An association betweeen gastroesophageal reflux and asthma has been postulated though the pathophysiology underlying the association has been difficult to investigate. Two theories have been proposed: aspiration of refluxed gastric contents and neurogenic reflux bronchoconstriction stimulated by esophageal exposure to acid. The present study was done to study the effect of distal esophageal acid infusion on PEFR as previous similar studies have produced inconsistent results.
Thirty adult asthmatics meeting the criteria of the American Thoracic Society were selected. Ambulatory 24-hour esophageal pH monitoring was done to detect GER in the selected group. Patients with significant GER underwent a modified Bernstein test with distal esophageal infusion of 0.1 N hydrochloric acid and PEFR measurement. The primary outcome measurement was peak expiratory flow rate.
The study population consisted of 18 (60%) females and 12 (40%) males. The mean age of the study group was 33.33 years (range 16-77). The mean duration of asthma was 2.64 years (range 9 months to 10 years). Twenty one patients (70 %) were found to have significant GER. The mean PEFR on initial saline infusion showed 20.7% reduction on intraesophageal acid infusion (175.23 ± 64.23 L/min to 138.93 ±57.03 L/min, p<0.001).
Low distal esophageal pH decreases PEFR by causing bronchoconstriction. This supports the hypothesis of neurogenic reflux bronchoconstriction due to stimulation of vagal receptors in the distal esophagus by acid.
Gastroesophageal reflux may contribute to exacerbations of asthma in some patients. Physicians should identify and treat GER in these patients. This may help in better asthma control, reduced dosages of antiasthma medications and higher quality of life in these patients.
B. Sharma, None.