Table 2.
Muscle Activity, Lung Volume, and Ventilatory Parameters During Stable Stage 2, Stable SWS, and in All Stage 2 Sleep (Cyclical and Stable Breathing Combined)
| Stable Stage 2 | Slow Wave Sleep | All stage 2 | |
|---|---|---|---|
| EMGGG Peak (% total activity) | 99 ± 3.2 | 109.7 ± 4.1 | 91.4 ± 1.9* |
| EMGGG Tonic (% total activity) | 98.5 ± 3.4 | 105.5 ± 6.2 | 96.1 ± 3.1 |
| EMGTP (% total activity) | 86.9 ± 6.9 | 92.0 ± 17.1 | 121.1 ± 19.2 |
| EELV (mL change from wake) | −24.2 ± 144.2 | −161.6 ± 105.3 | −82.9 ± 87.6 |
| VT (L) | 0.40 ± 0.06* | 0.38 ± 0.06 | 0.36 ± 0.06 |
| FB (breaths/min) | 16.4 ± 0.7 | 16.9 ± 0.7 | 16.3 ± 0.7 |
| VI (L/min) | 6.2 ± 0.8 | 6.1 ± 0.7 | 5.7 ± 0.8 |
| VT/TI (L/sec) | 0.24 ± 0.03* | 0.22 ± 0.03 | 0.21 ± 0.04 |
| PEPI (cm H2O) | −18.1 ± 2.5* | −21.8 ± 2.9 | −17.2 ± 1.7* |
| PETCO2 (mm Hg) | 42.5 ± 1.5 | 42.4 ± 1.7 | n/a |
Definitions of abbreviations: EMGGG = genioglossus muscle activity; EMGTP = tensor palatini muscle activity (both expressed as a % of the average level across all conditions); EELV = end-expiratory lung volume; VT = tidal volume; FB = Frequency of breathing; VI = inspired minute ventilation; VT/TI = mean inspiratory flow; PEPI = minimum epiglottic pressure during inspiration; PETCO2 = end tidal partial pressure of carbon dioxide. PETCO2 is not given in all stage 2 sleep because it can not accurately be measured during apneas/hypopneas. Means ± SEM,
*
P < 0.05 compared to SWS.