Measurement of snoring and stertor using the Sonomat to assess effectiveness of upper airway surgery in children

Study Objectives: The success of surgical treatment for pediatric sleep-disordered breathing is typically assessed using the mixed and obstructive apnea-hypopnea index (MOAHI). Although an important metric, previous work has shown that snoring and stertor are also associated with sleep disruption. Our aim was to assess the efficacy of surgery using the Sonomat (Sonomedical Pty Ltd), a noncontact sleep assessment system, that accurately records complete and partial upper airway obstruction. Methods: Forty children (< 18 years) had a Sonomat study, in their own beds, before and after surgery. As an MOAHI >= 1 event/h is considered abnormal, the same threshold was applied to snore/stertor runs. Median (interquartile range) values are reported. Results: Respiratory event-induced movements decreased from 12.0 (8.7-19.0) to 0.5 (0.1-3.2) events/h (P <.01), with no significant change in spontaneous movements: 12.8 (9.8-17.9) to 16.5 (13.7-26.1) events/ h (P =.07). The MOAHI decreased from 4.5 (1.9-8.6) to 0.0 (0.0-0.4) events/h (P <.01). Snoring and/ or stertor runs decreased from 32.8 (23.4-44.4) to 3.0 (0.2-14.6) events/h (P <.01). Thirty-four children had an MOAHI < 1 event/h following surgery; however, 20 had snore and/or stertor runs = 1 event/h and 11 had snore and/or stertor runs >= 5 events/h. Only 14 (35%) children had a postsurgery MOAHI < 1 event/h combined with snoring and/or stertor < 1 runs/h. Conclusions: Although surgery is effective in improving breathing, success rates are overestimated using the MOAHI. Our results indicate that snoring and/or stertor are still present at levels that may disrupt sleep despite a normalization of the MOAHI and that when obstructed breathing was objectively measured, there was a large variation in its response to surgery.