Objective The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration.
Experimental Design Prospective randomized experimental study.
Animals Six adult ponies, 135 to 275 kg.
Methods Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tmax) to reach peak serum concentration (Cmax), and the area under the AP serum concentration versus time curve (AUC) were determined for each treatment group.
Results Tmax was 31 mins in the control group, and this increased significantly (P < .05) after sedation. Cmax decreased (P < .05) after xylazine administration, and AUC decreased (P < .05) after acepromazine.
Conclusions This study indicated that sedation has a significant effect on the gastric emptying rate of a liquid in ponies.
Clinical Relevance Although sedation produced a significant delay in gastric emptying, the influence was transient and unlikely to be of clinical significance in healthy ponies. However, the ability of these agents to slow gastric emptying should be considered in the surgical patient.