Haemostatic, Coagulation, and Platelet Disorders — WACS Viva & Clinical Scenarios (Haematology and Medical Oncology)

Exam-style haemostatic, coagulation, and platelet disorders viva scenarios with examiner probes and model answers for Internal Medicine candidates.

Scenarios covered

• SCENARIO 1: A 24-year-old woman presents to the acute medical unit with sudden-onset petechiae, spontaneous gingival bleeding, and severe menorrhagia. Her complete blood count reveals haemoglobin 11.8 g/dL, white cell count 6.2 x 10^9/L, and platelet count 8 x 10^9/L. The peripheral blood smear confirms isolated thrombocytopenia with occasional large platelets and no schistocytes. Outline your step-by-step diagnostic evaluation to distinguish primary immune thrombocytopenia (ITP) from secondary causes and microangiopathies, and formulate an emergency management protocol for life-threatening mucosal bleedi
• SCENARIO 2: A 19-year-old male undergoing pre-operative evaluation for an elective inguinal hernia repair is found to have an isolated prolonged activated partial thromboplastin time (aPTT) of 68 seconds (control 30 seconds), while his prothrombin time (PT/INR), thrombin time, and platelet count are normal. Describe the pathophysiological basis of the coagulation cascade pathways involved, explain the diagnostic algorithm using 1:1 mixing studies (immediate and incubated), and specify how to definitively differentiate Factor VIII deficiency, Factor IX deficiency, and Lupus Anticoagulant.
• SCENARIO 3: A 46-year-old man with decompensated alcohol-related liver cirrhosis presents with acute upper gastrointestinal bleeding. Coagulation profile demonstrates PT 24 seconds (INR 2.2), aPTT 48 seconds, fibrinogen 1.1 g/L, and platelet count 45 x 10^9/L. Rationalize the physiological differences between the coagulopathy of chronic liver disease (rebalanced haemostasis) and acute Disseminated Intravascular Coagulation (DIC), and defend your blood component transfusion strategy in this bleeding patient.
• SCENARIO 4: A 32-year-old woman at 10 weeks postpartum presents with acute, painful swelling of the left lower limb. Compression ultrasonography confirms extensive deep vein thrombosis involving the femoral and popliteal veins. She has a history of two unexplained early pregnancy losses and one late intrauterine fetal demise at 22 weeks gestation. Outline the clinical and laboratory criteria required to establish a diagnosis of Antiphospholipid Syndrome (APS) and detail your acute and long-term anticoagulation strategy.
• SCENARIO 5: A 28-year-old male with known severe Haemophilia A presents to the emergency department with an expanding right iliopsoas haematoma accompanied by femoral nerve compressive neuropathy following minor trauma. Detail your immediate emergency management, calculation and administration of Factor VIII replacement targets, indications for adjunctive antifibrinolytics, and the systematic approach if the patient fails to achieve haemostasis due to high-titre Factor VIII inhibitors.