24th July 2024

Major haemorrhage

The Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee defines major haemorrhage as:

• Loss of more than one blood volume within 24 hours (around 70 mL/kg, i.e. > 5L in a 70 kg adult)
• Half of total blood volume lost in less than 3 hours
• Bleeding in excess of 150 mL/minute.

This is difficult to calculate in an acute setting.  A more pragmatic approach is bleeding which leads to a systolic blood pressure of below 90 mmHg or heart rate above 110 beats per minute.

Management of major haemorrhage

All hospitals in the UK have a major haemorrhage protocol that will include the involvement of the blood products laboratory, haematologists, medical emergency team and porters. Major haemorrhages should be approached in an ABCDE manner with identification of bleeding source and stabilisation of the patient taking priority.

It is important not to forget the other blood products that are required in major bleeding. As well as red cells being lost in bleeding, plasma is also lost, which contains key components of the clotting cascade. If large quantities of only blood and IV fluids are transfused, this will lead to a dilutional coagulopathy. FFP, cryoprecipitate and platelets are therefore also required in major haemorrhage situations.

Anticoagulant therapy is common and it is important to reverse these agents during bleeding.

Certain conditions which cause major haemorrhage also require specific treatments. Terlipressin, a somatostatin analogue, is indicated in variceal bleeding as it acts as a splanchnic vasoconstrictor. In major trauma, immediate tranexamic acid is recommended, however in upper GI bleeds the recent HALT-IT trial has not endorsed its use. The management of bleeding in thrombophilic conditions such as haemophilia are covered elsewhere.