CSB SIA1, MR ANANDA-RAJAH1,2,3, NR ADLER1,4 Y-W BAEY1, D LIEW3, EY TONG1,5, AR KAR AUNG1,2,3
1Department of General Medicine, Alfred Hospital, Prahran, Victoria, Australia. 2Department of Infectious Diseases, Alfred Hospital, Prahran, Victoria, Australia; 3Monash University, Victoria, Australia; 4School of Public Health and Preventative Medicine, Monash University; 5Department of Pharmacy, Alfred Hospital, Prahran, Victoria, Australia
Aim: To determine the incidence of acute kidney injury (AKI) in elderly patients receiving a short course of gentamicin, clinical risk factors and outcomes related to AKI.
Background: A short course of gentamicin is recommended by the Australian Therapeutic Guidelines as empiric treatment for gram negative bacteria, however the incidence of nephrotoxicity in elderly patients has not been studied.
Methods: Retrospective cohort study from April 2013 to 2015 at the Alfred and Sandringham Hospital, Melbourne Australia. Participants included elderly (aged ≥65 years) patients admitted to hospital from the ED who received gentamicin. The primary outcome, AKI was defined as a rise in serum creatinine by ≥50% and/or ≥26.5µmol/L within 14 days of first gentamicin dose.
Results: The incidence of AKI was 14.9% (36/242 patients). A composite serious adverse renal outcome (persistent kidney injury, requirement for renal replacement therapy or inpatient death in a patient with AKI) occurred in 10 (4.1%) patients. Patients who developed AKI were older (median 80.5 vs 78 years, p=0.026), had higher Charlson co-morbidity index (median 7 vs 5, p=0.0004), had more advanced chronic kidney disease (CKD) at baseline (Stage IV and V) (OR 4.38, 95% CI=1.45-13.2, p=0.013) and were more likely to have received diuretics within the first 72 hours (OR 2.35, 95% CI 1.13-4.92, p=0.025). Mortality was increased in those with AKI (13.9% vs. 4.4%, p=0.04). When adjusted for confounders, Stage IV CKD or worse remained associated with AKI.
Conclusions: In a cohort of elderly patients with predominantly Stage II CKD, in whom the majority received a single dose of gentamicin, the incidence of AKI was 14.9%. AKI was transient in the majority of patients.