Effect of ventilatory support pressure during exercise on endurance time in patients with COPD: a systematic review.

Rationale Noninvasive ventilation during exercise has been proposed to improve exercise tolerance in patients with COPD. However, the influence of fixed pressure support intensity on endurance performance and exercise-related physiological responses remains insufficiently clarified.

Materials and methods: A systematic review and meta-analysis were conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO CRD420251018584). Randomised controlled and crossover trials evaluating noninvasive ventilation delivered in fixed pressure support mode during exercise were included. Random-effects models were applied to pool standardised mean differences (SMD). Mixed-effects meta-regression analyses assessed the association between pressure support level and outcomes. The primary outcome was endurance time. Secondary outcomes included dyspnoea (modified Borg scale) and hypercapnia.

Results: A total of 15 studies (285 participants) were included. Noninvasive ventilation significantly improved endurance time compared with control conditions (SMD 0.47, 95% CI 0.20 to 0.73). Pressure support intensity was not significantly associated with endurance time (β=0.0345 per cmH 2 O, p=0.25). Dyspnoea was significantly reduced in pooled analysis (SMD -0.50, 95% CI -0.92 to -0.08) and showed a significant dose-response relationship with pressure support (β= -0.0880 per cmH 2 O, p=0.019). Carbon dioxide tension was significantly reduced with noninvasive ventilation (SMD -0.48, 95% CI -0.92 to -0.04, I 2 =68.2%), with a pressure-dependent reduction observed when post-exercise measurements were excluded (β= -0.1055 per cmH 2 O, p=0.033).

Conclusion: Noninvasive ventilation during exercise improves endurance and dyspnoea in COPD. Pressure support intensity influences ventilatory unloading, but endurance performance appears multifactorial. Further standardised studies are needed to optimise pressure titration during exercise.