Clinical Outcomes in Ventilator-Associated Pneumonia Patients with and without Chronic Obstructive Pulmonary Disease: A Retrospective Observational Study

Abstract

Abstract Background Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. Critically ill patients with COPD exacerbations may require invasive mechanical ventilation (IMV). Ventilator-associated pneumonia (VAP) commonly occurs in the intensive care unit (ICU) and is usually associated with high mortality. Current studies on the relationship between COPD and VAP are limited. This work compares the etiology and clinical outcomes of VAP between patients with and without COPD in Taiwan. Methods This retrospective observational study was conducted at the Chiayi Chang Gung Memorial Hospital. Patients with VAP were enrolled between January 2015 and December 2019. The COPD diagnosis was based on post-bronchodilator pulmonary function tests. We compared the bacterial etiology, ICU and hospital stay length, IMV duration, and mortality. Results A total of 175 patients with VAP were enrolled, 44% of whom presented pre-existing COPD. The disease severity on the day of admission was similar in both groups. Microorganisms were identified in 83 (47%) patients, with Pseudomonas aeruginosa, Acinetobacter spp., and Stenotrophomonas maltophilia being the most common pathogens. Acinetobacter spp. were more frequently isolated from patients with COPD than from those without. The proportion of multi-drug resistant isolates showed no significant differences between groups. Most patients underwent antibiotic treatment before VAP onset. The length of ICU and hospital stays and IMV duration after VAP onset were similar between groups, as well as ICU mortality and 30-, 60-, and 90-day mortalities. Conclusions Our study revealed that COPD was not associated with worse clinical outcomes in patients with VAP. Patients with VAP and concomitant COPD were more susceptible to Acinetobacter spp. than those without COPD. Our results may provide a rationale for empirical antibiotic coverage in this group.