Longer respiratory events in childhood obstructive sleep apnea syndrome constitute a trait of older children with excessive daytime sleepiness

Figures

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  Fig. 1. Relationship between arterial desaturation and alveolar PO2 in NREM sleep. Arterial desaturation was characterized by the slope (%.s−1) of linear decrease in SpO2 during an isolated apnea in NREM sleep. End-Tidal PO2 (PETO2) was measured during measurement of tidal ventilation during wakefulness allowing to compute loop gain.

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  Fig. 2. Relationships between MAD and both clinical or endotypic characteristics. Mean apnea-hypopnea duration (MAD) of both NREM and REM sleep (MAD) was calculated from the whole polysomnography. The upper left panel A describes its relationship with age, the lower left panel C describes its relationship with excessive daytime sleepiness (Epworth score), the right upper panel B describes its relationship with medium-frequency plant gain and the lower right panel D describes its relationship with medium-frequency controller gain.

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  Fig. 3. Relationships between MAD and HRV indices. Mean apnea-hypopnea duration (MAD) of both NREM and REM sleep (MAD) was calculated from the whole polysomnography. HRV indices were obtained from the whole night. The upper left panel A describes its relationship with RMSSD (an index of parasympathetic modulation), the lower left panel C describes its relationship with SD1 (an index of parasympathetic modulation), the right upper panel B describes its relationship with the fractal dimension (Katz index, higher values indicate greater dynamical complexity) and the lower right panel D describes its relationship with Lyapunov exponent (higher values indicate lower predictability, or higher chaos).