Acute kidney injury in subarachnoid hemorrhage: Exploring its clinical significance and prognostic implications

Objectives: Subarachnoid hemorrhage (SAH) from spontaneous aneurysm rupture is a debilitating condition with high morbidity and mortality. Patients with SAH remain understudied, particularly concerning the evaluation of incidence and consequences of subsequent acute kidney injury (AKI). In this study, we aim to explore the risk factors and outcomes of AKI in SAH patients. Materials and Methods: International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes were used to query the National Inpatient Sample (NIS) for patients with a diagnosis of SAH between 2010-2019. Subgroup analysis was stratified by AKI diagnosis during the same hospitalization. AKI and non-AKI groups were assessed for baseline clinical characteristics, interventions, complications, and outcomes. Descriptive statistics, multivariate regressions, and propensity score-matching were performed using IBM SPSS 28. Results: Of 76,553 patients diagnosed with nontraumatic SAH between 2010-2019, 10,634 (13.89 %) had a comorbid diagnosis of AKI. SAH patients with AKI were older (p < 0.01) and more often obese (p < 0.01) compared to the non-AKI group. A multivariate regression found the diagnosis of AKI to be independently correlated with poor functional outcome (p < 0.001), above average length of stay (p < 0.001), and in-hospital mortality (p < 0.001) when controlling for age, SAH severity, and other comorbidities. Conclusions: This study showed significant association between AKI and adverse outcomes in SAH patients, and a correlation between AKI and heightened complication rates, poor functional outcome, extended hospital stays, and elevated mortality rates. Early detection of AKI in SAH patients is vital to improve their chances of recovery.