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New simple devices are available that allow a continuous noninvasive monitoring of CO 2. 11– 13 The diagnosis of alveolar hypoventilation requires the recording of pulse oximetry (S pO 2) or transcutaneous oxygen (P tcO 2) and transcutaneous carbon dioxide (P tcCO 2) or exhaled CO 2. 10, 11 Even if it is admitted that actigraphy provides only a fair indication of the level of arousal from sleep in children, by identifying mainly arousals accompanied by movements, and that the fragmentation index from this technique is not as accurate as the traditional sleep fragmentation measured on PSG, the simplicity of its use may be helpful to evaluate sleep quality outside the sleep laboratory. Actigraphy has been shown to give an acceptable estimation for sleep efficiency and number of awakenings in adults 8, 9 and children. One of these alternatives is actigraphy, which consists of wrist movement recording by a piezoelectric accelerometer. Simpler alternative investigations are thus necessary for the recording of sleep characteristics of larger populations. PSG is time consuming, expensive, technically demanding, and not feasible on a routine basis. 1 As such, the deleterious consequences of OSA have been mainly correlated to this index, and to a lesser extent to gas exchange anomalies. Polysomnography (PSG) is widely accepted as the gold standard for the diagnosis of OSA, and the apnea-hypopnea index is generally used for the quantification of OSA severity. 4– 7 However, sleep quality has been poorly studied in these patients, and, in particular, the correlation between nocturnal gas exchange and sleep efficiency during spontaneous breathing and NIV. The demonstration of nocturnal hypoxia and hypercapnia in these patients constitutes an indication for noninvasive ventilation (NIV), which aims to normalize alveolar ventilation.
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2, 3 The most severe OSA events may be accompanied by nocturnal desaturations and periods of alveolar hypoventilation with hypercapnia.Ĭhildren with neuromuscular or lung disease may present with periods of alveolar hypoventilation during sleep in the absence of obstructive events. During an apnea, slowing of the heart rate may occur, with an acceleration of heart rate during the arousal, due to the activation of the sympathetic nervous system. Obstructive apneas are often followed by an arousal, leading to sleep fragmentation and poor sleep quality. 1 Its main cause is hypertrophy of the adenoids and the tonsils. Obstructive sleep apnea (OSA) is a common disorder in children, characterized by repetitive episodes of upper airway narrowing and breathing pauses.