ABSTRACT
Background: Cardiopulmonary bypass (CPB) may reduce the numbers of platelets and cause platelet function disorder. Postoperative bleeding is one of the most common complications in patients undergoing cardiac surgery. Objectives: (1) To study changes platelet count and platelet aggregation with ADP in patients undergoing CPB. (2) To identify the relationship between the postoperative bleeding and these parameters. Subjects and method: Crossectional descriptive study on 35 patients of three groups: congenital heart diseases, valvular heart diseases and coronary artery disease. Results: Platelet count and platelet aggregation with ADP reduce. Conclusion: There is a considerably change in the number of platelets and disturbance of platelet function in patients undergoing CPB. No remarkable evidence on relationship between posttoperative bleeding and above disorders.