The cardiopulmonary bypass pump-priming fluid and nitrogen balance after open-heart surgery in adults

Different crystalloid cardiopulmonary bypass pump-priming fluids provide very different substrate loads to patients undergoing open-heart surgery. As a result they may modulate the endocrine milieu, and thus might be expected to alter postoperative nitrogen balance. To test this hypothesis, 24 adult patients undergoing open-heart valve surgery were randomized into four matched groups each to receive a different prime, namely: Hartmann's solution, Plasmalyte 148 R , Solution 11 R and a prime consisting of equal volumes of Hartmann's solution and 5% dextrose. Accurate nitrogen balance studies were obtained each 24 hours from one day preoperatively to seven days postoperatively. The results obtained demonstrated that postoperative nitrogen balance was unaffected by the nature of the crystalloid pump prime. Nitrogen balance in the patients studied was better than that reported from other centres in similar patients.