Evaluation of the perioperative stress response in dogs administered medetomidine or acepromazine as part of the preanesthetic medication.
OBJECTIVE
To compare the perioperative stress response in dogs administered medetomidine or acepromazine as part of the preanesthetic medication.


METHODS
42 client-owned dogs that underwent elective ovariohysterectomy.


METHODS
Each dog was randomly allocated to receive medetomidine and butorphanol tartrate (20 microgram/kg and 0.2 mg/kg, respectively, IM) or acepromazine maleate and butorphanol (0.05 and 0.2 mg/kg, respectively, IM) for preanesthetic medication. Approximately 80 minutes later, anesthesia was induced by administration of propofol and maintained by use of isoflurane in oxygen. Each dog was also given carprofen before surgery and buprenorphine after surgery. Plasma concentrations of epinephrine, norepinephrine, cortisol, and beta-endorphin were measured at various stages during the perioperative period. In addition, cardiovascular and clinical variables were monitored.


RESULTS
Concentrations of epinephrine, norepinephrine, and cortisol were significantly lower for dogs administered medetomidine. Concentrations of beta-endorphin did not differ between the 2 groups. Heart rate was significantly lower and mean arterial blood pressure significantly higher in dogs administered medetomidine, compared with values for dogs administered acepromazine.


CONCLUSIONS
Results indicate that for preanesthetic medications, medetomidine may offer some advantages over acepromazine with respect to the ability to decrease perioperative concentrations of stress-related hormones. In particular, the ability to provide stable plasma catecholamine concentrations may help to attenuate perioperative activation of the sympathetic nervous system.
Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Helsinki, Finland.
Misse
M
Väisänen
Marja
M
Raekallio
Erja
E
Kuusela
Pirkko
P
Huttunen
Juhani
J
Leppäluoto
Petra
P
Kirves
Outi
O
Vainio
D000075:Acepromazine / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002077:Butorphanol / Q000494:pharmacology; D004285:Dogs / Q000378:metabolism* / Q000601:surgery; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004837:Epinephrine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006854:Hydrocortisone / Q000097:blood; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007044:Hysterectomy / Q000662:veterinary; D007530:Isoflurane / Q000008:administration & dosage; D020926:Medetomidine / Q000494:pharmacology*; D009638:Norepinephrine / Q000097:blood; D011229:Preanesthetic Medication / Q000379:methods / Q000662:veterinary*; D015742:Propofol / Q000008:administration & dosage; D011897:Random Allocation; D013312:Stress, Physiological / Q000188:drug therapy / Q000378:metabolism / Q000662:veterinary*; D001615:beta-Endorphin / Q000097:blood
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D018492:Dopamine Antagonists; D006993:Hypnotics and Sedatives; D000075:Acepromazine; D001615:beta-Endorphin; D007530:Isoflurane; D020926:Medetomidine; D002077:Butorphanol; D006854:Hydrocortisone; D009638:Norepinephrine; D015742:Propofol; D004837:Epinephrine