Association of the exclusive use of intraoperative phenylephrine for treatment of hypotension with the risk of acute kidney injury after noncardiac surgery

Study objective: The hypothesis that the exclusive use of the commonly used vasopressor phenylephrine during the intraoperative period in noncardiac surgery is associated with postoperative acute kidney injury (AKI) was tested.

Design: A retrospective cohort analysis of 16,306 adults undergoing major noncardiac surgery who either did or did not receive phenylephrine was conducted. The primary outcome was the association of the use of phenylephrine with the risk of postoperative AKI defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Logistic regression models with all independently associated potential confounders, and an exploratory model considering only patients with no untreated minutes of hypotension (post-phenylephrine in the exposed cohort, or entire case in the unexposed cohort) were used in the analysis.

Setting: The study was conducted in a tertiary care university hospital where a total of 8,221 patients were exposed to phenylephrine, and 8,085 were not.

Results: In unadjusted analysis, phenylephrine exposure was associated with an increased risk of AKI (OR 1.615, 95% CI [1.522-1.725], p < 0.001). In an adjusted model including several variables associated with AKI, phenylephrine remained associated with AKI (OR 1.325 [1.153-1.524]), as did post-phenylephrine exposure lengths of hypotension. Exclusion of patients with >1 min of post-phenylephrine exposure hypotension, also demonstrated that phenylephrine use was associated with AKI (OR 1.478, [1.245-1.753]).

Conclusions: The exclusive use of intraoperative phenylephrine is associated with an increased risk of postoperative renal injury. Anesthesiologists must consider a balanced approach to correct hypotension under anesthesia, including judicious choices for fluids, inotropic support when indicated, and an appropriate adjustment of the plane of anesthesia.