Saturday, December 4, 2010

Revising a Diagnosis: Acid Reflux

When Nolan had his first pH probe done, it was placed all the way down by his stomach- just above the lower esophageal sphincter (LES). The doctor had to verify its placement with an X-ray, since you can't visually detect if the probe is in the right location. The probe demonstrated that Nolan had severe gastro-esophageal reflux disease, or GERD. His LES was opening at inappropriate times, allowing stomach acid to reflux up into his esophagus. Symptoms typical of GERD are (Nolan's symptoms are in red):

Burning sensation in the throat
Difficulty Swallowing (Dysphagia)
Sensation of a lump in the throat
Reflux is worse when lying down
Slow esophageal motility
Delayed Gastric Emptying
Difficulty gaining weight/failure to thrive

Since starting the Nexium, the dysphagia has disappeared and he has been gaining weight. We thought the GERD was resolved with the addition of proton-pump inhibiting medication: the Nexium has been a literal Godsend for his growth and weight gain.

I thought it was very strange, then, when the ENT placed a probe that was very short, and sat behind Nolan's uvula. It had a red LED light that blinked, and I could see it blinking when he opened his mouth. How could a probe placed that high detect reflux in the esophagus?

As it turns out, they weren't looking for typical GERD. Instead, the probe was a new type created by the Resmed corporation, to detect a type of reflux called laryngopharyngeal reflux disease (LPR). This is the same condition as extra-esophageal reflux disease (EEGD), but is not the same as isolated GERD.

LPR is a distinct diagnosis, because it involves the dysfunction of the upper esophageal sphincter (UES). Acid reflux is normally stopped by the UES, and does not enter the lungs or the pharynx space where the voice box is located. Unfortunately, in Nolan's case, the upper esophageal sphincter isn't functioning, so the reflux comes up and hits his larynx/pharynx. The diagnosis used to be based on clinical evidence (see symptoms below: Nolan's symptoms are in red).

Chronic cough
Reactive airway disease (asthma)
Sleep disordered breathing
Frank spit up
Feeding difficulty
Turning blue
Pauses in breathing (apnea)
Apparent life threatening event (ALTE)
Failure to thrive
Reflux is worse when upright, during the day
Chronic otitis media
Normal esophageal motility

Children with LPR often lack the esophagitis that occurs with GERD, because the acid shoots past the esophagus and pools in the pharynx.

The Resmed probe can be placed visually, because it is placed above the upper esophageal sphincter. The probe detects small droplets of reflux in the air, as opposed to liquid reflux in the lower esophagus.

While LPR is a distinct diagnosis from GERD, the treatment is the same. Proton pump inhibitors are always required for LPR (sometimes GERD can be handled with H2 blockers alone). LPR tends to be more difficult to control, as we have seen in Nolan's case. Children over the age of three do not generally outgrow LPR, since it is caused by a permanent neuromuscular or anatomical problem. If medication fails to control LPR, surgery is sometimes recommended.

It is highly likely that Nolan's LPR is the cause of his laryngomalacia, and we have to control the reflux before we try to do any sort of airway surgery. Since his pharynx is getting sprayed with acid droplets, the laryngomalacia will likely recur if we don't get the reflux under control.

This is why we have our fingers (and toes) crossed that the Zantac + Nexium combination will be sufficient to keep his pH levels in the right range (above 5.5 for daytime readings). Once we can get this reflux under control, we can fix his airway and hopefully many of his other symptoms will disappear!


Melanie said...

Wow. That's a lot of info. Hope the new med combo works!


That is such exciting news! Knowing exactly what is going on is 9/10 of the battle! I am so happy for you! It is simply amazing what God has allowed the medical community to do with technology...I'm so thankful!
Praying the meds will do their job,

Herding Grasshoppers said...

So when do you get your medical degree?!

Praying for Nolan,


Joey @ Big Teeth and Clouds said...

Julie is right! You are one informed parent. It's amazing the stuff we learn for our children.

I hope the combo of meds does the trick!