Exp Ther Med. 2020 Dec;20(6):273. doi: 10.3892/etm.2020.9403. Epub 2020 Oct 27.
The purpose of the present systematic review and meta-analysis was to uncover whether chronic obstructive pulmonary disease (COPD) as a co-morbidity influences outcomes of patients with ventilator-associated pneumonia (VAP) compared to VAP alone and whether the development of VAP in patients with COPD is associated with poor outcome in comparison to COPD alone. An electronic search of the PubMed, Embase, Scopus, BioMed Central, CENTRAL and Google scholar databases for all types of studies assessing the influence of COPD on outcomes of patients with VAP and vice versa was performed. A total of 7 studies were included. Of these, 3 studies assessed the impact of COPD on outcomes of patients with VAP. Meta-analysis indicated that the presence of COPD significantly increased the mortality of patients with VAP [risk ratio (RR): 1.37, 95% CI: 1.14-1.65, I2=3%, P=0.007]. The analysis failed to demonstrate any significant effect of COPD on the duration of mechanical ventilation in patients with VAP [mean difference (MD): 2.37, 95% CI: -5.77 to 10.50, I2=38%, P=0.57]. However, the duration of the intensive care unit (ICU) stay was significantly longer in patients with COPD and VAP as compared with that of patients with VAP without COPD (MD: 5.53, 95% CI: 0.73-10.33, I2=0%, P=0.02). A total of 4 studies assessed the impact of VAP on outcomes of patients with COPD. Meta-analysis indicated that the presence of VAP significantly increased mortality of patients with COPD (RR: 1.52, 95% CI: 1.08-2.12, I2=71%, P=0.02). Pooled analysis indicated that the presence of VAP in patients with COPD significantly increased the duration of mechanical ventilation (MD: 13.73, 95% CI: 7.86-19.61, I2=92%, P<0.00001) and the duration of the ICU stay as compared to patients with COPD but without VAP (MD: 17.36, 95% CI: 9.55-25.17, I2=90%, P<0.0001). To conclude, within the limitations of the study, the present results indicated that the combination of COPD and VAP significantly increased patient mortality and the duration of ICU stay. The development of VAP in patients with COPD also significantly increased the duration of mechanical ventilation. Further case-matched studies are required to assess the influence of the severity of COPD in combination with VAP on patient outcomes.