Reflux monitoring (intraluminal impedance pH monitoring)


Reflux monitoring works by the assessment of the flow of fluid along a catheter positioned in the lumen of the esophagus. Impedance technology allows us to assess the direction of a flow of fluid: influx vs. Reflux. Correlation of flows of fluid (influx vs Reflux) with symptoms ( Heartburn etc.) enables us to say, if influx/ Reflux causes the symptoms. In addition the combination of Impedance and pH monitoring allows us to discriminate between acid and non acid refluxes. This is the rational background for our Reflux monitoring.


Persons scheduled for Anti reflux surgery should undergo Reflux monitoring. Reflux monitoring can be conducted with and without medical therapy (on and off PPI therapy).


The catheter for Reflux monitoring includes 6 Impedance tracings and 1-2 pH sensors. The catheter is connected to a battery powered portable data logger.

Preparation for reflux monitoring

Preparation for Reflux monitoring is the same as for Esophageal manometry. The test is conducted in the fasting state. You are allowed to take your morning medication with a small cup of water. For an off therapy test you are asked to discontinue the PPI administration for 10 days. For an on therapy test do not discontinue PPI administration and take the morning dose.

Performance of reflux monitoring

Following Esophageal manometry the Reflux monitoring catheter is introduced into the esophagus via the anesthetized nostrils. The pH electrode is positioned 5 cm above the upper limit of the pressure zone of the lower esophageal sphincter, as assessed by manometry. Impedance is montiored at 6 sites between 3 and 17 cm proximal to the high pressure zone. The test does not hurt and lasts 22-24 hrs. The recorder is equipped with 3 individually configured buttons for entering symptoms  by the patient. This enables us to assess if Reflux causes your symptoms ( Heartburn, regurgitation, cough, wheezing, asthma). After 24 hrs the catheter is removed and the data are transferred from the recorder to the computer for analysis.

Reflux monitoring

Esophageal Reflux monitoring uses a catheter and assesses any type of Reflux (acid and non- Acid reflux). Persons with Heartburn frequently have an increased number of Reflux episodes and abnormal Acid exposure of the esophagus.

Reflux monitoring report

The Reflux monitoring report lists the number of acid and non Acid reflux episodes, the esophageal Acid exposure time and the temporal correlation between Reflux and symptoms.

Normal values for Reflux monitoring ( Impedance pH monitoring  
parameter Normal value
Acid exposure pH < 4.0 < 4.2 % of the time
Reflux episodes < 73
Symptom correlation < 50 %

Relevance of reflux monitoring

Reflux monitoring helps us to tailor the management of your Reflux (life style, eating behavior, medical or surgical treatment). Feel free to contact us for further information regarding the management of your Reflux.

Expert opinion

Johannes Lenglinger (Physiologist, Vienna):

Esophageal Reflux monitoring assesses any type of Reflux, irrespective of the pH (acid, non acid). In addition the test shows us if your Heartburn is caused by the Reflux. A negative Reflux monitoring indicates that surgery is not a good option. Reflux is not the cause for your complaints. The novel technologies enable us to provide fast diagnosis for early treatment.

Martin Riegler (Surgeon, Vienna):

Esophageal Reflux monitoring revolutionized the diagnosis of Reflux. Symptom correlation helps us to assess the cause of the symptoms: Reflux or not Reflux. Therefore before we do the test we have to define the 2 or 3 major symptoms ( Heartburn, acid regurgitation, asthma) in order to see if they are provoked by the Reflux. The positive test makes live easy for the patient and for us: we can consider the surgical option. A negative test tells us not to operate.

Sebastian Schoppmann (Surgeon, Vienna):

There is another great advantage of esophageal Reflux monitoring. Patients can have the test on PPI therapy. This means they do not have to discontinue the anti Reflux medication. There are patients who cannot stop the PPI therapy due to the severity of the symptoms. So we have good diagnostic options for all different types of Reflux patients.


  1. Agrawal A, Roberts J, Sharma N, et al. Symptoms with acid and nonacid Reflux may be produced by different mechanisms. Dis Esoph 2009; 22(5): 467-70.
  2. Savarino E, Zentilin P, Tutuian R, et al. Impedance pH Reflux patterns can differentiate non-erosive Reflux disease from functional Heartburn patients. J Gastroenterol 2012; 159-68. Ahead of print.
  3. Castell DO. Reflux testing in the 21st century: is there a role for pH only? Clin Gastroenterol Hepatol 2008 6(9): 1062.