Gastroesophageal Reflux Disease (GERD)
In patients with symptoms that suggest uncomplicated GERD (heartburn and/or regurgitation often occurring after meals and aggravated by lying down or bending over, with relief obtained from antacids), the recommended course of action is treatment for GERD with a trial of acid-suppression therapy. If the patient responds to this initial therapy, then it is reasonable to assume GERD (DeVault 2005).
Self-assessments can be useful in diagnosing uncomplicated GERD. The GERD questionnaire (GerdQ) is a simple, easily interpreted six question assessment of GERD symptom frequency. In one study of 300 patients, GerdQ had 65 percent sensitivity, a result similar to the diagnostic accuracy achieved by gastroenterologists (Jones 2009). Using GerdQ as a patient-tailored diagnostic and therapeutic evaluation tool is beneficial compared with standard approaches to GERD management (Ponce 2011).
Further diagnostic testing is only recommended if the patient does not respond to acid-suppression therapy, presents symptoms suggestive of complicated GERD (e.g., dysphagia), or has been symptomatic long enough to put them at risk for Barrett’s esophagus (DeVault 2005).
Tests for GERD may include:
Barium esophagram. Viewing the esophagus via x-ray radiography after swallowing a barium contrast solution can give insight into esophageal motility as well as detect esophageal strictures, ulcers, or severe esophagitis. It is not as sensitive or accurate at diagnosing mild esophagitis or reflux. Compared to newer techniques, it may not be as suitable for the routine diagnosis of GERD (DeVault 2005).
Upper GI Endoscopy. Direct viewing of the esophagus via flexible esophagoscope can identify mucosal breaks, areas of sloughed cells, ulceration, or redness that is distinct from areas of normal mucous membranes. Mucosal breaks are the minimum reliable indicator of GERD (Stefanidis 2010). Esophageal changes indicative of Barrett’s esophagus can also be seen with an endoscope. However, a biopsy is required before a definitive diagnosis can be made (Vakil 2006).
Esophageal pH monitoring. Esophageal pH monitoring is the current gold standard for diagnosing GERD. While a person is upright and mobile, esophageal pH is monitored using a flexible catheter with pH sensor (inserted through the nose and positioned in the lower esophagus), or more recently, a wireless pH capsule attached to the lower esophagus (Roman 2012). Measurements of pH are logged over a 24 hour period (Domingues 2011). Normal esophageal pH is close to 7.0, while a reflux event is recorded as a sudden (< 30 second) drop in pH to below 4.0. One method measures six parameters over the study period including the percentage of time that the esophageal pH is <4 (while upright, reclined, and total), the number of reflux episodes (both total episodes and those > 5 minutes), and the duration of the longest reflux episode. These parameters are then assembled into a composite score (DeMeester score) where normal is less than 14.7 (Johnson 1974). Unlike endoscopy, esophageal pH monitoring provides direct physiologic measurement of acid in the esophagus and is the most objective method to document reflux disease, assess the severity of the disease, and monitor the response of the disease to medical or surgical treatment.
Bilitec. The Bilitec System uses a fiberoptic sensor to detect the presence of bile in reflux. Bile has been implicated in symptomatic reflux that is difficult to manage by conventional acid-suppression therapy (Lazarescu 2008).
Esophageal manometry. Esophageal manometry assesses esophageal and LES function by measuring pressure changes in the esophagus induced by swallowing and peristalsis. A physician passes a pressure-sensing catheter through the nose and esophagus into the stomach. The patient performs a series of 5 mL water swallows, and pressure measurements are made of the peristaltic activity of the esophagus and LES. Since manometry measures esophageal function, it is more suited for diagnosing dysphagsia, or abnormal relaxation of the lower esophageal sphincter (Holloway 2006).