[Prolonged esophageal pH monitoring utilization in the diagnosis of pathologic reflux in neonates]

OBJECTIVES: To present indications and results of prolonged esophageal pH monitoring in diagnosing pathologic gastroesophageal reflux in newborns during their stay in the neonatal unit. METHODS: This retrospective descriptive-analytical study of 85 prolonged esophageal pH monitoring in neonates was performed, between October 1995 and March 1998, in a tertiary intensive care unity. A Digitrapper MKIII device, pH probes with one or two channels, and antimony electrodes were utilized. The probe was placed 3 cm above the gastroesophageal junction. RESULTS: The main indications of this esophageal pH study were hypoxemia episodes demanding supplemental oxygen, and caffeine resistant apnea. The means -/+ SD of birth-weight and gestational age in the patients evaluated were, respectively, 1,204-/+460 g and 30.5 -/+ 2.9 weeks. There was no statistical difference observed in newborns with and without pathologic gastroesophageal reflux according to clinical manifestations and monitoring conditions. Forty-eight newborns (56.4%) presented 17.6-/+9.1% of the whole examination time with a pH below 4. Of these patients, 31.1% presented birth-weight below 1,000 g. Duodenogastroesophagic was diagnosed in two cases. Of the studied premature with chronic lung disease, 66.7% presented pathologic reflux. CONCLUSION: Prolonged pH esophageal monitoring is helpful in the differential diagnosis of the unspecific and very frequent clinic manifestations in very low birth-weight infants.