Transfusion reactions and massive transfusion: Viva

Opening question

The candidate is expected to start with the stop-the-transfusion rule. The first response to any suspected acute transfusion reaction is to stop the transfusion at once, keep the intravenous line open with normal saline, check the airway, the breathing and the circulation, verify the identity of the child and the unit at the bedside, and return the unit and the fresh samples to the blood bank. The candidate who states that the rule is the same for the mild fever and the haemolytic crisis, because the mild reaction cannot be told from the severe one in the first minutes, has the discipline that the topic rewards. [4]

Branch 1 — The acute haemolytic reaction

The examiner may press for the mechanism and the cause. The acute haemolytic reaction is almost always an ABO mismatch from a clerical error that gave the wrong unit to the wrong patient, and the mechanism is the binding of a preformed immunoglobulin M antibody against the A or the B antigen to the transfused red cells, the activation of the complement cascade and the intravascular haemolysis. The candidate should name the features of fever, rigors, flank or back pain, hypotension and haemoglobinuria within minutes, and the management of intravenous fluids to maintain the urine output and the renal perfusion, with vasopressors, blood components and intensive care as the shock, the renal failure and the coagulopathy demand. [3][4]

Branch 2 — TACO versus TRALI

The examiner may hand over a breathless child after transfusion and ask for the distinction. The expected answer is that TACO is circulatory overload with a raised jugular venous pressure, hypertension and crackles, treated by stopping the transfusion, oxygen and a diuretic, while TRALI is non-cardiogenic pulmonary oedema from a donor anti-leucocyte antibody, with hypoxaemia, bilateral infiltrates and no overload, treated by stopping the transfusion and respiratory support and no diuretic. The candidate who states that the diuretic helps the TACO child and harms the TRALI child, and who uses the volume history, the blood pressure and the jugular venous pressure to separate them at the bedside, has the heart of the distinction. [5][8]

Branch 3 — The massive transfusion protocol

The examiner may ask how the shocked bleeding child is resuscitated. The massive transfusion protocol is activated with red cells, fresh frozen plasma and platelets delivered in a balanced ratio that approaches one to one to one, so that the dilutional coagulopathy is prevented as the bleeding is controlled. Tranexamic acid is given early in trauma, the blood is warmed to prevent the hypothermia, and the ionised calcium is monitored and replaced to prevent the citrate toxicity. The candidate who names the hyperkalaemia of the stored unit and the choice of the freshest unit for the large transfusion, and who links the protocol to the prevention of the lethal triad of acidosis, hypothermia and coagulopathy, has the management of the bleeding child. [9][1]