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Question 1
Incorrect
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A 22-year-old male arrives at the emergency department with excessive epistaxis. Despite applying pressure on the anterior nares for the past four hours, the bleeding has not stopped. Nasal packing has also failed to control the bleeding. The on-call ENT specialist administers topical tranexamic acid to a visibly bleeding artery, which results in a reduction in bleeding.
What is the mode of action of tranexamic acid?Your Answer: Inhibits anticlotting factors protein C and protein S
Correct Answer: Prevents plasmin from breaking down fibrin clots
Explanation:Tranexamic acid prevents major haemorrhage by binding to plasminogen and preventing plasmin from breaking down fibrin clots. Its mechanism of action is not related to increasing the availability of vitamin K or inhibiting anticlotting factors protein C and S. Similarly, reducing the availability of vitamin K would not be the mechanism of action of tranexamic acid. While stimulating anticlotting factors protein C and S would maintain clots, it is not the mechanism of action of tranexamic acid.
Understanding Tranexamic Acid
Tranexamic acid is a synthetic derivative of lysine that acts as an antifibrinolytic. Its primary function is to bind to lysine receptor sites on plasminogen or plasmin, preventing plasmin from degrading fibrin. This medication is commonly prescribed to treat menorrhagia.
In addition to its use in treating menorrhagia, tranexamic acid has been investigated for its role in trauma. The CRASH 2 trial found that administering tranexamic acid within the first 3 hours of bleeding trauma can be beneficial. In cases of major haemorrhage, tranexamic acid is given as an IV bolus followed by an infusion.
Ongoing research is also exploring the potential of tranexamic acid in treating traumatic brain injury. Overall, tranexamic acid is a medication with important applications in managing bleeding disorders and trauma.
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This question is part of the following fields:
- Haematology And Oncology
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Question 2
Correct
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A 65-year-old smoker visits his doctor complaining of a persistent mouth ulcer that has not healed with conventional treatment for the past 3 months. The ulcer is situated in the middle of the right side of his tongue. Upon biopsy, it is revealed that the ulcer is a squamous cell carcinoma. Further examination is conducted to determine the possibility of lymphatic spread.
What is the primary group of regional lymph nodes that may be affected by the spread of this tumor?Your Answer: Submandibular
Explanation:The submandibular lymph nodes are the primary drainage site for the mid-portion of the tongue. Subsequently, the lymphatic fluid will spread to the deep cervical lymph nodes.
Lymphatic Drainage of the Tongue
The lymphatic drainage of the tongue varies depending on the location of the tumour. The anterior two-thirds of the tongue have minimal communication of lymphatics across the midline, resulting in metastasis to the ipsilateral nodes being more common. On the other hand, the posterior third of the tongue has communicating networks, leading to early bilateral nodal metastases being more common in this area.
The tip of the tongue drains to the submental nodes and then to the deep cervical nodes, while the mid portion of the tongue drains to the submandibular nodes and then to the deep cervical nodes. If mid tongue tumours are laterally located, they will usually drain to the ipsilateral deep cervical nodes. However, those from more central regions may have bilateral deep cervical nodal involvement. Understanding the lymphatic drainage of the tongue is crucial in determining the spread of tumours and planning appropriate treatment.
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This question is part of the following fields:
- Haematology And Oncology
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Question 3
Incorrect
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A 30-year-old pregnant woman (28 weeks gestation) presents with severe abdominal pain and per-vaginal (PV) bleeding. Upon examination, it is suspected that she is experiencing placental abruption. While attempting to establish IV access, the patient suddenly develops epistaxis, bruising on her arms, and bleeding from the cannulation site. Blood test results reveal thrombocytopenia and low fibrinogen levels, and her prothrombin time (PT), activated partial thromboplastin time (APTT), and D-dimer results are all elevated. What is the most likely explanation for these complications?
Your Answer: Thrombotic thrombocytopenic purpura (TTP)
Correct Answer: Disseminated intravascular coagulopathy (DIC)
Explanation:DIC is often associated with pregnancy complications such as placental abruption and shock, as well as bleeding from multiple sites and abnormal blood test results. Placenta praevia is characterized by painless vaginal bleeding, but when combined with other haematological results and occurring in a pregnant woman, it may indicate DIC rather than ITP. TTP typically presents with jaundice, low platelets, fever, renal complications, and CNS signs, which are not evident in this case, and clotting test results do not support this diagnosis. While von Willebrand’s disease can cause spontaneous bleeding, the platelet count is usually normal.
Disseminated Intravascular Coagulation: A Condition of Simultaneous Coagulation and Haemorrhage
Disseminated intravascular coagulation (DIC) is a medical condition characterized by simultaneous coagulation and haemorrhage. It is caused by the initial formation of thrombi that consume clotting factors and platelets, ultimately leading to bleeding. DIC can be caused by various factors such as infection, malignancy, trauma, liver disease, and obstetric complications.
Clinically, bleeding is usually the dominant feature of DIC, accompanied by bruising, ischaemia, and organ failure. Blood tests can reveal prolonged clotting times, thrombocytopenia, decreased fibrinogen, and increased fibrinogen degradation products. The treatment of DIC involves addressing the underlying cause and providing supportive management.
In summary, DIC is a serious medical condition that requires prompt diagnosis and management. It is important to identify the underlying cause and provide appropriate treatment to prevent further complications. With proper care and management, patients with DIC can recover and regain their health.
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This question is part of the following fields:
- Haematology And Oncology
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Question 4
Incorrect
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A 70-year-old man is undergoing investigation for small intestine cancer due to his history of Crohn's disease. An adenocarcinoma of his duodenum is detected through endoscopy and histology. The oncologist is now examining his previous abdominal CT scan to determine if there is any nodal involvement.
Which group of lymph nodes could potentially be affected in this scenario?Your Answer: Internal iliac lymph nodes
Correct Answer: Superior mesenteric lymph nodes
Explanation:The superior mesenteric lymph nodes are responsible for draining the duodenum, which is the second section of the gastrointestinal system. This lymphatic drainage is important for staging gastrointestinal cancers, and is similar to the blood supply of the gut. While the coeliac lymph nodes drain the first part of the gastrointestinal system, the inferior mesenteric lymph nodes drain the third part, and the internal iliac lymph nodes drain the lower part of the rectum and some of the anal canal. The para-aortic lymph nodes are not involved in the drainage of the gastrointestinal system, but instead drain the genito-urinary system. It is important to understand the correct lymphatic drainage patterns for accurate cancer staging.
Lymphatic drainage is the process by which lymphatic vessels carry lymph, a clear fluid containing white blood cells, away from tissues and organs and towards lymph nodes. The lymphatic vessels that drain the skin and follow venous drainage are called superficial lymphatic vessels, while those that drain internal organs and structures follow the arteries and are called deep lymphatic vessels. These vessels eventually lead to lymph nodes, which filter and remove harmful substances from the lymph before it is returned to the bloodstream.
The lymphatic system is divided into two main ducts: the right lymphatic duct and the thoracic duct. The right lymphatic duct drains the right side of the head and right arm, while the thoracic duct drains everything else. Both ducts eventually drain into the venous system.
Different areas of the body have specific primary lymph node drainage sites. For example, the superficial inguinal lymph nodes drain the anal canal below the pectinate line, perineum, skin of the thigh, penis, scrotum, and vagina. The deep inguinal lymph nodes drain the glans penis, while the para-aortic lymph nodes drain the testes, ovaries, kidney, and adrenal gland. The axillary lymph nodes drain the lateral breast and upper limb, while the internal iliac lymph nodes drain the anal canal above the pectinate line, lower part of the rectum, and pelvic structures including the cervix and inferior part of the uterus. The superior mesenteric lymph nodes drain the duodenum and jejunum, while the inferior mesenteric lymph nodes drain the descending colon, sigmoid colon, and upper part of the rectum. Finally, the coeliac lymph nodes drain the stomach.
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This question is part of the following fields:
- Haematology And Oncology
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Question 5
Incorrect
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A 4-year-old boy visits the doctor complaining of occasional vomiting. He appears to be unstable while walking and his mother reports that he frequently complains of headaches. What is the probable diagnosis?
Your Answer: Acute myeloid leukaemia
Correct Answer: Medulloblastoma
Explanation:Diagnosis of a Posterior Fossa Tumor in a Young Girl
This young girl is showing symptoms of a posterior fossa tumor, which affects the cerebellar function. Ataxia, slurred speech, and double vision are common symptoms of this type of tumor. Additionally, headaches and vomiting are signs of increased intracranial pressure. The most likely diagnosis for this young girl is medulloblastoma, which is the most frequent posterior fossa tumor in children.
Craniopharyngioma is an anterior fossa tumor that arises from the floor of the pituitary, making it an unlikely diagnosis for this young girl. Acute myeloid leukemia is rare in children and has a low rate of CNS involvement, unlike acute lymphoblastic leukemia. Ataxia telangiectasia is a hereditary condition that causes degeneration of multiple spinal cord tracts, but it would not present with features of a space-occupying lesion. Becker’s muscular dystrophy is an X-linked condition that causes weakness in boys.
In summary, this young girl’s symptoms suggest a posterior fossa tumor, with medulloblastoma being the most likely diagnosis. It is important to accurately diagnose and treat this condition to ensure the best possible outcome for the patient.
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This question is part of the following fields:
- Haematology And Oncology
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Question 6
Incorrect
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An eager nursing student comes to you with a set of inquiries regarding blood transfusion reactions. Which of her subsequent statements is inaccurate?
Your Answer: Thrombocytopaenia may occur in women with a prior pregnancy
Correct Answer: Graft versus host disease involves neutrophil proliferation
Explanation:A helpful mnemonic for remembering transfusion reactions is Got a bad unit. Each letter represents a potential complication:
G – Graft vs. Host disease
O – Overload
T – Thrombocytopenia
A – Alloimmunization
B – Blood pressure unstable
A – Acute hemolytic reaction
D – Delayed hemolytic reaction
U – Urticaria
N – Neutrophilia
I – Infection
T – Transfusion-associated lung injuryGraft vs. Host disease occurs when the patient’s own lymphocytes are similar to the donor’s lymphocytes, causing severe complications. Thrombocytopenia may occur a few days after transfusion and may resolve on its own. Patients with IGA antibodies require IgA deficient blood transfusions.
Blood product transfusion complications can be categorized into immunological, infective, and other complications. Immunological complications include acute haemolytic reactions, non-haemolytic febrile reactions, and allergic/anaphylaxis reactions. Infective complications may arise due to transmission of vCJD, although measures have been taken to minimize this risk. Other complications include transfusion-related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), hyperkalaemia, iron overload, and clotting.
Non-haemolytic febrile reactions are thought to be caused by antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell during storage. These reactions may occur in 1-2% of red cell transfusions and 10-30% of platelet transfusions. Minor allergic reactions may also occur due to foreign plasma proteins, while anaphylaxis may be caused by patients with IgA deficiency who have anti-IgA antibodies.
Acute haemolytic transfusion reaction is a serious complication that results from a mismatch of blood group (ABO) which causes massive intravascular haemolysis. Symptoms begin minutes after the transfusion is started and include a fever, abdominal and chest pain, agitation, and hypotension. Treatment should include immediate transfusion termination, generous fluid resuscitation with saline solution, and informing the lab. Complications include disseminated intravascular coagulation and renal failure.
TRALI is a rare but potentially fatal complication of blood transfusion that is characterized by the development of hypoxaemia/acute respiratory distress syndrome within 6 hours of transfusion. On the other hand, TACO is a relatively common reaction due to fluid overload resulting in pulmonary oedema. As well as features of pulmonary oedema, the patient may also be hypertensive, a key difference from patients with TRALI.
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This question is part of the following fields:
- Haematology And Oncology
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Question 7
Incorrect
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A 56-year-old man is sent home following an uneventful left total hip replacement. He has been prescribed a direct factor Xa inhibitor for thromboprophylaxis.
What is the probable medication that the patient has been prescribed?Your Answer: Warfarin
Correct Answer: Apixaban
Explanation:Apixaban directly inhibits factor Xa, while bivalirudin and dabigatran directly inhibit thrombin. On the other hand, enoxaparin is a type of low molecular weight heparin that indirectly inhibits factor Xa by forming a complex with antithrombin III, leading to irreversible inactivation of factor Xa.
Direct oral anticoagulants (DOACs) are medications used to prevent stroke in non-valvular atrial fibrillation (AF), as well as for the prevention and treatment of venous thromboembolism (VTE). To be prescribed DOACs for stroke prevention, patients must have certain risk factors, such as a prior stroke or transient ischaemic attack, age 75 or older, hypertension, diabetes mellitus, or heart failure. There are four DOACs available, each with a different mechanism of action and method of excretion. Dabigatran is a direct thrombin inhibitor, while rivaroxaban, apixaban, and edoxaban are direct factor Xa inhibitors. The majority of DOACs are excreted either through the kidneys or the liver, with the exception of apixaban and edoxaban, which are excreted through the feces. Reversal agents are available for dabigatran and rivaroxaban, but not for apixaban or edoxaban.
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This question is part of the following fields:
- Haematology And Oncology
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Question 8
Incorrect
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A 27-year-old female presents with abnormal vaginal bleeding and dyspareunia. After an abnormal smear test, she receives her colposcopy results indicating cervical malignancy. The gynaecologist refers her for a PET scan to determine if the cancer has spread to her lymph nodes. Which lymph nodes are typically the first to be affected if the cancer has spread?
Your Answer: Inferior inguinal lymph nodes
Correct Answer: Internal and external iliac lymph nodes
Explanation:The lymphatic drainage of the cervix is important to consider in cases of cervical cancer. The cervix drains into three main channels: the external and internal iliac lymph nodes, the obturator and presacral lymph nodes, and the nodes along the uterine arteries. The initial nodes to be involved in cervical cancer would be the internal and external iliac lymph nodes. The caval lymph nodes, cisterna chyli, inferior inguinal lymph nodes, and para-aortic lymph nodes are not the initial sites of spread for cervical cancer.
Lymphatic Drainage of Female Reproductive Organs
The lymphatic drainage of the female reproductive organs is a complex system that involves multiple nodal stations. The ovaries drain to the para-aortic lymphatics via the gonadal vessels. The uterine fundus has a lymphatic drainage that runs with the ovarian vessels and may thus drain to the para-aortic nodes. Some drainage may also pass along the round ligament to the inguinal nodes. The body of the uterus drains through lymphatics contained within the broad ligament to the iliac lymph nodes. The cervix drains into three potential nodal stations; laterally through the broad ligament to the external iliac nodes, along the lymphatics of the uterosacral fold to the presacral nodes and posterolaterally along lymphatics lying alongside the uterine vessels to the internal iliac nodes. Understanding the lymphatic drainage of the female reproductive organs is important for the diagnosis and treatment of gynecological cancers.
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This question is part of the following fields:
- Haematology And Oncology
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Question 9
Incorrect
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A 90-year-old male has received a diagnosis of anorectal cancer. Imaging studies indicate that the cancer is confined to an area below the pectinate line. If left untreated, which set of lymph nodes is most likely to be affected by metastasis?
Your Answer: Pararectal
Correct Answer: Superficial inguinal
Explanation:When rectal cancer occurs below the pectinate line, it has the potential to spread to the superficial inguinal lymph nodes. Conversely, if the cancer is located above the line, it may spread to the internal iliac lymph nodes. Additionally, the internal iliac and sacral nodes can receive drainage from various regions including the rectum, perineum, cervix, and prostate.
Lymphatic drainage is the process by which lymphatic vessels carry lymph, a clear fluid containing white blood cells, away from tissues and organs and towards lymph nodes. The lymphatic vessels that drain the skin and follow venous drainage are called superficial lymphatic vessels, while those that drain internal organs and structures follow the arteries and are called deep lymphatic vessels. These vessels eventually lead to lymph nodes, which filter and remove harmful substances from the lymph before it is returned to the bloodstream.
The lymphatic system is divided into two main ducts: the right lymphatic duct and the thoracic duct. The right lymphatic duct drains the right side of the head and right arm, while the thoracic duct drains everything else. Both ducts eventually drain into the venous system.
Different areas of the body have specific primary lymph node drainage sites. For example, the superficial inguinal lymph nodes drain the anal canal below the pectinate line, perineum, skin of the thigh, penis, scrotum, and vagina. The deep inguinal lymph nodes drain the glans penis, while the para-aortic lymph nodes drain the testes, ovaries, kidney, and adrenal gland. The axillary lymph nodes drain the lateral breast and upper limb, while the internal iliac lymph nodes drain the anal canal above the pectinate line, lower part of the rectum, and pelvic structures including the cervix and inferior part of the uterus. The superior mesenteric lymph nodes drain the duodenum and jejunum, while the inferior mesenteric lymph nodes drain the descending colon, sigmoid colon, and upper part of the rectum. Finally, the coeliac lymph nodes drain the stomach.
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This question is part of the following fields:
- Haematology And Oncology
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Question 10
Incorrect
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A 47-year-old man is given a significant amount of whole blood transfusion that is three weeks old. How will the blood handle oxygen?
Your Answer: It will have a low affinity for oxygen
Correct Answer: It will have an increased affinity for oxygen
Explanation:Blood that has been stored has a decreased level of 2,3 DPG, resulting in a greater attraction to oxygen and a reduced capacity to release it at tissues that are undergoing metabolism.
Oxygen Transport and Factors Affecting Haemoglobin Saturation
Oxygen transport in the body is mainly carried out by erythrocytes, with only 1% of oxygen being transported as a solution due to its limited solubility. The amount of oxygen transported depends on the concentration of haemoglobin and its degree of saturation. Haemoglobin is a globular protein composed of four subunits, with two alpha and two beta subunits forming globin. Haem, which surrounds an iron atom in its ferrous state, can form two additional bonds with oxygen and a polypeptide chain. The oxygenation of haemoglobin is a reversible reaction, and the molecular shape of haemoglobin facilitates the binding of subsequent oxygen molecules.
The oxygen dissociation curve describes the relationship between the percentage of saturated haemoglobin and partial pressure of oxygen in the blood, and it is not affected by haemoglobin concentration. The curve can be shifted to the right or left by various factors. Chronic anaemia, for example, causes an increase in 2,3 DPG levels, which shifts the curve to the right, resulting in lower oxygen delivery. The Haldane effect causes a shift to the left, resulting in decreased oxygen delivery to tissues, while the Bohr effect causes a shift to the right, resulting in enhanced oxygen delivery to tissues. Factors that shift the curve to the left include low levels of H+, pCO2, 2,3-DPG, and temperature, as well as the presence of HbF, methaemoglobin, and carboxyhaemoglobin. Factors that shift the curve to the right include raised levels of H+, pCO2, and 2,3-DPG, as well as increased temperature.
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This question is part of the following fields:
- Haematology And Oncology
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