A 35-year-old man is evaluated during a follow-up appointment for persistent heartburn with chronic cough. He has a 1-year history of gastroesophageal reflux disease and takes pantoprazole twice daily. He reports no nausea, vomiting, or dysphagia. Upper endoscopy performed 1 year earlier showed no abnormal findings.
His vital signs and physical examination are normal. Results of an ear, nose, and throat evaluation are noncontributory.
Which of the following is the most appropriate next diagnostic test?
A. Ambulatory pH testing
B. Barium esophagography
C. Esophageal manometry
D. Upper endoscopy
MKSAP Answer and Critique
The correct answer is A. Ambulatory pH testing. This content is available to MKSAP 18 subscribers as Question 48 in the Gastroenterology and Hepatology section. More information about MKSAP is available online.
Ambulatory pH testing is the most appropriate next diagnostic test for this patient. The patient has persistent cough, which may be an extraesophageal symptom of gastroesophageal reflux disease (GERD) resulting from laryngopharyngeal reflux. Additional extraesophageal symptoms of GERD include asthma, globus sensation, hoarseness, throat clearing, and chronic laryngitis. It appears that the laryngopharynx is more sensitive to the erosive effects of acid, and small amounts of reflux may produce symptoms. The selection of a diagnostic test to confirm or exclude laryngopharyngeal reflux is controversial. Ambulatory pH testing, if positive, can help to confirm the diagnosis of GERD and supports the diagnosis of laryngopharyngeal reflux. Negative ambulatory pH testing suggests that the patient does not have GERD and that proton pump inhibitor therapy should be discontinued and another cause of the persistent hoarseness sought. Other experts propose laryngoscopy as the gold standard to diagnose laryngopharyngeal reflux. Common findings during laryngoscopy include edema and erythema, but these findings are also seen in 80% of healthy controls. While laryngoscopy should not be used as the sole test to diagnose extraesophageal GERD, abnormal findings in patients with an appropriate clinical history suggest that cough is related to GERD. Other causes of cough may include allergy, smoking, and voice abuse, and these should be ruled out with an ear, nose, and throat evaluation.
Barium esophagography should not be used as the initial diagnostic test for GERD and is not useful for evaluating this patient's symptoms, which primarily involve the laryngopharynx.
Esophageal manometry is used for patients suspected of having an underlying motility disorder involving peristalsis or lower esophageal sphincter dysfunction. This patient reports no dysphagia, a common presenting symptom of motility disorders, and his heartburn symptoms are controlled, so esophageal manometry is not indicated.
Upper endoscopy is the primary tool used to evaluate patients with GERD for complications such as erosive esophagitis, stricture, Barrett esophagus, and esophageal cancer. Because this patient does not have esophageal symptoms and had a normal endoscopy 1 year ago, upper endoscopy is not indicated.
- Ambulatory pH testing can be a helpful diagnostic test in patients with suspected extraesophageal manifestations of gastroesophageal reflux disease.