Acute limb ischaemia refers to a sudden reduction in blood flow to a limb, which puts the limb’s viability at risk. This condition is most commonly caused by either a sudden blockage of a previously partially blocked artery due to a blood clot or by an embolus that travels from a distant site. It is considered a surgical emergency, as without prompt surgical intervention, complete acute ischaemia can lead to extensive tissue death within six hours.

The leading cause of acute limb ischaemia is the sudden blockage of a narrowed arterial segment due to a blood clot, accounting for 60% of cases. The second most common cause is an embolism, which makes up 30% of cases. Emboli can originate from various sources, such as a blood clot in the left atrium of patients with atrial fibrillation (which accounts for 80% of peripheral emboli), a clot formed on the heart’s wall following a heart attack, or from prosthetic heart valves. It is crucial to differentiate between these two conditions, as their treatment and prognosis differ.

To properly investigate acute limb ischaemia, several important tests should be arranged. These include a hand-held Doppler ultrasound scan, which can help determine if there is any remaining arterial flow. Blood tests, such as a full blood count, erythrocyte sedimentation rate, blood glucose level, and thrombophilia screen, are also necessary. If there is uncertainty regarding the diagnosis, urgent arteriography should be performed.

In cases where an embolus is suspected as the cause, additional investigations are needed to identify its source. These may include an electrocardiogram to detect atrial fibrillation, an echocardiogram to assess the heart’s function, an ultrasound of the aorta, and ultrasounds of the popliteal and femoral arteries.

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Allopurinol should not be started during an acute gout attack as it can make the attack last longer and even trigger another one. However, if a patient is already taking allopurinol, they should continue taking it and treat the acute attack with NSAIDs or colchicine as usual.

The first choice for treating acute gout attacks is non-steroidal anti-inflammatory drugs (NSAIDs) like naproxen. Colchicine can be used if NSAIDs are not suitable, for example, in patients with high blood pressure or a history of peptic ulcer disease. In this case, the patient has no reason to avoid NSAIDs, so naproxen would still be the preferred option.

Once the acute attack has subsided, it would be reasonable to gradually increase the dose of allopurinol, aiming for urate levels in the blood of less than 6 mg/dl (<360 µmol/l). Febuxostat (Uloric) is an alternative to allopurinol that can be used for long-term management of gout.

ACE inhibitors should not be used in individuals with HAE because they can enhance the effects of bradykinin. This can lead to drug-induced angioedema, which is a known side effect of ACE inhibitors. In individuals with HAE, ACE inhibitors can trigger attacks of angioedema.

Further Reading:

Angioedema and urticaria are related conditions that involve swelling in different layers of tissue. Angioedema refers to swelling in the deeper layers of tissue, such as the lips and eyelids, while urticaria, also known as hives, refers to swelling in the epidermal skin layers, resulting in raised red areas of skin with itching. These conditions often coexist and may have a common underlying cause.

Angioedema can be classified into allergic and non-allergic types. Allergic angioedema is the most common type and is usually triggered by an allergic reaction, such as to certain medications like penicillins and NSAIDs. Non-allergic angioedema has multiple subtypes and can be caused by factors such as certain medications, including ACE inhibitors, or underlying conditions like hereditary angioedema (HAE) or acquired angioedema.

HAE is an autosomal dominant disease characterized by a deficiency of C1 esterase inhibitor. It typically presents in childhood and can be inherited or acquired as a result of certain disorders like lymphoma or systemic lupus erythematosus. Acquired angioedema may have similar clinical features to HAE but is caused by acquired deficiencies of C1 esterase inhibitor due to autoimmune or lymphoproliferative disorders.

The management of urticaria and allergic angioedema focuses on ensuring the airway remains open and addressing any identifiable triggers. In mild cases without airway compromise, patients may be advised that symptoms will resolve without treatment. Non-sedating antihistamines can be used for up to 6 weeks to relieve symptoms. Severe cases of urticaria may require systemic corticosteroids in addition to antihistamines. In moderate to severe attacks of allergic angioedema, intramuscular epinephrine may be considered.

The management of HAE involves treating the underlying deficiency of C1 esterase inhibitor. This can be done through the administration of C1 esterase inhibitor, bradykinin receptor antagonists, or fresh frozen plasma transfusion, which contains C1 inhibitor.

In summary, angioedema and urticaria are related conditions involving swelling in different layers of tissue. They can coexist and may have a common underlying cause. Management involves addressing triggers, using antihistamines, and in severe cases, systemic corticosteroids or other specific treatments for HAE.

The blood gas measurement of pO2 should be equal to or greater than 18 kilopascals (kPa) at a level of 10.

Further Reading:

Rapid sequence induction (RSI) is a method used to place an endotracheal tube (ETT) in the trachea while minimizing the risk of aspiration. It involves inducing loss of consciousness while applying cricoid pressure, followed by intubation without face mask ventilation. The steps of RSI can be remembered using the 7 P’s: preparation, pre-oxygenation, pre-treatment, paralysis and induction, protection and positioning, placement with proof, and post-intubation management.

Preparation involves preparing the patient, equipment, team, and anticipating any difficulties that may arise during the procedure. Pre-oxygenation is important to ensure the patient has an adequate oxygen reserve and prolongs the time before desaturation. This is typically done by breathing 100% oxygen for 3 minutes. Pre-treatment involves administering drugs to counter expected side effects of the procedure and anesthesia agents used.

Paralysis and induction involve administering a rapid-acting induction agent followed by a neuromuscular blocking agent. Commonly used induction agents include propofol, ketamine, thiopentone, and etomidate. The neuromuscular blocking agents can be depolarizing (such as suxamethonium) or non-depolarizing (such as rocuronium). Depolarizing agents bind to acetylcholine receptors and generate an action potential, while non-depolarizing agents act as competitive antagonists.

Protection and positioning involve applying cricoid pressure to prevent regurgitation of gastric contents and positioning the patient’s neck appropriately. Tube placement is confirmed by visualizing the tube passing between the vocal cords, auscultation of the chest and stomach, end-tidal CO2 measurement, and visualizing misting of the tube. Post-intubation management includes standard care such as monitoring ECG, SpO2, NIBP, capnography, and maintaining sedation and neuromuscular blockade.

Overall, RSI is a technique used to quickly and safely secure the airway in patients who may be at risk of aspiration. It involves a series of steps to ensure proper preparation, oxygenation, drug administration, and tube placement. Monitoring and post-intubation care are also important aspects of RSI.

Ketamine should not be used in individuals who have pulmonary hypertension, as it can worsen their condition. Additionally, it is contraindicated in children under 12 months old, as they are at a higher risk of experiencing laryngospasm and airway complications. Other contraindications include a high risk of laryngospasm (such as having an active respiratory infection or asthma), unstable or abnormal airway (due to tracheal surgery or stenosis), active upper or lower respiratory tract infection, proposed procedure within the mouth or pharynx, severe psychological problems, significant cardiac disease, intracranial hypertension with cerebrospinal fluid obstruction, intraocular pathology, previous psychotic illness, uncontrolled epilepsy, hyperthyroidism or taking thyroid medication, porphyria, prior adverse reaction to ketamine, altered conscious level due to acute illness or injury, and drug or alcohol intoxication.

Further Reading:

Ketamine sedation in children should only be performed by a trained and competent clinician who is capable of managing complications, especially those related to the airway. The clinician should have completed the necessary training and have the appropriate skills for procedural sedation. It is important for the clinician to consider the length of the procedure before deciding to use ketamine sedation, as lengthy procedures may be more suitable for general anesthesia.

Examples of procedures where ketamine may be used in children include suturing, fracture reduction/manipulation, joint reduction, burn management, incision and drainage of abscess, tube thoracostomy placement, foreign body removal, and wound exploration/irrigation.

During the ketamine sedation procedure, a minimum of three staff members should be present: a doctor to manage the sedation and airway, a clinician to perform the procedure, and an experienced nurse to monitor and support the patient, family, and clinical staff. The child should be sedated and managed in a high dependency or resuscitation area with immediate access to resuscitation facilities. Monitoring should include sedation level, pain, ECG, blood pressure, respiration, pulse oximetry, and capnography, with observations taken and recorded every 5 minutes.

Prior to the procedure, consent should be obtained from the parent or guardian after discussing the proposed procedure and use of ketamine sedation. The risks and potential complications should be explained, including mild or moderate/severe agitation, rash, vomiting, transient clonic movements, and airway problems. The parent should also be informed that certain common side effects, such as nystagmus, random purposeless movements, muscle twitching, rash, and vocalizations, are of no clinical significance.

Topical anesthesia may be considered to reduce the pain of intravenous cannulation, but this step may not be advisable if the procedure is urgent. The clinician should also ensure that key resuscitation drugs are readily available and doses are calculated for the patient in case they are needed.

Before administering ketamine, the child should be prepared by encouraging the parents or guardians to talk to them about happy thoughts and topics to minimize unpleasant emergence phenomena. The dose of ketamine is typically 1.0 mg/kg by slow intravenous injection over at least one minute, with additional doses of 0.5 mg/kg administered as required after 5-10 minutes to achieve the desired dissociative state.

Patients who have Eron class III or IV cellulitis should be hospitalized and treated with intravenous antibiotics. In this case, the patient is experiencing cellulitis along with symptoms of significant systemic distress, such as rapid heart rate and breathing. This places the patient in the Eron Class III category, which necessitates admission for intravenous antibiotic therapy.

Further Reading:

Cellulitis is an inflammation of the skin and subcutaneous tissues caused by an infection, usually by Streptococcus pyogenes or Staphylococcus aureus. It commonly occurs on the shins and is characterized by symptoms such as erythema, pain, swelling, and heat. In some cases, there may also be systemic symptoms like fever and malaise.

The NICE Clinical Knowledge Summaries recommend using the Eron classification to determine the appropriate management of cellulitis. Class I cellulitis refers to cases without signs of systemic toxicity or uncontrolled comorbidities. Class II cellulitis involves either systemic illness or the presence of a co-morbidity that may complicate or delay the resolution of the infection. Class III cellulitis is characterized by significant systemic upset or limb-threatening infection due to vascular compromise. Class IV cellulitis involves sepsis syndrome or a severe life-threatening infection like necrotizing fasciitis.

According to the guidelines, patients with Eron Class III or Class IV cellulitis should be admitted for intravenous antibiotics. This also applies to patients with severe or rapidly deteriorating cellulitis, very young or frail individuals, immunocompromised patients, those with significant lymphedema, and those with facial or periorbital cellulitis (unless very mild). Patients with Eron Class II cellulitis may not require admission if the necessary facilities and expertise are available in the community to administer intravenous antibiotics and monitor the patient.

The recommended first-line treatment for mild to moderate cellulitis is flucloxacillin. For patients allergic to penicillin, clarithromycin or clindamycin is recommended. In cases where patients have failed to respond to flucloxacillin, local protocols may suggest the use of oral clindamycin. Severe cellulitis should be treated with intravenous benzylpenicillin and flucloxacillin.

Overall, the management of cellulitis depends on the severity of the infection and the presence of any systemic symptoms or complications. Prompt treatment with appropriate antibiotics is crucial to prevent further complications and promote healing.

The qCSI Score, also known as the Quick COVID-19 Severity Index, is a tool that can predict the risk of critical respiratory illness in patients who are admitted from the emergency department with COVID-19. This score takes into consideration three criteria: respiratory rate, pulse oximetry, and oxygen flow rate. By assessing these factors, the qCSI Score can provide an estimation of the 24-hour risk of severe respiratory complications in these patients.

On the other hand, the qSOFA Score is a different tool that is used to identify high-risk patients for in-hospital mortality when there is a suspicion of infection, particularly in cases of sepsis. However, it is important to note that the qSOFA Score is not specifically designed for use in the setting of febrile neutropenia.

Another scoring system, known as the CURB-65 Score, is utilized to estimate the mortality risk associated with community-acquired pneumonia. This score helps healthcare professionals determine whether a patient should receive inpatient or outpatient treatment based on their likelihood of experiencing adverse outcomes.

Lastly, the SCAP Score is a scoring system that predicts the risk of adverse outcomes in patients with community-acquired pneumonia who present to the emergency department. By assessing various clinical factors, this score can provide valuable information to healthcare providers regarding the potential severity of the illness and the need for further intervention.

In addition to these scores, there is also the MASCC Risk Index Score, which is specifically used in the context of cancer patients receiving supportive care. This score helps assess the risk of complications in this vulnerable population and aids in making informed decisions regarding their treatment and management.

The classic ECG features of atrial fibrillation include an irregularly irregular rhythm, the absence of p-waves, an irregular ventricular rate, and the presence of fibrillation waves. This irregular rhythm occurs because the atrial impulses are filtered out by the AV node.

In addition, Ashman beats may be observed in atrial fibrillation. These beats are characterized by wide complex QRS complexes, often with a morphology resembling right bundle branch block. They occur after a short R-R interval that is preceded by a prolonged R-R interval. Fortunately, Ashman beats are generally considered harmless.

The disorganized electrical activity in atrial fibrillation typically originates at the root of the pulmonary veins.

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).

Vascular dementia is the second most common form of dementia, accounting for approximately 25% of all cases. It occurs when the brain is damaged due to various factors, such as major strokes, multiple smaller strokes that go unnoticed (known as multi-infarct), or chronic changes in smaller blood vessels (referred to as subcortical dementia). The term vascular cognitive impairment (VCI) is increasingly used to encompass this range of diseases.

Unlike Alzheimer’s disease, which has a gradual and subtle onset, vascular dementia can occur suddenly and typically shows a series of stepwise increases in symptom severity. The presentation and progression of the disease can vary significantly.

There are certain features that suggest a vascular cause of dementia. These include a history of transient ischemic attacks (TIAs) or cardiovascular disease, the presence of focal neurological abnormalities, prominent memory impairment in the early stages of the disease, early onset of gait disturbance and unsteadiness, frequent unprovoked falls in the early stages, bladder symptoms (such as incontinence) without any identifiable urological condition in the early stages, and seizures.

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.

The finger has a total of four digital nerves. Two of these nerves, known as the palmar digital nerves, run along the palm side of each finger. The other two nerves, called the dorsal digital nerves, are located on the back side of the finger. However, the dorsal nerve supply changes slightly at the level of the proximal IP joint. Beyond this point, the dorsal nerve supply comes from the dorsal branch of the palmar digital nerve.

Further Reading:

Digital nerve blocks are commonly used to numb the finger for various procedures such as foreign body removal, dislocation reduction, and suturing. Sensation to the finger is primarily provided by the proper digital nerves, which arise from the common digital nerve. Each common digital nerve divides into two proper digital nerves, which run along the palmar aspect of the finger. These proper digital nerves give off a dorsal branch that supplies the dorsal aspect of the finger.

The most common technique for digital nerve blocks is the digital (ring) block. The hand is cleaned and the injection sites are cleansed with an alcohol swab. A syringe containing 1% lidocaine is prepared, and the needle is inserted at the base of the finger from a dorsal approach. Lidocaine is infiltrated under the skin, and the needle is then advanced towards the palmar aspect of the finger to inject more lidocaine. This process is repeated on the opposite side of the finger.

It is important not to use lidocaine with adrenaline for this procedure, as it may cause constriction and ischemia of the digital artery. Lidocaine 1% is the preferred local anesthetic, and the maximum dose is 3 ml/kg up to 200 mg. Contraindications for digital nerve blocks include compromised circulation to the finger, infection at the planned injection site, contraindication to local anesthetic (e.g. allergy), and suspected compartment syndrome (which is rare in the finger).

Complications of digital nerve blocks can include vascular injury to the digital artery or vein, injury to the digital nerve, infection, pain, allergic reaction, intravascular injection (which can be avoided by aspirating prior to injection), and systemic local anesthetic toxicity (which is uncommon with typical doses of lidocaine).

Acute limb ischaemia refers to a sudden decrease in blood flow to a limb, which puts the limb at risk of tissue death. This condition is most commonly caused by either a sudden blockage of a partially blocked artery or an embolus that travels from another part of the body. It is considered a surgical emergency, as without prompt surgical intervention, the limb may suffer extensive tissue damage within six hours.

The typical signs of acute limb ischaemia are often described using the 6 Ps: constant and persistent pain, absence of pulses in the ankle, paleness or discoloration of the limb, loss of power or paralysis, reduced sensation or numbness, and a sensation of coldness. The leading cause of acute limb ischaemia is a sudden blockage of a previously narrowed artery (60% of cases). The second most common cause is an embolism, such as from a blood clot in the heart or following a heart attack. It is important to differentiate between these two causes, as the treatment and prognosis differ.

Other potential causes of acute limb ischaemia include trauma, Raynaud’s syndrome, iatrogenic injury (caused by medical procedures), popliteal aneurysm, aortic dissection, and compartment syndrome. If acute limb ischaemia is suspected, it is crucial to seek immediate assessment by a vascular surgeon.

The management of acute limb ischaemia in a hospital setting depends on factors such as the type and location of the blockage, duration of ischaemia, presence of other medical conditions, type of blood vessel affected, and the viability of the limb. Treatment options may include percutaneous catheter-directed thrombolytic therapy, surgical embolectomy, or endovascular revascularisation if the limb can still be saved. The choice between surgical and endovascular techniques will depend on various factors, including the urgency of revascularisation and the severity of sensory and motor deficits.

In cases where the limb is beyond salvage, amputation may be necessary. This is because attempting to revascularise a limb with irreversible ischaemia and extensive muscle death can lead to a condition called reperfusion syndrome, which can cause inflammation and damage to multiple organs, potentially resulting in death.

During the first trimester of pregnancy, the use of warfarin can lead to a condition known as fetal warfarin syndrome. This condition is characterized by nasal hypoplasia, bone stippling, bilateral optic atrophy, and intellectual disability in the baby. However, if warfarin is taken during the second or third trimester, it can cause optic atrophy, cataracts, microcephaly, microphthalmia, intellectual disability, and both fetal and maternal hemorrhage.

There are several other drugs that can have adverse effects during pregnancy. For example, ACE inhibitors like ramipril can cause hypoperfusion, renal failure, and the oligohydramnios sequence if taken during the second and third trimesters. Aminoglycosides such as gentamicin can lead to ototoxicity and deafness in the baby. High doses of aspirin can result in first trimester abortions, delayed onset labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses of aspirin (e.g. 75 mg) do not pose significant risks.

Benzodiazepines like diazepam, when taken late in pregnancy, can cause respiratory depression and a neonatal withdrawal syndrome. Calcium-channel blockers, if taken during the first trimester, can cause phalangeal abnormalities, while their use in the second and third trimesters can lead to fetal growth retardation. Carbamazepine can result in hemorrhagic disease of the newborn and neural tube defects. Chloramphenicol can cause gray baby syndrome. Corticosteroids, if taken during the first trimester, may cause orofacial clefts.

Danazol, if taken during the first trimester, can cause masculinization of the female fetuses genitals. Finasteride should not be handled by pregnant women as crushed or broken tablets can be absorbed through the skin and affect male sex organ development. Haloperidol, if taken during the first trimester, may cause limb malformations, while its use in the third trimester increases the risk of extrapyramidal symptoms in the newborn.

Heparin can lead to maternal bleeding and thrombocytopenia. Isoniazid can cause maternal liver damage and neuropathy and seizures in the baby. Isotretinoin carries a high risk of teratogenicity, including multiple congenital malformations and spontaneous abortion.

Metformin is a type of biguanide medication that, when taken alone, does not lead to low blood sugar levels (hypoglycemia). However, it can potentially worsen hypoglycemia when used in combination with other drugs like sulphonylureas.

Gliclazide, on the other hand, is a sulphonylurea medication known to cause hypoglycemia. Pioglitazone, a thiazolidinedione drug, is also recognized as a cause of hypoglycemia.

It’s important to note that Actrapid and Novomix are both forms of insulin, which can also result in hypoglycemia.

Chancroid is a sexually transmitted infection caused by the bacteria Haemophilus ducreyi. It is not very common in the UK but is prevalent in Africa, Asia, and South America. HIV is often associated with chancroid, particularly in Africa where there is a 60% correlation.

The main symptom of chancroid is the development of painful ulcers on the genitalia. In women, these ulcers typically appear on the labia majora. Sometimes, kissing ulcers can form when ulcers are located on opposing surfaces of the labia. Painful swelling of the lymph nodes occurs in 30-60% of patients, and in some cases, these swollen nodes can turn into abscesses known as buboes.

The CDC recommends treating chancroid with a single oral dose of 1 gram of azithromycin or a single intramuscular dose of ceftriaxone. Alternatively, a 7-day course of oral erythromycin can be used. It’s important to note that Haemophilus ducreyi is resistant to several antibiotics, including penicillins, tetracyclines, trimethoprim, ciprofloxacin, aminoglycosides, and sulfonamides.

Possible complications of chancroid include extensive swelling of the lymph nodes, large abscesses and sinuses in the groin area, phimosis (a condition where the foreskin cannot be retracted), and superinfection with Fusarium spp. or Bacteroides spp.

Syphilis, caused by Treponema pallidum, presents with a painless ulcer called a chancre during its primary stage. This is different from chancroid, which causes painful ulcers. Chlamydia trachomatis can lead to lymphogranuloma venereum, where a painless genital ulcer may develop initially and go unnoticed. Granuloma inguinale, caused by Klebsiella granulomatis, causes painless nodules and ulcers on the genitals that eventually burst and create open, oozing lesions. Neisseria gonorrhoeae, on the other hand, typically causes vaginal or urethral discharge and is often asymptomatic, rather than causing genital ulceration.

Hyperventilation leads to the constriction of blood vessels in the brain, which in turn reduces the flow and volume of blood in the brain, ultimately decreasing intracranial pressure (ICP). This is because hyperventilation lowers the levels of carbon dioxide (PaCO2) in the blood, resulting in an increase in pH and causing the arteries in the brain to constrict and reduce blood flow. As a result, cerebral blood volume and ICP decrease. The effects of hyperventilation are immediate, but they gradually diminish over a period of 6-24 hours as the brain adjusts its bicarbonate levels to normalize pH. However, caution must be exercised when discontinuing hyperventilation after a prolonged period, as the sudden increase in PaCO2 can lead to a rapid rise in cerebral blood flow and a detrimental increase in ICP.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.

Bronchiolitis is a short-term infection of the lower respiratory tract that primarily affects infants aged 2 to 6 months. It is commonly caused by a viral infection, with respiratory syncytial virus (RSV) being the most prevalent culprit. RSV infections are most prevalent during the winter months, typically occurring between November and March. In the UK, bronchiolitis is the leading cause of hospitalization among infants.

The typical symptoms of bronchiolitis include fever, difficulty breathing, coughing, poor feeding, irritability, apnoeas (more common in very young infants), and wheezing or fine inspiratory crackles. To confirm the diagnosis, a nasopharyngeal aspirate can be taken for RSV rapid testing. This test is useful in preventing unnecessary further testing and facilitating the isolation of the affected infant.

Most infants with acute bronchiolitis experience a mild, self-limiting illness that does not require hospitalization. Treatment primarily focuses on supportive measures, such as ensuring adequate fluid and nutritional intake and controlling the infant’s temperature. The illness typically lasts for 7 to 10 days.

However, hospital referral and admission are recommended in certain cases, including poor feeding (less than 50% of usual intake over the past 24 hours), lethargy, a history of apnoea, a respiratory rate exceeding 70 breaths per minute, nasal flaring or grunting, severe chest wall recession, cyanosis, oxygen saturations below 90% for children aged 6 weeks and over, and oxygen saturations below 92% for babies under 6 weeks or those with underlying health conditions.

If hospitalization is necessary, treatment involves supportive measures, supplemental oxygen, and nasogastric feeding as needed. There is limited or no evidence supporting the use of antibiotics, antivirals, bronchodilators, corticosteroids, hypertonic saline, or adrenaline nebulizers in the management of bronchiolitis.

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.

For adults and children over the age of 12 who are suspected to have glandular fever and have a normal immune system, it is recommended to conduct a Full Blood Count (FBC) and a monospot test during the second week of the illness. The timing and choice of investigations for glandular fever vary depending on the patient’s age, immune system status, and duration of symptoms. For children under the age of 12 and individuals with compromised immune systems, it is advised to perform a blood test for Epstein-Barr virus (EBV) viral serology after at least 7 days of illness. However, for immunocompetent adults and children older than 12, a FBC with differential white cell count and a monospot test (heterophile antibodies) should be conducted during the second week of the illness.

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.

The initial indication of progressive compression on the oculomotor nerve is the dilation of the pupil. In cases where the oculomotor nerve is being compressed, the outer parasympathetic fibers are typically affected before the inner motor fibers. These parasympathetic fibers are responsible for stimulating the constriction of the pupil. When they are disrupted, the sympathetic stimulation of the pupil is unopposed, leading to the dilation of the pupil (known as mydriasis or blown pupil). This symptom is usually observed before the drooping of the eyelid (lid ptosis) and the downward and outward positioning of the eye.

Further Reading:

Intracranial pressure (ICP) refers to the pressure within the craniospinal compartment, which includes neural tissue, blood, and cerebrospinal fluid (CSF). Normal ICP for a supine adult is 5-15 mmHg. The body maintains ICP within a narrow range through shifts in CSF production and absorption. If ICP rises, it can lead to decreased cerebral perfusion pressure, resulting in cerebral hypoperfusion, ischemia, and potentially brain herniation.

The cranium, which houses the brain, is a closed rigid box in adults and cannot expand. It is made up of 8 bones and contains three main components: brain tissue, cerebral blood, and CSF. Brain tissue accounts for about 80% of the intracranial volume, while CSF and blood each account for about 10%. The Monro-Kellie doctrine states that the sum of intracranial volumes is constant, so an increase in one component must be offset by a decrease in the others.

There are various causes of raised ICP, including hematomas, neoplasms, brain abscesses, edema, CSF circulation disorders, venous sinus obstruction, and accelerated hypertension. Symptoms of raised ICP include headache, vomiting, pupillary changes, reduced cognition and consciousness, neurological signs, abnormal fundoscopy, cranial nerve palsy, hemiparesis, bradycardia, high blood pressure, irregular breathing, focal neurological deficits, seizures, stupor, coma, and death.

Measuring ICP typically requires invasive procedures, such as inserting a sensor through the skull. Management of raised ICP involves a multi-faceted approach, including antipyretics to maintain normothermia, seizure control, positioning the patient with a 30º head up tilt, maintaining normal blood pressure, providing analgesia, using drugs to lower ICP (such as mannitol or saline), and inducing hypocapnoeic vasoconstriction through hyperventilation. If these measures are ineffective, second-line therapies like barbiturate coma, optimised hyperventilation, controlled hypothermia, or decompressive craniectomy may be considered.

Arterial blood gas (ABG) interpretation is crucial in evaluating a patient’s respiratory gas exchange and acid-base balance. While the normal values on an ABG may slightly vary between analysers, they generally fall within the following ranges: pH of 7.35 – 7.45, pO2 of 10 – 14 kPa, PCO2 of 4.5 – 6 kPa, HCO3- of 22 – 26 mmol/l, and base excess of -2 – 2 mmol/l.

In this particular case, the patient’s medical history raises concerns about a potential diagnosis of pulmonary embolism. The relevant ABG findings are as follows: significant hypoxia (indicating type 1 respiratory failure), elevated pH (alkalaemia), low PCO2, and normal bicarbonate levels. These findings suggest that the patient is experiencing primary respiratory alkalosis.

By analyzing the ABG results, healthcare professionals can gain valuable insights into a patient’s respiratory function and acid-base status, aiding in the diagnosis and management of various conditions.

Cardiac tamponade is characterized by several classic clinical signs. These include distended neck veins, hypotension, and muffled heart sounds. These three signs are collectively known as Beck’s triad. Additionally, patients with cardiac tamponade may also experience pulseless electrical activity (PEA). It is important to recognize these signs as they can indicate the presence of cardiac tamponade.

Further Reading:

Cardiac tamponade, also known as pericardial tamponade, occurs when fluid accumulates in the pericardial sac and compresses the heart, leading to compromised blood flow. Classic clinical signs of cardiac tamponade include distended neck veins, hypotension, muffled heart sounds, and pulseless electrical activity (PEA). Diagnosis is typically done through a FAST scan or an echocardiogram.

Management of cardiac tamponade involves assessing for other injuries, administering IV fluids to reduce preload, performing pericardiocentesis (inserting a needle into the pericardial cavity to drain fluid), and potentially performing a thoracotomy. It is important to note that untreated expanding cardiac tamponade can progress to PEA cardiac arrest.

Pericardiocentesis can be done using the subxiphoid approach or by inserting a needle between the 5th and 6th intercostal spaces at the left sternal border. Echo guidance is the gold standard for pericardiocentesis, but it may not be available in a resuscitation situation. Complications of pericardiocentesis include ST elevation or ventricular ectopics, myocardial perforation, bleeding, pneumothorax, arrhythmia, acute pulmonary edema, and acute ventricular dilatation.

It is important to note that pericardiocentesis is typically used as a temporary measure until a thoracotomy can be performed. Recent articles published on the RCEM learning platform suggest that pericardiocentesis has a low success rate and may delay thoracotomy, so it is advised against unless there are no other options available.

The recommended diagnostic tests for Cushing’s syndrome include the 24-hour urinary free cortisol test, the 1 mg overnight dexamethasone suppression test, and the late-night salivary cortisol test. In this case, the patient exhibits symptoms of Cushing syndrome such as a moon face, abdominal striae, and hirsutism. These symptoms may be caused by Cushing’s disease, which is Cushing syndrome due to a pituitary adenoma. The patient also experiences headaches and visual disturbances, which could potentially be caused by high blood sugar levels. It is important to note that Cushing syndrome caused by an adrenal or pituitary tumor is more common in females, with a ratio of 5:1. The peak incidence of Cushing syndrome caused by an adrenal or pituitary adenoma occurs between the ages of 25 and 40 years.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

During pericardiocentesis, a needle is inserted approximately 1-2 cm below and to the left of the xiphisternum. The procedure involves the following steps:
1. Prepare the skin and administer local anesthesia, if time permits.
2. Ensure ECG monitoring is in place.
3. Puncture the skin using a long 16-18g catheter, 1-2 cm below and to the left of the xiphisternum.
4. Advance the catheter towards the tip of the left scapula at a 45-degree angle to the skin.
5. Aspirate fluid from the pericardium while monitoring the ECG for any signs of injury.
6. Once blood from the pericardium is aspirated, leave the catheter in place with a 3-way tap until a formal thoracotomy can be performed.
It is important to note that knowledge of pericardiocentesis is included in the CEM syllabus, although the RCEM may recommend direct thoracotomy as the preferred approach.

Further Reading:

Cardiac tamponade, also known as pericardial tamponade, occurs when fluid accumulates in the pericardial sac and compresses the heart, leading to compromised blood flow. Classic clinical signs of cardiac tamponade include distended neck veins, hypotension, muffled heart sounds, and pulseless electrical activity (PEA). Diagnosis is typically done through a FAST scan or an echocardiogram.

Management of cardiac tamponade involves assessing for other injuries, administering IV fluids to reduce preload, performing pericardiocentesis (inserting a needle into the pericardial cavity to drain fluid), and potentially performing a thoracotomy. It is important to note that untreated expanding cardiac tamponade can progress to PEA cardiac arrest.

Pericardiocentesis can be done using the subxiphoid approach or by inserting a needle between the 5th and 6th intercostal spaces at the left sternal border. Echo guidance is the gold standard for pericardiocentesis, but it may not be available in a resuscitation situation. Complications of pericardiocentesis include ST elevation or ventricular ectopics, myocardial perforation, bleeding, pneumothorax, arrhythmia, acute pulmonary edema, and acute ventricular dilatation.

It is important to note that pericardiocentesis is typically used as a temporary measure until a thoracotomy can be performed. Recent articles published on the RCEM learning platform suggest that pericardiocentesis has a low success rate and may delay thoracotomy, so it is advised against unless there are no other options available.

Adenosine is given through a rapid IV bolus, followed by a flush of saline solution. In adults, the starting dose is 6 mg, and if needed, an additional dose of 12 mg is given. If necessary, another dose of either 12 mg or 18 mg can be administered at intervals of 1-2 minutes until the desired effect is observed.

It is important to note that the latest ALS guidelines recommend an 18 mg dose for the third administration, while the BNF/NICE guidelines suggest a 12 mg dose.

However, patients who have undergone a heart transplant are particularly sensitive to the effects of adenosine. Therefore, their initial dose should be reduced to 3 mg, followed by 6 mg, and then 12 mg.

Loss of reactivity, in contrast to heightened reactivity, is a common trait seen in individuals with depression. The clinical manifestations of depression encompass various symptoms. These include experiencing a persistent low mood, which may fluctuate throughout the day. Another prominent feature is anhedonia, which refers to a diminished ability to experience pleasure. Additionally, individuals with depression often exhibit antipathy, displaying a lack of interest or enthusiasm towards activities or people. Their speech may become slow and have a reduced volume. They may also struggle with maintaining attention and concentration. Furthermore, depression can lead to a decrease in self-esteem, accompanied by thoughts of guilt and worthlessness. Insomnia, particularly early morning waking, is a classic symptom of depression. Other common signs include a decrease in libido, low energy levels, increased fatigue, and a poor appetite resulting in weight loss.

Chvostek’s sign is an indication of latent tetany and is observed in individuals with hypocalcaemia. When the angle of the jaw is tapped, the facial muscles on the same side of the face will momentarily contract.

Trousseau’s sign is another indication of latent tetany seen in hypocalcaemia. To test for this sign, a blood pressure cuff is placed around the subject’s arm and inflated to 20 mmHg above systolic blood pressure. This occludes arterial blood flow to the hand for a period of 3 to 5 minutes. In the presence of hypocalcaemia, carpopedal spasm will occur, characterized by flexion at the wrist and MCP joints, extension of the IP joints, and adduction of the thumb and fingers.

Blumberg’s sign is a diagnostic tool for peritonitis. It is considered positive when rebound tenderness is felt in the abdominal wall upon slow compression and rapid release.

Froment’s sign is a test used to assess ulnar nerve palsy, specifically evaluating the action of the adductor pollicis muscle. The patient is instructed to hold a piece of paper between their thumb and index finger. The examiner then attempts to pull the paper from between the thumb and index finger. A patient with ulnar nerve palsy will struggle to maintain a grip and may compensate by flexing the flexor pollicis longus muscle to sustain the pinching effect.

Gower’s sign is observed in children with Duchenne’s muscular dystrophy. When attempting to stand up from the ground, these children will start with both hands and feet on the floor and gradually use their hands to work up their legs until they achieve an upright posture.

Paracetamol overdose is the most common overdose in the U.K. and is also the leading cause of acute liver failure. The liver damage occurs due to a metabolite of paracetamol called N-acetyl-p-benzoquinoneimine (NAPQI), which depletes the liver’s glutathione stores and directly harms liver cells. Severe liver damage and even death can result from an overdose of more than 12 g or > 150 mg/kg body weight.

The clinical manifestations of paracetamol overdose can be divided into four stages:

Stage 1 (0-24 hours): Patients may not show any symptoms, but common signs include nausea, vomiting, and abdominal discomfort.

Stage 2 (24-48 hours): Right upper quadrant pain and tenderness develop, along with the possibility of hypoglycemia and reduced consciousness.

Stage 3 (48-96 hours): Hepatic failure begins, characterized by jaundice, coagulopathy, and encephalopathy. Loin pain, haematuria, and proteinuria may indicate early renal failure.

Stage 4 (> 96 hours): Hepatic failure worsens progressively, leading to cerebral edema, disseminated intravascular coagulation (DIC), and ultimately death.

The earliest and most sensitive indicator of liver damage is a prolonged INR, which starts to rise approximately 24 hours after the overdose. Liver function tests (LFTs) typically remain normal until 18 hours after the overdose. However, AST and ALT levels then sharply increase and can exceed 10,000 units/L by 72-96 hours. Bilirubin levels rise more slowly and peak around 5 days.

The primary treatment for paracetamol overdose is acetylcysteine. Acetylcysteine is a highly effective antidote, but its efficacy diminishes rapidly if administered more than 8 hours after a significant ingestion. Ingestions exceeding 75 mg/kg are considered significant.

Acetylcysteine should be given based on a 4-hour level or administered empirically if the presentation occurs more than 8 hours after a significant overdose. If the overdose is staggered or the timing is uncertain, empirical treatment is also recommended. The treatment regimen is as follows:

– First dose: 150 mg/kg in 200 mL 5% glucose over 1 hour
– Second dose 50 mg/kg in 500 mL 5% glucose over 4 hours
– Third dose 100 mg/kg in 1000 mL 5% glucose over 16 hours

Acute epiglottitis is inflammation of the epiglottis, which can be life-threatening if not treated promptly. When the soft tissues surrounding the epiglottis are also affected, it is called acute supraglottitis. This condition is most commonly seen in children between the ages of 3 and 5, but it can occur at any age, with adults typically presenting in their 40s and 50s.

In the past, Haemophilus influenzae type B was the main cause of acute epiglottitis, but with the introduction of the Hib vaccination, it has become rare in children. Streptococcus spp. is now the most common causative organism. Other potential culprits include Staphylococcus aureus, Pseudomonas spp., Moraxella catarrhalis, Mycobacterium tuberculosis, and the herpes simplex virus. In immunocompromised patients, Candida spp. and Aspergillus spp. infections can occur.

The typical symptoms of acute epiglottitis include fever, sore throat, painful swallowing, difficulty swallowing secretions (especially in children who may drool), muffled voice, stridor, respiratory distress, rapid heartbeat, tenderness in the front of the neck over the hyoid bone, ear pain, and swollen lymph nodes in the neck. Some patients may also exhibit the tripod sign, where they lean forward on outstretched arms to relieve upper airway obstruction.

To diagnose acute epiglottitis, fibre-optic laryngoscopy is considered the gold standard investigation. However, this procedure should only be performed by an anaesthetist in a setting prepared for intubation or tracheostomy in case of airway obstruction. Other useful tests include a lateral neck X-ray to look for the thumbprint sign, throat swabs, blood cultures, and a CT scan of the neck if an abscess is suspected.

When dealing with a case of acute epiglottitis, it is crucial not to panic or distress the patient, especially in pediatric cases. Avoid attempting to examine the throat with a tongue depressor, as this can trigger spasm and worsen airway obstruction. Instead, keep the patient as calm as possible and immediately call a senior anaesthetist, a senior paediatrician, and an ENT surgeon. Nebulized adrenaline can be used as a temporary measure if there is critical airway obstruction.