Effects of Expiratory Positive Airway Pressure on Dynamic Hyperinflation During Exercise in Patients With COPD

Relation of Exercise Capacity With Lung Volumes Before and After 6-Minute Walk Test in Subjects With COPD

“…Recently, 2 stud- 6MWD ϭ 6-min walk distance 6MWT ϭ 6-min walk test TLC ϭ total lung capacity FRC ϭ functional residual capacity RV ϭ residual volume IC ϭ inspiratory capacity IVC ϭ inspiratory vital capacity HR ϭ heart rate ies assessed TLC before and immediately after submaximal exercise using body plethysmography and reported an increase of 0.14 L (not significant) and 0.58 L (P Ͻ .05) in 17 and 20 subjects with COPD, respectively. 26,41 The experience gained from body plethysmography measurements after exercise in the present study and previous reports therefore warrants further and detailed studies on the effects of exercise on TLC in subjects with COPD. The current study was driven by the hypothesis that, due to the development of dynamic hyperinflation during exercise, end-exercise pulmonary function could be more closely related to exercise capacity than resting pulmonary function at baseline.…”

Effects of Expiratory Positive Airway Pressure on Dynamic Hyperinflation During Exercise in Patients With COPDThe Authors Respond:

“…I read the interesting study by Monteiro et al 1 However, I would like to point out the relevant findings by Cordoni et al 2 Monteiro et al reported 17 (37%) patients with COPD and substantial dynamic hyperinflation (DH) as defined by at least a 15% reduction from pre-exercise inspiratory capacity (IC). They concluded that the application of expiratory positive airway pressure (EPAP) reduced DH, as shown by lower operational lung volumes after submaximal exercise in COPD patients who previously manifested exercise DH.…”

“…They concluded that the application of expiratory positive airway pressure (EPAP) reduced DH, as shown by lower operational lung volumes after submaximal exercise in COPD patients who previously manifested exercise DH. 1 Cordoni et al evaluated 30 patients with COPD. 2 Nineteen (63.30%) patients had significant reduction in IC and were classified in the DH group, and 11 showed no reduction in IC or even had an increase in IC and were therefore included in the no-DH group.…”

Inspiratory Capacity as an Indirect Measure of Immediate Effects of Positive Expiratory Pressure and CPAP Breathing on Functional Residual Capacity in Healthy Subjects

“…[6][7][8][9] However, PEP and CPAP may also be used to decrease FRC in patients with hyperinflation, as in COPD. 10,11 Studies comparing effects of PEP and CPAP on FRC are few, have variable results, [12][13][14] and require methods that are difficult to use in clinical situations because they require advanced equipment.…”