A 48-year-old man appears following a negative evaluation for a two-year history of atypical chest pain. The patient relates three episodes of pneumonitis during that time but denies dysphagia, regurgitation, or weight loss. The test most likely to aid in a definitive diagnosis is

A. barium swallow.
B. esophageal manometry.
C. provocative esophageal testing with edrophonium.
D. twenty-four hour pH testing.
E. upper endoscopy.

Answer D

Classic symptoms of reflux are heartburn and regurgitation aggravated by postural changes such as stooping or lying flat. Reflux is usually relieved by ingestion of food or antacids. Regurgitated gastric contents are sour, burns or tastes bitter. Dysphagia is a common symptom with reflux and may occur in the absence of esophagitis, attributed to a degree of esophageal spasm or inefficient motor contraction of the esophagus. The pain pattern of angina pectoris may be mimicked by esophageal spasm triggered by reflux. Aspiration caused by reflux most commonly presents as nocturnal cough associated with regurgitation of food in the mouth, often awakening the patient. Severe aspiration from reflux can lead to lung abscess, recurrent pneumonia, or bronchiectasis.

In any patient suspected of having esophageal disease, a barium swallow is the first study indicated. If the patient complains of dysphagia or barium swallow reveals a mechanical abnormality in the esophagus, flexible fiberoptic endoscopy is done. 

Esophageal function tests may be necessary to make an exact diagnosis. The esophageal function tests frequently used include esophageal manometry, a standardized acid reflux test using the pH electrode in the esophagus, an acid clearing test, and the acid perfusion test. In more difficult cases in which the diagnosis is still uncertain, 24-hour pH monitoring and prolonged esophageal manometry provide essential additional information.

In patients who have undergone previous esophageal therapy, in those whose symptoms are complicated or overlap with other known conditions, and in patients suspected of having reflux-induced aspiration or angina-like pain, 24-hour pH monitoring in the esophagus is invaluable. The number of bouts of reflux can be measured quantitatively based on their frequency and duration in both the supine and upright position. By this method, patients can be categorized as normal or abnormal for both upright and supine reflux, disorders of acid clearing can be identified, and correlation of unusual symptoms with reflux may be observed. At present, 24-hour pH testing is the most sensitive and quantitative method for evaluating possible gastroesophageal reflux.

O'Sullivan GC, DeMeester TR, Smith RB, et al. Twenty-four hour pH monitoring of esophageal function. Arch Surg 1981;116:581-90.
The incidence and character of gastrointestinal reflux after truncal vagotomy and gastric resection or drainage were studied prospectively in 42 symptomatic patients. Gastroesophageal reflux, proven by 24-hour pH monitoring, occurred in 31 patients. Initial symptoms of heartburn, regurgitation, or dysphagia were similar in patients with and without reflux. Eighteen patients had pure acid, nine had acid-alkaline, and four had pure alkaline reflux. Reflux occurred predominantly in the supine position. Esophagitis occurred only in patients with reflux and was not dependent on the pH of refluxed material. Reflux was eventually controlled by antireflux repair in 19 and by colon interposition in three patients. Twenty-four-hour esophageal pH monitoring is beneficial in evaluating symptoms after gastric surgery. It quantifies both acid and alkaline reflux, provides an objective assessment of the patient's subjective complaints, and gives a rational basis management.

Richter JE. Extraesophageal presentations for gastroesophageal reflux disease. Sem Gastrointestinal Dis 1997;8:75-89.
Gastroesophageal reflux disease is increasingly being recognized as a common factor contributing to asthma and many ear, nose, and throat complaints. For example, studies suggest that acid reflux is present in 50% to 80% of asthmatic patients, 10% to 20% of chronic coughers, up to 80% of patients with difficult-to-manage hoarseness, 25% to 50% of patients with globus sensation, and a small but definite group of patients with laryngeal cancer. Clinical suspicion is the key to the diagnosis because many patients do not have classic reflux symptoms of heartburn or acid regurgitation. Prolonged esophageal pH monitoring with pH probes in the distal esophagus and proximal esophagus or hypopharynx and laryngeal examinations are the most helpful diagnostic tests. Prolonged acid suppression, either medically or surgically, will cure or help many of these patients.

Vaezi MF, Schroeder PL, Richter JE. Reproducibility of proximal probe pH parameters in 24-hour ambulatory esophageal pH monitoring. Am J Gastroenterol 1997;92:825-9.
OBJECTIVES: To assess the reproducibility and reliability of the proximal pH probe in detecting acid reflux into the proximal esophagus. METHODS: Using dual probe ambulatory esophageal pH monitoring, we studied 32 subjects (11 healthy control subjects, 10 patients with distal esophageal acid reflux, and 11 patients with both distal and proximal esophageal acid exposure) on two separate days within a 20-day period. The distal pH probe was placed 5 cm above the manometrically determined lower esophageal sphincter, and the proximal probe was positioned immediately distal to the upper esophageal sphincter. Patients were categorized on the basis of the esophageal pH data obtained during the first study. Reflux parameters assessed were the percentages of time in which pH was >4 in the total, upright, and supine positions. To be considered reproducible, all three of the above parameters had to remain in the same category as the first day's results. RESULTS: Intrasubject reproducibility of the proximal probe was 91-100% in healthy subjects, 70-90% in patients with distal esophageal acid reflux, and 45-73% in patients with proximal esophageal acid reflux. The proximal probe reproducibility for the overall diagnosis of gastroesophageal reflux disease was 91% in healthy subjects, 70% in patients with distal esophageal acid reflux, and only 55% in those with proximal esophageal acid reflux. Statistical analysis demonstrated only a fair index of concordance (kappa=0.40) for the proximal probe. CONCLUSIONS: The proximal pH probe has excellent specificity (91%) but poorer sensitivity and reproducibility (55%) for identifying abnormal amounts of proximal esophageal acid reflux. Therefore, a negative test result does not exclude proximal reflux with microaspiration as a cause of atypical reflux symptoms.

Weinberg DS, Kadish SL. The diagnosis and management of gastroesophageal reflux disease. Med Clin N Amer 1996;80:411-29.
GERD is common clinical problem. Generally, its clinical presentation and management are straightforward. Greater awareness of the numerous extra-esophageal manifestations of the disease aids patients and physicians in appropriate recognition and treatment. Medical therapy is effective in the majority of cases but often requires long-term medication for acceptable symptom control. A small, but significant proportion of patients presents with or develops complications of GERD, most importantly Barrett's esophagus. Although the logistics of long-term surveillance of persons with Barrett's esophagus is unclear, the association of this metaplastic change with esophageal adenocarcinoma underscores the importance of regular follow-up.