Association of haptoglobin administration and post-cardiopulmonary bypass acute kidney injury: a propensity score matching analysis

Abstract

　Purpose: We aimed to retrospectively investigate whether intraoperative haptoglobin administration is associated with a lower incidence of acute kidney injury (AKI) after cardiac surgery under cardiopulmonary bypass.

　Methods: A review of the medical records identified 142 patients who had undergone cardiac surgery under cardiopulmonary bypass. Using propensity score matching, we compared the incidence of postoperative AKI in the HAPTOGLOBIN cohort to that in the CONTROL cohort. The HAPTOGLOBIN cohort was defined as the patient cohort that was administered haptoglobin in the presence of hemolytic urine and the CONTROL cohort was defined as the patient cohort that was not administered haptoglobin in the absence of hemolytic urine.

　Results: AKI occurred in 37% of the patients. Haptoglobin was administered in 29% of the patients. In the crude cohort, AKI occurred in the HAPTOGLOBIN cohort more frequently than in the CONTROL cohort (53.7% vs 29.7%, P=0.013). However, in the propensity score matched cohort (27 patients in each cohort), the incidence of AKI was not significantly different between the HAPTOGLOBIN and CONTROL cohorts (48.1% vs 40.7%, P=0.78).

　Conclusion: This study suggests that intraoperative haptoglobin administration after the appearance of hemolytic urine may not be associated with postoperative AKI.