Gastroesophageal reflux monitoring: pH and impedance
The armoury of tools available to diagnose GORD has become more sophisticated as new technologies and approaches have been introduced.
pH monitoring studies have been recently included with medical investigation of oesophageal symptoms (heartburn, regurgitation, dysphagia, etc.) and more recently to understand the causes of persistent oesophageal symptoms in patients.
Oesophageal pH can be monitored over extended periods of time using either conventional, catheter-based systems or more recently wireless, pH capsules attached to the distal oesophagus.
Normal oesophageal pH is considered to be close to pH 7.0. Where gastroesophageal reflux is suspected, during pH monitoring a sudden drop in intra-oesophageal pH is seen, to lower than 4.0.