Abstract 1517

Background: GER occurs in nearly all infants. It is not known where the line that separates pathologic from physiologic GER. GER is purported to be a cause of A/B. The degree to which GER contributes to A/B has not been well established. Theophylline treatment for apnea has been reported to be associated with increased frequency of GER. Little information is available regarding these relationship.

Purpose: To study the incidence of GER in preterm infants, its association with A/B and the effect of theophyllin on GER.

Material & Method: Inclusion criteria : all preterm infants with a history of A/B. Exclusion criteria : Infants on anti-reflux or anti-acid medication. A 5 channel pneumocardiogram (PCG) was performed. These 5 channels include HR, RR, O2 sat, nasal thermister and esophageal pH. Each infant was studied for 12 hours. PCG's were performed utilizing an Edentrace II recorder and Sandhill pH meter. Each event is then qualified manually and an official interpretation made. The definition of an abnormal PCG includes: (1) apnea > 20 sec (2) apnea < 20 sec associated with bradycardia and/or desaturation of < 85% (3) bradycardia of < 85/min for > 10 sec. (4) absence of nasal air flow associated with brady or desaturation. (5) esophageal pH of < 4 for ≥ 10% of recorded time. Reflux index (RI) is defined as the duration of esophageal pH < 4 divided by the duration of the total investigation. GER is considered causative of A/B if the onset of GER preceded A/B by < 2 min.

Result: 89 infants were included in the study. GA at birth 29±3 wk (range 24-37 wk). BW 1374±623 g (range 520-2850 g). Post conceptional age at study 37±3 wk. Reflux index : range 0 - 21.4%, mean (SD) 4(5)%. Median 2.2%, 50 percentile 2%, 90 percentile 12% & 95 percentile 13%. 9% of infants had no reflux and 91% had some degree of GER during 12 hr of study. 35% of infants had RI >=5%. 16% of infants had RI of >=10%. There was no correlation between GA and RI, nor between BW & RI. RI was not significantly higher in infants on theophylline compared to infants without it (15% vs 16%). A/B occurred in 60% of infants with varying degree of GER. None of these events are preceeded by GER within 2 minutes.

Conclusion: GER is a common event in preterm infants but only 16% have significant degree (RI>10%) of GER. In this study the frequency of GER was not correlated with GA, BW or theophylline. GER and A/B occurred independently of each other.