Epidemiology of acute kidney injury in patients with stroke: a retrospective analysis from the neurology ICU

Acute kidney injury (AKI) is proven to be an independent risk factor for adverse clinical outcomes in patients with stroke, but data about the epidemiology of AKI in these patients are not well characterized. Therefore, we investigated the incidence, risk factors, and the impact of AKI on the clinical outcomes in a group of Chinese patients with stroke. We retrospectively recruited 647 stroke patients from the neurology ICU between 2012 and 2013. AKI was identified according to the 2012 KDIGO criteria. Baseline estimated glomerular filtration rate (eGFR) was calculated using modified Chronic Kidney Disease Epidemiology Collaboration equation for Chinese patients. National Institutes of Health Stroke Scale (NIHSS) score was assessed for the stroke severity. A total of 135 (20.9%) patients developed AKI. Patients with AKI stages from 1 to 3 were 84 (62.2%), 26 (19.3%), and 25 (18.5%), respectively. Logistic regression analysis showed that independent risk factors for AKI were higher NIHSS score (OR, 1.027; 95% CI 1.003-1.051), lower baseline eGFR (OR, 0.985; 95% CI 0.977-0.993), the presence of hypertension (OR, 1.592; 95% CI 1.003-2.529), and infectious complications (OR, 3.387; 95% CI 1.997-5.803) (P < 0.05 for all). AKI patients were also significantly associated with all-cause mortality in the neurology ICU [OR and 95% CI of AKI-stage 1, AKI-stage 2, and AKI-stage 3 were 4.961 (2.191-11.232), 19.722 (6.354-61.217), and 48.625 (17.616-134.222), respectively (P < 0.001 for all)]. AKI is common among patients with stroke and is associated with worse clinical outcomes after stroke. Prevention of AKI seems to be very important among these patients, because they are exposed to many risk factors for developing AKI.