Gastroesophageal Reflux Disease (GERD) in Children Diagnostics

Laboratory Tests and Ancillaries

Diagnostic tests are used to document pathologic reflux and presence of complications.  

Laboratory Tests  

Esophageal pH Monitoring  

Esophageal pH monitoring is used to quantify the frequency and duration of esophageal acid exposure per episode. However, it does not correlate with the severity of acid reflux in GER and GERD. Instead, it depends on the total number of reflux episodes, number of episodes with duration lasting >5 minutes, duration of longest reflux episode, and reflux index. Reflux index or RI is the percentage of the total duration with recorded esophageal pH of <4.0. Esophageal pH monitoring is not recommended for routine use but may be considered in patients suffering from unexplained apnea, nonepileptic seizure-like episodes, upper airway inflammation, atypical asthma, recurrent pneumonia, frequent otitis media, and dental erosion.  

Multichannel Intraluminal Impedance (MII) Monitoring  

MII monitoring measures electrical impedance between multiple electrodes placed throughout the esophageal lining. It detects changes caused by fluid, gas, solid, and mixed boluses, and can detect even small bolus volumes. This test is usually combined with esophageal pH monitoring to be able to monitor whether refluxed material is acidic, non-acidic, or weakly acidic.  

Biopsy  

Biopsy is required after obtaining histologic material during endoscopy. Histologic abnormalities characteristic of GERD includes intraepithelial eosinophilia, basal hyperplasia, spongiosis, and epithelial extensions (rete pegs).  

Imaging

Upper Gastrointestinal (GI) Tract Contrast Radiography  

Upper GI tract contrast radiography involves the administration of contrast medium to obtain a series of images up to the ligament of Treitz to fully visualize the upper GI tract. It has a 31-86% sensitivity and a specificity of 21-83% for GERD, however, it is not recommended for routine use. It may be useful in differentiating GERD from anatomic abnormalities such as antral web, pyloric stenosis, or intestinal malrotation.  

Endoscopy  

Endoscopy is indicated for patients with heartburn, hematemesis, melena, epigastric abdominal pain, and/ or dysphagia. It has a high specificity (95%) but low sensitivity (<50%) for GERD. Since proton pump inhibitor (PPI) therapy is usually started prior to any test, the sensitivity of endoscopy as a diagnostic test for GERD is poor. About 60% of patients with GERD may also have nonerosive reflux disease (NERD). Endoscopy is the first diagnostic test to consider in the presence of alarm symptoms or risk factors for Barrett’s esophagus, in evaluating symptom response to twice-daily PPI therapy, and prior to antireflux surgery. However, it is still not recommended in the general population.  

Esophageal Manometry  

Esophageal manometry measures the upper and lower sphincter pressures, esophageal peristalsis, and motility of the esophageal mucosa during swallowing. It is not recommended in diagnosing GERD but can be used to study the mechanisms causing GERD in patients, and to rule our other causes of motility problems in the esophagus (eg achalasia, neurologic disorders).  

Gastroesophageal Scintigraphy (Milk Scan)  

Gastroesophageal scintigraphy utilizes ^99mTc-labeled material to scan the gastroesophageal tract in order to evaluate postprandial reflux and gastric emptying. It helps identify patients with delayed gastric emptying and/or aspiration of refluxed material. It is not recommended for routine use because of low sensitivity (15-59%) and specificity (83-100%) for GERD.    

Ultrasonography  

Esophageal or gastric ultrasound may be considered when barium contrast study is not available. It may help detect the presence of fluid in the gastroesophageal junction, length and position of the LES, and gastroesophageal angle of His measurement.