Can pulsatile cardiopulmonary bypass prevent perioperative renal dysfunction during myocardial revascularization in elderly patients?

Backgrounds/aims: 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.

Methods: 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.

Results: 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.

Conclusions: 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.