Massive transfusion is defined, in adults, as replacement of >1 blood volume in 24 hours or >50% of blood volume in 4 hours (adult blood volume is approximately 70 mL/kg).
In children, it is defined as transfusion of >40 mL/kg (blood volume in children over 1 month old is approximately 80 mL/kg).
Massive transfusion occurs in settings such as severe trauma, ruptured aortic aneurysm, surgery and obstetrics complications. The goals to the management of massive transfusion include:
early recognition of blood loss
maintenance of tissue perfusion & oxygenation by restoration of blood volume & haemoglobin (Hb)
arrest of bleeding including with early surgical or radiological intervention, and
- judicious use of blood component therapy to correct coagulopathy.
A Massive Transfusion Protocol (MTP) should be used in critically bleeding patients anticipated to require massive transfusion.(1) The parameters in the table below should be measured early and frequently (30 minutes to 1 hour, or after blood component transfusion).
Parameters in Massive Transfusion Investigation & Monitoring (1)
|Parameters||Values to aim for|
|Acid-base status||ph >7.2, base excess <–6, lactate <4 mmol/L|
|Ionised calcium (Ca)||>1.1 mmol/L|
|Haemoglobin (Hb)||This should not be used alone as transfusion trigger; and, should be interpreted in context with haemodynamic status, organ & tissue perfusion.|
|Platelet (Plt)||>50 x 10^9 /L|
|PT/APTT||<1.5x of normal|
Mortality is high in massive transfusion and its aetiology is multifactorial, which includes hypotension, acidosis, coagulopathy, shock and the underlying condition of the patient. You must note of the lethal triad—patients with acidosis, hypothermia and coagulopathy have the highest mortality.
- National Blood Authority. Patient Blood Management Guidelines: Module 1 – Critical Bleeding/Massive Transfusion. [cited 2011 Jun 30]. Available from: http://www.nba.gov.au.