Bajaj Jasmohan S, Bajaj Shailesh, Dua Kulwinder S, Jaradeh Safwan, Rittmann Tanya, Hofmann Candy, Shaker Reza
Division of Gastroenterology and Hepatology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
Gastroenterology. 2006 Jan;130(1):17-25. doi: 10.1053/j.gastro.2005.10.003.
BACKGROUND & AIMS: Airways are most vulnerable to aspiration during sleep. Esophago-upper esophageal sphincter (UES) contractile reflex (EUCR) and secondary peristalsis (2P) have been proposed to protect the airway by reflexively contracting the UES and clearing the esophagus of refluxate, respectively. Our aim was to study EUCR and 2P elicitation in "awake" state, stage II, slow-wave (stage III/IV), and rapid eye movement (REM) sleep.
Thirteen healthy volunteers were studied in the supine position using concurrent UES and esophageal manometry and polysomnography. Threshold volume (Tvol) to trigger EUCR and 2P and changes in sleep stages were recorded during injection of 2.7 mL/min water into the proximal esophagus after sleep stages were confirmed.
UES pressure progressively declined with deeper stages of sleep. Tvol for EUCR and 2P elicitation was not significantly different between the stage II and "awake" state (EUCR: 4.0 +/- 1.8 mL vs 6.1 +/- 3.6 mL stage II; 2P: 5.8 +/- 2.2 mL vs 8.0 +/- 4.0 mL stage II). Tvol for EUCR and 2P elicitation during REM sleep were significantly lower than during the stage II and "awake" state (REM EUCR: 2.2 +/- 1.1 mL; 2P: 3.5 +/- 1.2 mL). Arousal and cough preempted development of EUCR and 2P during slow-wave sleep.
(1) EUCR/2P can be elicited in stage II and REM but is preempted by arousal in slow-wave sleep. (2) Tvol for EUCR/2P elicitation is significantly lower in REM, compared with the stage II and "awake" state, suggesting a heightened sensitivity of these reflexes during REM sleep. (3) Although UES pressure progressively declines with deeper stages of sleep, it can still reflexively contract during REM sleep, despite generalized hypotonia.
气道在睡眠期间最易受到误吸的影响。食管-上食管括约肌（UES）收缩反射（EUCR）和继发性蠕动（2P）分别被认为可通过使UES反射性收缩和清除食管内反流物来保护气道。我们的目的是研究在“清醒”状态、II期、慢波（III/IV期）和快速眼动（REM）睡眠期诱发EUCR和2P的情况。
对13名健康志愿者采用仰卧位，同时进行UES和食管测压及多导睡眠图检查。在确认睡眠阶段后，以2.7 mL/分钟的速度向食管近端注入水的过程中，记录触发EUCR和2P的阈值体积（Tvol）以及睡眠阶段的变化。
UES压力随着睡眠深度的增加而逐渐下降。诱发EUCR和2P的Tvol在II期和“清醒”状态之间无显著差异（EUCR：II期为4.0±1.8 mL，“清醒”状态为6.1±3.6 mL；2P：II期为5.8±2.2 mL，“清醒”状态为8.0±4.0 mL）。REM睡眠期诱发EUCR和2P的Tvol显著低于II期和“清醒”状态（REM期EUCR：2.2±1.1 mL；2P：3.5±1.2 mL）。在慢波睡眠期，觉醒和咳嗽会先于EUCR和2P的发生。
（1）EUCR/2P可在II期和REM期诱发，但在慢波睡眠期会被觉醒先占。（2）与II期和“清醒”状态相比，REM期诱发EUCR/2P的Tvol显著更低，表明这些反射在REM睡眠期敏感性增强。（3）尽管UES压力随着睡眠深度的增加而逐渐下降，但在REM睡眠期它仍可反射性收缩，尽管存在全身性肌张力减退。
