Materials and Methods
Predetermined entry criteria allowed inclusion of only those children who: (1) had no family history of asthma; (2) had no personal or family history of atopic disease; (3) had been receiving treatment for asthma for at least 2 years; (4) had parents who did not smoke; (5) had at least three emergency visits or hospital admissions per year in the preceding 1 year; (6) required a combination of short- and long-acting bronchodilators, leuko-triene antagonists, and inhaled or oral corticosteroids for the management of asthma; (7) did not have a history of respiratory syncytial virus bronchiolitis; and (8) could swallow a tablet or capsule. All the patients were derived from a geographically distinct region where all children with asthma, who are deemed to require care by a specialist, are referred to the only one specialist, and all the patients with GI problems are referred to the only pediatric gastroenterologist in that region.
All consecutive children with asthma fulfilling these entry criteria and referred to the gastroenterologist for ruling out GER disease underwent extended esophageal pH monitoring (20 to 24 h) using a dual-channel (10 cm apart) pH probe with the distal channel placed and confirmed radiologically at approximately 3 cm proximal to the gastroesophageal junction. All asthma medications were continued uninterrupted. No advice regarding diet or positioning was given. Care was taken to ensure that no antacids were consumed during or up to 3 days before the study. Those children who had an abnormal pH study finding (pH < 4 in the distal esophagus for > 5% of the time) underwent aggressive anti-GER treatment with lifestyle changes, a prokinetic, and a proton-pump inhibitor. At the initial visit, extensive counseling was provided about the different components of anti-GER treatment as well as the role of anti-GER surgery.
These children then underwent regular follow-up at intervals of 4 weeks for asthma management based on symptoms in the preceding 4 weeks. Medications were added or deleted based on this assessment. Patients were also seen for acute exacerbation, and medications were adjusted accordingly. Every 4 weeks, the dose of the prokinetic was adjusted based on current weight. The children with a normal pH probe study finding were given the option of no anti-GER treatment or an empiric therapeutic trial of anti-GER treatment as outlined above. The latter was based on the premise that results of an esophageal pH monitoring are not 100% sensitive for diagnosing GER disease. Treatments were instituted after obtaining informed consent.
The prokinetics used were either cisapride, 1 mg/kg/d divided in three doses, or metoclopramide, 0.15 mg/kg per dose tid administered before meals. The proton-pump inhibitor used was lansoprazole, 30 mg/d, as a single dose early in the morning. The inhaled corticosteroids used were either budesonide, 200 to 400 pg bid, or fluticasone, 110 to 220 pg bid.