How to Diagnose Your LPR by using Restech pH Monitoring

Letzte Aktualisierung:
8. June 2024

Interview with Dr Mark Noar

Most refluxers get pH monitoring done to diagnose their LPR.

But most of them have no clue how to interpret the results. At the same time, many patients feel their physician did not take the time to properly explain the results.

So it might be helpful for you to know more about how to interpret those results yourself.

This is why I have talked with Dr. Mark Noar about this matter. He does pH monitoring to diagnose LPR frequently. In our talk, we focus on pH probes manufactured by the company Restech. Their probes are currently the most accepted tool to diagnose LPR.

This is the second part of the interview. In the first part, we spoke about the role of the sphincters in LPR. In the third part, we will talk about the Stretta procedure and operations in general

Part #2 – pH Monitoring and Restech Probes

How is pH monitoring used by physicians to diagnose LPR?

Dr. Mark Noar: Doctors are always talking about pH – that very low pH means you have reflux and only that.

But it is not that easy.

Sometimes they do a pH study and cannot find that the pH drops low enough or often enough to say you have reflux.

Instead, they want to give you antidepressants, not because they think you’re depressed or crazy, but because antidepressants deaden the sensation of pain.

They call you hypersensitive or even functional, but you’re not hypersensitive.

You’re just refluxing weak acid but all the time. So you are refluxing a lot without reaching a certain pH threshold that they want to see to make the diagnosis of reflux. Then they brand you as hypersensitive, discounting the fact that you’re having these symptoms.

I’ll tell you a very brief anecdote.

There is a patient who was seen at a well-known university hospital. The pH monitoring showed that she was refluxing, but only 40 times. Each time she was refluxing, she pushed a button that indicated that she was feeling the reflux.

She was told by her famous doctor that because she only refluxed 40 times, she was just hypersensitive and it was not real reflux. She was advised to see a psychologist.

This is essentially like saying that unless the number of reflux events was 91 or more times with a pH below 4, that there was no real reflux taking place. It is almost like saying that you have to hit someone in the head 91 times before you accept that they have been hit in the head.

Now that’s a very violent example, but saying this to a patient suffering from reflux is very violent because you’re discounting their symptoms and ignoring the mechanism of action of this disease. All refluxers should be treated equally. It’s not about whether someone refluxes once or a hundred times. They’re telling you they’re in pain. It’s real. You’re just detecting acid in their esophagus. Get away from the idea of quantification and start understanding that even one episode can be too much to bear for many.

Doctors want to quantify events so that they can put you into a group. If your number of symptoms do not fit well in the group, you won’t get treated effectively.

I want to talk with you specifically about Restech. These probes are used more and more often to diagnose LPR by monitoring the pH. What is the difference between Restech probes and others?

Conventional pH probes measure pH in the esophagus. They also do not tell you what’s happening in the larynx, because for LPR it is about looking for gas coming up, not so much liquid.

Also, sometimes the traditional type sensors can dry out, and you don’t get perfect readings.

The Restech probe remains hydrated because of its technology. This makes it also possible to measure both liquid and gas, which other probes cannot do. A little bit of fluid will swell the sensor so that it can measure both liquid and gas.

Can you give me an example of what the results of a Restech study looks like?

This is what the graph of a typical Restech pH study looks like. It is of a real patient.

graph of a restech test

The green color shows the normal pH range of the larynx: 6.5 to just around 8. Anything that’s either above or below that are either reflux episodes of acid or bile or episodes where the patient has drunk some fluid that’s acidic. Typically, a digestion-associated spike is extremely narrow.

These tiny little spikes are where the patient is drinking something acidic. The wider areas are laryngeal reflux episodes. They don’t last for a second or two but for longer periods of time. The one in the night around 4 AM lasted about 45 minutes.

This turquoise-colored bar at the bottom shows when the patient was sleeping. So during the day there is not a lot of reflux taking place, but as the patient lies down we begin to see drops in pH all the way down to 4 – for very long periods of time. Imagine you’ve got 45 minutes where the pH is sitting down below 4.0, and you don’t know. This is what’s causing a lot of diseases.

Quantified data that you get from ph testing

You also get a report that shows you clear numbers.

In this patient, the pH was below 6.5 while they were lying down 30 percent of the time. That means that 30 percent of the time this patient was asleep, their larynx was being bathed by acid.

What you have to understand is that even a small number of events can cause serious problems if they last long enough. When Dr. Koufman first presented the concept of LPR, she determined that the number of reflux episodes into the larynx that you need to cause LPR is three times per week. That’s astounding because this patient had 12 events that were more than five minutes long – in just one night. You can see why people like that develop symptoms.

the ryan scores show by a pH study how likely people profit from a fundoplication

The report also provides you with these scores, which are called RYAN scores. They tell you whether a patient would be a good candidate for a reflux correction procedure like a Nissen fundoplication.

These numbers are based on doing Nissen fundoplication in patients after they did a Restech study. In this case, the scores are high. That means that this patient would be expected to profit from a Nissen fundoplication.

Interesting. When you look at this report, how strong would you say this person’s LPR is?

This person has very strong LPR. This is a patient of mine. This is someone who is constantly coughing, clearing their voice constantly, and having episodes of bronchitis.

These are the results of a patient after we have put him on medication:

ph levels become normal with treatment

You put patients on medication to normalize their acid scores, but you’re measuring acid. So we have only made sure that they’re not getting a lot of acid into their throat, but we’re not stopping them from refluxing pepsin, which is the actual cause of damage in LPR.

What is the effect of PPIs on LPR symptoms?

The patient feels better for a period of time, which is classically what we find in many patients on chronic proton-pump inhibitor therapy, whether with LPR or standard reflux.

They feel great for a while, and then all of a sudden their symptoms start coming back. Because all we were doing was hindering acid from coming up, but they continue to reflux pepsin. So they still get inflammation. It is just decreased.

Going back to what causes the LPR symptoms: you reflux pepsin, which is reactivated by acidic foods or regurgitated acid. Because of the PPIs, they do not have much acid coming up. But they still drink or eat acid. It takes longer to see symptoms because it’s less acid to stimulate the pepsin. They feel better for a period of time, but then it’s just a matter of time before the pepsin is activated enough because of dietary reasons.

Talking about the acid in reflux, what is alkaline reflux?

This is an example of alkaline reflux:

reflux reaches alkaline levels

This study was done with a patient on medication, who was still having a lot of LPR symptoms. What you see is that the pH is above 8 a lot of the time and goes up to 9. This is clearly alkaline reflux.

Very interesting. I have some readers who say they have that, but I have never seen it myself. What happens in alkaline reflux?

When you are taking an acid suppressant, there’s no acid or there’s very little acid.

However, they have bile pooling in their stomach, which is normal.

Bile is alkaline. On acid-suppressing medication, the only thing you have to reflux is the alkaline component from your stomach, the bile, and that’s what you’re seeing in the chart. This is a great example of alkaline reflux. Unfortunately, many physicians will fail to recognize alkaline reflux because they believe that acid is the only thing that causes reflux.

Alkaline reflux is typical in patients who had their gallbladder removed. The gallbladder stores bile. If it’s gone, then the bile has to go somewhere else….for example, into the stomach.

One completely different question: What about the placement of the device? Is it hard to place?

It’s hard to place it wrong. They ask the patient to open their mouth. Then you should see the blinking light of the probe.

When they open their mouth, and you don’t see the light, the probe is either too high or too low.

Normally pH testing is done for 24 hours. Is there a reason why you would do longer than 24 hours?

It would be unusual.

The value might be that in one day the patient wasn’t refluxing but the second day they were. So maybe you’ll capture something you wouldn’t have seen in 24 hours. But that would be rare.

What difference does the skill of the person looking at the report make?

The old Restech software required skill.

The new Restech software where everything is broken down by pH zones is very easy for people to read.

The big difference is that you have to interpret it differently than conventional pH studies in the esophagus – like most gastroenterologists are doing with standard pH monitoring. For standard esophageal reflux the intervals are short. With the Restech study, you are instead looking for different signs. In particular, with LPR the peaks are few and very long. So if you are new to Restech and used pH probes for the esophagus before you have to change how you look at the data.

But I think the new Restech software is very easy to understand and interpret. So everybody should be able to do it.

End of Part #2 of the Interview

The interview with Dr. Mark Noar was packed with useful information.

I have split the content into multiple parts to make it easier to digest. The first part was about the sphincters. The next part is about the Stretta procedure, and surgeries in general.

test for silent reflux

About the author 

Gerrit Sonnabend

Gerrit is a German data scientist & medical publisher. His formal education is in qualitative research. He had severe reflux himself. Read more about him here.