Association Between Exogenous Nitric Oxide Given During Cardiopulmonary Bypass and the Incidence of Postoperative Kidney Injury in Children.

Abstract Objective To compare the incidence and severity of acute kidney injury following open heart surgery with cardiopulmonary bypass in children after administration of exogenous nitric oxide. Design Retrospective cohort study. Setting Single institution, university hospital. Participants: All children less than 18 years of age who underwent surgery with cardiopulmonary bypass. Interventions Medical records of all eligible patients between January 4, 2017 and June 28, 2019 were reviewed.  Patients were divided into 2 groups based on whether they received exogenous nitric oxide. Measurements and Main results The primary endpoint was change in serum creatinine level as defined as the difference between the preoperative creatinine and peak postoperative creatinine. The secondary endpoint was the incidence and severity of post-operative acute kidney injury. A difference-in-difference method using fixed-effect multiple linear regression was carried out to compare difference in maximum serum creatinine changes between the control and intervention groups. 591 patients were included in the analysis: 298 (50.5%) in the control group and 293 (49.5%) in the intervention group. Control and intervention groups did not vary significantly in terms of baseline characteristics except for bypass time. After adjusting for all baseline variables, there was no statistically significant difference in increase in serum creatinine between the control and the intervention groups (0.01 [95% CI: -0.03, 0.05], p= 0.545). Conclusions This single center retrospective cohort study found no change in the incidence and severity of postoperative acute kidney injury after the administration of nitric oxide into the cardiopulmonary bypass circuit in children.