title: The effect of topical treatment on esophageal pH during acid reflux in dogs.
abstract: OBJECTIVE
  To determine the effect of suction, lavage and instillation of sodium bicarbonate solution on esophageal pH during acidic gastro-esophageal reflux (GER) in anesthetized dogs.
  
  
  METHODS
  Prospective, clinical trial.
  
  
  METHODS
  Ten healthy dogs, 4.8 +/- 2.4 years old, and weighing 37.1 +/- 7.9 kg.
  
  
  METHODS
  Dogs were admitted to the study if they were under general anesthesia and regurgitation occurred. A sensor-tipped catheter was used to measure esophageal pH. On study entry the esophagus was suctioned. After an interval of at least 5 minutes, if the esophageal pH was still less than 4 the esophagus was lavaged with tap water and again suctioned. In 6 dogs 20 mL of dilute bicarbonate solution was instilled into the esophageal lumen.
  
  
  RESULTS
  Suctioning fluid from the esophagus did not change the pH significantly. Lavage with tap water caused the pH to increase above 4 in four dogs, with the average pH increasing from 1.2 +/- 0.5 to 3.5 +/- 4.9. In all dogs where dilute bicarbonate solution was instilled, esophageal pH increased to above 6 for up to 180 (mean +/- SD, 89 +/- 81) minutes.
  
  
  CONCLUSIONS
  Suctioning refluxate from the esophagus does not change the pH of the esophageal lumen. Instillation of a small volume of bicarbonate solution predictably increased the pH above 4 following an episode of acidic GER. Care must be taken that fluid is instilled into the lumen of the esophagus, and not into the trachea.
authors.affiliation: College of Veterinary Medicine, Michigan State University, East Lansing, MI 48867, USA. wilsondv@cvm.msu.edu
authors.forename: Deborah V
authors.initials: DV
authors.lastname: Wilson
authors.forename: A Tom
authors.initials: AT
authors.lastname: Evans
mesh_terms: D000758:Anesthesia / Q000662:veterinary*; D000818:Animals; D004283:Dog Diseases / Q000503:physiopathology / Q000517:prevention & control*; D004285:Dogs; D004947:Esophagus / Q000187:drug effects* / Q000502:physiology; D005751:Gastric Lavage / Q000662:veterinary; D005764:Gastroesophageal Reflux / Q000517:prevention & control / Q000662:veterinary*; D006863:Hydrogen-Ion Concentration; D011446:Prospective Studies; D017693:Sodium Bicarbonate / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D017693:Sodium Bicarbonate