Influence of noninvasive ventilation by BiPAP® on exercise tolerance and respiratory muscle strength in chronic obstructive pulmonary disease patients (COPD)

Dirceu Costa,Audrey Borghi E Silva,Luciana Maria Malosá Sampaio,Andreza Toledo

doi:10.1590/s0104-11692006000300011

Abstract

This study aimed to assess the effect of BiPAP, by nasal mask, on exercise tolerance and respiratory muscle strength in patients with a clinical and spirometric diagnosis of moderate/severe COPD (FEV1 < 60% of predicted). Ten patients of 59.4+/-8.9 years old, with FEV1/FVC <70% of predicted level, were treated with 30 minutes of BiPAP (IPAP:10 and 15 cmH2O; EPAP:4 cmH2O), three days per week, during two months. Before and after the treatment, spirometry, inspiratory (MIP) and expiratory (MEP) muscle strength and the distance walked in six minutes (6MWT) were measured. We observed a significant increase (Wilcoxon, p<0.05) in the mean values of MIP (from -55+/-17 to -77+/-19, respectively), MEP (from 75+/-20 to 109+/-36, respectively) and walking distance (from 349+/-67 to 448+/-75). Based on these results, we concluded that BiPAP improves respiratory muscle strength and exercise tolerance in these COPD patients.

Highlights

Noninvasive ventilation (NIV) has been used successfully for treating respiratory insufficiency due to different causes, including sleep apnea, chronic obstructive pulmonary disease (COPD) and pulmonary edema(1)
Similar results have been found in other studies(4), which attributed the increase in respiratory muscle strength to the muscle rest promoted by NIV
As COPD patients present ventilatory limitations that lead to progressive intolerance to efforts(6), due to dyspnea, weakness and deconditioning of respiratory and peripheral muscles(7), making them vulnerable to hospitalization, this study aims to assess the effects of bi-level NIV in COPD patients on exercise tolerance and respiratory muscle strength

Summary

Introduction

Noninvasive ventilation (NIV) has been used successfully for treating respiratory insufficiency due to different causes, including sleep apnea, chronic obstructive pulmonary disease (COPD) and pulmonary edema(1). Some studies(3) have attempted to analyze the influence of BiPAP® on the respiratory muscles and exercise tolerance in patients with COPD. Their results showed that patients who are treated with BiPAP® two hours per day, during five consecutive days, present greater respiratory muscle rest, improved tolerance and reduced dyspnea. Similar results have been found in other studies(4), which attributed the increase in respiratory muscle strength to the muscle rest promoted by NIV. Other research(5) has not demonstrated any significant growth in respiratory muscle strength

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Conclusion