Ambulatory pH monitoring of gastro-oesophageal reflux in "morning dipper" asthmatics.

A causal relation between gastro-oesophageal reflux and nocturnal asthma has been postulated. Forty four adult asthmatics underwent ambulatory monitoring of their oesophageal pH over 24 hours to find out if there was such a relation. Of these 21 showed significant "morning dipping" in which the peak expiratory flow falls during the night. Asthmatics with morning dipping had a history of nocturnal wheeze and a higher incidence of reflux symptoms, but measurement of oesophageal pH showed no significant difference in the amount or pattern of reflux when compared with "non-dippers." Overall, 15 asthmatics had gastro-oesophageal reflux, and these participated in a randomised, double blind crossover trial of ranitidine versus placebo. No significant difference was found in the peak expiratory flow rates or subjective evaluation of well being of the patients.