Acute Renal Failure in Aneurysmal Subarachnoid Hemorrhage: Nationwide Analysis of Hospitalizations in the United States

Abstract

Objective: Medical complications in the setting of aneurysmal subarachnoid hemorrhage (aSAH) are common and associated with poor prognosis. We analyzed the incidence, risk factors, and short-term outcomes associated with acute renal failure (ARF) in aSAH.

Methods: We queried discharge records from all patients admitted to U.S. hospitals between 2002 and 2011 to identify primary diagnoses of aSAH and secondary diagnoses of ARF. The effect of demographics, hospital characteristics, and pre-existing comorbidity on ARF occurrence and the impact of ARF occurrence on length of stay (LOS), in-hospital costs, moderate to severe disability, and in-hospital mortality were explored in both bivariate and multivariable analyses.

Results: The incidence of ARF in patients hospitalized for aSAH (N = 260,885) was 4.0% and increased from 2.1% in 2002 to 5.7% in 2011 (P < 0.0001). The strongest predictors of ARF in multivariable analysis were fluid and electrolyte disorder (odds ratio [OR], 3.24; 95% confidence interval [CI], 3.07-3.42), coagulopathy (OR, 2.43; 95% CI, 2.25-2.63), HIV (OR, 2.42; 95% CI, 1.79-3.27), and diabetes (OR, 2.37; 95% CI, 2.08-2.69). ARF onset in aSAH increased the mean length of stay by 7.2 days and mean total costs by $28,813 (all P < 0.0001). After adjusting for confounding factors, patients with ARF had increased likelihood of moderate to severe disability (OR, 2.03; 95% CI, 1.89-2.19) and in-hospital death (OR, 2.14; 95% CI, 2.03-2.26).

Conclusion: The burden of ARF in hospitalized patients with aSAH has increased in the past decade and is detrimental to patient outcomes and healthcare costs. The identification of patient-centered risk factors may allow for close surveillance of high-risk patients.

Keywords: Acute renal failure; Aneurysm; Epidemiology; Nationwide inpatient sample; Subarachnoid hemorrhage.