Table 1

 Muscle activity and respiratory data during basal breathing and passive ventilation during wakefulness

Basal breathingPassive ventilationp ValueMean difference(95% CI)
DIAEMG, diaphragm electromyogram; GGEMG, genioglossus electromyogram; TPEMG, tensor palatini electromyogram; Ti, inspiratory time; Ti/Ttot, duty cycle; RR, respiratory rate; Vt, tidal volume; Ve, minute ventilation; Sao2, oxygen saturation; Petco2, end-tidal carbon dioxide tension.
*Average muscle activity of each breath.
†Wilcoxon signed rank test.
DIAEMG (% max)
    Peak12.0 (3.1)6.8 (1.6)*
    Tonic5.7 (1.2)
    Phasic6.2 (2.0)
GGEMG (% max)
    Peak5.3 (1.4)1.6 (0.4)*
    Tonic2.1 (0.5)
    Phasic3.2 (1.0)
TPEMG (% max)4.4 (2.2)*5.1 (2.2)*
Ti (s)1.6 (0.1)1.2 (0.1)<0.0010.4 (0.3 to 0.6)
Ti/Ttot0.42 (0.0)0.35 (0.0)<0.0010.08 (0.05 to 0.10)
RR (breaths/min)16.6 (0.8)17.7 (0.7)0.1481.1 (−0.7 to 3.0)
Vt (l)0.39 (0.0)0.43 (0.0)0.1370.04 (0.00 to 0.10)
Ve (l/min)6.3 (0.5)7.8 (0.6)0.0021.5 (0.8 to 2.2)
Sao2 (%)96.8 (0.2)97.4 (0.2)0.027†
Petco2 (mm Hg)42.3 (1.1)40.7 (0.5)0.1471.6 (−0.1 to 3.2)