[Comparison and intervention of differences in upper airway obstruction in children with OSAS between awake and asleep]

Objective:Drug induced sleep endoscopy（DISE） is a useful tool to locate the upper airway obstructions in patients with obstructive sleep apnea syndrome（OSAS）. The goal of our research was to compare the sites, degree and patterns of upper airway obstruction detected by DISE versus endoscopy in awake children. The benefit of DISE-mediated upper airway surgery in pediatric OSAS was evaluated. Method:This is a retrospective case series of children with OSAS who had adenoid hypertrophy（the area where adenoids block the postnaris ≥2/3） and tonsils ≤2 degrees（Friedman classification method） . All children underwent sleep monitoring by pulse oximeter before and after operation. DISE was performed before adenoidectomy in DISE group. If obstruction of oropharynx caused by tonsils was found, tonsillectomy was performed at the same time with adenoidectomy. The children who did not undergo DISE before operation were enrolled in the control group. Differences in the degrees and patterns of upper airway obstruction in the DISE group under wakefulness and drug induction were analyzed. Result:The study included 126 children in DISE group, and 200 children in control group. In the DISE group, 56 cases（44.4%） had grade 2 tonsils, and 70 cases（55.6%） had grade 1 tonsils. The patterns of obstruction at velum, tongue base and epiglottis were significantly different in DISE compared with awake endoscopy（P<0.05）; the patterns of obstruction at adenoid and oropharynx were the same in both techniques. There were significant differences in endoscopy scores between the lateral wall of oropharynx and the tongue base（P<0.05）. DISE revealed 57 （45.2%） cases had grade 2 obstruction in the oropharyngeal level. Among them, 44 cases （34.9%） had tonsils at 2 degrees and 13 cases （10.3%） had tonsils at 1 degrees.. There was an improvement in respiratory disturbance index（RDI） and oxygen saturation nadir in the DISE and control groups 1 year after surgery（P<0.05）, and the RDI improvement was better in the DISE group compared with controls（P=0.04）. Conclusion:DISE is an effective method to evaluate the sites and severity of upper airway obstruction in children with OSAS, which was conductive to make the upper airway personalized surgical plan for patients.