Pulsatile vs. non-pulsatile flow during cardiopulmonary bypass. A comparison of early postoperative changes.

The aim of the study was to evaluate possible haemodynamic and metabolic effects of pulsatile flow in cardiopulmonary bypass. The subjects were 20 patients undergoing coronary artery bypass grafting. They had no complicating diseases. Ten consecutive patients with pulsatile perfusion were compared with ten consecutive patients with non-pulsatile perfusion. The haemodynamic parameters, chest X-rays, fluid balance and changes in circulating thrombocytes were unaffected by adding pulsatile flow to cardiopulmonary bypass. The arterial-venous oxygen content difference and intrapulmonary shunting were also unaffected. Whole-body oxygen consumption was higher in the pulsatile group immediately after bypass, but subsequently there were no differences. The haemoglobin and haematocrit values were higher in the non-pulsatile group two hours postoperatively, but did not differ in the rest of the observation period. The clinical course was similar in the two groups.