Utility of Diagnostic Studies for Upper Gastrointestinal Symptoms in Children with Orthostatic Intolerance.

OBJECTIVE: To assess the utility of gastrointestinal (GI) diagnostic studies in the evaluation of patients with orthostatic intolerance. STUDY DESIGN: Medical records of 103 consecutive children/young adults with orthostatic intolerance and gastrointestinal symptoms were reviewed. All patients had undergone antroduodenal manometry in conjunction with the tilt table test, autonomic testing, and upper gastrointestinal endoscopy (EGD). A gastric emptying study (GES) was performed in 81 patients. RESULTS: The median age of the cohort was 17 years (IQR, 15-19) with a female predominance (females:males, 3:1). As expected, the tilt table test was abnormal in all patients. Antroduodenal manometry was abnormal in 83 of 103 patients (81%), showing neurogenic intestinal dysmotility in 50%, rumination in 20%, and visceral hyperalgesia in 10%. The GES results were abnormal in 23 of 81 patients (28.4%), mostly (21 of 23) with delayed GES. None of the tilt table test or autonomic results were predictive of abnormal antroduodenal manometry or GES. Analysis of EGD biopsy samples revealed nonspecific esophagitis and/or gastritis in 16 of 103 patients (15%). CONCLUSIONS: Antroduodenal manometry with the tilt table test were the most insightful investigations in adolescents and young adults with orthostatic intolerance and gastrointestinal symptoms. GES and EGD provided limited information. Gastrointestinal symptoms were related more to functional rather than mucosal or organic etiologies, suggesting a limited role of endoscopy alone in evaluating patients with orthostatic intolerance presenting with gastrointestinal symptoms.

Antroduodenal Manometry Is Abnormal in Children Presenting With Orthostatic Intolerance and Gastrointestinal Symptoms.

OBJECTIVES: Gastrointestinal (GI) symptoms of nausea, vomiting, and abdominal pain are common in patients with orthostatic intolerance (OI), including neurally mediated hypotension (NMH) and postural orthostatic tachycardia syndrome (POTS). Autonomic dysregulation is considered the underlying pathophysiology behind the cardiovascular symptoms of POTS. Because the autonomic nervous system also regulates GI motility, we hypothesized that patients with POTS and GI symptoms will have evidence of autonomic dysmotility of the upper GI tract. METHODS: Thirty-five subjects with OI and GI symptoms were studied. All the subjects had a 24-hour antroduodenal manometry (ADM) study, in conjunction with pharmacologic challenge and autonomic and tilt table testing (TTT). RESULTS: The mean subject age was 16.2 ±â€Š2.8 years (range 10-23.8 years), and male to female ratio was 10:25. TTT was abnormal in all the 35 subjects, whereas Valsalva testing was abnormal (+40 mmHG) in 21 of 34 (62%) subjects, and corrected QT interval was ≥0.44 seconds in 19 of 35 (54%) subjects. During TTT, GI symptoms were reproduced in 31 of 35 (89%) studies. ADM was found to be abnormal at baseline, before the TTT in 5 of 35 (14%) subjects, whereas it became abnormal in 23 of 34 (68%) subjects during TTT. In addition, the expected response to the pharmacologic challenge was limited. Overall, ADM was abnormal in 26 of 35 (74%) patients either at baseline or during TTT in these subjects with OI. CONCLUSIONS: ADM is frequently abnormal in children with OI and GI symptoms. Upper GI motility studies should be a part of the comprehensive evaluation in this population.

The effects of nebulized albuterol on esophageal function in asthmatic patients.

PURPOSE: Albuterol reduces lower esophageal sphincter (LES) pressure in normal volunteers, although the effects of albuterol on esophageal function in asthmatic patients are not known. The aim of this study was to evaluate the effects of nebulized albuterol on lower esophageal function in asthmatic patients. Symptoms and a methacholine challenge test were used to identify asthmatic patients who were then enrolled in a prospective, randomized, placebo-controlled, double-blinded, crossover trial. Changes in esophageal function in response to nebulized albuterol or placebo were evaluated over two sessions spaced 1 week apart. RESULTS: Albuterol induced a dose-dependent drop in lower esophageal sphincter basal pressure with a threshold dose as low as 2.5 mg. Albuterol did not affect the amplitude of esophageal contractions. CONCLUSIONS: Nebulized albuterol induces a dose-dependent reduction in LES basal pressure in asthmatic patients. These effects raise the possibility that gastroesophageal reflux may occur after bronchodilator therapy.