The most appropriate next step in management is ambulatory pH impedance monitoring. This patient has features of refractory gastroesophageal reflux disease (GERD). The first step in treating refractory GERD is to optimize proton pump inhibitor (PPI) therapy by verifying correct administration (30-60 minutes before meals) or increasing to twice-daily dosing. Despite increasing this patient's PPI therapy to twice daily, symptoms have persisted. Upper endoscopy has been performed, and the normal results have ruled out an alternative cause of symptoms such as eosinophilic esophagitis or erosive esophagitis. Ambulatory pH impedance monitoring is usually performed in patients who do not respond to antireflux medications and who have a negative upper endoscopy to make a definitive diagnosis. Ambulatory pH impedance testing while not taking a PPI is useful in patients who have atypical symptoms to determine if reflux is the cause of the symptoms. If pH testing is done with impedance, the PPI can be continued, as impedance can measure nonacid reflux. Testing is also helpful in patients who have had a partial response to treatment to determine if there is continued acid exposure despite the use of a PPI. The finding of continued acid exposure despite the proper dose and use of a PPI is most helpful in patients considering GERD surgery (fundoplication). Ambulatory pH impedance monitoring can be done with a pH catheter over 24 hours or with an endoscopically placed wireless transmitter over 48 hours.
A barium esophagogram would be the appropriate test for evaluation of dysphagia. Barium radiographs have low sensitivity in the evaluation of GERD and should not be performed.
Esophageal manometry measures the pressure levels in the esophagus and is useful in evaluating esophageal motility disorders such as achalasia. This patient does not have dysphagia or signs of a motility disorder, so manometry is not needed.
Fundoplication may be considered for patients with refractory GERD; however, a pH monitoring study is needed to help determine if antireflux surgery is appropriate.