Perceptions of Noninvasive Ventilation During Exercise in Noninvasive Ventilation-Naïve Patients With COPD.

BACKGROUND: The perceptions of using noninvasive ventilation (NIV) during exercise in patients with COPD who are naïve to NIV is unknown. The present study aimed to examine the perceptions of using NIV during exercise in people with COPD and to determine the relationship between patient perceptions with both baseline patient characteristics and exercise outcomes. METHODS: During a trial examining the effect of NIV during exercise on dynamic hyperinflation in people with COPD who were naïve to NIV, participants completed a 5-point Likert scale questionnaire (scored strongly disagree -2 to strongly agree +2) before and after using NIV during exercise and a semi-structured interview after using NIV during exercise. RESULTS: Eighteen participants, mean age (SD) 69 (7) y, FEV1/FVC 0.44 (0.08), FEV1 39 (7)% predicted, completed the study. Prior to exercise with NIV, participants were neutral about NIV, (mean [SD]) (0.67[0.84]). After exercise with NIV, participants felt that NIV made breathing easier (1.00 [0.77]) and that it helped exercise (1.06 [0.64]). There were moderate correlations between feeling that NIV was comfortable or effective and a change in exercise endurance time (ρ = - 0.588, P = .02), isotime inspiratory capacity (ρ = 0.488, P = .03), and measures of resting hyperinflation (ρ = 0.603, \P = .02). Interviews revealed that despite feeling comfortable using NIV during exercise, NIV might be too complicated for patients to manage outside a supervised environment. CONCLUSIONS: Individuals with COPD, naïve to NIV, and using NIV during exercise for the first time reported a positive effect of NIV on breathlessness and exercise performance. Participants' perceived benefit of NIV correlated moderately with increased endurance time and resting hyperinflation and with a reduction in dynamic hyperinflation during exercise, suggesting that patient reports could also aid selection of those who will benefit from NIV during exercise.

Bilevel Noninvasive Ventilation During Exercise Reduces Dynamic Hyperinflation and Improves Cycle Endurance Time in Severe to Very Severe COPD.

BACKGROUND: During exercise, dynamic hyperinflation (DH), measured by a reduction in inspiratory capacity (IC), increases exertional dyspnea and reduces functional capacity in many patients with severe COPD. Although noninvasive ventilation (NIV) during exercise can improve exercise duration, the effect on DH is unclear. RESEARCH QUESTIONS: In people with COPD, resting hyperinflation, and evidence of DH during exercise, does bilevel NIV during exercise reduce DH and increase endurance time compared with exercise with no NIV, and does NIV with an individually titrated expiratory positive airway pressure (T-EPAP) reduce DH and increase exercise endurance time more than NIV with standardized EPAP (S-EPAP) of 5 cm H2O? STUDY DESIGN AND METHODS: A randomized crossover trial in which investigators and participants were blinded between NIV interventions was performed. Participants (N = 19; FEV1 of 1.02 ± 0.24 L (39% ± 6% predicted) completed three constant work rate endurance cycle tests in random order-no NIV, NIV with S-EPAP, and NIV with T-EPAP-during exercise. Primary outcomes were isotime IC and exercise endurance time. Outcome measures from each intervention were compared at isotime and at end exercise by using a linear mixed-model analysis. RESULTS: Compared with no NIV, isotime IC and endurance time were greater with both NIV with S-EPAP (mean difference: 95% CI, 0.19 L [0.10-0.28]; 95% CI, 153 s [24-280], respectively) and T-EPAP (95% CI, 0.22 L [0.13-0.32]; 95% CI, 145 s [28-259], respectively). There was no difference between NIV with S-EPAP and NIV with T-EPAP. INTERPRETATION: In people with COPD and DH during exercise, NIV during exercise reduced DH and increased cycle endurance time. An S-EPAP of 5 cm H2O was adequate to obtain these benefits. TRIAL REGISTRY: Australian New Zealand Clinical Trials Registry; No.: ACTRN12613000804785; URL: http://www.anzctr.org.au.