Is single-dose prophylactic gentamicin associated with acute kidney injury in patients undergoing cardiac surgery? A matched-pair analysis

Objective: Although aminoglycoside treatment has been associated with nephrotoxic effects, single-dose gentamicin has been considered safe in surgery. However, the effect of a single-dose prophylactic aminoglycoside on the risk of acute kidney injury among patients undergoing cardiac surgery remains uncertain. Methods: A population-based cohort study with matched-pair analysis of 2892 consecutive patients undergoing cardiac surgery at Aarhus University Hospital, Denmark, was performed. Two different prophylactic antibiotic regimens were used during the study period. The patients exposed to a single dose of prophylactic gentamicin were compared with those had not received gentamicin. Statistical analysis for matched data was performed. The data were retrieved from the Western Denmark Heart Registry. Results: Matching resulted in 668 patient pairs. Patients receiving gentamicin had higher maximum serum creatinine during the first postoperative 72 hours (median, 96 vs 90 mmol/L; P = .0002). Also, a greater fraction of patients receiving gentamicin developed acute kidney injury according to the Acute Kidney Injury Network criteria (22% vs 17%; P = .02). The hospital length of stay was shorter in the control group (5.0 vs 5.6 days; P < .0001). No difference was found in the incidence of patients requiring postoperative dialysis, 30-day and 1-year mortality, or the incidence of sternal infection between the 2 groups. Conclusions: A single-dose prophylactic aminoglycoside in adult cardiac surgery patients was associated with an increased risk of acute kidney injury but not with a greater frequency of postoperative dialysis or mortality. No differences in the incidence of sternal infections between groups were observed.