Polysomnographic studies in children with adenotonsillar hypertrophy and suspected obstructive sleep apnea.

Upper airway obstruction causes many sleep-related respiratory disorders that can culminate in obstructive sleep apnea syndrome (OSAS). Polysomnography is routinely used to define OSAS in adults, but problems remain in diagnosing children by this method. The current study was designed to analyze the polysomnographic patterns in children with symptomatic adenotonsillar hypertrophy and to determine whether obstructive respiratory events shorter than 10 sec could have pathophysiological significance. Furthermore, we analyzed the correlation between clinical data on children with adenotonsillar hypertrophy and polysomnographic findings. Twelve children (mean age, 4.5 +/- 1.5 years) with airflow obstruction due to adenotonsillar hypertrophy were observed in our Sleep Laboratory. Prior to study, a questionnaire was used to score symptom severity. Overnight polysomnography was then performed to measure total sleep time, sleep efficiency, desaturation index, minimal arterial oxygen saturation (SaO2), apneahypopnea (AH) episodes < or = 5 sec and those > or = 10 sec, and AH index, AH percentage of total test time, and number of spontaneous and respiratory event-associated desaturations were recorded. Respiratory events of 5 sec or longer resulted in increases in the AH index and an increase in the number of oxyhemoglobin desaturations due to respiratory events. A significant relationship was found between the AH index and AH episodes > or = 5 sec and > or = 10 sec. There was, however, no association between polysomnographic parameters and symptom severity scores. An appraisal of AH recordings > or = 10 sec showed that desaturation episodes were more frequent than respiratory events, and the desaturation index was closely related to spontaneous and respiratory event-associated desaturations. When considering all obstructive episodes > or = 5 sec, the number of desaturations did not exceed the number of respiratory events. The correlation between the desaturation index and spontaneous or respiratory event associated desaturations was similar. The occurrence of short AH episodes that lead to hemoglobin desaturation are important in the evaluation of OSAS in children.