January 9, 2009

New technique measures reflux not caused by acid

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Patient Cathy Brashera is taking part in a new study, called impedance pH monitoring, that measures non-acid reflux. (photo by Susan Urmy)

New technique measures reflux not caused by acid

Michael Vaezi, M.D., Ph.D.

Michael Vaezi, M.D., Ph.D.

Most people have experienced acid reflux at least once in their life — that painful burning sensation often accompanied by regurgitation, nausea or hiccups that usually goes away with medication such as antacids.

But for a few patients, the symptoms don't go away and often worsen into cough, hoarseness and asthma.

This group may have non-acid reflux, siad Michael Vaezi, M.D., Ph.D., professor of Medicine in the Division of Gastroenterology.

“Reflux is so common and is usually treated with acid suppression, but many don't respond well because it's regurgitation of non-acid reflux as opposed to acid reflux,” Vaezi explained.

Vaezi employs a novel technique called impedance pH monitoring to measure non-acid reflux in patients who continue to have reflux symptoms despite aggressive acid suppression.

Vanderbilt Medical Center is one of only a few institutions in the world to use this technique.

“The procedure has been performed on more than 150 patients, and we're recognized as one of the main centers in the country for doing this,” Vaezi said. “There are seven to eight others, but they focus more on typical reflux disease, whereas here at Vanderbilt we focus on atypical reflux.”

Vaezi said impedance pH monitoring gets to the bottom of what exactly is being refluxed into the esophagus.

“It is the most sensitive way of physiologically measuring reflux of any type in the esophagus, whether it's acid, non-acid, liquid or gas,” he said. “The unknown is the extent to which non-acid is present.”

The monitoring is an outpatient procedure. A catheter is inserted through the nose and sits in the esophagus. Patients are sent home with the device and can eat and drink normally.

For a 24-hour period, the catheter measures pH plus the change in impedance along the esophagus, and then transmits measurements to a recording device the patient wears over his or her shoulder. The recorded information is downloaded, and doctors analyze a report showing the peaks and valleys of various measurements.

“We can see all episodes of reflux and whether they are acidic or not,” Vaezi said.

Once doctors know exactly what is being refluxed into the esophagus and correlate this finding with patients' symptoms, they can formulate a better treatment plan and give patients the relief they have been seeking.