[24-hour esophageal impedance-ph monitoring: technical aspects, indications and results].

Background: Classical techniques like endoscopy and esophageal pH-metry are the gold standard to study patients with symptoms related to gastroesophageal reflux disease. Although these techniques have been useful over the years both for diagnosis and therapeutic guidance, there are still many patients with typical or atypical gastroesophageal reflux disease symptoms with normal endoscopy and pH-metry that do not respond adequately to antisecretory therapy. Ambulatory esophageal impedance-pH monitoring is a new technique that can be used to evaluate all types of gastroesophageal reflux, achieving higher rates of sensitivity and specificity than standard techniques.
Aim: To precise the technical aspects of the esophageal impedancepH monitoring, indications and results of this technique in clinical practice.
Methods: Literature revue of the esophageal impedance - pH monitoring Results: Combined multichannel intraluminal impedance and pH monitoring is a new technique that can be used to evaluate both bolus transport and all types of reflux (acid, weakly acidic and weakly alkaline), without radiation hazards. With this technique, higher rates of sensitivity and specificity than standard techniques are obtained in the diagnosis of pathological gastroesophageal reflux. The technique has also been used in the evaluation of atypical gastroesophageal reflux symptoms, in the assessment of the association of different patterns of reflux with symptoms, and in the evaluation of therapeutic outcome mainly in patients with refractory gastroesophageal reflux disease.
Conclusion: The esophageal impedance represents real progress in understanding the different mechanisms involved in the pathophysiology of gastroesophageal reflux. This technique should also allow a better understanding of the responsibility of non-acid reflux in special clinical situations, such as patients resistant to antisecretory or extra-intestinal manifestations of gastroesophageal reflux.