Nocturnal periodic breathing and transient respiratory events
| Children | Adults | |||||
| Baseline 490 m | 3450 m | Baseline 490 m | 3450 m | |||
| Day 1 | Day 2 | Day 1 | Day 2 | |||
| Subjects n | 20 | 19 | 17 | 20 | 19 | 19 |
| O2 desaturation index ≥4% per h TIB | 5.3±2.6 | 34.7±26.1+,§ | 36.0±31.9§ | 2.3±1.6 | 56.6±25.7§ | 43.2±26.9¶,§ |
| Drop in Sp,O2 during desaturations % | NA | 9±2 | 9±3 | NA | 8±2 | 7±2¶ |
| Minimal Sp,O2during desaturations % | NA | 81±4 | 81±4 | NA | 80±3 | 82±4¶ |
| AHI·h−1 TIB | 7.1±2.8 | 32.5±24.6+,§ | 32.5±26.8§ | 3.5±2.3 | 54.1±26.2§ | 39.5±23.9¶,§ |
| Time with periodic breathing % of TIB | 0±0 | 8±11+,§ | 9±13+,§ | 0±0 | 34±24§ | 22±17¶,§ |
| Cycle length s | NA | 17.0±2.1+ | 18.5±4.1+ | NA | 28.0±5.1 | 31.5±7.7 |
| Apnoea duration s | 8.5±1.5+ | 7.4±0.8+ | 7.9±0.9+ | 12.0±1.4 | 11.6±3.2 | 11.9±2.0 |
| Hyperpnoea duration s | NA | 9.4±2.0+ | 10.5±4.1+ | NA | 16.5±5.5 | 19.7±8.1 |
| CO2 apnoea threshold mmHg | NA | 27±2+ | 27±2+ | NA | 30±2 | 30±2 |
| CO2 reserve, ΔPET,CO2# mmHg | NA | 4.6±3.5+ | 6.4±3.1+ | NA | 1.7±2.5 | 1.2±1.4 |
| Circulation time s | NA | 11.8±1.2+ | 11.6±0.8+ | NA | 22.2±4.1 | 21.6±1.9 |
| Circulation time s/body height m | NA | 8.3±0.9+ | 8.1±0.7+ | NA | 12.4±2.2 | 12.0±0.9 |
| Sighs during TIB | 41±17 | 54±23+,§ | 42±26+ | 24±13 | 29±22 | 18±11 |
Data are presented as mean±sd, unless otherwise stated. TIB: time in bed; Sp,O2: O2 saturation by pulse oximetry; AHI: apnoea/hypopnoea index; ΔPET,CO2: change in end-tidal CO2 tension; NA: not applicable as no periodic breathing was detected. #: was calculated as the difference between eupnoeic PET,CO2 and the CO2 apnoea threshold. ¶: p<0.05 versus day 1; +: p<0.05 versus adults; §: p<0.05 versus 460 m.