Clinical treatment of hospital-acquired pneumonia caused by extensively drug-resistant Acinetobacter baumannii: single-centre retrospective study

Abstract Background: Extensively drug-resistant Acinetobacter baumannii (XDRAB) has strong ability to acquire drug resistance genes, which are then rapidly cloned and transmitted, leading to worldwide spread posing a significant treatment challenge. Currently, limited drugs are available for the treatment of XDRAB infection, and their clinical effects are not clear; therefore, the specific factors that affect the treatment response and patient outcome require further exploration. The aim of this was to clarify effective treatment methods during XDRAB infection and the factors affecting patient prognosis according to a retrospective review of cases at our hospital.Methods: Hospital-acquired XDRAB pneumonia cases clinically diagnosed at Guangzhou First Municipal People’s Hospital from January 2016 to December 2017 were selected, and their clinical features, treatment, and prognosis were retrospectively analysed.Results: Forty-eight patients met the diagnostic criteria of hospital-acquired pneumonia caused by XDRAB in the study period, 20 of whom survived and 28 of whom died for an overall mortality rate of 58.3%. There was no significant difference in anti-A. baumannii activity according to the type of antibiotic administered or their combinations between the patients that survived and those that died from the infection. The use of antibacterial drugs during infection did not effectively improve the clinical outcome. Advanced age, multiple organ failure, and disease severity (APACHE score) were significantly negatively correlated with bacterial clearance, whereas effective airway management (tracheotomy and sputum suction during infection) had a positive impact on bacterial clearance. In multivariate analysis, age [odds ratio (OR) 1.1, 95% confidence interval (CI) 1.0–1.3] and APACHE score (OR 1.5, 95% CI 1.1–2.0) were independent risk factors affecting prognosis. Tracheotomy during infection (OR 0.0, 95% CI 0.0–0.55) was a protective factor contributing to survival.Conclusion: XDRAB hospital-acquired pneumonia has a high mortality rate. Advanced age and severe disease are independent risk factors that affect patient prognosis. The use and type of antibacterial drugs for treatment do not appear to substantially affect the prognosis during XDRAB infection. Overall, timely and effective airway management is the key to improving the prognosis of patients with hospital-acquired XDRAB infection.