Risk factors for aminoglycoside-associated nephrotoxicity in surgical intensive care unit patients

Aminoglycosides are commonly used antibiotics in the intensive care unit (ICU), but are associated with nephrotoxicity. This study evaluated the development of aminoglycoside-associated nephrotoxicity (AAN) in a single surgical intensive care unit.

Adult patients in our surgical ICU who received more than two doses of aminoglycosides were retrospectively reviewed for demographics, serum creatinine, receipt of nephrotoxins [angiotensin converting enzyme (ACE) inhibitors, angiotensin-II receptor blockers, diuretics, non-steroidal anti-inflammatory drugs, cyclosporine, tacrolimus, vasopressors, vancomycin and intravenous iodinated contrast] and the need for dialysis. AAN was defined as an increase in serum creatinine >0.5 mg/dL on at least 2 consecutive days. Univariate and multiple regression analyses were performed.

Sixty-one patients (43 males) receiving aminoglycoside were evaluated. Mean age, weight, initial serum creatinine, and duration of aminoglycoside therapy were 58.7 (±15) years, 83.3 (±24.4) kg, 0.9 (±0.5) mg/dL, and 4 (±2.3) days, respectively. Thirty-one (51%) aminoglycoside recipients also received additional nephrotoxins. Seven aminoglycoside recipients (11.5%) developed AAN, four of whom required dialysis and all had received additional nephrotoxins. Only concurrent use of vasopressors (P = 0.041) and vancomycin (P = 0.002) were statistically associated with AAN. Receipt of vasopressors or vancomycin were independent predictors of acute kidney insufficiency (AKI) with odds ratios of 19.9 (95% CI: 1.6-245, P = 0.019) and 49.8 (95% CI: 4.1-602, P = 0.002), respectively. Four patients (6.6%) required dialysis.

In critically ill surgical patients receiving aminoglycosides, AAN occurred in 11.5% of the patients. Concurrent use of aminoglycosides with other nephrotoxins increased the risk of AAN.