Noninvasive positive pressure ventilation in subjects with stable COPD: a randomized trial

Abstract

Background

The use of domiciliary noninvasive positive pressure ventilation (NPPV) in stable chronic obstructive pulmonary disease (COPD) with chronic hypercapnic respiratory failure has yielded variable effects on survival, quality of life, and dyspnea. We hypothesized that use of NPPV in stable COPD and partial pressure of carbon dioxide (PaCO₂) <52 mmHg might result in improvement in quality of life and dyspnea.

Methods

Thirty patients with stable COPD (forced expiratory volume in the first second <50% predicted and PaCO₂ <52 mmHg) were prospectively randomized to receive domiciliary NPPV (bilevel positive airway pressure, 15/5 cm H₂O) or usual therapy for 6 months. Measurements were made at baseline, 6 weeks, 3 months, and 6 months. Primary outcomes were quality of life as assessed by the Chronic Respiratory Disease Questionnaire (CRQ), and dyspnea as measured by the Transitional Dyspnea Index (TDI).

Results

Fifteen subjects in the NPPV arm and 12 controls completed all the study visits. At 6 weeks and 3 months, the NPPV arm showed significant improvement in TDI total score. However, this effect persisted only in the TDI-Task at 6 months (P=0.03). NPPV use was associated with a small improvement in the CRQ-Mastery domain (0.6 versus −0.1, P=0.04). The arterial partial pressure of oxygen (PaO₂) in the control arm worsened over the period of the study, whereas it remained stable in the NPPV arm (change −7.2 mmHg versus +2.1 mmHg, respectively, P=0.02).

Conclusion

NPPV resulted in a small improvement in quality of life indices in stable COPD patients with PaCO₂ <52 mmHg. Future larger studies will clarify the role of NPPV in this stable subgroup of patients with COPD.

Keywords:

• noninvasive
• ventilation
• chronic obstructive pulmonary disease
• normocapnia

Supplementary material

Table S1 Comparison between groups at each time point and over all time points (repeated-measures analysis of variance)

Acknowledgments

We extend our gratitude to the study subjects, to Charles Dayton for help with the institutional review board approval process, and to Bridget Zimmerman for statistical assistance.

Disclosure

The study was sponsored by Respironics Inc, which had no input in the design, data, or writing of the paper. Otherwise none of the authors have any conflicts of interest to declare.