Can pulsatile cardiopulmonary bypass prevent perioperative renal dysfunction during myocardial revascularization in...

We recently demonstrated that pulsatile cardiopulmonary bypass (CPB) versus standard linear CPB is associated with better perioperative renal function. Since older subjects have a higher risk of acute renal failure, we have extended our study to evaluate the specific impact of pulsatile CPB on the perioperative renal function in elderly patients.

We enrolled 50 patients with normal preoperative renal function: they were stratified by age (65-75 vs. 50-64 years) and randomized to nonpulsatile (group A) or pulsatile CPB (group B). Twenty-seven patients aged > or =50 years and <65 years were randomized to group A (n = 12) or to group B (n = 15) and 23, aged > or =65 years and < or =75 years, to group A (n = 13) or to group B (n = 10). Glomerular filtrate rate (GFR), daily diuresis, lactatemia and other parameters were measured during the pre- and perioperative period.

The percent perioperative decrease in GFR was lower in group A than in group B (p < 0.001), without differences between older and younger patients. By contrast, perioperative plasma lactate levels were higher in group A than in group B (p < 0.001), both in older and younger patients. No difference was observed for 24 h urine output and blood urea nitrogen.

Pulsatile CPB preserves renal function better than standard CPB even in patients older than 65. CPB could be adopted as the procedure of choice in this subgroup of patients.