Plasma and cryoprecipitate for transfusion
Stanworth SJ., Tinmouth AT.
General recommendations for plasma transfusion have been well described in many guidelines. Therapeutic uses of plasma, in association with bleeding and abnormalities of coagulation tests (except in emergencies) are based on pathophysiological rationale, but questions about optimal dose and schedule of plasma. A recurring theme in many settings is an overall paucity of high-level evidence to inform optimal plasma transfusion practice remain unanswered, and this particularly applies to prophylactic uses of plasma. There should be more recognition of the limitations of current standard coagulation screening tests, and appreciation that in vitro abnormalities of coagulation screening tests do not equate with an in vivo failure of clinical haemostasis and the presence of clinical coagulopathy. Newer global tests of haemostasis may be better markers of abnormal bleeding risk, but should be assessed and validated in larger clinical studies. Given current evidence, a more appropriate plasma transfusion strategy may be one that emphasises the therapeutic use of plasma in bleeding patients. The role, if any, of prophylactic plasma transfusion in non-bleeding patients with abnormalities of standard coagulation tests, which have limited value in predicting bleeding remains very uncertain. Future research should identify the constituents in plasma that are providing the most benefit (e.g. by analogy the role of ADAMTS13 in TTP). With a better mechanistic understanding of disorders with acquired deficiencies of one or more coagulation factors, replacement might also be more appropriately managed in the future with concentrates of multiple coagulation factors, and which would minimise risks of circulatory overload described when high volume plasma transfusions are given.