Goal-directed resuscitation following cardiac surgery reduces acute kidney injury: A quality initiative pre–post analysis

Objective: Acute kidney injury (AKI) occurs in 20% of patients following cardiac surgery. To reduce AKI in our institution, we instituted a quality improvement (QI) initiative using a goal-directed volume resuscitation protocol. Our protocol was designed to achieve quantifiable physiologic goals (eg, cardiac index > 2.5 L/min/m², mean arterial pressure > 65 mm Hg) using fluid and vasoactive agents. The objective of this study was to evaluate AKI in the pre- and post-QI eras, hypothesizing that AKI incidence would decrease in the post-QI era. Methods: In this observational retrospective cohort study, we identified patients who underwent cardiac operations from July 2011 to July 2015 with a risk score available. Kidney injury was determined using the lowest postoperative GFR within 7 days of surgery and standard Risk, Injury, Failure, Loss of Kidney Function, and End-Stage Kidney Disease (RIFLE) classification criteria. The primary outcome was the rate of AKI, as defined by glomerular filtration rate-based RIFLE classification criteria injury, in the post- versus pre-QI eras. Results: A total of 1979 patients were included, of whom 725 were in the pre-QI cohort, and 1254 in the post-QI cohort. Overall, rates of RIFLE classification criteria risk, injury and failure were 27.5%, 5.9%, and 3.6%, respectively. RIFLE classification criteria injury saw the largest decrease in the post-QI cohort (8.1% vs 4.6%; P = .001). Multivariable analysis demonstrated a 37% reduction in the odds of AKI in the post-QI cohort (adjusted odds ratio, 0.63; 95% confidence interval, 0.43-0.90). Conclusions: A goal-directed volume resuscitation protocol centered on patient fluid responsiveness is associated with significantly reduced risk for AKI after cardiac surgery. Protocol-driven approaches should be employed in intensive care units to improve outcomes.