Impedance–pH monitoring

Impedance–pH monitoring is a diagnostic technique used in gastroenterology to measure gastroesophageal reflux (GER) and acid reflux. This technique combines impedance monitoring, which detects the flow of fluids and gases in the esophagus, with pH monitoring, which measures the acidity in the esophagus.

Overview

Impedance–pH monitoring is a catheter-based test that allows physicians to determine if the patient's symptoms are related to acid reflux. The test can detect both acid reflux and non-acid reflux, providing a more comprehensive view of the patient's condition than pH monitoring alone.

Procedure

During an impedance–pH monitoring test, a thin, flexible tube with sensors is passed through the patient's nose and into the esophagus. The sensors measure the impedance, or resistance, to the flow of electrical current, which changes as different substances pass through the esophagus. The pH is also measured to determine the acidity of these substances. The data is then recorded and analyzed to identify episodes of reflux and their correlation with the patient's symptoms.

Clinical Applications

Impedance–pH monitoring is used to diagnose conditions such as gastroesophageal reflux disease (GERD), laryngopharyngeal reflux (LPR), and eosinophilic esophagitis (EoE). It can also be used to evaluate the effectiveness of treatments for these conditions, such as proton pump inhibitors (PPIs) and antireflux surgery.

Advantages and Limitations

Impedance–pH monitoring has several advantages over other diagnostic techniques for GER. It can detect both acid and non-acid reflux, and it can identify reflux regardless of the pH of the refluxate. However, the procedure is invasive and can be uncomfortable for the patient. It also requires specialized equipment and trained personnel to perform and interpret the test.

See Also

• Esophageal manometry
• 24-hour esophageal pH test
• Bravo pH monitoring