Noninvasive mechanical ventilation with helmet in patients with exacerbation of chronic obstructive pulmonary disease: a randomized controlled trial

Objective ‒ to compare the incidence of complications and the main treatment outcomes of non-invasive mechanical ventilation (NIV) with a helmet versus NIV with a full face mask.Materials and methods. A monocentric randomized open-labeled controlled clinical trial. Patients with exacerbation of chronic obstructive pulmonary disease (COPD) with signs of respiratory failure were randomized to receive NIV through a mask or helmet. The study included 59 patients who were randomized into two groups: NIV through helmet (n = 29) or mask (n = 30). The average age of the patients was (59.24 ± 14.20) and (59.06 ± 15.90) years, respectively. In both groups men predominated ‒ 23 (79 %) and 27 (90 %) respectively. Ventilation was performed with a Draeger Carina apparatus in pressure support (PS) mode. The primary endpoint was the cumulative incidence of NIV complications. Secondary endpoints were PaO2/FiO2 ratio, tolerance to therapy, frequency of intubations, duration of stay in the intensive care unit (ICU), and ICU mortality. A total of 59 patients were involved in the study.Results. The complication rate was lower in the helmet group (10 % (n = 3) versus 43 % (n = 13), p = 0.004) and the PaO2/FiO2 ratio was higher at the first hour and at the end of NIV (253.14 ± 64.74) mm Hg versus (216.06 ± 43.86) mm Hg and (277.07 ± 84.89) mmHg versus (225.81 ± 63.64) mm Hg, p = 0.013 and p = 0.012) compared with NIV through a full face mask. More patients noted excellent helmet tolerance than masks at the 4th hour of therapy (24 (83 %) versus 14 (47 %), p = 0.004) and at the end of ventilation (69 % (20/29) versus 30 % (9/30), p = 0.03). One patient was unable to continue therapy due to mask intolerance. Differences in intubation rates, length of ICU stay, and mortality were statistically insignificant (p = 0.612, p = 0.100, p = 1.000 respectively).Conclusions. NIV through a helmet can reduce the incidence of complications and increase the PaO2/FiO2 ratio, as well as improve tolerance compared to NIV through a face mask in patients with exacerbation of COPD. A larger scale of study is needed to establish the effect of interface choice on ICU mortality, time spent in ICU, and frequency of intubation.