Text Box: THE RELATIONSHIP STUDY OF THE SLEEP DISORDERED BREATHING AND THE NOCTURNAL ASTHMA IN CHILDREN
Cai X-H, Xie Y-P, Chen Y-F
Affiliated Children's Hospital, Wenzhou Medical College, Wenzhou, China

Objective: To explore the mechanism and cause of nocturnal asthma attacks.   
Methods: The sleep breathing was monitored in 14 asthmatic children with nocturnal attacks and 8 cases as control without attacks. The peak expiratory flow rates (PEFR) was recorded in three distinct periods that is on the day before sleep, getting up and 3 hours later of the next morning.
Results: The apnea hypoventilation index of the nocturnal asthma group was higher than that of control. Compared with the control, statistical significance also existed in items of the lowest SaO2, the time percentage of SaO2 below 90%, the time percentage of sleep phases and rapid eye movement and the arousal index. The PEFR before sleep was lower than that of getting up on the next morning in the nocturnal asthmatic group. 
Conclusion: obstructive sleep apnea syndrome, heavy snoring and sleep hypoxia is the main reason provoking nocturnal asthma attacks. The mechanism is associated with narrow upper airway, increased vagal tone and neural reflex causing bronchoconstriction. 



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