Pulmonary embolism and vascular injury: What is the role of thrombin?

Lungs possess dynamic and complex coagulation-thrombolytic and inflammatory sets of innate reactive responses, which generate changes that cause a dramatic alteration in its parenchyma. Clinically, since its steps are reciprocally inter-connected, the pulmonary embolic injury is very complex to describe as one exclusive progression. For example, each step in a coagulation-fibrinolytic-inflammation-integrated pathway produces more side-steps, which later plays an important role in a specific lung damage description. In this clinical review, the enzyme thrombin, an ontogenetically very old and key blood coagulation serine protease is centrally placed as a mediator, activator and up-regulator of post-pulmonary embolic damage to reveal its enormous flexibility in post-pulmonary embolism damage and its reparative processes. Additionally, some beneficial aspects of its control throughout its inhibition are discussed.