Pulsatile flow during routine cardiopulmonary bypass.

The effect of pulsatile flow during cardiopulmonary bypass (CPB) was studied on two groups of 11 patients each (aged between 18 and 48 years) undergoing open valvular and congenital heart surgery. In the nonpulsatile group, mean blood pressure (BP) and systemic vascular resistance index (SVRI) increased steadily during CPB; while in the pulsatile group, both BP and SVRI remained stationary. The difference of SVRI between the two groups was not significant within 30 minutes after initiation of CPB (3136 +/- 882 to 2536 +/- 530 dynes X sec X cm-5 X m2). Contrarily, it was significantly higher in the nonpulsatile group after 40 minutes of CPB (3748 +/- 562 to 2612 +/- 609 dynes X sec X cm-5 X m2, p less than 0.02) and thereafter. Oxygen consumption index (59.6 +/- 12.9 to 77.8 +/- 32.6 ml X min-1 X m-2) and carbon dioxide production index (41.1 +/- 16.0 to 59.3 +/- 28.1 ml X min-1 X m-2) measured 20 minutes after institution of CPB seemed lower in the nonpulsatile group than in the pulsatile group, but the differences were not statistically significant. Increased urine flow during CPB (1.8 +/- 1.1 to 6.3 +/- 3.8 ml X min-1 X m-2, p less than 0.001) with less variability indicated better reserve of renal function in the pulsatile group; and less percent change of postoperative sGOT from preoperative level (529.8 +/- 129.8 to 310.0 +/- 175.2%, p less than 0.005) also showed better hepatic function in the pulsatile group.(ABSTRACT TRUNCATED AT 250 WORDS)