Gastro-oesophageal reflux and the sudden infant death syndrome.

Gastro-oesophageal reflux (GOR) has been reported in infants presenting as 'near miss' for the sudden infant death syndrome (SIDS). This study investigated the occurrence of GOR in infants at increased risk for SIDS and examined the relation between GOR and cardio-respiratory abnormalities, particularly during sleep. 82 infants were studied by radionuclide scan: suspected tracheo-bronchial aspiration (7), sibs of SIDS victims (12), persistent possetters (8), mentally retarded (4), minor cardio-respiratory 'events' eg choking (29) and 'near miss' for SIDS (22). In 22 children respiration and heart rate were recorded simultaneously. To assess the relationship between GOR and cardio-respiratory events during sleep 24 infants, including 17 with significant GOR on scan, were monitored polygraphically during sleep at night with simultaneous lower oesophageal pH monitoring to detect acid GOR. Radionuclide scan images were collected for two hours following a labelled milk feed. Severe GOR (to the upper oesophageal/pharyngeal level) was observed in 58 (70%), from each of the groups studied. 7/22 infants had both severe GOR and respiratory pauses >6sec but no clear relation between GOR and such pauses was observed. The night studies confirmed that GOR was frequent in all 'at risk' groups. Cardio-respiratory abnormalities were also frequent but only 5 central apneas lasted longer than l0sec and no significant bradycardia (=10sec) was observed. A pathological finding was the presence of 56 mixed and obstructive apneas. No direct temporal relation was observed between the occurrence of GOR and cardio-respiratory abnormalities. An association between gross body movements and pH drops was noted with movement often preceding a pH drop. These studies confirm that GOR is common in 'near miss' SIDS infants but demonstrate that it is also found frequently in other 'at risk' groups. Despite its frequent occurrence, GOR did not precipitate respiratory pauses or bradycardia.