Hypertension after coronary operation. Can it be prevented by pulsatile perfusion?

Nonpulsatile perfusion during cardiopulmonary bypass (CPB) has been implicated as a causative factor of postoperative hypertension. In a consecutive series, patients undergoing coronary bypass were selected for perfusion with either nonpulsatile flow (American Optical roller pump) or pulsatile flow (Desjardin's modification of the roller pump). The incidence of postoperative hypertension and the levels of peripheral renin were noted. No differences could be observed in renin activity, with either modality of perfusion, before CPB, after 30 minutes of stable CPB, or 2 hours postoperatively. Hypertension, necessitating treatment, occurred in 60% of the patients having pulsatile and 68% of those having nonpulsatile perfusion (p less than 0.05). Although pulsatile CPB would appear to be more physiological than nonpulsatile perfusion, this method of creating pulsatile flow does not appear to eliminate postoperative hypertension.