Transfusion reactions and massive transfusion: SAQ

Part A — The acute transfusion reaction (10 marks)

The first response to any suspected acute transfusion reaction is to stop the transfusion at once and keep the intravenous line open with normal saline, then check the airway, the breathing and the circulation and give oxygen if the child is breathless or hypoxaemic. The identity of the child, the wristband and the unit label are checked against the paperwork at the bedside, because the acute haemolytic reaction is most often an ABO mismatch from a clerical error that gave the wrong unit to the wrong patient. The unit and the fresh blood samples are returned to the blood bank with a report, and the reaction is reported through the haemovigilance system. ^[4][11]

The diagnosis of the acute haemolytic reaction is confirmed by the direct antiglobulin test, which shows that antibody or complement has coated the transfused red cells, together with a fall in haemoglobin, a rise in lactate dehydrogenase and bilirubin, a fall in haptoglobin and haemoglobinuria. The repeat of the group and the antibody screen identifies the antibody and the mismatch, and the blood bank repeats the crossmatch on the unit and the samples. 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 destruction of the red cells within the blood vessel, with the free haemoglobin and the complement fragments driving the fever, the hypotension, the renal injury and the disseminated intravascular coagulation. ^[3][4]