Incidence, Predictors, and Prognosis of Acute Kidney Injury Among Cardiac Arrest Survivors

Background: Acute kidney injury (AKI) is common among cardiac arrest survivors. However, the outcomes and predictors are not well studied. Methods: This is a cohort study of cardiac arrest patients enrolled from January 2012 to December 2016 who were able to survive for 24 hours post-cardiopulmonary resuscitation. Patients with anuria, chronic kidney disease (stage 5), and end-stage renal disease were excluded. Acute kidney injury (stage 1) or higher was defined using Kidney Disease: Improving Global Outcomes classification. Multivariable adjusted regression models were used to compute hazard ratio (HR) for association of AKI with risk of mortality and odds ratio (OR) with risk of poor neurological outcomes after adjusting for demographics, comorbidities, and medical therapy. Multivariable logistic regression model was used to compute OR for association of various predictors with AKI. Results: Of 842 cardiac arrest survivors, 588 (69.8%) developed AKI. Among AKI patients, 69.4% died compared with 52.0% among non-AKI patients. In multivariable adjusted Cox proportional hazard model, development of AKI post-cardiac arrest was significantly associated with mortality (HR: 1.35; 95% confidence interval [CI]: 1.07-1.71, P = .01) and poor neurological outcomes defined as cerebral performance category >2 (OR: 2.27; 95% CI: 1.45-3.57, P < .001) and modified Rankin scale >3 (OR: 2.22; 95% CI: 1.43-3.45, P < .001). Postdischarge dialysis was also associated with increased risk of mortality (HR: 2.57; 95% CI: 1.57-4.23, P < .001). Use of vasopressors was strongly associated with development of AKI and continued need for postdischarge dialysis. Conclusions: Acute kidney injury was associated with increased risk of mortality and poor neurological outcomes. There is need for further studies to prevent AKI in cardiac arrest survivors.