Abstract
The interactions between inspiratory neural drive (IND) and inspiratory muscle activity during sleep in COPD are poorly understood. We compared diaphragmatic electromyography (EMGdi) and respiratory mechanics during supine wakefulness (W) and sleep (rapid eye movement, REM; and non-REM stage 2, N2) in COPD and health.
Patients with COPD (n=20; FRC 147.1±31.5%pr; post-BD FEV1 55.7±15.9%pr) and age-matched healthy controls (CTRL, n=20) completed overnight polysomnography with EMGdi(%max), tidal esophageal (Pes,%max), gastric (Pga,%max) and transdiaphragmatic pressure (Pdi,%max) measurement during stable breathing in W, N2 and REM at equivalent time-points.
EMGdi, Pdi, and Pes were consistently higher in COPD vs CTRL (+167-234%; p<0.05) in W, N2 and REM, but Pga did not differ between groups. EMGdi, Pdi, and Pes were unchanged by wake-sleep transitions in CTRL. In COPD, EMGdi fell 42% and 37% from W-N2 and W-REM, respectively (p<0.05), but Pdi, Pes, and Pga were unchanged. Neuromuscular efficiency (EMGdi : Pdi & Pes) was similar between CTRL and COPD and decreased from W to sleep.
IND and inspiratory muscle activity were elevated in COPD vs CTRL in wake and sleep. Despite this marked mechanical disadvantage in COPD, high diaphragmatic and total inspiratory effort were maintained during sleep even through IND declined sharply. This suggests additional activation of accessory muscles of inspiration during both REM and N2 sleep.
Footnotes
Cite this article as: European Respiratory Journal 2020; 56: Suppl. 64, 4995.
This abstract was presented at the 2020 ERS International Congress, in session “Respiratory viruses in the "pre COVID-19" era”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2020
