Objective: Noninvasive ventilation (NIV) had been successfully used in patients with severe hypercapnic acute respiratory failure (HARF). Being lack of a large number of randomized control trials to support NIV in chronic obstructive pulmonary disease (COPD) patients with severe HARF, the effect of NIV for patients with life-threatening HARF should be further confirmed. In order to confirm the effect of NIV on selected patients with HARF due to COPD, we conducted a comparative prospective observational study of NIV vs. IMV (invasive mechanical ventilation) + NIV in COPD patients with HARF.
Methods: A total of 420 patients with acute respiratory failure secondary to COPD were prospective screened; 52 cases with PaCO2 ≥ 90 mmHg or PaCO2 <90 mmHg but ≥ 80 mmHg with pH value ≤ 7.20 were enrolled. Twentyone cases received sequential IMV to NIV treatment and were designated as the IMV+NIV group; 31 cases received NIV and were designated as the NIV group. The primary outcome was hospital mortality and mortality within 30 days of discharge. The secondary outcomes included risk factors for mortality and re-hospitalization, length of hospital stay, time of mechanical ventilation and re-admission rate within 30 days of discharge.
Results: Mortality in-hospital and within 30 days of discharge had no differences between NIV group and IMV +NIV group (p=0.699). Binary logistic regression found no risk factor for mortality and re-hospitalization in two groups. The length of hospital stay (p=0.000) and time of mechanical ventilation (p=0.000) were significantly longer in the IMV+NIV group compared with the NIV group. Conclusion: Compared to IMV+NIV, NIV has similar efficacy for select patients with severe HARF secondary to acute exacerbation of COPD, and NIV can be safely used in these patients.