Hematologic effects of cardiac and noncardiac surgery

The intraoperative and postoperative changes in number and type of WBCs in patients undergoing cardiac surgery were studied. These changes were then compared with those that occurred in patients undergoing four noncardiac surgical procedures (abdominal vascular reconstruction, thoracotomy, cholecystectomy, and carotid thromboendarterectomy). Both cardiac surgery and abdominal vascular surgery resulted in a marked increase in bands and decrease in lymphocytes. Thoracotomy and cholecystectomy resulted in similar but smaller changes. Carotid thromboendarterectomy did not produce hematologic changes. We conclude that the hematologic changes that occur with cardiac surgery are primarily a result of the stress and trauma of major surgery rather than a result of cardiopulmonary bypass itself.