Early failure of noninvasive ventilation in chronic obstructive pulmonary disease with acute hypercapnic respiratory failure

Noninvasive ventilation (NIV) in the management of chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure is considered a first-line therapy. However, patients who fail NIV and then require invasive mechanical ventilation have been found to have higher mortality than patients initially treated with invasive mechanical ventilation. We tried to find parameters associated with early NIV failure (need for intubation or death <24 h of starting NIV) in patients presenting to the ED with acute exacerbation of COPD. A retrospective analysis was conducted of the medical records of 218 patients with acute exacerbation of COPD visiting Asan Medical Center and managed with NIV during their stay in the ED from January 2007 to December 2013. NIV was successful in 200 (91.7 %) and 18 (8.3 %) had early NIV failure. Of the variables obtained before NIV treatment, heart rate (≥120/min: OR 2.5, 95 % CI 1.2–7.0) and pH (7.25–7.29: OR 2.1, 95 % CI 1.0–8.8; <7.25: OR 11.7, 95 % CI 3.5–38.6) were significant factors associated with early NIV failure. Of the variables obtained after 1 h of NIV treatment, heart rate (≥120/min: OR 7.5, 95 % CI 2.3–24.3) and pH (7.25–7.29: OR 4.7, 95 % CI 1.5–15.1; <7.25: OR 20.9, 95 % CI 5.4–61.2) were still significant. The presence of tachycardia and severe acidosis before NIV treatment and persistence of tachycardia and severe acidosis after 1 h of NIV treatment were associated with early NIV failure.