title: Effects of indwelling nasogastric intubation on gastric emptying of a liquid marker in horses.
abstract: OBJECTIVE
  To determine the effects of indwelling nasogastric intubation on the gastric emptying rate of liquid in horses.
  
  
  METHODS
  6 healthy horses.
  
  
  METHODS
  Horses were assigned to treatment and control groups in a prospective randomized crossover study with a washout period of at least 4 weeks between trials. Acetaminophen (20 mg/kg) diluted in 1 L of distilled water was administered via nasogastric tube at time points of 0, 12, 30, 48, and 72 hours to evaluate the liquid-phase gastric emptying rate. In control horses, nasogastric tubes were removed after administration of acetaminophen. In horses receiving treatment, the tube was left indwelling and maintained for 72 hours. A 10-mL sample of blood was collected from a jugular vein immediately before and 20, 40, 60, 80, 100, 120, and 180 minutes after acetaminophen administration. Serum acetaminophen concentrations were measured by use of a colorimetric method.
  
  
  RESULTS
  Peak serum acetaminophen concentration was significantly higher in the control group (38.11 microg/mL) than in the treatment group (29.09 microg/mL), and the time required to reach peak serum acetaminophen concentration was significantly shorter in the control group (22.79 minutes) than in the treatment group (35.95 minutes).
  
  
  CONCLUSIONS
  Results indicated that indwelling nasogastric intubation has a delaying effect on the gastric emptying rate of liquids. Veterinarians should consider the potential for delayed gastric emptying when placing and maintaining an indwelling nasogastric tube for an extended period of time after surgery. Repeated nasogastric intubation may be better than maintenance of an indwelling tube in horses with ileus.
authors.affiliation: Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada.
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Cruz
authors.forename: Ronald
authors.initials: R
authors.lastname: Li
authors.forename: Dan G
authors.initials: DG
authors.lastname: Kenney
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Monteith
mesh_terms: D000082:Acetaminophen / Q000097:blood / Q000493:pharmacokinetics; D018712:Analgesics, Non-Narcotic / Q000097:blood / Q000493:pharmacokinetics; D000818:Animals; D018592:Cross-Over Studies; D005746:Gastric Emptying / Q000502:physiology*; D005766:Gastrointestinal Contents; D006736:Horses / Q000502:physiology*; D007408:Intestinal Absorption; D007441:Intubation, Gastrointestinal / Q000379:methods / Q000662:veterinary*; D008297:Male
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen