title: Inhaled Beta Agonist Bronchodilator Does Not Affect Trans-diaphragmatic Pressure Gradient but Decreases Lower Esophageal Sphincter Retention Pressure in Patients with Chronic Obstructive Pulmonary Disease (COPD) and Gastroesophageal Reflux Disease (GERD).
abstract: Chronic obstructive pulmonary disease (COPD) patients have a high incidence of gastroesophageal reflux disease (GERD) whose pathophysiology seems to be linked to an increased trans-diaphragmatic pressure gradient and not to a defective esophagogastric barrier. Inhaled beta agonist bronchodilators are a common therapy used by patients with COPD. This drug knowingly not only leads to a decrease in the lower esophageal sphincter (LES) resting pressure, favoring GERD, but also may improve ventilatory parameters, therefore preventing GERD.
  
  
  
  This study aims to evaluate the effect of inhaled beta agonist bronchodilators on the trans-diaphragmatic pressure gradient and the esophagogastric barrier.
  
  
  
  We studied 21 patients (mean age 67 years, 57 % males) with COPD and GERD. All patients underwent high-resolution manometry and esophageal pH monitoring. Abdominal and thoracic pressure, trans-diaphragmatic pressure gradient (abdominal-thoracic pressure), and the LES retention pressure (LES basal pressure-transdiaphragmatic gradient) were measured before and 5 min after inhaling beta agonist bronchodilators.
  
  
  
  The administration of inhaled beta agonist bronchodilators leads to the following: (a) a simultaneous increase in abdominal and thoracic pressure not affecting the trans-diaphragmatic pressure gradient and (b) a decrease in the LES resting pressure with a reduction of the LES retention pressure.
  
  
  
  In conclusion, inhaled beta agonist bronchodilators not only increase the thoracic pressure but also lead to an increased abdominal pressure favoring GERD by affecting the esophagogastric barrier.
authors.affiliation: Department of Surgery, Escola Paulista de Medicina, Federal University of Sao Paulo, Rua Diogo de Faria 1087 cj 301, Sao Paulo, SP, 04037-003, Brazil.
authors.forename: Leonardo M
authors.initials: LM
authors.lastname: Del Grande
authors.affiliation: Department of Surgery, Escola Paulista de Medicina, Federal University of Sao Paulo, Rua Diogo de Faria 1087 cj 301, Sao Paulo, SP, 04037-003, Brazil. herbella.dcir@epm.br.
authors.forename: Fernando A M
authors.initials: FA
authors.lastname: Herbella
authors.affiliation: Department of Medicine, Respiratory Division, Escola Paulista de Medicina, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Amilcar M
authors.initials: AM
authors.lastname: Bigatao
authors.affiliation: Department of Medicine, Respiratory Division, Escola Paulista de Medicina, Federal University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Jose R
authors.initials: JR
authors.lastname: Jardim
authors.affiliation: Department of Surgery, Pritzker School of Medicine, University of Chicago, Chicago, USA.
authors.forename: Marco G
authors.initials: MG
authors.lastname: Patti
mesh_terms: D000368:Aged; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D003964:Diaphragm / Q000503:physiopathology; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000503:physiopathology*; D050782:Esophageal pH Monitoring; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000503:physiopathology* / Q000517:prevention & control; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D011312:Pressure; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000188:drug therapy*
chemical_list: D001993:Bronchodilator Agents
keywords: Ambulatory pH monitoring; Bronchodilators; Chronic obstructive pulmonary disease; Gastroesophageal reflux disease; High-resolution manometry; Trans-diaphragmatic pressure gradient