Addition of a metoclopramide constant rate infusion to prevent ptyalism, regurgitation and vomiting in brachycephalic dogs undergoing spinal surgery.

Objective: To assess whether adding metoclopramide to a protocol of maropitant and pantoprazole would reduce incidence of ptyalism, vomiting and regurgitation in brachycephalic dogs undergoing thoracolumbar spinal surgery.

Study Design: Randomized blinded controlled trial.

Animals: A total of 43 brachycephalic dogs undergoing thoracolumbar spinal surgery.

Methods: In addition to a standardized anaesthetic regimen, dogs were randomized to be administered either a 2 mg kg day metoclopramide constant rate infusion (CRI) or a saline solution at an equivalent infusion rate, started after anaesthetic induction and discontinued 5 hours after tracheal extubation. The presence of vomiting, regurgitation and pytalism, and short form of the Glasgow Composite Pain Scale pain scores were assessed by a blinded observer hourly for 4 hours, starting 1 hour postextubation.

Results: Regurgitation occurred in six dogs postoperatively; three dogs were in the placebo group and three in the metoclopramide group. The odds ratio (OR) of regurgitation after surgery did not differ between groups [OR: 0.76, 95% confidence interval (CI): 0.13-4.3, p = 0.76]. The odds of observing ptyalism at 3 and 4 hours was approximately 15 times less than 1 hour postoperatively (both OR: 15.4, 95% CI: 1.8-130.7, p = 0.012) and did not differ based on the addition of metoclopramide (OR: 0.73, 95% CI: 0.07-8.0, p = 0.79). The odds of observing pain did not change over time and did not differ based on the addition of metoclopramide (OR: 0.71, 95% CI: 0.12-4.2, p = 0.71). Vomiting did not occur during the study (0.0%, 95% CI: 0.0-8.2%). No adverse effects were observed during the study period in either group.

Conclusions And Clinical Relevance: The addition of a metoclopramide CRI to maropitant and pantoprazole did not result in a significant reduction in ptyalism or regurgitation in brachycephalic dogs undergoing thoracolumbar spinal surgery.