The history and clinical manifestations of Acid Reflux Disease are the most important diagnostic aids; objective testing can quantify the extent and severity of the process. In the vast majority of sufferers, typical symptoms of Acid Reflux Disease and the response to initial gastric acid suppressive therapy make the diagnosis relatively easy. Diagnostic evaluation becomes important when symptoms are atypical and/or do not respond to therapy.
DOCUMENTING REFLUX.
Reflux during a barium swallow in adults is uncommon unless vigorous provocative maneuvers are employed. When spontaneous reflux of barium is seen, it usually denotes free reflux. The absence of reflux seen radiographically does not, however, imply that the sufferer does not have Acid Reflux Disease.
The 24-hour monitoring of esophageal pH can be performed with a portable unit, which allows the sufferer to follow an almost normal lifestyle. During the prolonged monitoring period, the relationship between symptoms (heartburn, chest pain, wheezing) and episodes of acid reflux can be ascertained, and calculations can be made of the number of episodes of reflux and the amount of time the esophagus is acidified (pH - 4). A small amount of reflux, especially in the postprandial period, can be seen normally. Repeated and prolonged bursts of acid exposure suggest that abnormal gastroesophageal reflux is present.
In children and infants, reflux can be measured noninvasively by scanning the esophageal area with a gamma-camera after placing a solution of 99m Tc sulfur colloid in the stomach. An abdominal binder is used to increase intra-abdominal pressure and to stress the gastroesophageal junction if free reflux is not seen.
LINKING REFLUX TO SYMPTOMS.
If pain is the predominant symptom, rather than heartburn, a Bernstein test may be performed using the same catheter as is used for esophageal manometry. After a 5-minute period of dripping normal saline in the mid-esophagus, the infusion is changed to 0.1 N hydrochloric acid. Reproduction of the symptoms during acid infusion (usually 4 to 5 minutes into the infusion), followed by rapid symptom disappearance after returning to a saline infusion, suggests an esophageal cause of the discomfort.
As another approach, the sufferer is asked to signal the time of discomfort during prolonged pH monitoring of the esophagus. If the sufferer signals discomfort at the same time that acid reflux is demonstrated by the pH probe, then a causal relationship is more likely.
ASSESSING THE EFFECT OF REFLUX ON THE ESOPHAGEAL MUCOSA.
A barium swallow detects gross changes, such as stricture formation or a deep esophageal ulcer, but misses the much more common shallow ulcerations and erosions, which are detected by endoscopy. Only discrete lesions such as erosions and ulcerations should be taken as proof of esophageal damage, because endoscopic findings, such as erythema, edema, or friability, are subject to wide interobserver variation. In approximately one-half of sufferers with moderate to severe symptoms of Acid Reflux Disease, the mucosa appears absolutely normal, but a biopsy may demonstrate the histologic changes of reflux.
APPROACH
Endoscopy is generally indicated if symptoms are prolonged and do not respond to empiric treatment, or if systemic manifestations, such as weight loss, anemia, and occult blood-positive stool are present. If the appearance of the esophageal mucosa is normal during endoscopy, biopsies can also be obtained to search for objective evidence of microscopic esophagitis. If dysphagia is present, a barium swallow is appropriate. Uncommonly, reflux is demonstrated, a stricture found, or a deep ulcer seen, which leads to immediate endoscopy for more complete evaluation. After first evaluation, it may be appropriate to begin empiric therapy (see Treatment, below). If the response to therapy is poor, esophageal pH monitoring can confirm the diagnosis. At the same time, esophageal manometry may be performed to estimate LES pressure and to determine the presence or absence of peristaltic waves.
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