[Non invasive ventilation for acute exacerbation of chronic obstructive pulmonary disease: a meta-analysis].

BACKGROUND AND OBJECTIVES: The purpose of this study was: 1) To determine the effect of non invasive ventilation (NIV) in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure, and 2) To find out whether there are differences in the results according to the site where ventilation in applied.

PATIENTS AND METHOD: Meta-analysis of randomized controlled trials (RCTs) published included studies in MEDLINE, EMBASE, Cochrane Controled Trials Register and Teseo. Study selection included RCTs in COPD patients with acute respiratory failure with PaCO2 > 45 mmHg or pH < 7.35, with underwent NIV versus standard therapy. Mortality, rate of tracheal intubation and length of stay were analized. Individual studies were rated as to their validity and quality by two investigators using the Jadad score. A different meta-analysis was made for intensive-care unit (ICU) RCTs and wards RCTs.

RESULTS: Five ICU RCTs and four ward RCTs were included. There was a reduction in hospital mortality (ICU, OR = 0.35; 95% confidence interval [CI], 0.15 to 0.83; n = 166; p = 0.02; ward, OR = 0.39; 95% CI, 0.20 to 0.76; n = 296; p = 0.005) and in the need for intubation (ICU, OR = 0.18; 95% CI, 0.10 to 0.35; n= 219; p < 0,00001; ward, OR = 0.43; IC 95%, 0.24-0.78; n = 270; p = 0.006). Length of stay was lower in the NIV group upon ICU trials (WMD, 3.7 days; 95% CI, 5.46 to 1.93 days). Only one ward RCT showed significant differences in the length of stay. Published data did not allow a meta-analysis for length of stay.

CONCLUSIONS: NIV decreases mortality and the need for intubation in COPD patients with acute respiratory failure both in ICU and ward. In ICU non-invasive ventilation decreases the length of stay too.