ABSTRACT
Timely recognition and management of hemorrhage and thrombosis is fundamental to
surgical critical care. Bleeding is a potential complication of almost every surgical
procedure, and when appropriately anticipated, it can be managed with relative ease.
The risk of venous thromboembolism is high postsurgery, but frequently can be
reduced dramatically with appropriate prophylactic measures. This chapter reviews
aspects of the pathophysiology of bleeding and thrombosis that are important to the criti-
cal care surgeon. By way of definition, the term “hemostasis” is used in reference to the
normal physiologic (and usually desirable) blood clotting response to breaching of blood
vessel integrity. Thrombosis is a term that refers to the pathologic (and therefore
undesirable) response of the coagulation system to some form of insult, whether recog-
nized or not.