Noninvasive vs invasive ventilation in COPD patients with severe acute respiratory failure deemed to require ventilatory assistance

Objective. To determine whether non-invasive ventilation (NIV) may be an effective and safe alternative to invasive mechanical ventilation in chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) meeting criteria for mechanical ventilation. Design and setting. Matched case-control study conducted in ICU. Patients and intervention. NIV was prospectively applied to 64 COPD patients with advanced ARF. Their outcomes were compared with those of a control group of 64 COPD patients matched on age, FEV1, Simplified Acute Physiology Score II, and pH at ICU admission, previously treated in the same ICU with conventional invasive mechanical ventilation. Methods and results. NIV failed in 40 patients who required intubation. Mortality rate, duration of mechanical ventilation, and lengths of ICU and post-ICU stay were not different between the two groups. The NIV group had fewer complications (P = 0.01) and showed a trend toward a lower proportion of patients remaining on mechanical ventilation after 30 days (P = 0.056). Compared to the control group, the outcomes of the patients who failed NIV were no different. Compared to the patients who received intubation, those who succeeded NIV had reduced mortality rate and lengths of ICU and post-ICU stay. Conclusions. In COPD patients with advanced hypercapnic acute respiratory failure, NIV had a high rate of failure, but, nevertheless, provided some advantages, compared to conventional invasive ventilation. Subgroup analysis suggested that the delay in intubation was not deleterious in the patients who failed NIV, whereas a better outcome was confirmed for the patients who avoided intubation.