Can Pulsatile Cardiopulmonary Bypass Prevent Perioperative Renal Dysfunction during Myocardial Revascularization in Elderly Patients?
Background: 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 >/=50 years and <65 years were randomized to group A (n = 12) or to group B (n = 15) and 23, aged >/=65 years and =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.