ABSTRACT
Major haemorrhage has various definitions relating to transfusion requirements, including replacement of the circulating volume in a 24-hour period, blood transfusion exceeding six units of packed red cells, and acute administration of over 1.5 times the patient's blood volume. Prompt recognition of haemorrhage is essential; successful haemostasis depends on stopping the source of blood loss while maintaining blood coagulation as near normal as possible. Once major haemorrhage is recognised the local major haemorrhage protocol should be activated. This will involve a coordinated response from different members of the hospital team including blood bank, haematologist, porter, senior anaesthetist or clinician on duty, depending on the location, and theatre staff or nursing staff, depending on location. Coagulopathy is common in major haemorrhage and is usually caused by coagulation factor dilution. In some patients it may also be due to drugs or a consumptive coagulopathy.
