A meta-analysis of renal benefits to pulsatile perfusion in cardiac surgery

Multiple studies have evaluated the efficacy of pulsatile flow during cardiopulmonary bypass (CPB) showing controversial results. Suggested benefits to pulsatile perfusion include reducing the systemic inflammatory response syndrome associated with bypass, decreased need for inotropic support, shortened hospital stay, and superior organ preservation. This study aims to compare prior studies to determine if there is a significant difference in post-operative renal function with pulsatile perfusion compared to non-pulsatile perfusion during cardiac surgery. Studies included in the analysis were identified by searching keywords--pulsatile perfusion, pulse, pulsatile flow, cardiopulmonary bypass, and cardiac surgery. To maintain a homogenous sample, manuscripts were included if they met the following criteria: research was prospective in nature, subjects were human, paper contained documented baseline demographics, outcome data included markers of renal function. A meta-analysis was performed to compare post-op renal function between pulsatile and non-pulsatile perfusion groups. A total of 298 articles were screened. Ten articles met the criteria, of these, 477 patients underwent non-pulsatile perfusion while 708 received pulsatile perfusion during CPB. There was insufficient evidence to show a difference in mean postoperative creatinine or BUN between the groups, however, the pulsatile perfusion group had significantly higher creatinine clearance (standardized difference in means = 2.48, p = .004) and lower serum lactate levels (standardized difference in means = -2.08, p = .012) in the intensive care unit. This study found that there is great variability among pulsatile perfusion research. The methods to create and assess effective pulsatility on bypass varied widely among manuscripts. This analysis suggests that pulsatile perfusion during CPB is beneficial in renal preservation and should be considered.