OBJECTIVE

To investigate whether pulse pressure (PP) in anesthetized patients undergoing cardiac surgery before and after cardiopulmonary bypass (CPB) is associated with higher postoperative acute kidney injury (AKI) stage.

DESIGN

Retrospective cohort of 597 patients undergoing cardiac surgery.

SETTING

Single academic health care center.

PARTICIPANTS

Adult patients undergoing cardiac surgery requiring CPB (coronary artery bypass grafting, valve, aortic, or combined surgery).

INTERVENTIONS

Pulse pressure was assessed during 3 time periods: pre- and post-CPB, and in the first postoperative hour in the intensive care unit. Pulse pressure, patient characteristics, and intraoperative variables were evaluated using univariable generalized estimating equation analysis for a relationship with AKI stage. Significant risk factors from the univariable analysis then were evaluated in a multivariable generalized estimating equation analysis. Acute kidney injury stage was defined using the Acute Kidney Injury Network criteria.

PRIMARY OUTCOME

Stage of postoperative AKI.

MEASUREMENTS AND MAIN RESULTS

Intraoperative prebypass PP was associated independently and significantly with postoperative AKI stage (odds ratio 1.0107; 95% Confidence Interval, 1.0046-1.0168; p = 0.0005). For every 1-mmHg increase in PP, the odds of a higher AKI stage increased 1.07%. The 2 other periods were not found to be significant predictors of AKI stage.

CONCLUSION

During general anesthesia prior to initiation of CPB, elevated PP is significantly predictive of postoperative AKI stage. This finding merits further research.