Lack of significant proximal esophageal acid reflux in infants presenting with respiratory symptoms

The effects of proximal esophageal acid reflux on upper and lower respirato ry tract symptoms in infants with gastroesophageal reflux (GER) remain cont roversial. We studied 116 infants with either respiratory or gastrointestin al symptoms to determine whether acid reflux in the proximal esophagus play s an etiologic role in the elicitation of respiratory symptoms in compariso n to causing gastrointestinal (GI) symptoms only. Sixty-two infants (age ra nge, 1-12 months) with respiratory symptoms suggestive of GER and 54 infant s with gastrointestinal symptoms only (age range, 1-10 months) were evaluat ed with dual level esophageal pH monitoring. Mean duration of dual-level pH monitoring in infants with respiratory symptoms was 20.4 h, and in those w ith GI symptoms was 20.7 h. Seventeen of 54 infants with GI symptoms only and 16 of 63 infants with res piratory symptoms had abnormal distal esophageal acid reflux indices (i.e., pH <4.0 for >5% of the duration of study). In infants with abnormal distal pH monitoring, the median proximal acid reflux index in the GI group was 4 .0% in comparison to 0.95% in the respiratory group (P< 0.01 by Wilcoxon ra nk sum W test). Values for other reflux parameters were also higher in the GI than in the respiratory group. We conclude that reflux-associated respiratory symptoms are more likely due to mechanisms other than the mere presence of refluxed acid in the proxima l esophagus. (C) 1999 Wiley-Liss, Inc.