Proximal reflux as a cause of adult-onset asthma: the case for hypopharyngeal impedance testing to improve the sensitivity of diagnosis.

Objectives: To determine the patterns and proximity of reflux events in patients with adult-onset asthma (AOA) using hypopharyngeal multichannel intraluminal impedance (HMII) and to assess outcomes of antireflux surgery (ARS) in patients with AOA. DESIGN Retrospective review of prospectively collected data.
Setting: University hospital. PATIENTS, INTERVENTIONS, AND OUTCOMES: All patients with AOA referred to our testing center underwent HMII, and those with abnormal proximal exposure, defined as laryngopharyngeal reflux at least once a day and/or high esophageal reflux at least 5 times a day, subsequently underwent ARS.
Results: From October 1, 2009, through June 30, 2011, a total of 31 patients with AOA (4 men and 27 women; mean age, 53 years) underwent HMII. Of 27 patients with available information, 11 (41%) had objective evidence of reflux disease. Nineteen patients (70%) had concomitant typical reflux symptoms. Despite a frequently negative DeMeester score, abnormal proximal exposure, which occurred in the upright position, was observed in 19 patients (70%). Of 20 patients who subsequently underwent ARS, asthma symptoms improved in 18 (90%), and 6 of them discontinued or reduced pulmonary medications at a mean (range) follow-up of 4.6 (0.6-15.2) months. Pulmonary function test results before and after ARS revealed that of 5 patients, 4 (80%) had improvement of the forced expiratory volume in the first second of expiration and/or the peak expiratory flow rate, which correlated with symptomatic improvement.
Conclusions: Adult-onset asthma is associated with abnormal proximal exposure of the aerodigestive tract to refluxate; these patients respond to ARS despite negative pH test results. Patients with AOA should undergo testing with HMII because they would not be detected with conventional pH testing.