Association of gastroesophageal reflux and O2 desaturation: A novel study of simultaneous 24-h MII-pH and continuous pulse oximetry

Background: Proof of the relationship between gastroesophageal reflux disease (GERD) and respiratory symptoms remains a challenge. Our aim was to determine the association between reflux events and O2 desaturation in GERD patients with primary respiratory symptoms (RS) compared to those with primary esophageal symptoms (ES) using ambulatory monitoring systems. Methods: One thousand eight hundred fifty-one reflux episodes were detected by multichannel intraluminal impedance (MII)-pH testing in 30 patients with symptoms of GERD (20 RS, ten ES.) All patients underwent simultaneous 24-h MII-pH and continuous O2 saturation monitoring via pulse oximetry. Reflux-associated desaturation events were determined by correlating synchronized 24-h esophageal pH and/or impedance and O2 desaturation. Results: One thousand one hundred seventeen reflux events occurred in patients with RS and 734 in those with ES. Nearly 60% of these 1,851 reflux events were associated with O2 desaturation. Markedly more events were associated with O2 desaturation in patients with RS (74.5%, 832/1,117) than in patients with ES (30.4%, 223/734, p∈<∈0.0001). The difference in reflux desaturation association was more profound with proximal reflux-80.3% with RS vs. 29.4% with ES (p∈<∈0.0001). Conclusions: A remarkably high prevalence of O2 desaturation associated with gastroesophageal reflux was noted in patients with RS. Given further study, simultaneous combined esophageal reflux and O2 saturation monitoring may prove a useful diagnostic tool in this difficult group of patients. © 2009 The Society for Surgery of the Alimentary Tract.