Training with inspiratory pressure support in patients with severe COPD.
This study evaluates the effects of training with noninvasive ventilatory support in patients with chronic obstructive pulmonary disease in a randomised, controlled, observer-blinded trial. Twenty-nine patients with chronic obstructive pulmonary disease and with a ventilatory limited exercise capacity (forced expiratory volume in one second < 60% predicted, breathing reserve at maximal exercise < 20% of maximally voluntary ventilation, resting arterial oxygen tension > or = 8 kPa (60 mmHg), end-exercise arterial oxygen saturation measured by pulse oximetry > or = 85%) completed an 8-week supervised outpatient cycle exercise programme. Fourteen patients were randomised to training with inspiratory pressure support of 10 cmH2O and 15 patients to training with control (sham) inspiratory pressure support of 5 cmH2O. Outcome measures were the incremental shuttle walking test and a constant-load cycle endurance test at 75% of peak work rate including the measurement of physiological responses, and health status measured using the St. George's Respiratory Questionnaire. Statistically significant between-group differences were found in favour of the inspiratory pressure support of 10 cmH2O group for improvement in shuttle walking distance (16+/-17 versus 3+/-13%), cycle endurance (164+/-124 versus 88+/-128%), and the reduction in minute ventilation during exercise (-11+/-10 versus -2+/-9%). It was concluded that exercise training with inspiratory pressure support of 10 cmH2O resulted in statistically significantly larger improvements in exercise performance than training with inspiratory pressure support of 5 cmH2O in patients with chronic obstructive pulmonary disease suffering from a ventilatory limited exercise capacity. Inspiratory pressure support of 10 cmH2O may be considered as adjunct during high-intensity exercise training.