INTRAOPERATIVE FLUID BALANCE AND PERIOPERATIVE OUTCOMES FOLLOWING AORTIC VALVE SURGERY

Abstract Background The effect of intraoperative fluid balance on postoperative acute kidney injury (AKI) in cardiac surgical patients is poorly defined. Methods Retrospective study of patients undergoing aortic valve replacement (AVR) for aortic stenosis. The primary outcome of interest was postoperative AKI. Secondary outcomes included postoperative fluid balance, cardiac index, vasopressor use, hospital free days, stroke, myocardial infarction (MI), hospital readmission, 30- and 90-day mortality. Results 2327 patients were analyzed. Positive intraoperative fluid balance was associated with lower odds of AKI - lowest odds 20-39 mL/kg group [OR=0.56, 95% CI (0.38, 0.81); p=0.002]. Positive intraoperative fluid balance was associated with lower postoperative fluid balance. Increased ultrafiltration volume was associated with increased postoperative fluid resuscitation and vasopressor use. AKI was associated with increased 30- and 90-day mortality. Increased fluid balance was associated with increased odds of MI and 30-day mortality. Increased ultrafiltration volume was associated with increased odds of 30- and 90-day mortality. Conclusions In patients who underwent AVR for aortic stenosis, positive intraoperative fluid balance was associated with decreased odds of AKI. Patients developing AKI had increased 30- and 90-day mortality. While the overall incidence was low, increased intraoperative fluid balance was associated with MI and 30-day mortality, while increased ultrafiltration volume was associated with 30- and 90-day morality. Prospective studies are needed to better define proper intraoperative fluid management in patients undergoing cardiac surgery.