Room air | PET,CO2 5 mmHg above baseline | PET,CO2 10 mmHg above baseline | ||||
Pentobarbital | Placebo | Pentobarbital | Placebo | Pentobarbital | Placebo | |
Upper airway resistance cmH2O·L−1·s | 6.4±8.5+ | 2.3±2.5 | 7.0±11.1 | 2.7±2.1 | 9.4±16§,ƒ | 3.3±3.2§ |
V′E L·min−1 | 6.0±2.3 | 5.3±1 | 9.6±3.8 | 7.9±2.5 | 12.1±6.5§ | 12.1±3.5§ |
VT L·min−1 | 0.41±0.15 | 0.37±0.07 | 0.61±0.19 | 0.53±0.17 | 0.87±0.33§ | 0.79±2.4§ |
Duty cycle# | 0.43±0.13 | 0.41±0.04 | 0.44±0.23 | 0.42±0.05 | 0.50±0.30 | 0.42±0.03 |
Flow rate¶ mL·s−1 | 0.27±0.08 | 0.27±0.05 | 0.38±0.10 | 0.36±0.08 | 0.52±0.22§ | 0.53±0.15§ |
Phasic GG-EMG activity % max | 4.6±7.9 | 2.1±4.9 | 5.8±9.9 | 2.1±1.9 | 14±24ƒ,## | 3.3±7.7 |
Tonic GG-EMG activity % max | 2.4±6.3 | 0.64±2.2 | 3.8±10.4 | 0.8±3.8 | 5.2±13.8## | 1.0±3.4 |
Data are presented as mean±sd. PET,CO2: end-tidal carbon dioxide tension; V′E: minute ventilation; VT: tidal volume; GG-EMG: genionglossus electromyogram. #: measured as time taken for inspiration (tI)/total time of respiratory cycle; ¶: measured as VT/tI. +: p<0.05 for drug effect, i.e., higher GG-EMG during pentobarbital versus placebo (all GG-EMG data during carbon dioxide insufflation, general linear model (mixed model)), §: p<0.05 versus placebo treatment (Wilcoxon); ƒ: p<0.05 versus baseline, same study day; ##: p<0.1 versus placebo treatment.