Oxygenator thrombosis: an international phenomenon

Oxygenator thrombosis, despite adequate anticoagulation, has become a recent concern amongst perfusionists worldwide. The phenomenon is characterized by a transient increase in oxygenator inlet pressure of up to 900 mmHg about 10-15 min after the institution of cardiopulmonary bypass (CPB). Depending on the size and location of the thrombus, shunting may occur that compromises gas transfer to the extent where oxygenator change-out is necessary. This article presents various case reports and publications, both domestic and international, detailing this phenomenon. Research hypothesizes that it is the activation of platelets that subsequently may cause the deposition of fibrin, yielding thrombus formation; however, the primary etiology of this phenomenon remains unknown. Possible catalysts include bypass techniques, equipment selection, pharmacological agents, prime and the patient. This paper will review all of the above with an emphasis on the often overlooked factor--the patient, as there are certain variables in patient hematology that provoke a hypercoagulable state leading to thrombosis, including blood type, genetics, age, disease state, gender and heparin.