Association Between Intraoperative Hyperoxia and Acute Kidney Injury After Cardiac Surgery: A Retrospective Observational Study
Objective
Optimal oxygen management during cardiac surgery has not been established, and studies on the effects of perioperative hyperoxia on postoperative acute kidney injury (AKI) are scarce. The association between intraoperative hyperoxia and AKI after cardiac surgery involving cardiopulmonary bypass was evaluated for the present study.
Design
Retrospective observational study.
Setting
A tertiary teaching hospital.
Participants
Adult patients who underwent cardiac surgery with cardiopulmonary bypass from November 2006–December 2018.
Interventions
None.
Measurements and Main Results
The area above arterial oxygen partial pressure (PaO 2) threshold of 300 mmHg (AOT 300, mmHg × h) was used as a metric of intraoperative hyperoxia and was associated with postoperative AKI, using the logistic regression analysis. Data also were fitted using the restricted cubic spline model. Sensitivity analyses were conducted using different PaO 2 thresholds (150, 200, 250, and 350 mmHg). A total of 2,926 patients were analyzed. Intraoperative AOT 300 independently was associated with the risk of AKI (odds ratio 1.0009; 95% confidence interval 1.0002-1.0015). A PaO 2 increment of 100 mmHg above PaO 2 300 mmHg for an hour was associated with an increased risk of AKI by 9.4% (1.0009 100 ≈ 1.094). In the spline model, the log-odds of AKI increased as AOT 300 increased. In the sensitivity analyses, AOT 250 and AOT 350 also significantly were associated with the risk of AKI, whereas AOT 150 and AOT 200 were not. As the PaO 2 threshold increased from 150 to 350 mmHg, the odds ratio gradually increased.
Conclusions
Intraoperative hyperoxia significantly was associated with the risk of AKI after cardiac surgery involving cardiopulmonary bypass.