Objectives: Gastroesophageal reflux (GER) may underlie respiratory manifestations via vagally mediated airway hyperresponsiveness or microaspiration, and intraesophageal pH monitoring is generally used to identify GER in patients with such manifestations. We aimed to establish the frequency of retrograde pulmonary aspiration in patients with unexplained respiratory manifestations.
Methods: Fifty-one patients with refractory respiratory symptoms (cough, n = 18; pneumonia, n = 14; apnea, n = 8; asthma, n = 7; and laryngitis, n = 4) were prospectively evaluated. They underwent 24-h intraesophageal pH monitoring and gastroesophageal 99Tc scintigraphy with lung scan 18 to 20 h after the test meal.
Results: Thirteen of 51 patients (25.5%) had abnormal intraesophageal pH study results (mean reflux index, 11.3%; range, 6.5 to 50%); and in 25 of 51 patients (49%), overnight scintigraphy showed pulmonary aspiration. Nineteen of these 25 patients had entirely normal pH study results, whereas 6 of 13 patients with abnormal pH study results had aspiration. Pulmonary aspiration was demonstrated in all patients with apnea and 61.5% of patients with recurrent pneumonia. Nine of 25 patients (36%) with aspiration had histologic evidence of esophagitis, whereas histologic esophagitis was present in 5 of 13 patients (38.4%) with pathologic GER as shown by intraesophageal pH monitoring.
Conclusions: Pulmonary aspiration as demonstrated by overnight scintigraphy is common in children with unexplained and refractory respiratory manifestations, suggesting that GER could be the underlying cause of these manifestations. Since only a few children with chronic or recurrent respiratory symptoms have a pathologic gastroesophageal acid reflux, a normal intraesophageal pH study result does not rule out GER in these children.