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Manometry and motility testing

We returned home a week ago from our second and final experience with antroduodenal manometry testing (aka AD manometry). The first time we had it done, I was still very new to everything we were experiencing and hadn't had the time to wrap my head around all of it so I felt like a lot of it went over my head. I have spent nearly 5 years now trying to learn everything I can and trying to understand how the digestive system works, and how Raya's digestive system works. I've learned a lot in 5 years, both from experience and from textbooks, so I thought I would share what our experience was like for round 2 of manometry testing in the hopes that it will help someone else be more prepared going into motility testing.

(Our first experience was at Nationwide Children's Hospital in Columbus, Ohio in 2010. Read about it here and here.)

Here are a few key words to help this make sense:
*motility- the way that food and liquids move through the digestive tract
*dysmotility- problems with the way that food and liquids move through the digestive tract
*manometry study- a test that measures the strength and coordination of muscle contractions through the digestive tract
*antroduodenal manometry (or AD manometry)- a manometry study that looks specifically at the function of the digestive tract between the antrum of the stomach (the part that connects with the small intestine) and the duodenum (first portion of the small intestine)

This round of motility testing was done at Children's Hospital of Los Angeles.

We started with an EGD (endoscopy) to look at the condition of her esophagus, stomach, and duodenum. They all looked beautiful. My girl is beautiful on the inside and out. Literally. :)
While she was under anesthesia, her G tube was removed and the manometry catheter and an NG tube were threaded through the G tube stoma. The manometry catheter was guided into place in her small intestine and the NG tube was in her stomach so that she could be given a formula bolus and have the extra water from the manometry catheter drained out of her stomach during the study. The yellow tube is the NG tube and the clear tube is the manometry catheter:
(*Note: if she hadn't had a G tube, they would have placed the manometry catheter & NG tube through her nose instead. For that reason, I am SOOOO glad she already had a G tube because the catheter was probably about a 12fr, which would be huge in a little nose.)

Normally they would have waited for her to fully wake up on her own but because of how badly she usually wakes up from anesthesia, she has to get meds to help her sleep off the anesthesia drugs so that she wakes up more gently. We waited for about an hour but she was still completely out cold. We had to wake her up as much as we could get her to wake up so they could let her leave PACU and go back to her room. At Nationwide, she did not have an endoscopy and I was able to be in the room with her (in Interventional Radiology, aka IR) while they took out her GJ tube and put in the manometry catheter. There, the study was done in a special room in a different part of the hospital but at CHLA, they took us back to her hospital room and just brought the computer & equipment into her room. I liked that a LOT better. It made things much easier on me since the study lasts 6-8 hours. This is what the manometry catheter was connected to once we got her back to her room:
The blue tube coming from the lower left corner of the picture is the catheter that was in her stomach. Inside the catheter, there were 8 tiny tubes that each connected to another tube on the machine. You can see the dark blue caps connected to the lighter blue tubes in the middle of the picture. Here's a closer picture of that part where you can see each of the small tubes connected to the machine:
Each of the tiny tubes had a tiny pinhole at some point along the tube, and each pinhole rested at a different point in the stomach, pylorus, or duodenum. There was a constant flow of water from the canister (to the right of all the tubes in the middle of the picture) through the tiny tubes in the manometry catheter, and each time there was a muscle contraction at one of those points in her digestive tract, the muscle contraction would pinch the pinhole and obstruct the flow of water through the tube. The obstruction would cause pressure to build up between the pinhole and the computer, which would then register on the computer monitor as a spike on the reading.

On the monitor, there were 8 colored lines that each corresponded with one of the tiny tubes inside the manometry catheter. Here's what it looked like when her stomach still wasn't really doing anything:

And here's what it looked like when things started moving again after she finished waking up from the post-anesthesia fog:
That was the first real spike we saw in any of the sensors. We guessed (and the doctor later confirmed) that the 3rd sensor was in her pylorus. We could more or less tell which sensors were where based on the activity. The top 2 were in her stomach, the 3rd was in her pylorus, and the other 5 were in her small intestine.

The study was run on a very specific schedule. She was NPO (nothing by mouth) for the first 5 1/2 hours. At the 4 hour mark, she was given a dose of IV erythromycin to stimulate muscle contractions in her stomach. The medication went in over a 30 minute time frame and then we waited 1 hour from the time it finished. At that point, we had 20-30 minutes to get as close to 400 calories into her as we could, either by mouth or through the NG tube. When they first told me what the schedule of events would be, I thought it seemed backwards to give her the erythromycin before the food and I was afraid that doing it in that order would keep us from seeing an accurate representation of how her stomach behaves in the presence of food. They explained that the reasoning for the order of things was to first show us how her stomach & small intestine behave in the complete absence of food, then to show us if her stomach responds to erythromycin and how well it responds to it, and then to see how her stomach would respond to a meal. They assured me that her stomach would return to its baseline activity level in the hour we waited between the end of the erythromycin dose and her meal, and it did.

Most of the day was spent keeping Raya as still as we could keep her, telling her how many more minutes until she got to have a sip of apple juice, watching movies, playing games on the iPad, playing with toys, listening to a couple of different singing groups that came around to sing the kids Christmas songs, and staring at the computer monitor. I have to admit that the science nerd in me was totally fascinated with it. It was pretty amazing watching a visual representation of what was going on inside her body moving across the screen. One thing that the nurse pointed out to me (and the Chinese doctor that was observing) was something called a migrating motility complex (or migrating motor complex), also known as an MMC. Peristalsis is the wavelike muscle contractions that sweep food & liquids through the digestive tract in small portions. MMCs are a pattern of peristalsis that happens in the small intestine. We could see that Raya was having MMCs as we watched the screen and saw a pattern repeat progressively from one sensor to the next. It was pretty cool to see, and it was good to see an indicator that her small intestine was having normal function. This is what it looked like:
You can see that the MMC started at the orange line in the middle and then the contractile pattern continued to move through her small intestine, registering on each sensor as the muscles contracted in a wavelike pattern. You can also see in that picture that her stomach (the top 3 lines) was not active at all during that time.

Crazy things happened when they gave her the IV erythromycin. (Good crazy. It was supposed to happen.) Within a minute or two of the IV erythro starting, we started seeing a huge amount of activity in her stomach. As I mentioned before, the point of this was to see if her stomach would respond to erythromycin and how well it would respond to it. It most DEFINITELY responded!
The erythro started right around the where the red X is. There wasn't a whole lot going on in her stomach at that point. The blue X marked a spot where she had started laughing and it registered on all of the sensors. We marked it on the study because we were making note of how her demeanor was during certain points. Shortly after the blue X, the erythro really started to kick in, as evidenced by all of the huge spikes on the screen. The yellow X marks the point where she stopped smiling, stopped responding to verbal cues and questions, got very quiet, and became fidgety and squirmy. In other words, she didn't feel well.

When the erythro ended, we started the final 1 hour countdown before she could have some food and a drink of the apple juice she had been asking for all day. It feels really awful telling a child that we've spent 5 years begging/pleading/encouraging to eat that she can't even have a sip of water so it was a huge relief for everybody when it was finally time for her to eat. Since we knew there was no way she would eat enough food for the study, we also mixed up 240ml of formula so that she could get an 8 ounce bolus feed during the 20-30 minute mealtime while she ate her food. We ordered everything the cafeteria had that I knew I had a good chance of getting her to eat: baked potato with non-dairy margarine, corn, refried beans, French fries, and apple juice. {small rant: It was frustrating to know that even at a hospital, her food allergies were not fully accommodated but we did the best we could. Aside from cooking her fries in oil that was cross-contaminated with wheat and who knows what else, they also sent up crackers that we didn't ask for that she is quite obviously allergic to. It's kind of irritating to see that happen in a hospital where I had given her food allergies to multiple people when we were admitted.}

Moving on... She was really excited to get her food and she ate well for the first 10 minutes, just like she does on a great day at feeding therapy.
This is what the monitor looked like while she was eating and still feeling good:
 You can see the spikes in the top 2 lines that were measuring stomach activity, and also the 4 big spikes in the pylorus, which probably (if I had to wager a guess) showed that food was being segmented and pushed through the pylorus into the duodenum.

Also true to form, by the 10 minute mark, she was no longer very interested in eating her food. She was no longer leaning forward and engaging in the meal, but rather she was laying back against her pillows. She was having a great time talking to us, trying to distract us from the task of encouraging her to take bites, and playing with the fries, but they weren't making it into her mouth anymore. Within a couple more minutes, she just flat out didn't feel good anymore. It was written all over her face that she felt like puking.
It may sound strange but I was really encouraged at that point. Seeing that her body was doing exactly what it normally does meant that we were recording data that fit into the scope of Raya's "normal," which meant we were getting an accurate study. I didn't feel like we got an accurate study when we did the first manometry study 4 years ago because she had been vomiting several times a day for months, and only vomited twice that whole week, and neither time was during the manometry study. Having that prior experience, I felt really good about how things were going during her meal, and pretty much the whole day this time around. Interestingly, this is what the screen looked like at the point where she had stopped eating and felt sick:
There was very little activity happening. Since I really didn't know anything about what I was looking at, I had my fingers crossed that seeing her stomach stop moving was clinically significant but it turned out not to be. Boo.

We kept plugging along and encouraging her to eat as much as we could get her to while the nurse gravity fed her the 8 ounces of formula. (for the sake of reference, she has not had an 8 ounce bolus feed over 20-30 minutes in probably 2+ years, and I don't think she has EVER had an 8 ounce gravity feed, and I'm pretty sure the last time she had 8 ounces of formula in her stomach that fast was 2 years ago when she chugged a box of Splash and then threw the whole thing right back up. She hasn't been fed above 90ml/hour for close to a year.)
Then we got a beautiful serenade from a mariachi band:
It was seriously awesome. I wished they could have played music for us all day long!

From then on, we just sat around and tried to keep her stomach from leaking too much while we waited for the study to be over. There wasn't much of anything exciting going on in her stomach or intestine from what we could tell.
When the nurse thought we had everything we needed, the motility doctor came in to quickly look through and have a quick look at the data, and then the nurse carefully peeled off the tape, pulled out the probe, we put in the new G tube I had brought with us and we were done. (BRING YOUR OWN REPLACEMENT unless you're okay with getting whatever kind of tube the hospital happens to have or else getting the old G tube put back in. We were due for a change anyway so I brought a new one.)

So that's the basics of an AD manometry study. The hardest part is keeping an active child still and occupied all day long. There is also a LOT of extra pee, thanks to the constant stream of water from the manometry catheter. The nurse told me that for kids who are potty trained, they will bring in a bedside commode since they can't get to the bathroom with the manometry catheter in place.

The doctor came in the next day to go over the results with me (read about that here) and then we were discharged later that afternoon and flew home late that night. All things considered, it was a successful trip and even though the results were disappointing, the actual testing process went really well and I was happy with the way that CHLA does motility testing. The travel was really simple too. We flew into LAX, took a bus to the train station, and then got on the subway. There was a subway stop literally across the street from the hospital. The bus fare was $8 and the subway was $1.75 so it was really affordable and easy. I would highly recommend going to CHLA for motility testing, especially for anyone who lives closer to the west coast than to Ohio or one of the other motility centers.


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