REVIEW ARTICLE Bleeding Complications Associated With Cardiopulmonary Bypass

ARDIOPULMONARY bypass (CPB) for open-heart C surgery (OHS) is commonly performed in hospitals throughout the world. In the United States more than 250,000 OHS procedures are performed annually, primarily for coronary artery bypass grafting (CABG). ' With improve-ments in surgical techniques and extracorporeal oxygen-ation, the overall mortality for this procedure is low (1 % to 4%)., However, excessive perioperative bleeding continues to complicate CPB. Management of the abnormal bleeding often requires reoperation and frequently is associated with excessive, and sometimes inappropriate, blood product admin-istration that occasionally exceeds the available blood sup-ply. In some hospitals more than 25 % of all blood products are dedicated to OHS3 A concerted multispecialty approach between cardiac surgery, hematology, and transfusion medi-cine is required to reduce the need for reoperation and its increased and to minimize the possibility of transmit-ting transfusion-related diseases. The actual frequency of severe bleeding with CPB may vary, depending on the criteria used and the patient profile ~tudied.~ " An incidence of 3 % to 5 % is commonly reported when abnormal bleeding is defined as comprising more than 10 U of blood transfused in the perioperative p e r i ~ d. ~ When these patients undergo reoperation for excessive bleeding, more than half exhibit significant incomplete surgical hemo-stasis that is, a t least in part, corrected by exploration. However, the remaining patients bleed because of various acquired hemostatic defects, most commonly related to acquired transient platelet dysfunction (Table l).7 An appre-ciation for the various causes of bleeding following CPB and their incidence is essential for optimal management