Acute Kidney Injury in Patients Undergoing Cardiopulmonary Bypass for Lung Transplantation

Background: Cardiopulmonary bypass (CPB) is often used to support patients undergoing lung transplantation who are intolerant of anatomic manipulation or single lung ventilation during the procedure. However, CPB may be associated with adverse outcomes. We evaluated the hypothesis that CPB is associated with increased acute kidney injury (AKI) and postoperative mortality after lung transplantation. Materials and methods: This was a retrospective review of our institutional lung transplant database at the University of Texas Southwestern Medical Center from 2012 to 2018. Patients were grouped based on their need for CPB. The primary outcome was AKI within 48 h of transplantation, which was defined as Kidney Disease Improving Global Outcomes stage 1 or greater. Secondary outcomes included all-cause mortality. Results: A total of 426 patients underwent lung transplantation with 39.0% (n = 166) requiring CPB. There were no differences in demographics and comorbidities, including baseline renal function, between CPB and no CPB. CPB use was higher in recipients with interstitial lung diseases and primary pulmonary hypertension. Median lung allocation score was higher in those needing CPB (47 [interquartile range, 40-59] versus 39 [interquartile range, 35-47]). Patients requiring CPB were significantly more likely to experience AKI (61.44% versus 36.5.3%, P < 0.01) and postoperative hemodialysis (6.6% versus 0.4%, P < 0.01). On multivariable analysis, CPB was significantly associated with postoperative AKI (odds ratio, 1.66; 95% CI, 1.01-2.75; P = 0.04). Thirty-day mortality was higher in patients undergoing CPB (4.2% versus 0.8%, P = 0.03). Conclusions: CPB for lung transplantation is associated with a higher incidence of AKI, renal failure requiring hemodialysis, and 30-d mortality. CPB should be used selectively for lung transplantation.