KEYSTONE, COLO. — Physicians treating patients with asthma and other airway symptoms should not rely solely on gastroenterologists' interpretations of pH probe tests, because they might miss laryngeal-pharyngeal reflux that threatens the upper airway, Dr. Donna Bratton said at a meeting on allergy/clinical immunology, asthma, and pulmonary medicine.
“Gastroenterologists may not be familiar with patients with asthma, chronic cough, or laryngitis, and pH probe patterns may look unfamiliar in the context of what they usually see,” said Dr. Bratton, an allergist with the National Jewish Medical and Research Center in Denver. “If they don't find something significant in the lower esophagus, they may miss something significant in the larynx or pharynx.”
Asthma patients with suspected gastroesophageal reflux (GER) or laryngeal-pharyngeal reflux (LPR) are a heterogeneous population in terms of esophageal acidification. Some patients have short episodes of reflux and others show prolonged episodes associated with esophageal injury, she said at the meeting, which was sponsored by the National Jewish Medical and Research Center.
“GI doctors are very good at treating GER with proton pump inhibition therapy, which appears to work best in the most severe cases. But when patients have short periods of acid reflux that are full column to the top probe and don't result in prolonged acid exposure, they don't know what it means, and we see this same pattern in LPR,” the allergist said.
Some of the patterns and parameters that are known to injure the esophagus are not necessarily seen in airway dysfunction patients, but that doesn't mean they aren't having significant reflux that might go into the esophagus or even higher into the pharyngeal area, Dr. Bratton said in an interview.
Standard pH probe monitoring is unable to detect nonacid GER, which doesn't concern GI doctors because it doesn't injure the esophagus. Although the esophagus has many defense mechanisms against acid, other compounds in reflux might damage the airway, Dr. Bratton said.
“Bile and enzymes from the duodenum do not show up on a pH probe, and when you get all the way up out of the esophagus into the LP area, those tissues do not have some of the defenses that the esophagus does,” she said. Symptoms might be generated merely from those protective mechanisms being repeatedly triggered by nonacidic material, she added.
Dr. Bratton's message to doctors treating airway disease is simple: “Either have a close relationship with your GI doc if he or she shows an interest in airway disease, or look at these probe studies yourself and see if the patterns are posing significant problems that are correlated with patients' symptoms or disease,” she said.
The esophagus has many defense mechanisms against acid, but other compounds in reflux might damage the airway. DR. BRATTON