From the Guidelines
The most sensitive diagnostic tool for a patient presenting with symptoms of Gastroesophageal Reflux Disease (GORD) is ambulatory 24-hour esophageal pH monitoring, often combined with impedance monitoring. This test measures acid exposure in the esophagus over a full day while the patient goes about normal activities and records symptoms, providing the most direct correlation between acid reflux events and symptoms 1. The procedure involves placing a thin catheter with sensors through the nose into the esophagus, or alternatively using a wireless pH capsule attached to the esophageal wall. Patients maintain a diary of symptoms, meals, and position changes during the monitoring period.
This test is particularly valuable for patients with atypical symptoms, those who haven't responded to empiric treatment with proton pump inhibitors (PPIs), or when considering surgical intervention. While endoscopy can identify complications of GORD such as esophagitis or Barrett's esophagus, it often appears normal in many GORD patients. Other tests like barium swallow studies or esophageal manometry may complement the diagnostic workup but don't offer the same sensitivity for detecting reflux events and correlating them with symptoms as pH monitoring does.
Some key points to consider when using pH/impedance monitoring include:
- It allows diagnosis of increased acid exposure, association between symptoms and acid or non-acid reflux, and identification of phenotypes—ie, non-erosive reflux disease, hypersensitive oesophagus and functional heartburn 1.
- Approximately 60% of non-erosive reflux disease patients, who are refractory to proton pump inhibitors, have a positive reflux/symptom association, primarily due to non-acid reflux 1.
- Classifying patients with symptomatic non-acid reflux as having a hypersensitive oesophagus reduces the number of patients classified as having functional heartburn and guides therapy 1.
- pH/impedance monitoring off proton pump inhibitor therapy best predicts response to antireflux therapy, with key parameters including increased total acid exposure time and the correlation between symptoms and all reflux episodes (acid and non-acid) detected by impedance 1.
In the context of the provided options, 24h PH monitoring is the most sensitive for diagnosis, especially when combined with impedance monitoring, as it provides a comprehensive assessment of acid and non-acid reflux events and their correlation with symptoms.
From the Research
Diagnostic Tools for GORD
The most sensitive diagnostic tool for a patient presenting with symptoms of Gastroesophageal Reflux Disease (GORD) is:
- 24h PH monitoring The following points support this choice:
- A study published in 2024 2 used 24-hour pH-impedance testing to differentiate endoscopically negative patients with GERD symptoms and patients with Grade A EE by LA to NERD, HSE, and FH.
- Another study from 2008 3 found that ambulatory 24-h pH-impedance monitoring should preferably be performed after cessation of PPI therapy to demonstrate or exclude GERD in patients with PPI-resistant symptoms.
- While other diagnostic tools such as endoscopy and manometry are useful, 24h PH monitoring is considered the most sensitive for diagnosing GORD, especially in patients with non-erosive reflux disease (NERD) or functional heartburn (FH) 2, 4.
Comparison of Diagnostic Tools
The following diagnostic tools are available for GORD:
- a. 24h PH monitoring: considered the most sensitive for diagnosing GORD
- b. ECG: not relevant for diagnosing GORD
- c. Endoscopy: useful for visualizing the esophageal mucosa and detecting erosive esophagitis, but not as sensitive as 24h PH monitoring for diagnosing GORD
- d. Manometry: useful for assessing esophageal motility, but not as sensitive as 24h PH monitoring for diagnosing GORD 2, 5