Noninvasive Ventilation During Exercise in COPD Patients: A Systematic Review With Meta-analysis

Abstract

PURPOSE: COPD is a major cause of morbidity and mortality worldwide, representing a major public health problem due to the high health and economic resource consumption. Pulmonary rehabilitation is a standard care recommendation for these patients, in order to control the symptoms and optimize the functional capacity, reducing healthcare costs associated with exacerbations and activity limitations and participation. However, in patients with severe COPD exercise performance can be difficult, due to extreme dyspnea, decreased muscle strength and fatigue. In addition, hypoxemia and dyspnea during efforts and daily activities may occur, limiting their quality of life. Thus, NIV have been used as adjunct to exercise, in order to improve exercise capacity in these patients. However, there is no consensus for this technique recommendation. Our objective was to verify whether the use of NIV during exercise is effective than exercise without NIV in dyspnea, walked distance, blood gases and health status in COPD patients, through a systematic review and meta-analysis. METHODS: A systematic search for RCT published between 2002 and 2012 was performed in MEDLINE, PEDro, Cochrane, Science Direct and B-On databases, with "NIV", "Exercise", "Exercise training" and "COPD" as key-words. Only studies associating NIV and exercise in COPD population, accessing 6MWT, SGRQ, ABG or SpO2 were included. We used descriptive statistics and the "comprehensive meta analisys version 2.0" software for meta-analysis. RESULTS: From 208 identified randomized controlled trials, only 7 were included. Of these, only 4 allowed the metaanalysis for PaCO2 and dyspnea. 6 of the 7 studies indicated the benefit of NIV compared to the control group. CONCLUSIONS: We verified a positive influence of NIV during exercise, both in terms of acute and chronic responses to exercise in patients either hypercapnic and normocapnic, regardless of conducting training programs of exercise.