The Effect of Adding Noninvasive Ventilation to Supplemental Oxygen During Exercise Training in Severe COPD: A Randomized Controlled Study

Abstract

PURPOSE: We evaluated the effects of non-invasive ventilation (NIV) and supplemental oxygen during exercise training (ET+NIV+O2), in comparison with supplemental oxygen exercise training (ET+O2) and exercise trainig (ET) alone groups on lung functions, blood gas analysis, lactate levels, respiratory muscle strength, dyspnea, exercise capacity, health status, anxiety and depression in patients with severe COPD. METHODS: 35 patients (mean age 65.4 +/- 6.5 yrs) with COPD (mean FEV1 39.4+/-7) were randomized to either (ET+NIV+O2) or (ET+O2) or (ET) alone. Patients underwent an exercise training (ET) for 8 weeks and NIV was carried out with oxygen during exercise training. RESULTS: The baseline inspiratory and expiratory pressures were 12.0+/-1.5 cmH20 and 5.1+/-0.8 cmH20, respectively. In ET+NIV+O2 group, residual volume and total lung capacity decreased significantly (-305.0+/-489.1 and -325.0+/-524.8, both p=0.05, respectively). No significant change was found in lung functions in ET+O2 patients. There were significant increases in Pimax and Pemax in ET+NIV+O2 group and there was an increase in only Pimax in ET patients. The decrease in blood lactate level was not significant. Dyspnea improved only in ET+O2 group (-2.4+/-2.7, p=0.005). The increase in walking distance was better in ET+NIV+O2 group than ET+O2 patients. Symptom domain of SGRQ was significantly decreased only in ET+NIV+O2 group (-21.8+18.9, p=0.002) and the total score of SGRQ was improved in ET+O2 group. There was an improvement in depression only in ET+NIV+O2 group (-2.8+2.8, p=0.006). CONCLUSIONS: The addition of NIV to oxygen during exercise training in patients with severe COPD patients reduces hyperinflation, improves respiratory muscle strength, exercise capacity, symptom domain of SGRQ and depression compared to ET+O2 and ET alone groups. CLINICAL IMPLICATIONS: Adding non-inavsive ventilation to oxygen during exercise training in patients with severe COPD patients is the best adjunct for improving dyspnea by reducing hyperinflation, respiratory muscle strength, exercise capacity, quality of life and depression. We recommend clinicians to use non-invasive ventilation during exercise training in severe COPD patients.