西村 洋一

幼小児期の閉塞性睡眠時無呼吸症候群 (Obstructive Sleep Apnea Syndrome以下OSAS) はこれまで様々な診断基準があり統一されていなかったが, 2005年に初めてICSD2 (International Classification of Sleep Disorders 2nd)¹ により診断基準が提唱され, 小児においてもPSG (Polysomnography) 検査が標準化された. 今回我々はそれに沿って診断された幼小児睡眠時無呼吸症候群についての年齢, 身体発育 (体格), 無呼吸低呼吸指数 (AHI: Apnea Hypopnea Index), 重症度分類, 低酸素暴露率 (DR: Desaturatuin Rate), 術後の改善度, 睡眠構築の変化について検討を行なった. 症例は男児, 重症例が多く, 手術 (咽頭扁桃切除術, 両側口蓋扁桃摘出術) の後にPSG検査を施行できた症例については, 呼吸イベントは改善傾向を示したものの依然全例がAHI≥1であった. PSG検査を行なった6例中4例で深 (徐波) 睡眠の割合が手術前より増えていた. 術後の身体の成長改善の兆しは深睡眠の増加に伴うものと推測した.

Obstructive Sleep Apnea Syndrome (OSAS) is the condition of complete (Apnea) or partial (hypopnea) airway collapse during sleep. The cardinal daytime symptoms are excessive daytime sleepiness and non- rejuvenating sleep due to recurrent arousals and interrupted sleep caused by intermittent hypoxia and hypercapnia. OSAS is sometimes associated with serious cardiovascular complications, hypertension, stroke and abnormal glucose metabolism. The primary location of airway collapse is in the pharyngeal area, involving the tonsils, soft palate, and tongue base; all of which lay within the ENT specialty. The larynx is not usually a common site for collapse during sleep because of its rigid cartilaginous framework. In our department, the site of collapse is usually investigated through endoscopic examination during drug induced sleep. In the course of endoscopic examinations, a transient collapse in the laryngeal supraglottic structures is sometimes noticed. Nasal continuous positive airway pressure (CPAP) is considered the gold standard therapy for OSAS. For various reasons surgery is recommended as the primary treatment for patients experiencing OSAS due to the collapse of laryngeal supraglottic structures. Patients with mild to moderate OSAS and a corresponding AHI (apnea hypopnea index) less than 20 are restricted by the Japanese insurance system to be treated with CPAP. Another reason is the possibility of serious airway obstruction in that region if an infection and superimposed edema were to occur. <BR>In this paper we discuss the surgical procedure which is done in our department for patients with OSAS when the main site of obstruction is in the larynx or in laryngeal surrounding tissues.