Coagulopathy of massive transfusion: pathophysiology and monitoring

Coagulopathy associated with massive transfusion (MT) remains an important clinical problem. The author attempted to identify the causes of coagulopathy in massively transfused, adult and previously haemostatically competent patients and to differentiate between the elective surgical and the emergency settings. A MEDLINE search was conducted for articles published on 'massive transfusion', 'transfusion', 'trauma', 'surgery', 'coagulopathy' and 'haemostatic defects' A narrative format was adopted. Coagulopathy associated with NIT is an intricate, multifactorial and multicellular event. In patients undergoing elective surgery, a decrease in fibrinogen concentration is observed initially while thrombocytopenia is a late occurrence. Critically low levels of coagulation factors were seldom reported when whole blood was in common use. With the use of packed red blood cells (PRBC), dilution or consumption of coagulation factors has become a significant issue requiring specific treatment with, primarily, fresh frozen plasma (FFP). In the emergency setting (e.g., trauma, ruptured abdominal aortic aneurysm), tissue trauma, shock, tissue anoxia and hypothermia contribute to the development of disseminated intravascular coagulation and microvascular bleeding. It has been shown that the proactive administration of platelets and FFP improves coagulation, decreases haemorrhage and improves survival in these massively bleeding patients. We can only speculate that in this specific context, the benefits of early and aggressive platelet and coagulation factor replacement are related to the ongoing consumption coagulopathy at the time of surgery.