Gastro-oesophageal reflux and apnoeic pauses during sleep in infancy--no direct relation

We studied the relation of gastro-oesophageal reflux with apnoea during sleep in 24 infants with antecedent respiratory abnormalities and/or proven gastrooesophageal reflux (GOR), by combined lower oesophageal pH and polygraphic monitoring. GOR, indicated by pH less than 4, was confirmed in 24 infants. There were no episodes of prolonged (greater than 20 s) central apnoea (CA). Fifty-six mixed or obstructive breathing episodes were identified in 12 infants (14 studies), of which 28 lasted between 3 and 6 s. Bradycardia (heart rate less than less than 80 beats/min for 10 s was not observed. There were 80 falls in transcutaneous oxygen (PtcO2 greater than 5 mmHg) but only 6 exceeded 10 mmHg and one 20 mmHg. There was no relationship between GOR and obstructive episodes in terms of frequency, duration or temporal occurrence, except in one infant. There were 1276 gross body movements, mainly during active or indeterminate sleep and, of these, 7% were associated with decreases in pH to less than 4. Movements occurred during the 60 s period preceding 83% of pH decreases greater than 1 pH unit compared to only 30% in the 60 s succeeding a pH drop. We conclude that, while GOR and obstructive episodes may co-exist in the patient groups studied, decreases in pH in the lower oesophagus do not usually induce either central or obstructive apnoea, and vice versa. Of the variables monitored, only gross body movements were temporally associated with pH drops, and usually preceded them.