pH/Impedance Testing

To determine if you have the reflux disease, you may need to undergo pH/impedance testing. A pH test measures the amount of acidic material that comes from your stomach into your esophagus and into your throat. When evaluating laryngopharyngeal reflux (LPR, or reflux that affects your throat), it is particularly important that the acid levels be measured in both the esophagus AND your throat – testing that it is not available at most centers. We offer this dual-probe pH testing in combination with impedance, which both tells us the direction of the reflux (helping to distinguish a reflux event from a swallow) and also tells us if you are having NON-acid reflux.

Most reflux medications usually control acid production very well, but they don’t stop reflux. You may still be having reflux of stomach contents into the esophagus or throat, although it may be less damaging with less acid content. Some people are still very sensitive to this weakly acid, or non-acid reflux, particularly for cough and throat clearing. The impedance portion of this examination allows us to evaluate you for non-acid reflux.

What to Expect

Manometry is the first step in the pH/impedance test. After this 30 minute pressure test, the 2 mm soft catheter will be placed through your nose and positioned precisely in your esophagus. Then it will be secured to the side of your nose with clear tape. This catheter stays in place for 24 hours. Yes, you go home with it in place. Yes, people can see it. And yes, you can and should do all your normal activities, including working. The only thing you can’t do with the catheter in place is take a shower or bath (the water will ruin the equipment). You will have a monitor with buttons to push when you are having symptoms. You will also have a diary on which to record when you eat and when you lie down. The catheter is removed quickly the next day in the clinic. The results have to be analyzed carefully by our physicians, so they will not be available for 1-2 weeks.

Tips for improving the diagnostic value of your pH/impedance study:

  • Do not get the equipment wet.
  • Try to record the times of meals and lying down very specifically.
  • Avoid sipping on beverages through the day. If you do have a drink, remember to record this.
  • Try to do your normal activities – remember, if you are having reflux, we want to see it! You may not have any reflux if you sit very still on your couch all day and don’t eat anything! So eat your normal foods and do your normal activities, including exercise and working.
  • If you are frequently coughing or throat clearing, try to only push the button when the episode starts. Pushing the button 50 times during a cough episode makes the data much more difficult to interpret.

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Last Updated: 03-05-2014
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Disclaimer: The information on this website is for general informational purposes only and SHOULD NOT be relied upon as a substitute for sound professional medical advice, evaluation or care from your physician or other qualified health care provider.