Anesthesia induced in pigs by use of a combination of medetomidine, butorphanol, and ketamine and its reversal by administration of atipamezole.
OBJECTIVE
To develop an IM administrable anesthetic combination for pigs.


METHODS
Use of a combination of atropine, medetomidine, butorphanol, and ketamine (MB-K) was evaluated as an anesthetic regimen and compared with that of a combination of atropine, xylazine, butorphanol, and ketamine (XB-K). Cardiorespiratory effects of MB-K combination and use of atipamezole as a means of reversing anesthesia induced by MB-K were examined.


METHODS
18 castrated, mixed-breed, specific-pathogenfree pigs, aged 8 to 15 (mean, 12.1) weeks and weighing 14.5 to 26.0 (mean, 19.6) kg. were studied.


METHODS
Dosages of drugs used in this study were atropine, 25 micrograms/kg of body weight; medetomidine, 80 micrograms/kg; xylazine, 2 mg/kg; butorphanol, 200 micrograms/kg; ketamine, 10 mg/kg; and atipamezole, 240 micrograms/kg.


RESULTS
MB-K combination proved to be more effective than XB-K combination as an anesthetic combination. After quick and smooth induction by IM administration, MB-K-induced anesthesia was sustained for 98.8 +/- 22.5 minutes (mean +/- SD, 47.4 +/- 16.5 minutes by XB-K) with accompanying muscular relaxation (91 +/- 18 minutes) and loss of pedal (82 +/- 24 minutes) and laryngeal (75 +/- 19 minutes) reflexes. Loss of these reflexes was of significantly longer duration than the loss induced by XB-K, enabled tracheal intubation, and, thus, supported major surgery for at least 30 minutes after induction. Recovery from MB-K-induced anesthesia was smooth. MB-K combination had a slight stimulative effect on cardiovascular status, and a significant depressant effect on blood gas and acid-base status, but these effects were within biologically acceptable limits. Oxygen consumption of pigs under MB-K-induced anesthesia decreased significantly. MB-K-induced anesthesia could be effectively and quickly reversed by IM or IV administration of atipamezole.


CONCLUSIONS
The combination of medetomidine, butorphanol, and ketamine induces excellent surgical anesthesia in pigs, and results in moderate cardiorespiratory effects. A great advantage of the anesthetic regimen is that it can be effectively and quickly reversed by atipamezole.


CONCLUSIONS
Medetomidine, butorphanol, and ketamine-induced anesthesia is available for short-term major surgery in pigs.
Sakaguchi
M
M
Department of Veterinary Surgery, Faculty of Agriculture, University of Tokyo, Japan.
Nishimura
R
R
Sasaki
N
N
Ishiguro
T
T
Tamura
H
H
Takeuchi
A
A
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000700:Analgesics / Q000008:administration & dosage*; D000768:Anesthesia, General / Q000379:methods / Q000662:veterinary*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002077:Butorphanol / Q000008:administration & dosage*; D002302:Cardiac Output / Q000187:drug effects; D004347:Drug Interactions; D006439:Hemodynamics / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007093:Imidazoles / Q000008:administration & dosage* / Q000494:pharmacology*; D007273:Injections, Intramuscular; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D020926:Medetomidine; D009919:Orchiectomy; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011651:Pulmonary Artery; D012018:Reflex; D013318:Stroke Volume / Q000187:drug effects; D013552:Swine; D014655:Vascular Resistance / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D000700:Analgesics; D000778:Anesthetics, Dissociative; D006993:Hypnotics and Sedatives; D007093:Imidazoles; C050701:atipamezole; D007649:Ketamine; D020926:Medetomidine; D002077:Butorphanol; D010100:Oxygen