Abstract
Traumatic hemothoraces represent a readily available, normothermic, and ABO-compatible source of blood. As a resuscitation fluid, pleural blood presents a reduced risk of transmissible disease and hemolytic transfusion reactions, and it minimizes patient exposure to the storage lesion that affects allogeneic blood products. Pleural blood therefore retains more physiological concentrations of electrolytes and 2,3-diphosphoglycerate when compared to packed red blood cells. However, pleural blood also has a lower oxygen-carrying capacity than packed red blood cells and is largely depleted of coagulation factors. Yet, due to the presence of tissue factor and other proinflammatory mediators, it may paradoxically increase clot formation once transfused. Uncertainty remains regarding the clinical relevance of the supranormal levels of proinflammatory mediators and the effects of autotransfusion on coagulation in vivo. There is now a body of evidence suggesting that autotransfusion reduces the requirement for donor blood products, and small studies have not identified any signals of harm; however, any positive or negative effects on patient outcomes are yet to be conclusively demonstrated. Centers with access to a robust supply of allogeneic donor blood should continue with standard care until more comprehensive research is conducted to clarify both the clinical benefits and risks of autotransfusion. Nonetheless, autotransfusion retains a role in cases where there is a contraindication to allogeneic transfusion, and in low-resource centers where safe and reliable access to donor blood products is limited.