Acute kidney injury after aneurysmal subarachnoid hemorrhage and its effect on patient outcome: an exploratory analysis.

Objective: Acute kidney injury (AKI) is associated with death in critically ill patients, but this complication has not been well characterized after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of this study was to determine the incidence of AKI after aSAH and to identify risk factors for renal dysfunction. Secondary objectives were to examine what effect AKI has on patient mortality and functional outcome at 12 weeks post-aSAH.

Methods: The authors performed a post hoc analysis of the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial data set (clinical trial registration no.: NCT00111085, https://clinicaltrials.gov). The primary outcome of interest was the development of AKI, which was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. Secondary outcomes of interest were death and a modified Rankin Scale score greater than 2 at 12 weeks post-aSAH. Propensity score matching was used to assess for a significant treatment effect related to clazosentan administration and AKI. Univariate analysis, locally weighted scatterplot smoothing (LOWESS) curves, and stepwise logistic regression models were used to evaluate for associations between baseline or disease-related characteristics and study outcomes.

Results: One hundred fifty-six (38%) of the 413 patients enrolled in the CONSCIOUS-1 trial developed AKI during their ICU stay. A history of hypertension (p < 0.001) and the number of nephrotoxic medications administered (p = 0.029) were independent predictors of AKI on multivariate analysis. AKI was an independent predictor of death (p = 0.028) but not a poor functional outcome (p = 0.21) on multivariate testing. Unresolved renal dysfunction was the strongest independent predictor of death in this cohort (p < 0.001).

Conclusions: AKI is a common complication following aSAH. Patients with premorbid hypertension and those treated with nephrotoxic medications may be at greater risk for renal dysfunction. AKI appears to confer an increased probability of death after aSAH.