RT Journal Article
SR Electronic
T1 Effects of inspiratory muscle training on exertional breathlessness in patients with unilateral diaphragm dysfunction: a randomised trial
JF ERJ Open Research
JO erjor
FD European Respiratory Society
SP 00300-2023
DO 10.1183/23120541.00300-2023
VO 9
IS 5
A1 Schaeffer, Michele R.
A1 Louvaris, Zafeiris
A1 Rodrigues, Antenor
A1 Poddighe, Diego
A1 Gayan-Ramirez, Ghislaine
A1 Gojevic, Tin
A1 Geerts, Linde
A1 Heyndrickx, Elise
A1 Van Hollebeke, Marine
A1 Janssens, Luc
A1 Gosselink, Rik
A1 Testelmans, Dries
A1 Langer, Daniel
YR 2023
UL http://openres.ersjournals.com/content/9/5/00300-2023.abstract
AB Background Unilateral diaphragm dysfunction (UDD) is an underdiagnosed cause of dyspnoea. Inspiratory muscle training (IMT) is the only conservative treatment for UDD, but the mechanisms of improvement are unknown. We characterised the effects of IMT on dyspnoea, exercise tolerance and respiratory muscle function in people with UDD.Methods 15 people with UDD (73% male, 61±8 years) were randomised to 6 months of IMT (50% maximal inspiratory mouth pressure (PI,max), n=10) or sham training (10% PI,max, n=5) (30 breaths twice per day). UDD was confirmed by phrenic nerve stimulation and persisted throughout the training period. Symptoms were assessed by the transitional dyspnoea index (TDI) and exercise tolerance by constant-load cycle tests performed pre- and post-training. Oesophageal (Pes) and gastric (Pga) pressures were measured with a dual-balloon catheter. Electromyography (EMG) and oxygenation (near-infrared spectroscopy) of respiratory muscles were assessed continuously during exercise.Results The IMT group (from 45±6 to 62±23% PI,max) and sham group (no progression) completed 92 and 86% of prescribed sessions, respectively. PI,max, TDI scores and cycle endurance time improved significantly more after IMT versus sham (mean between-group differences: 28 (95% CI 13–28) cmH2O, 3.0 (95% CI 0.9–5.1) points and 6.0 (95% CI 0.4–11.5) min, respectively). During exercise at iso-time, Pes, Pga and EMG of the scalene muscles were reduced and the oxygen saturation indices of the scalene and abdominal muscles were higher post- versus pre-training only in the IMT group (all p<0.05).Conclusion The effects of IMT on dyspnoea and exercise tolerance in UDD were not mediated by an improvement in isolated diaphragm function, but may reflect improvements in strength, coordination and/or oxygenation of the extra-diaphragmatic respiratory muscles.Inspiratory muscle training is a well-tolerated conservative treatment option for people with unilateral diaphragm dysfunction that yields meaningful benefits in activity-related dyspnoea and exercise tolerance. https://bit.ly/3PhCS0a