Impact of acute kidney injury and nephrotoxic exposure on hospital length of stay

Objective Acute kidney injury (AKI) is a common occurrence among hospitalized children and leads to increased mortality and prolonged length of stay (LOS) in critically ill patients. Few studies have examined the impact of AKI on LOS for common pediatric conditions. We hypothesized that a diagnosis of AKI would be associated with a longer hospital LOS and increased exposure to nephrotoxic medications for all patients. Patients and methods We performed a multicenter retrospective cross-sectional analysis of 34 children’s hospitals in the Pediatric Health Information System (PHIS) database from 1/2009 through 12/2013. Patients were grouped based on primary discharge diagnosis, number of days spent in an intensive care unit, and assignment of a secondary diagnostic code for AKI. Median LOS was compared among different patient groupings. Exposure to commonly used nephrotoxic medications was collected for each admission. Results A total of 588,884 admissions from 423,337 patients were included in the analysis. The median LOS among non-critically ill patients with and without AKI was 5 days [95% CI 3–10] versus 2 days [95% CI 1–4], respectively. Among critically ill patients, median LOS for those with and without AKI was 12 days [95% CI 7–20] versus 4 days [95% CI 2–7], respectively. Patients who developed AKI were more likely to have significant nephrotoxic exposure. Conclusions Development of AKI was associated with longer hospital length of stay and increased nephrotoxic medication exposure for all diagnostic categories. Non-critically ill children with AKI were hospitalized the same length or longer than critically ill children without AKI.