Transfusion Medicine — Written Clinical Reasoning

Model answer — Part A: post-transfusion dyspnoea

Frame the problem first. New respiratory distress within 6 hours of transfusion is TACO or TRALI until proven otherwise; both are reportable to the blood bank. The first moves are identical: stop the transfusion, keep the line open with saline, check the unit against the patient's identity, assess ABC and call for review [1].

The discrimination is hydrostatic versus permeability oedema. For TACO: hypertension, raised JVP, positive fluid balance, elevated BNP, response to diuretics, and a vulnerable heart (age, HFpEF, renal impairment). For TRALI: normal or low blood pressure, no volume overload, often fever, normal BNP, and no diuretic response [1].

Investigations: chest X-ray (both show bilateral infiltrates — it does not discriminate), BNP, fluid balance chart, ECG and troponin if ischaemia is plausible, FBC/coagulation/DAT and haemolysis markers to exclude a haemolytic reaction, and cultures if febrile [1].

Management: sit up, oxygen; for TACO — IV diuretic, and future transfusions restricted to single units at slow rates with diuretic cover; for suspected TRALI — supportive respiratory care (escalate to ICU if hypoxaemia progresses), no diuretics, and blood-bank notification for donor investigation. Close with the report: both reactions require formal documentation and haemovigilance reporting [1].

Model answer — Part B: GI bleed on apixaban

Immediate management follows the bleeding-patient rule: transfusion thresholds do not apply — resuscitate. Two large-bore cannulae, group and crossmatch, FBC/coagulation/biochemistry, and activate a major haemorrhage pathway if shock persists. A discriminating point: tranexamic acid is NOT routine in gastrointestinal bleeding — HALT-IT showed no mortality benefit and a signal of harm — unlike trauma and postpartum haemorrhage where it saves lives [5].

Component therapy: red cells for oxygen-carrying capacity; if the bleed is massive, move to ratio-based packs (plasma:platelets:red cells approaching 1:1:1) on the PROPPR rationale rather than dribbling single components [2]. Replace fibrinogen when documented low.

Reversal reasoning: apixaban has no routine reversal for a bleed of this severity without a specific antidote available — andexanet alfa where accessible, or prothrombin complex concentrate as the pragmatic alternative; FFP is a distant third. Weigh this against his thrombotic risk from AF. The strong exam answer states that reversal is for life-threatening bleeding — which this is — while endoscopy is arranged urgently [4].

Resumption is the mark of a physician answer: GI bleeding on anticoagulation recurs, and AF stroke risk does not disappear. State that you will restart anticoagulation once haemostasis is secure and the source is treated, after multidisciplinary discussion — typically within one to two weeks — and document the shared decision [3].