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School of Anesthesia


Anesthesiology | Medical Education | Nursing


Background Acute kidney injury (AKI) is a serious postoperative complication that increases a patient’s risk for both long and short-term morbidity and mortality.1 Intraoperative hypotension (IOH) is an independent risk factor for AKI,2-5 which can be readily modified by anesthesia providers. This project aims to describe the risk factors and rates of AKI following IOH at various absolute mean arterial blood pressure (MAP) thresholds for specified durations of time among adults undergoing non-cardiac surgery at Providence Sacred Heart Medical Center (PSHMC).

Methods PSHMC approved this retrospective, observational evidence-based project and deemed the project exempt by the Institutional Review Board from human subjects testing. Project inclusion criteria consisted of adults undergoing general anesthesia for non-cardiac surgery at PSHMC from 2015-2019 with pre- and postoperative serum creatinine lab results to evaluate for AKI via the KDIGO Criteria. Obstetrics, urology, dialysis history and records with missing serum creatinine values were excluded. The study group was further stratified by recorded MAP measurement intervals of ≤ 5 minutes to capture IOH. An a-priori power analysis revealed 2,181 records would power results (1-β=0.80, α=0.05, Df=1, W=0.06). PSHMC sponsor extracted, deidentified, encrypted and stored data in a HIPAA compliant REDCap database. Project team members performed univariate, bivariate and multivariable analyses using Microsoft Excel, MedCalc and G*Power platforms on PSHMC designated computers.

Discussion Project findings revealed that 8.3% of patients had both pre- and postoperative serum creatinine results to evaluate for AKI. Of this study population (n=4,603), 8.9% experienced postoperative AKI. The literature reports rates of AKI to be 5- 7.5%. 5 Risk for AKI increased from 7.7% to 11.3% among patients exposed to MAPs less than 60mmHg for at least 10 minutes (RR 1.48, 95% CI [1.19-1.84], p<0.001). According to the literature, AKI risk increases with the duration and severity of IOH exposure. 5 In a fully adjusted model, IOH, ASA 4 or greater, history of chronic kidney disease, baseline eGFR less than 60 ml/min/1.73m2 , and vascular surgery were identified as independent risk factors for AKI at PSHMC. Exploring AKI rates and risk factors at PSHMC helps identify potential areas of anesthesia practice improvement and informs further research surrounding AKI. As blood pressure is a modifiable risk factor for AKI, limiting IOH exposure may mitigate end organ damage and improve patient outcomes.

Clinical Institute

Kidney & Diabetes





Conference / Event Name

AANA 2020 Virtual Congress


Virtual Conference

Intraoperative Hypotension and Acute Kidney Injury in Non-Cardiac Surgery at Providence Sacred Heart Medical Center