Citric acid cough threshold in patients with gastroesophageal reflux disease rises after laparoscopic fundoplication

Background: It has been reported that antireflux surgery can diminish chronic cough due to gastroesophageal reflux disease (GERD) that is resistant to pharmacologic therapy. The aim of this study was the assessment of citric acid cough threshold (CACT) in patients with chronic cough due to GERD before and 3 months after laparoscopic Toupet fundoplication. Methods: Thirty subjects (20 women and 10 men; median age, 45.3 years) with chronic cough due to GERD and 15 healthy volunteers underwent cough challenge with doubling concentrations of citric acid. Twenty subjects with GERD, a group of 14 women and 6 men (mean age, 45.5 years), underwent the same protocol 3 months after laparoscopic fundoplication. Daytime and nighttime cough score questionnaires (verbal category descriptive score) were completed in all groups. Results: The geometric mean of CACT was significantly lower in GERD patients (9.62 mg/mL) than in healthy volunteers (50.8 mg/mL, p < 0.001). The results of cough score measurement significantly improved within 2 weeks after laparoscopic surgery. In 13 weeks of postoperative follow-up, cough disappeared or was greatly improved in 14 of the 20 patients (70%); in 3 other patients, cough resolved partially. In three patients. there was no improvement in cough. Cough challenge after surgery revealed a significant increase in mean cough threshold, from 8.28 to 19.03 mg/mL (p < 0.05). Conclusions: The results suggest that GERD influences CACT, which was significantly lower in GERD patients compared to healthy subjects. A significant correlation was found between subjective and objective measurements of cough in GERD patients. We found laparoscopic fundoplication to be objectively beneficial in GERD-induced chronic cough, as it reduced the CACT.