Respiratory Department, Sydney Children's Hospital, Randwick, NSW, Australia.
School of Women's and Children's Health, University of New South Wales, Sydney Children's Hospital, Randwick, NSW, Australia.
Exp Physiol. 2019 May;104(5):755-764. doi: 10.1113/EP087441. Epub 2019 Mar 20.
What is the central question of this study? Recent studies have suggested potential utility of non-normalized respiratory muscle EMG as an index of neural respiratory drive (NRD). Whether NRD measured using non-normalized surface EMG of the lateral chest wall overlying the diaphragm (sEMGcw) recorded during nocturnal clinical polysomnography can differentiate children with and without obstructive sleep apnoea (OSA) is not known. What is the main finding and its importance? Non-normalized sEMGcw was increased in children with OSA and an additional group of snoring children without OSA but subjectively increased respiratory effort compared with primary snorers. The sEMGcw has potential clinical utility in evaluation of children with sleep-disordered breathing as an objective, non-invasive, non-volitional marker of NRD.
Our aim was to investigate whether neural respiratory drive measured by non-normalized surface EMG recorded from the chest wall overlying the diaphragm (sEMGcw) differentiates children with and without obstructive sleep apnoea (OSA). Polysomnography data of children aged 0-18 years were divided into the following three groups: (i) primary snorers (PS); (ii) snoring children without OSA but with increased work of breathing (incWOB; subjective physician report of increased respiratory effort during sleep); and (iii) children with OSA [obstructive apnoea-hypopnoea index (OAHI) >1 h ]. Excerpts of sEMGcw obtained during tidal unobstructed breathing from light, deep and rapid eye movement sleep were exported for quantitative analysis. Overnight polysomnography data from 45 PS [median age 4.4 years (interquartile range 3.0-7.7 years), OAHI 0 h (0.0-0.2 h )], 19 children with incWOB [age 2.8 years (2.4-5.7 years), OAHI 0.1 h (0.0-0.4 h )] and 27 children with OSA [age 3.6 years (2.6-6.2 years), OAHI 3.7 h (2.3-6.9 h )] were analysed. The sEMGcw was higher in those with OSA [8.47 μV (5.98-13.07 μV); P < 0.0001] and incWOB [8.97 μV (5.94-13.43 μV); P < 0.001] compared with PS [4.633 μV (2.98-6.76 μV)]. There was no significant difference in the sEMGcw between children with incWOB and OSA (P = 0.78). Log sEMGcw remained greater in children with OSA and incWOB compared with PS after age, body mass index centiles, sleep stages and sleep positions were included in the mixed linear models (P < 0.0001). The correlation between sEMGcw and OAHI in children without OSA was small (r = 0.254, P = 0.04). The sEMGcw is increased in children with OSA and incWOB compared with PS.
本研究的核心问题是什么？最近的研究表明，非规范化呼吸肌肌电图作为神经呼吸驱动（NRD）的指标可能具有潜在的效用。在夜间临床多导睡眠图记录中，膈上侧胸壁的非规范化表面肌电图（sEMGcw）测量的 NRD 是否可以区分有无阻塞性睡眠呼吸暂停（OSA）的儿童尚不清楚。主要发现及其重要性是什么？与原发性打鼾者相比，OSA 患儿和另一组无 OSA 但呼吸努力增加的打鼾患儿的非规范化 sEMGcw 增加。sEMGcw 在评估睡眠呼吸障碍儿童方面具有潜在的临床应用价值，作为 NRD 的客观、非侵入性、非自主标志物。
我们旨在研究通过记录膈上侧胸壁的非规范化表面肌电图（sEMGcw）测量的神经呼吸驱动是否可以区分有无阻塞性睡眠呼吸暂停（OSA）的儿童。将 0-18 岁儿童的多导睡眠图数据分为以下三组：（i）原发性打鼾者（PS）；（ii）无 OSA 但呼吸努力增加的打鼾儿童（incWOB；医生报告睡眠时呼吸努力增加）；和（iii）OSA 患儿[阻塞性呼吸暂停-低通气指数（OAHI）>1 h]。从浅、深和快速眼动睡眠的无阻塞性呼吸中提取 sEMGcw 片段进行定量分析。分析了 45 例 PS [中位年龄 4.4 岁（四分位距 3.0-7.7 岁），OAHI 0 h（0.0-0.2 h）]、19 例 incWOB 儿童[年龄 2.8 岁（2.4-5.7 岁），OAHI 0.1 h（0.0-0.4 h）]和 27 例 OSA 患儿[年龄 3.6 岁（2.6-6.2 岁），OAHI 3.7 h（2.3-6.9 h）]的整夜多导睡眠图数据。与 PS 相比，OSA [8.47 μV（5.98-13.07 μV）；P <0.0001]和 incWOB [8.97 μV（5.94-13.43 μV）；P <0.001]患儿的 sEMGcw 更高。与 PS 相比，incWOB [8.97 μV（5.94-13.43 μV）；P <0.001]和 OSA [8.47 μV（5.98-13.07 μV）]患儿的 sEMGcw 更高。与 OSA 患儿相比，incWOB 患儿的 sEMGcw 无显著差异（P = 0.78）。在将年龄、体重指数百分位数、睡眠阶段和睡眠体位纳入混合线性模型后，OSA 和 incWOB 患儿的 sEMGcw 仍然大于 PS [P <0.0001]。无 OSA 儿童的 sEMGcw 与 OAHI 之间的相关性较小（r = 0.254，P = 0.04）。与 PS 相比，OSA 和 incWOB 患儿的 sEMGcw 增加。
