Pepsin, activated by acid, is the damaging factor in both reflux conditions, Dr. Koufman told ENToday. The theoretical basis for this is very sound, added Dr. Ford, because the larynx is not well protected with carbonic anhydrase-releasing enzymes and so it’s going to be damaged if even a little squirt of stomach acid which includes pepsin gets up there. But there are no anti-peptic drugs, so H2 antagonists or, more commonly now, proton pump inhibitors are the treatments of choice for both conditions. In fact, with LPR, a good response to PPIs can confirm a diagnosis suggested by the symptoms.
Explore this issue:May 2006
Tools for Diagnosis
One diagnostic aid is the Reflux Symptom Index (see left). Designed by Dr. Koufman, Peter Belafsky, MD, and others, it can be administered to patients both before and after initial treatment to confirm the diagnosis. Patients grade a list of possible LPR symptoms on a 0 to 5 point scale; a score greater than 13 strongly suggests the presence of LPR.
The importance of various laryngoscopic findings in the LPR diagnosis can be assessed with the Reflux Finding Score, also designed by the Wake Forest group (see right). This scale rates eight possible LPR-associated signs on a variably weighted score of 0 to 4: subglottic edema, ventricular obliteration, erythema/hyperemia, vocal fold edema, diffuse laryngeal edema, posterior commissure hypertrophy, granuloma, and thick endolaryngeal edema. A score of 7 or higher yields a 95% certainty that LPR is present.
The definitive approach to confirming LPR is pH monitoring, specifically ambulatory 24-hour double-probe (simultaneous esophageal and pharyngeal) pH monitoring. The simplest of such devices have sensors just above the lower esophageal sphincter and just where the esophagus opens into the hypopharynx. The placement of these tubes is very important, noted Dr. Ford, because if the top is too high it gets exposed to air, which gives a false reading, or to enzymes in the mouth that neutralize the acid.
Also available are tubes that have sensors all along this distance. The more sophisticated version, which is the multichannel impedance test, measures not only liquids that come up from stomach but also gases, and it’s possible with this device to monitor and recreate on a computer the whole process of materials going up and down the esophagus, Dr. Ford said. The sensors let you know the resistance between the walls of the esophagus. If the patient is not swallowing there’s very little resistance. If he patient does swallow, a bolus of air goes through, separating the walls and giving maximum resistance. Fluids give another reading entirely. So if gases ascend and foods ascend they can be differentiated and, in addition, the pH can be measured at those levels.
Room for Improvement in Diagnostic Methods
Dr. Ford added, though, that this sophisticated and sensitive multichannel impedance device has only been around for a few years, so experience is somewhat lacking. Practice is essential. Also, the software programs aren’t well worked out yet, so use of the device is labor intensive. Most often, gastroenterologists rather than otolaryngologists place the device. If it’s positive or the pH test is positive, the patient probably has reflux.