Use of aminoglycosides in patients with intra-abdominal infections in a secondary acute care hospital

Abstract

Aminoglycosides (AMG) are bactericidal, narrow-spectrum, and low-cost antibiotics, whose main limitation for clinical use is the risk of nephrotoxicity. The aim of this study was to characterize patients with intra-abdominal infections, describe the bacteriology and resistance profile, assess the frequency of acute kidney injury (AKI), and evaluate surgical outcomes. Materials and Methods: A prospective, observational study was conducted over one year, including hospitalized patients with intra-abdominal infections who received AMG therapy. AKI was defined as an increase in plasma creatinine of ≥0.3 mg/dL from baseline. Gentamicin serum levels and minimum inhibitory concentration (MIC) testing were performed. Results: A total of 126 patients were included, with a mean age of 51.6 years. The mean Karnofsky score was 89.8, and the mean Charlson comorbidity index was 1.8. The most frequent surgical diagnoses were appendicitis (38.9%), cholangitis (23%), and diverticulitis (13.5%). All patients received gentamicin, with a mean daily dose of 338.4 mg and a mean duration of 4.3 days. Escherichia coli was the most frequently isolated pathogen (68.8%), with 92.5% susceptibility to gentamicin. Clinical failure occurred in 15.1% of patients. AKI developed in 10.5% of cases, being mild in 91.7% and transient in 50%. Overall mortality was 3.2%. Patients who developed AKI were older and had higher Charlson and lower Karnofsky scores compared with controls (p<0.01). Conclusions: Aminoglycosides remain the antibiotic of choice in our setting, given their concordance with local antimicrobial susceptibility patterns. They showed a low rate of AKI and minimal therapeutic failure.