Acinetobacter baumannii: assessing susceptibility patterns, management practices, and mortality predictors in a tertiary teaching hospital in Lebanon

Abstract

Background: Acinetobacter baumannii is a major nosocomial pathogen capable of causing life-threatening infections. This bacterium is highly resistant to antibiotics and associated with high mortality rates. Therefore, this study aimed to evaluate A. baumannii's susceptibility patterns to antimicrobials, assess the appropriateness of the initiated antimicrobial therapy, determine the mortality rate, and identify predictors associated with mortality. Methods: A retrospective observational study was conducted among patients infected with A. baumannii at a university hospital in Lebanon through the revision of medical records. Kaplan–Meier survival analysis and log-rank tests were used to analyze time-to-mortality. Binary logistic regression was performed to identify predictors of mortality. Results: The records of 188 patients were screened, and 111 patients with A. baumannii infection were enrolled. Almost all isolates were resistant to carbapenem, and 43% of the isolates were extensively-drug resistant. Almost half of the patients received initial inappropriate antimicrobial therapy (n = 50, 45.1%). The 30-day mortality rate associated with A. baumannii infection was 71.2% (79/111). The time to mortality in patients who received inappropriate antimicrobial therapy (5.70 ± 1.07 days) was significantly shorter than in those who received appropriate antimicrobial therapy (12.43 ± 1.01 days, P < 0.01). Binary logistic regression revealed that inappropriate antimicrobial therapy (adjusted odds ratio [AOR] = 16.22, 95% CI 2.68–9.97, P = 0.002), mechanical ventilation (AOR = 14.72, 95% CI 3.27–6.61, P < 0.001), and thrombocytopenia (AOR = 8.82, 95% CI 1.12–9.75, P = 0.003) were more likely associated with mortality. Conclusions: A. baumannii exhibits an alarming mortality rate among infected patients. Thrombocytopenia, mechanical ventilation, and inappropriate antibiotic administration are associated with mortality in patients infected with A. baumannii. The prompt initiation of appropriate antimicrobial therapy, infection control measures, and effective stewardship program are crucial to reduce the incidence of A. baumannii and improve the treatment outcomes.