Background: In the past decade, noninvasive positive pressure ventilation (NIPPV) has been successfully used in chronic obstructive pulmonary disease (COPD) with acute exacerbation. Nonetheless, its effect in stable COPD remains controversial. Theoretically, differences in the mode of ventilation such as pressure versus volume preset, or interfaces such as nasal versus full facial mask could have an impact on the efficacy of NIPPV. Few published studies have focused on this topic.
Methods: In this crossover study, bilevel positive airway pressure (BiPAP) for pressure preset ventilation or PLV-100 as a home-care volume preset ventilator was used via a nasal or facial mask in 12 patients with stable hypercapnic COPD. The four types (2 ventilators and 2 masks) of NIPPV were used for 20 minutes each, with a randomized sequence. The patient breathed spontaneously for 10 minutes before and between each type of NIPPV as a baseline for comparison.
Results: Respiratory rate, tidal volume, pulse rate, Borg scale and phase angle were all significantly improved during BiPAP ventilation via either a nasal or facial mask (p < 0.05 for all). Suppression of inspiratory muscle activity was obvious, although not statistically significant. In contrast, inspiratory muscle activity, phase angle and respiratory rate increased and tidal volume decreased significantly during PLV-100 ventilation with either nasal or facial masks (p < 0.05 for all). Peak expiratory flow rate and maximum inspiratory and expiratory mouth pressures remained unchanged after each type of NIPPV.
Conclusions: For patients with stable hypercapnic COPD, short-term use of BiPAP via either a nasal or facial mask markedly rests the inspiratory muscles, improves the respiratory pattern and reduces the sense of dyspnea for patients. In contrast, short-term use of PLV-100 via either a nasal or facial mask worsens the above parameters.