Responses to Different Levels of Esophageal Acidification During Waking and Sleep

The purpose of this study was to assess theeffect of hydrogen ion concentration of intraesophagealinfusions during sleep on acid clearance time andlatency to swallow and arousal responses from sleep. We studied 10 normal volunteers during sleepvia polysomnography and concomitant esophageal pHmonitoring. Sleep prolonged the acid clearance time ofboth pH 3.0 and 1.2. Swallow and arousal latencies were both progressively decreased with decreasing pHof the infusate (P < 0.05, 0.07, respectively). Weconcluded that intraluminal hydrogen ion concentrationcreates an afferent warning stimulus that produces prompt airway-protective responses.