Temporal Changes in Fibrinolysis following Injury

Trauma patients present to the emergency department with a spectrum of fibrinolytic activity. This wide variance in fibrinolysis activity is a complex multifactorial process impacted by the degree of hemorrhagic shock and the amount of tissue injury the individual sustains. The fibrinolytic activity of the trauma patient at presentation to the hospital has prognostic and therapeutic implications. Those patients with high fibrinolytic activity (hyperfibrinolysis) are at risk of mortality from hemorrhage, whereas those patients with low fibrinolytic activity (shutdown or hypofibrinolysis) are at an increased risk of delayed mortality from traumatic brain injury or organ failure. These phenotypes of fibrinolysis acutely following injury change with resuscitation, and the majority of trauma patients will transition to a fibrinolytic resistant state several hours after injury. The mechanism for this near-global transition to this acquired fibrinolysis appears to be related to the generation of plasminogen activator inhibitor-1 in the liver. Those patients who do not recover from this fibrinolytic state 24 hours after injury have a poor prognosis. The purpose of this article is to review the different states of fibrinolytic activity following injury and how they change over time following resuscitation and in the intensive care unit.