Value of pH Probe Testing in Pediatric Patients with Extraesophageal Manifestations of Gastroesophageal Reflux Disease: A Retrospective Review

Abstract

Extended pH probe testing is often performed in patients believed to have extraesophageal symptoms of gastroesophageal reflux disease (GERD), although for this indication its diagnostic value is not well established. A retrospective review of all patients who underwent pH probe testing between 1994 and 1998 was conducted to determine the outcome of antireflux therapy in the subgroup with probable extraesophageal symptoms of GERD. Sixty-eight patients underwent antireflux therapy and had adequate follow-up after pH probe testing to be included in the study. Fifty-eight patients (85%) responded to antireflux therapy (improved, 44%; cured, 41%). The positive predictive value of distal pH probe testing was greater than 90%, but the negative predictive value was less than 50%. The reproducibility of pH probe testing on different study days was poor, but pH probe testing was helpful in assessing the adequacy of antireflux therapy. The presence of gastrointestinal symptoms did not correlate with the response of extraesophageal symptoms to antireflux therapy. Thirteen patients underwent double-probe pH studies. The mean percent time the pH was less than 4 in the upper esophagus was 2.6% (range, 1% to 9.6%). Twelve of these patients were improved or cured with antireflux therapy. Distal pH probe testing is of limited benefit in predicting whether patients with extraesophageal symptoms of GERD will respond to antireflux therapy. If extraesophageal symptoms of GERD are suspected, patients should undergo an empiric trial of antireflux therapy. Distal pH probe testing should be reserved for assessing the adequacy of antireflux therapy if symptoms persist. A prospective, randomized, controlled study will aid in determining the predictive value of double-probe pH studies in pediatric patients with probable extraesophageal symptoms of GERD.