Total intravenous anaesthesia in ponies using detomidine, ketamine and guaiphenesin: pharmacokinetics, cardiopulmonary and endocrine effects.
Pharmacokinetics and some pharmacological effects of anaesthesia induced by a combination of detomidine, ketamine and guaiphenesin were investigated in eight ponies. Cardiopulmonary function was studied and plasma met-enkephalin, dynorphin, beta-endorphin, arginine vasopressin, adrenocorticotrophin, cortisol, 11-deoxycortisol and catecholamine concentrations were measured. The combination produced slight cardiorespiratory depression, hyperglycaemia and a reduction in haematocrit. There were no changes in plasma opioids, pituitary peptides or catecholamines. Plasma cortisol concentration decreased and plasma 11-deoxycortisol increased indicating a suppression of steroidogenesis. Steady state ketamine and guaiphenesin concentrations were attained during the infusion period, and ketamine concentrations likely to provide adequate analgesia for surgical operations were achieved (more than 2.2 micrograms ml-1). Steady state detomidine concentration was not attained. The ponies took on average 68 minutes to recover to standing and the recovery was uneventful.
Nuffield Department of Anaesthetics, John Radcliffe Hospital, University of Oxford.
P M
PM
Taylor
S P
SP
Luna
J W
JW
Sear
M J
MJ
Wheeler
D000771:Anesthesia, Intravenous / Q000662:veterinary*; D000777:Anesthetics / Q000493:pharmacokinetics* / Q000494:pharmacology*; D000778:Anesthetics, Dissociative / Q000494:pharmacology; D000818:Animals; D004347:Drug Interactions; D004702:Endocrine Glands / Q000187:drug effects* / Q000378:metabolism; D006140:Guaifenesin / Q000493:pharmacokinetics / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D006736:Horses; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007093:Imidazoles / Q000493:pharmacokinetics / Q000494:pharmacology; D007649:Ketamine / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D012119:Respiration / Q000187:drug effects
D000777:Anesthetics; D000778:Anesthetics, Dissociative; D006993:Hypnotics and Sedatives; D007093:Imidazoles; D006140:Guaifenesin; D007649:Ketamine; C041255:detomidine