Use of low doses of ketamine administered by constant rate infusion as an adjunct for postoperative analgesia in dogs.
OBJECTIVE
To compare indicators of postoperative pain and behavior in dogs with and without a low-dose ketamine infusion added to usual perioperative management.


METHODS
Prospective, randomized, blinded clinical study.


METHODS
27 dogs undergoing forelimb amputation.


METHODS
Dogs were anesthetized with glycopyrrolate, morphine, propofol, and isoflurane. Thirteen dogs were treated with ketamine IV, as follows: 0.5 mg/kg (0.23 mg/lb) as a bolus before surgery, 10 microg/kg/min (4.5 microg/lb/min) during surgery, and 2 microg/kg/min (0.9 microg/lb/min) for 18 hours after surgery. Fourteen dogs received the same volume of saline (0.9% NaCl) solution. All dogs received an infusion of fentanyl (1 to 5 microg/kg/h [0.45 to 2.27 pg/lb/h]) for the first 18 hours after surgery. Dogs were evaluated for signs of pain before surgery, at the time of extubation, and 1, 2, 3, 4, 12, and 18 hours after extubation. Owners evaluated their dogs' appetite, activity, and wound soreness on postoperative days 2, 3, and 4.


RESULTS
Dogs that received ketamine infusions had significantly lower pain scores 12 and 18 hours after surgery and were significantly more active on postoperative day 3 than dogs that received saline solution infusions.


CONCLUSIONS
Results suggest that perioperative administration of low doses of ketamine to dogs may augment analgesia and comfort in the postoperative surgical period.
Wagner
Ann E
AE
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Walton
Judy A
JA
Hellyer
Peter W
PW
Gaynor
James S
JS
Mama
Khursheed R
KR
D000671:Amputation, Surgical / Q000662:veterinary; D000698:Analgesia / Q000379:methods / Q000662:veterinary*; D000700:Analgesics / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs / Q000502:physiology* / Q000601:surgery; D004311:Double-Blind Method; D005552:Forelimb / Q000601:surgery*; D007262:Infusions, Intravenous / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage*; D010147:Pain Measurement / Q000662:veterinary; D010149:Postoperative Pain / Q000188:drug therapy / Q000662:veterinary*; D011446:Prospective Studies; D013997:Time Factors
D000700:Analgesics; D007649:Ketamine