Sleep apneas and acid esophageal reflux in control infants and in infants with an apparent life-threatening event

Clinical experience shows that episodes of apnea can occur during regurgitations or vomiting. We questioned whether sleep apneas could be related temporally to documented falls in esophageal pH, when no clinical symptoms of emesis are witnessed. Twenty infants admitted after an apparently life-threatening event ('ALTE') during sleep, but with no clinical symptoms of vomiting or regurgitations at the time of the event, and ten control infants were studied. All infants had occasional episodes of regurgitations. Polygraphic monitoring of state of alertness, cardiorespiratory activity and low esophageal pH was performed continuously during 1 night. The data were analyzed blindly. A total of 334 central and 36 obstructive apneas were monitored, mainly in the ALTE group, during NREM sleep. A total of 116 falls in esophageal pH below 4 units were seen in 18 infants; 50% occurred during wakefulness, and 31% in REM sleep. Arousals or body movements preceded the pH fall in 50% of the cases. Within 5 min following the reflux onset, 18 central apneas (7.2% of the apneas) were seen. There was no correlation between the duration, or the lowest values of esophageal pH measured, and the number or duration of apneas. No obstructive apnea, bradycardia or arousal followed the falls in esophageal pH. Acid esophageal reflux did not play a significant role in the development of apnea in our population.