Hospital-Acquired Acute Kidney Injury in Noncritical Care Setting: Clinical Characteristics and Outcomes

BACKGROUND: There is limited Australian data on the incidence and outcomes of hospital-acquired acute kidney injury (HA-AKI) in noncritically ill patients. AIMS: This study aimed to characterise HA-AKI and assess the impact of nephrology consultations on outcomes. METHODS: A retrospective cohort of all noncritically ill patients with HA-AKI admitted to a large tertiary hospital in 2018 were followed up from hospital admission to discharge. HA-AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The primary outcome of this study was the clinical characteristics of patients who developed HA-AKI and the difference in these characteristics by nephrology consultation. RESULTS: A total of 222 noncritically ill patients were included in the study. The mean age of included patients was 74.8 ± 15.8 years and 57.2% were females. While most patients (92%)were characterised to have KDIGO stage 1, 14% received a nephrology consultation, and 80% had complete or partial recovery of kidney function at discharge. Lower recovery rates (65% versus 83%, P = 0.022), longer hospitalisations (10 versus 5 days, P = 0.001), and higher serum creatinine values on discharge (152 versus 101 μmol/L, P < 0.001) were associated with receipt of nephrology consultation. There was no difference in mortality rates (13% versus 11%, P = 0.754) between those with and without nephrology consultation. CONCLUSIONS: Our findings indicate that signficant proportion of noncritically ill patients experience mild form of AKI and have good recovery of kidney function during hospitalisation. Although severity of AKI and length of hospitalisation were associated with nephrology interventions, large scale study is required to understand the impact of such interventions on clinical outcomes, such as hospital readmission and mortality.