Clinical Outcomes and Associated Factors for Mortality among Pediatric Patients with Carbapenem-Resistant Acinetobacter baumannii

Abstract

Background: Acinetobacter baumannii bacteremia is a hospital-acquired infection with a high mortality rate. Up to 80% of hospital-acquired A. baumannii infections are caused by carbapenem-resistant Acinetobacter baumannii (CRAB) strains. Objective: To determine the overall 30-day mortality rate, factors associated with mortality, and antibiotic drug susceptibility patterns of CRAB isolates among children with hospital-acquired CRAB bloodstream infections. Materials and Methods: A retrospective review was conducted among hospitalized pediatric patients between January 2017 and September 2022 at King Chulalongkorn Memorial Hospital, Bangkok. The inclusion criteria were CRAB bacteremia in children under 18 years of age. Thirty-day mortality after CRAB bacteremia was analyzed using Kaplan-Meier estimates. Associated factors were analyzed by Poisson regression. Antibiotic susceptibility patterns of nine antimicrobial agents were summarized. Results: Fifty-eight patients with 66 episodes of CRAB bacteremia were identified. The median age was 7.5 months (IQR 0.8 to 60.0), and 86.4% of the patients were admitted to the intensive care unit. Central line-associated bloodstream infections (CLABSI) were identified in 90.9% of cases. Most patients (74.2%) received colistin combination with sulbactam regimen. The 30-day mortality rate was 19.7% (95% CI 10.9 to 31.3). Associated factors for mortality rate were septic shock (aRR 7.6, 95% CI 2.3 to 25.0) and underlying congenital heart disease (aRR 3.4, 95% CI 1.0 to 11.7). Drug susceptibility of colistin and tigecycline were 93% and 48%, respectively. Sulbactam was not susceptible. Conclusion: One-fifth of children with CRAB bacteremia died within 30 days. Associated factors with mortality were septic shock and congenital heart disease. Colistin had the highest in vitro drug susceptibility rate. The common regimen used in the present study was colistin combination with sulbactam therapy. Keywords: Acinetobacter baumannii; Bacteremia; Carbapenem resistance; Susceptibility; Mortality; Pediatrics