Abstract: Objective To investigate the long-term efficacy of non-invasive ventilation in children with moderate to severe obstructive sleep apnea-hypopnea syndrome(OSAS), especially those with residual postoperative OSAS after tonsillectomy and/or adenoidectomy. Methods We conducted a follow-up study between October 2012 and October 2017 in children who were diagnosed with moderate to severe OSAS through polysomnography(PSG)and were treated with non-invasive positive pressure ventilation(NPPV). Most of them had underlying diseases or postoperative residual OSAS after tonsillectomy and/or adenoidectomy. Polysomnography was performed during non-invasive ventilatory support; pressure titration was performed manually in the sleep center, while the mode was chosen based on disease conditions in individual patients. Polysomnography data were recorded and compared between before and after treatment with NPPV. Patients who received NPPV support after discharge were examined at follow-up visits 3 and 6 months later, and every 6 months after that. Clinical symptoms and PSG parameters were monitored during therapy, and factors associated with compliance were evaluated. Results Thirty patients received non-invasive ventilation treatment through October 2017; 26 of them were boys. The average age was 7.2±3.7 years. Ventilation was stopped in 11(36.7%)children after discharge, while 19(63.3%)children received non-invasive ventilation at home. The apnea-hypopnea index(P<0.001), the lowest SpO₂(P<0.001), and the percentage of sleep time with the SpO₂<0.90(P<0.001)were improved in all children receiving NPPV treatment at the time of hospitalization. Most OSAS patients experienced relief from snoring and apnea and improvement in respiratory distress and daytime symptoms. However, there was no improvement in irritability and distraction after 6 months of treatment. Parental awareness of the importance of this disease(P=0.001), craniofacial malformation(P=0.008), and frequent sleep apnea or dyspnea before treatment(P=0.029)were associated with compliance with NPPV treatment. Conclusion Non-invasive ventilation therapy can be performed successfully in special pediatric populations. Long-term NPPV treatment can improve clinical symptoms considerably in children with moderate to severe OSAS, especially those with underlying diseases or residual OSAS after tonsillectomy and/or adenoidectomy. Education for parents about sleep-disordered breathing and reducing adverse reactions might improve compliance with NPPV treatment in children.

Key words: Sleep apnea, obstructive, Child, Follow-up study, Non-invasive positive pressure ventilation