Department of Otorhinolaryngology - Head & Neck Surgery, Kangdong Sacred Heart Hospital, Seoul, South Korea.
Department of Biomedical Engineering, School of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, South Korea.
Sleep Breath. 2021 Dec;25(4):2025-2038. doi: 10.1007/s11325-021-02334-y. Epub 2021 Mar 8.
Breath-by-breath tidal volume (TV) and beat-by-beat stroke volume (SV) were continuously measured in patients with OSA undergoing polysomnography (PSG). The objectives were to (1) determine the changes in TV/SV in response to respiratory events and (2) assess the relationship between these changes and the disease severity.
From the PSG data of nine patients with OSA, six different types of respiratory events were identified, i.e., flow limitation (FL), respiratory effort related arousal (RERA), hypopnea with arousal only (Ha), hypopnea with desaturation only (Hd), hypopnea with arousal and desaturation (Had), and apnea. The measured TV and SV values during and after each respiratory event were compared with the pre-event baseline values.
The mean TV/SV reductions during all hypopneas and apneas were 38.1%/4.2% and 70.5%/8.8%, respectively. Among three different hypopnea types, the reductions in TV during Hd and Had were significantly greater than those during Ha. The TV reductions during Ha and FL were similar. After RERA, Ha, Had, and apnea, there was an overshoot in TV and SV values, whereas there was no overshoot after FL and Hd. During RERA, there was no reduction in TV/SV.
The changes in TV during and after each type of respiratory event were significantly different in most cases. The changes in SV between hypopnea and apnea were different with statistical significance. The AHI does not properly account for the ventilation losses caused by respiratory events. Thus, TV measurements might be useful in the future in assessing the OSA severity in conjunction with the AHI.
在接受多导睡眠图（PSG）检查的阻塞性睡眠呼吸暂停（OSA）患者中，连续测量潮气容积（TV）和每搏量（SV）。目的是：（1）确定 TV/SV 对呼吸事件的反应变化；（2）评估这些变化与疾病严重程度之间的关系。
从 9 名 OSA 患者的 PSG 数据中，确定了 6 种不同类型的呼吸事件，即气流受限（FL）、呼吸努力相关觉醒（RERA）、单纯觉醒的低通气（Ha）、单纯低氧饱和度的低通气（Hd）、伴有觉醒和低氧饱和度的低通气（Had）和呼吸暂停。比较了每个呼吸事件期间和之后测量的 TV 和 SV 值与事件前基线值。
所有低通气和呼吸暂停期间的平均 TV/SV 减少分别为 38.1%/4.2%和 70.5%/8.8%。在三种不同的低通气类型中，Hd 和 Had 期间的 TV 减少明显大于 Ha。Ha 和 FL 期间的 TV 减少相似。在 RERA、Ha、Had 和呼吸暂停后，TV 和 SV 值有过冲，而在 FL 和 Hd 后没有过冲。在 RERA 期间，TV/SV 没有减少。
在大多数情况下，每种呼吸事件期间和之后 TV 的变化明显不同。SV 在轻中度阻塞性睡眠呼吸暂停与重度阻塞性睡眠呼吸暂停之间的变化有统计学意义。AHI 不能正确反映呼吸事件引起的通气损失。因此，TV 测量可能在未来与 AHI 结合评估 OSA 严重程度方面有用。
