Effects of intraoperative blood pressure variability on development of postoperative acute kidney injury among Japanese

To investigate the effects of intraoperative blood pressure (BP) variability on development of postoperative acute kidney injury (AKI) in patients undergoing non-cardiac surgery. In this retrospective observational study, a total 8504 adult (≥ 20 years) cases who underwent non-cardiac surgery with general anesthesia performed at Fukuoka University Hospital from 2017 to 2019 were included in the present analysis. Standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and minimum value of intraoperative systolic BP based on oscillometric measurement were used as indices of BP variability. Postoperative AKI was defined as an increase serum creatinine level by more than 0.3 mg/dL or 1.5 times from preoperation within 48 h after surgery. A total of 184 (2.16%) cases developed AKI postoperatively. Incidence of AKI increased with elevation of SD, CV and ARV of intraoperative systolic BP. Although the association of SD and CV became non-significant after adjustment for confounding factors including intraoperative hypotension (minimum systolic BP < 80 mm Hg) (both P > 0.05 for trend). However, ARV of intraoperative systolic BP were remained significantly associated with postoperative AKI after adjustment for confounding factors including intraoperative hypotension (P > 0.007 for trend). In contrast, lower minimum systolic BP was associated with increased cumulative incidence of postoperative AKI even after adjustment for other confounding factors (P < 0.001 for trend). In a large-scale observational study of Japanese who underwent non-cardiac surgery, intraoperative BP variability, which was defined by ARV and minimum value of systolic BP, was associated with higher risks of postoperative AKI. This study was approved by the Fukuoka University Medical Ethics Committee (No. H19-12-006).