The Association Between Pulsatile Cardiopulmonary Bypass and Acute Kidney Injury After Cardiac Surgery: A Before-and-After Study

Abstract

To investigate the association between pulsatile perfusion and cardiac surgery-associated acute kidney injury. An uncontrolled, retrospective before-and-after study. Single tertiary hospital. A total of 2,489 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Pulsatile versus nonpulsatile perfusion. Data for nonpulsatile perfusion was collected from April 1, 2016, to March 31, 2017 (n = 1,223). A practice change to universal pulsatile CPB occurred on April 3, 2017. Data for pulsatile perfusion was collected from May 1, 2017, to June 30, 2018 (n = 1,266). The primary outcome was the incidence of acute kidney injury (AKI) after cardiac surgery. Multivariable analysis was carried out to adjust for known confounders. Secondary outcomes included AKI stage, stroke, length of stay, and mortality. Subgroup analyses were carried out using prolonged CPB and chronic kidney disease. The primary outcome, incidence of AKI, did not differ between the nonpulsatile control group and the pulsatile group (23.9% v 25.4%, p = 0.392). The pulsatile group was not associated with AKI in the multivariable analysis (Odds ratio 1.09, p = 0.413). There were no differences in stages of AKI in the nonpulsatile group v pulsatile group (13.6% v 14.9%, 2.9% v 4.3%, and 7.4% v 6.1% for stages 1, 2, and 3, respectively, p = 0.12). There were no differences in subgroup analyses or secondary outcomes. There was no association found between kidney injury and pulsatile perfusion. It is likely that there is either no association between pulsatile perfusion and reduced kidney injury or that the difference is extremely small.