24 Hour Esophageal Impedance PH Test
The esophageal impedance pH test evaluates the extent of gastric reflux into the esophagus over a prolonged period of time – typically 24 hours. Sensors on the catheter measure the level of acidity at various levels in the esophagus, as well as reflux of stomach contents (regardless of its level of acidity) up the esophagus.
It is the most accurate test to document gastroesophageal reflux (GERD), and is the preferred test because it measures acidity at different levels and measures “nonacid” reflux, and has the best ability to correlate symptoms (e.g. heartburn) with reflux events.
Indications for 24 hour PH impedance testing:
- Patients with GERD who are non-responsive to medications. Intra-esophageal PH monitoring is important to confirm the diagnosis of GERD, particularly in patients with normal endoscopy findings.
- Patients with extra-esophageal symptoms of GERD who do not respond to medications or who have normal endoscopy reports. These patients present with allergic cough, atypical asthma or hoarseness of voice.
- Before anti-reflux surgery, especially in patients with no response to medications.