Recommendations for the transfusion of platelets in the critically ill patient is primarily extrapolated from the oncology literature; literature that is predominantly observational and expert opinion.
Nevertheless, indications for the transfusion of platelets in a critically ill ED patient include:
active bleeding with a plt count < 50 x 109/L
plt count < 10 x 109/L (high risk of spontaneous bleeding)
prior to an invasive procedure when the plt count is < 50 x 109/L
Importantly, the decision to transfuse platelets should also take into account the clinical setting (ie. a uremic patient with active bleeding)
References
Netzer G, Hess JR, Shanholtz C. Use of blood products in the intensive care unit: Concepts and controversies. Contemporary Critical Care June 2010;8(1):1-12.
