anaemia, jaundice and haemoglobuinuria. Direct antiglobulin (Coombs) test positive. Due to low titre antibody too weak to detect in cross-match and unable to cause lysis at time of transfusion. Most delayed haemolytic reactions have a benign course and require no treatment. Monitor anaemia and renal function and treat as required.

Von Willebrand disease (vWD) is a common hereditary coagulation disorder that affects about 1 in 100 people. It occurs due to a deficiency in Von Willebrand factor (vWF), which is responsible for protecting factor VIII from breaking down too quickly in the blood. Additionally, vWF is necessary for proper platelet adhesion, so a lack of it can lead to abnormal platelet function. As a result, both the APTT and bleeding time are prolonged, while the platelet count and thrombin time remain unaffected.

In many cases, vWD goes unnoticed as patients do not experience any symptoms. It is often diagnosed incidentally during a routine clotting profile check. However, if symptoms do occur, the most common ones are easy bruising, nosebleeds, and heavy menstrual bleeding. In severe cases, more serious bleeding and joint bleeds can occur.

For mild cases of von Willebrand disease, bleeding can be treated with desmopressin. This medication helps increase the patient’s own levels of vWF by releasing stored vWF from the Weibel-Palade bodies in the endothelial cells. These bodies are storage granules found in the inner lining of blood vessels and the heart. In more severe cases, replacement therapy is necessary, which involves infusing cryoprecipitate or Factor VIII concentrate. Replacement therapy is recommended for patients with severe von Willebrand’s disease who are undergoing moderate or major surgical procedures.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

Blood transfusion is a potentially life-saving treatment that can provide great clinical benefits. However, it also carries several risks and potential problems. These include immunological complications, administration errors, infections, immune dilution, and transfusion errors. While there have been improvements in safety procedures and efforts to minimize the use of transfusion, errors and serious adverse reactions still occur and often go unreported.

One rare complication of blood transfusion is transfusion-associated graft-vs-host disease (TA-GVHD). This condition typically presents with fever, rash, and diarrhea 1-4 weeks after the transfusion. Laboratory findings may show pancytopenia and abnormalities in liver function. Unlike GVHD after marrow transplantation, TA-GVHD leads to severe marrow aplasia with a mortality rate exceeding 90%. Unfortunately, there are currently no effective treatments available for this condition, and survival is rare, with death usually occurring within 1-3 weeks of the first symptoms.

During a blood transfusion, viable T lymphocytes from the donor are transfused into the recipient’s body. In TA-GVHD, these lymphocytes engraft and react against the recipient’s tissues. However, the recipient is unable to reject the donor lymphocytes due to factors such as immunodeficiency, severe immunosuppression, or shared HLA antigens. Supportive management is the only option for TA-GVHD.

The following summarizes the main complications and reactions that can occur during a blood transfusion:

Complication Features Management
Febrile transfusion reaction
– Presents with a 1-degree rise in temperature from baseline, along with chills and malaise.
– Most common reaction, occurring in 1 out of 8 transfusions.
– Usually caused by cytokines from leukocytes in transfused red cell or platelet components.
– Supportive management, with the use of paracetamol for symptom relief.

Acute haemolytic reaction
– Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine.
– Often accompanied by a feeling of ‘impending doom’.
– Most serious type of reaction, often due to ABO incompatibility caused by administration errors.
– Immediate action required: stop the transfusion, administer IV fluids, and consider diuretics if necessary.

Delayed haemolytic reaction
– Typically occurs 4-8 days after a blood transfusion.
– Symptoms include fever, anemia and/or hyperbilirubinemia

The majority of treatments provided to individuals with sickle cell disease are supportive measures that have limited impact on the underlying pathophysiology of the condition.

Currently, the only approved therapy that can modify the disease is Hydroxyurea. This medication is believed to function by increasing the levels of fetal hemoglobin, which in turn decreases the concentration of HbS within the cells and reduces the abnormal hemoglobin tendency to form polymers.

Hydroxyurea is currently authorized for use in adult patients who experience recurrent moderate-to-severe painful crises (at least three in the past 12 months). Its approval is specifically for reducing the frequency of these painful episodes and the need for blood transfusions.

The current recommendations from NICE for managing warfarin in the presence of bleeding or an abnormal INR are as follows:

In cases of major active bleeding, regardless of the INR level, the first step is to stop administering warfarin. Next, 5 mg of vitamin K (phytomenadione) should be given intravenously. Additionally, dried prothrombin complex concentrate, which contains factors II, VII, IX, and X, should be administered. If dried prothrombin complex is not available, fresh frozen plasma can be given at a dose of 15 ml/kg.

If the INR is greater than 8.0 and there is minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is greater than 8.0 with no bleeding, warfarin should be stopped. Oral administration of 1-5 mg of vitamin K can be given, and this dose can be repeated after 24 hours if the INR remains high. Warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with minor bleeding, warfarin should be stopped. Slow injection of 1-3 mg of vitamin K can be given, and warfarin can be restarted once the INR is less than 5.0.

If the INR is between 5.0-8.0 with no bleeding, one or two doses of warfarin should be withheld, and the subsequent maintenance dose should be reduced.

For more information, please refer to the NICE Clinical Knowledge Summary on the management of warfarin therapy and the BNF guidance on the use of phytomenadione.

Macrolide antibiotics, such as clarithromycin and erythromycin, are widely known to prolong the International Normalized Ratio (INR). Several drugs can increase the potency of warfarin, and the macrolides, along with ciprofloxacin and metronidazole, are the antibiotics that have the most significant impact on enhancing the effect of warfarin.

Further Reading:

Management of High INR with Warfarin

Major Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 5 mg.
– Administer 25-50 u/kg four-factor prothrombin complex concentrate.
– If prothrombin complex concentrate is not available, consider using fresh frozen plasma (FFP).
– Seek medical attention promptly.

INR > 8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR > 8.0 without Bleeding:
– Stop warfarin immediately.
– Administer oral vitamin K 1-5 mg using the intravenous preparation orally.
– Repeat vitamin K dose if INR remains high after 24 hours.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if any symptoms or concerns arise.

INR 5.0-8.0 with Minor Bleeding:
– Stop warfarin immediately.
– Administer intravenous vitamin K 1-3mg.
– Restart warfarin when INR is below 5.0.
– Seek medical advice if bleeding worsens or persists.

INR 5.0-8.0 without Bleeding:
– Withhold 1 or 2 doses of warfarin.
– Reduce subsequent maintenance dose.
– Monitor INR closely and seek medical advice if any concerns arise.

Note: In cases of intracranial hemorrhage, prothrombin complex concentrate should be considered as it is faster acting than fresh frozen plasma (FFP).

Target cells, also referred to as codocytes or Mexican hat cells, are a distinct type of red blood cells that display a unique appearance resembling a shooting target with a bullseye. These cells are commonly observed in individuals with sickle-cell disease, distinguishing it from the other conditions mentioned in the provided options. Hence, sickle-cell disease is the most probable diagnosis in this case. Additionally, target cells can also be associated with other conditions such as thalassaemia, liver disease, iron-deficiency anaemia, post splenectomy, and haemoglobin C disease.

Transfusion-associated circulatory overload (TACO) is a reaction that occurs when a large volume of blood is infused rapidly. It is the second leading cause of deaths related to transfusions, accounting for about 20% of all fatalities.

TACO typically happens in patients with limited cardiac reserve or chronic anemia who receive a fast blood transfusion. Elderly individuals, infants, and severely anemic patients are particularly vulnerable.

The common signs of TACO include acute respiratory distress, rapid heartbeat, high blood pressure, the appearance of acute or worsening fluid accumulation in the lungs on a chest X-ray, and evidence of excessive fluid retention.

The B-type natriuretic peptide (BNP) can be a helpful diagnostic tool for TACO. Usually, the BNP level is elevated to at least 1.5 times the baseline before the transfusion.

In many cases, simply slowing down the rate of transfusion, positioning the patient upright, and administering diuretics will be sufficient. In more severe cases, the transfusion should be stopped, and non-invasive ventilation may be considered.

Leukaemic infiltrates in the gingiva are frequently observed in cases of acute myeloid leukaemia. This type of leukaemia primarily affects adults and is most commonly seen in individuals between the ages of 65 and 70. The typical presentation of acute myeloid leukaemia involves clinical symptoms that arise as a result of leukaemic infiltration in the bone marrow and other areas outside of the marrow. These symptoms may include anaemia (resulting in lethargy, pallor, and breathlessness), thrombocytopaenia (manifesting as petechiae, bruising, epistaxis, and bleeding), neutropenia (leading to increased susceptibility to infections), hepatosplenomegaly, and infiltration of the gingiva.

Sickle-cell disease is a blood disorder that is inherited in an autosomal recessive manner. It is characterized by the production of abnormal red blood cells that have a sickle shape. These abnormal cells are triggered by various factors such as low oxygen levels, dehydration, stress, and infection. The disease is caused by a specific mutation in the beta-globin chain of hemoglobin, resulting in the substitution of glutamic acid with valine at the sixth position. The gene responsible for this mutation is located on chromosome 11.

On the other hand, sickle-cell trait refers to the carrier state of the disease. Individuals with sickle-cell trait have one normal allele and one abnormal allele. Both alleles are co-dominant, meaning that both normal and abnormal hemoglobin are produced. As a result, individuals with sickle-cell trait do not experience the same severity of symptoms as those with sickle-cell disease.

When both parents are carriers of the sickle-cell trait, there is a 50% chance that their child will also be an unaffected carrier, a 25% chance that the child will be unaffected, and a 25% chance that the child will develop sickle-cell disease. This is because the inheritance of the disease follows the principles of autosomal recessive inheritance.

Blood transfusion is a crucial medical treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion usage, errors and adverse reactions still occur.

One serious complication is acute haemolytic transfusion reactions, which happen when incompatible red cells are transfused and react with the patient’s own antibodies. This usually occurs due to human error, such as mislabelling sample tubes or request forms. Symptoms of this reaction include a feeling of impending doom, fever, chills, pain and warmth at the transfusion site, nausea, vomiting, and back, joint, and chest pain. Immediate action should be taken to stop the transfusion, replace the donor blood with normal saline or another suitable crystalloid, and check the blood to confirm the intended recipient. IV diuretics may be administered to increase renal blood flow, and urine output should be maintained.

Another common complication is febrile transfusion reaction, which presents with a 1-degree rise in temperature from baseline, along with chills and malaise. This reaction is usually caused by cytokines from leukocytes in the transfused blood components. Supportive treatment is typically sufficient, and paracetamol can be helpful.

Allergic reactions can also occur, usually due to foreign plasma proteins or anti-IgA. These reactions often present with urticaria, pruritus, and hives, and in severe cases, laryngeal edema or bronchospasm may occur. Symptomatic treatment with antihistamines is usually enough, and there is usually no need to stop the transfusion. However, if anaphylaxis occurs, the transfusion should be stopped, and the patient should be administered adrenaline and treated according to the ALS protocol.

Transfusion-related acute lung injury (TRALI) is a severe complication characterized by non-cardiogenic pulmonary edema within 6 hours of transfusion. It is associated with antibodies in the donor blood reacting with recipient leukocyte antigens. This is the most common cause of death related to transfusion reactions. Treatment involves stopping the transfusion, administering oxygen, and providing aggressive respiratory support in approximately 75% of patients. Diuretic usage should be avoided.

Transfusion-related lung injury (TRALI) is responsible for about one-third of all transfusion-related deaths, making it the leading cause. On the other hand, transfusion-associated circulatory overload (TACO) accounts for approximately 20% of these fatalities, making it the second leading cause. TACO occurs when a large volume of blood is rapidly infused, particularly in patients with limited cardiac reserve or chronic anemia. Elderly individuals, infants, and severely anemic patients are especially vulnerable to this reaction.

The typical signs of TACO include acute respiratory distress, rapid heart rate, high blood pressure, the appearance of acute or worsening pulmonary edema on a chest X-ray, and evidence of excessive fluid accumulation. In many cases, simply reducing the transfusion rate, positioning the patient upright, and administering diuretics will be sufficient to manage the condition. However, in more severe cases, it is necessary to halt the transfusion and consider non-invasive ventilation.

Transfusion-related acute lung injury (TRALI) is defined as new acute lung injury (ALI) that occurs during or within six hours of transfusion, not explained by another ALI risk factor. Transfusion of part of one unit of any blood product can cause TRALI.

Blood transfusion is a crucial treatment that can save lives, but it also comes with various risks and potential problems. These include immunological complications, administration errors, infections, and immune dilution. While there have been improvements in safety procedures and a reduction in transfusion use, errors and adverse reactions still occur.

Delayed haemolytic transfusion reactions (DHTRs) typically occur 4-8 days after a blood transfusion, but can sometimes manifest up to a month later. The symptoms are similar to acute haemolytic transfusion reactions but are usually less severe. Patients may experience fever, inadequate rise in haemoglobin, jaundice, reticulocytosis, positive antibody screen, and positive Direct Antiglobulin Test (Coombs test). DHTRs are more common in patients with sickle cell disease who have received frequent transfusions.

These reactions are caused by the presence of a low titre antibody that is too weak to be detected during cross-match and unable to cause lysis at the time of transfusion. The severity of DHTRs depends on the immunogenicity or dose of the antigen. Blood group antibodies associated with DHTRs include those of the Kidd, Duffy, Kell, and MNS systems. Most DHTRs have a benign course and do not require treatment. However, severe haemolysis with anaemia and renal failure can occur, so monitoring of haemoglobin levels and renal function is necessary. If an antibody is detected, antigen-negative blood can be requested for future transfusions.

Here is a summary of the main transfusion reactions and complications:

1. Febrile transfusion reaction: Presents with a 1-degree rise in temperature from baseline, along with chills and malaise. It is the most common reaction and is usually caused by cytokines from leukocytes in transfused red cell or platelet components. Supportive treatment with paracetamol is helpful.

2. Acute haemolytic reaction: Symptoms include fever, chills, pain at the transfusion site, nausea, vomiting, and dark urine. It is the most serious type of reaction and often occurs due to ABO incompatibility from administration errors. The transfusion should be stopped, and IV fluids should be administered. Diuretics may be required.

3. Delayed haemolytic reaction: This reaction typically occurs 4-8 days after a blood transfusion and presents with fever, anaemia, jaundice and haemoglobuinuria. Direct antiglobulin (Coombs) test positive. Due to low titre antibody too weak to detect in cross-match and unable to cause lysis at time of transfusion. Most delayed haemolytic reactions have a benign course and require no treatment. Monitor anaemia and renal function and treat as required.

Chronic myeloid leukaemia (CML) is a type of blood disorder that arises from an abnormal pluripotent haemopoietic stem cell. The majority of CML cases, more than 80%, are caused by a cytogenetic abnormality called the Philadelphia chromosome. This abnormality occurs when there is a reciprocal translocation between the long arms of chromosomes 9 and 22.

CML typically develops slowly over a period of several years, known as the chronic stage. During this stage, patients usually do not experience any symptoms, and it is often discovered incidentally through routine blood tests. Around 90% of CML cases are diagnosed during this stage. In the bone marrow, less than 10% of the white cells are immature blasts.

Symptoms start to appear when the CML cells begin to expand, which is known as the accelerated stage. Approximately 10% of cases are diagnosed during this stage. Between 10 and 30% of the blood cells in the bone marrow are blasts at this point. Common clinical features during this stage include tiredness, fatigue, fever, night sweats, abdominal distension, left upper quadrant pain (splenic infarction), splenomegaly (enlarged spleen), hepatomegaly (enlarged liver), easy bruising, gout (due to rapid cell turnover), and hyperviscosity (which can lead to complications like stroke, priapism, etc.).

In some cases, a small number of patients may present with a blast crisis, also known as the blast stage. During this stage, more than 30% of the blood cells in the bone marrow are immature blast cells. Patients in this stage are generally very ill, experiencing severe constitutional symptoms such as fever, weight loss, and bone pain, as well as infections and bleeding tendencies.

Laboratory findings in CML include a significantly elevated white cell count (often greater than 100 x 109/l), a left shift with an increased number of immature leukocytes, mild to moderate normochromic, normocytic anaemia, variable platelet counts (low, normal, or elevated), presence of the Philadelphia chromosome in more than 80% of cases, and elevated levels of serum uric acid and alkaline phosphatase.

Anaemia can be categorized based on the size of red blood cells. Microcytic anaemia, characterized by a mean corpuscular volume (MCV) of less than 80 fl, can be caused by various factors such as iron deficiency, thalassaemia, anaemia of chronic disease (which can also be normocytic), sideroblastic anaemia (which can also be normocytic), lead poisoning, and aluminium toxicity (although this is now rare and mainly affects haemodialysis patients).

On the other hand, normocytic anaemia, with an MCV ranging from 80 to 100 fl, can be attributed to conditions like haemolysis, acute haemorrhage, bone marrow failure, anaemia of chronic disease (which can also be microcytic), mixed iron and folate deficiency, pregnancy, chronic renal failure, and sickle-cell disease.

Lastly, macrocytic anaemia, characterized by an MCV greater than 100 fl, can be caused by factors such as B12 deficiency, folate deficiency, hypothyroidism, reticulocytosis, liver disease, alcohol abuse, myeloproliferative disease, myelodysplastic disease, and certain drugs like methotrexate, hydroxyurea, and azathioprine.

It is important to understand the different causes of anaemia based on red cell size as this knowledge can aid in the diagnosis and management of this condition.

There is a known connection between trisomy 21 and acute lymphoblastic leukemia. Therefore, it is important to investigate and rule out this possibility as the first step in this case.