Gastroesophageal reflux (GER) during general anesthesia is reported in 15-60% of dogs and can in some cases lead to esophagitis or esophageal stricture formation. The pH of the GER and the time it remains in the esophageal lumen are thought to play an important role in the development of esophageal disease. However, the incidence of esophagitis or stricture formation from GER is unknown. There are as yet no studies in dogs preventing GER from causing esophageal damage. The aim of this study is to determine esophageal pH and if esophageal lavage affects lumenal pH following GER.
Sixty dogs anesthetized for elective ovariectomy were evaluated for GER and 27 dogs identified with GER and having contents with a pH of < 4 were included in the study. An esophageal pH/impedance catheter (Divarsatek™, Milwaukee) was placed shortly following anesthesia using endoscopic guidance with the catheter tip placed approximately 3 cm cranial to the lower esophageal sphincter. A GER episode was defined as an orally progressing decrease in impedance (50% decrement in ohms) from the pre-episodic esophageal baseline recording. When esophageal pH < 4 remained at the conclusion of the surgery esophageal lavage was performed. Tap water in 60 mL aliquots was instilled through a gastric tube and carefully suctioned. If after an interval of 2 minutes post lavage esophageal pH was still under 4, another aliquot was instilled and again suctioned until pH > 4. Paired t test, Wilcoxon matched pairs test and Spearman’s rank correlation coefficient were used to analyze parametric and non-parametric data.
Of the 27 dogs having strongly acidic GER (pH < 4), 16 dogs were able to neutralize their esophageal lumen pH before the end of the procedure. These 16 dogs increased their esophageal lumen and GER pH from 2.1 ± 0.8 to 5.4 ± 0.9 during the anesthesia (p < 0.0001). 14/27 dogs did not neutralize their esophageal lumen and GER pH having esophageal lumen and GER pH of 2.9 ± 0.9 at the end of the procedure. Esophageal lavage with tap water increased the lumen and GER to 4.1 ± 1 in 11/14 (78%) of dogs (p = 0.003). The volume of water used for lavage was not associated with the changes in lumen and GER pH (r = -0.19, p = 0.50).
In the present study, we show for the first time that some dogs are capable of neutralizing strongly acidic GER. The dogs that were unable to clear acidic GER are possibly the ones more predisposed to esophagitis or stricture formation. Esophageal lumen lavage with water in dogs having strongly acidic pH increased the esophageal lumen and GER pH in a majority of dogs suggesting esophageal lavage might be beneficial in preventing GER complications.
Colorado State University/Veterinary Teaching Hospital
Thursday, June 14
1:30 PM – 1:45 PM
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