Lung volume and continuous positive airway pressure requirements in obstructive sleep apnea
Lung volume and continuous positive airway pressure requirements in obstructive sleep apnea
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DOI：
10.1164/rccm.200404-552oc
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发表时间：
2005-07-01
影响因子：
24.7
通讯作者：
White, DP
中科院分区：
文献类型：
--
作者：
Heinzer, RC;Stanchina, ML;White, DP
先前的研究已经证明，在清醒状态下的肺容量会影响上气道的大小和阻力，特别是在睡眠呼吸暂停患者中。我们试图确定肺容量对持续气道正压通气（CPAP）水平的影响，CPAP水平是防止睡眠呼吸暂停受试者在非REM睡眠期间出现流量限制所必需的。17名受试者（呼吸暂停低通气指数，42.6 +/- 6.2 [SEM]）在稳定的非REM睡眠期间在配备有正/负压附件的刚性头外壳中进行了研究，以操纵胸外压。会厌压力导管加面罩/呼吸速度计用于评估流量限制。当肺容量增加1,035 22 ml时，CPAP水平可从11.9 +/- 0.7 cm H2O降至4.8 +/- 0.7 cm H2O（p < 0.001），而无流量限制。在相同的负胸外压下，CPAP降低导致最终肺容量比初始值增加421 +/- 36 ml。相反，当肺容量减少732 74 ml（n = 8）时，CPAP水平必须从11.9 +/- 0.7增加到17.1 +/- 1.0 cm H2O（p < 0.001）以防止流量限制，最终肺容量减少567 78 ml。这些结果表明，在非REM睡眠期间，肺容量的相对较小的变化对睡眠呼吸暂停受试者的上气道有重要影响。
Previous studies have demonstrated that lung volume during wakefulness influences upper airway size and resistance, particularly in patients with sleep apnea. We sought to determine the influence of lung volume on the level of continuous positive airway pressure (CPAP) required to prevent flow limitation during non-REM sleep in subjects with sleep apnea. Seventeen subjects (apnea-hypopnea index, 42.6 +/- 6.2 [SEM]) were studied during stable non-REM sleep in a rigid head-out shell equipped with a positive/negative pressure attachment for manipulation of extrathoracic pressure. An epiglottic pressure catheter plus a mask/pneumotachometer were used to assess flow limitation. When lung volume was increased by 1,035 22 ml, the CPAP level could be decreased from 11.9 +/- 0.7 to 4.8 +/- 0.7 cm H2O (p < 0.001) without flow limitation. The decreased CPAP at the same negative extrathoracic pressure yielded a final lung volume increase of 421 +/- 36 ml above the initial value. Conversely, when lung volume was reduced by 732 74 ml (n = 8), the CPAP level had to be increased from 11.9 +/- 0.7 to 17.1 +/- 1.0 cm H2O (p < 0.001) to prevent flow limitation, with a final lung volume decrease of 567 78 mi. These results demonstrate that relatively small changes in lung volume have an important effect on the upper airway in subjects with sleep apnea during non-REM sleep.