Table 2. Changes in Peff with sleep stage and body position during CPAP upward and downward titration.
| Sleep variable | n | Peff, cm H2O | ΔPeff | p | AHI in Peff | p |
|---|---|---|---|---|---|---|
| CPAP upward titration | ||||||
| REM | 22 | 9.5±2.9 | 0.6±1.1 | 0.024 | 2.0±3.2 | n.s. |
| Non-REM | 22 | 8.9±2.7 | 1.2±2.0 | |||
| Supine | 4 | 9.4±3.0 | 2.0±2.2 | 0.109 | 2.2±3.9 | n.s. |
| Lateral | 4 | 7.0±3.6 | 2.7±4.1 | |||
| CPAP downward titration | ||||||
| REM | 22 | 7.4±3.3 | 0.0±1.7 | 0.903 | 1.4±2.4 | n.s. |
| Non-REM | 22 | 7.4±3.0 | 2.0±2.6 | |||
| Supine | 4 | 7.3±1.7 | 2.5±1.3 | 0.068 | 2.7±3.8 | n.s. |
| Lateral | 4 | 4.8±1.5 | 2.0±3.2 |
Data are mean±SD values.
AHI: apnea-hypopnea index, CPAP: continuous positive airway pressure, n.s.: not significant, Peff: effective pressure, REM: rapid eye movement.