The additional yield of esophageal impedance monitoring in identification of reflux as the cause of reflux symptoms is unknown.
Dr Albert Bredenoord and colleagues from the Netherlands assessed the yield of symptom-reflux association analysis of combined esophageal pH-impedance data.
The research team compared this with the yield of analysis of pH data alone.
In 60 patients with symptoms of heartburn and regurgitation combined, 24-hour pH-impedance monitoring was performed.
The patients stopped acid-suppressive medication 1 week in advance.
The researchers selected 48 patients with at least 1 symptom during the measurement period for further analysis.
Patients were instructed to note the time and nature of their symptoms.
The team defined 11 types of reflux episodes were defined.
|A positive symptom association probability varied between 63% and 77% in patients|
|American Journal of Gastroenterology|
The definitions were based on combinations of magnitude of the pH drop, nadir pH, and nature of the refluxate on impedance tracings.
Symptom association analysis—symptom index, the symptom sensitivity index, was performed for each definition of reflux.
The researchers also performed the symptom association probability for each definition.
The proportion of patients with a positive symptom association probability varied between 63% and 77%, depending on the definition of reflux episodes.
The team noted that when both pH and impedance parameters were used to identify reflux, more patients had a positive symptom association probability than with pH alone.
Symptom association analysis for acidic and weakly acidic reflux alone did not show a higher yield than for all reflux episodes pooled, regardless of pH.
Dr Bredenoord's team concludes, “In patients off proton pump inhibitor (PPI), the addition of impedance monitoring to esophageal pH monitoring leads to an increase in the proportion of patients in whom an association between reflux episodes and symptoms can be identified.”