2 Polysomnographic characteristics of children with sleep-disordered breathing before and after tonsillectomy and adenoidectomy, and of matched controls
| Before | After | p-value | Control | p-value# | |
| Subjects n | 19 | 19 | 19 | ||
| Sleep efficiency % | 90.0±0.01 | 93.0±0.01 | 89.0±0.01 | ||
| Sleep latency min | 31.5±6.8 | 18.4±3.6 | 0.029 | 27.2±6.5 | |
| REM latency min | 84.3±9.7 | 76.6±4.0 | 81.5±9.1 | ||
| Awake %¶ | 6.7±1.1 | 7.4±1.0 | 10.6±1.4 | 0.033 | |
| Sleep stage %+ | |||||
| 1 | 5.9±0.74 | 4.9±0.32 | 5.6±0.70 | ||
| 2 | 45.6±2.0 | 43.2±1.1 | 38.8±1.8 | ||
| Delta | 23.5±1.5 | 28.8±1.5 | 0.014 | 29.9±1.3 | 0.010 |
| REM | 25.0±0.98 | 22.1±0.74 | 0.003 | 24.7±1.20 | |
| Total sleep time min | 473.8±9.11 | 487.6±8.53 | 467.3±8.58 | ||
| Spontaneous arousal index | 6.3±0.81 | 7.3±0.44 | 7.7±0.52 | ||
| Respiratory arousal index | 7.3±2.7 | 0.42±0.13 | 0.022 | 0.20±0.06 | 0.017 |
| Total arousal index | 14.5±2.5 | 8.0±0.23 | 0.014 | 8.3±0.52 | 0.033 |
| Apnoea/hypopnoea index | 10.1±2.9 | 1.0±0.23 | 0.006 | 0.6±0.19 | 0.004 |
| Apnoea index | 5.8±1.8 | 1.0±0.23 | 0.015 | 0.8±0.19 | 0.010 |
| Baseline Sp,O2 % | 97±0.46 | 98±0.23 | 98±0.23 | ||
| Sp,O2 nadir % | 82±2.8 | 92±0.91 | 0.004 | 94±0.69 | 0.001 |
Data are presented as mean±sem. REM: rapid eye movement; Sp,O2: arterial oxygen saturation measured by pulse oximetry. #: control versus pre-operative value; ¶: calculation based on time from lights out to lights on; +: calculation based on total sleep time.