Comparison of transdermal administration of fentanyl versus intramuscular administration of butorphanol for analgesia after onychectomy in cats.
OBJECTIVE
To compare postoperative discomfort assessed by subjective pain score and plasma cortisol concentrations in cats undergoing onychectomy that received analgesia by use of transdermal fentanyl (TDF) patches or an i.m. injection of butorphanol.


METHODS
Randomized prospective clinical trial.


METHODS
22 client-owned cats weighing 2.2 to 5 kg (4.84 to 11 lb) undergoing onychectomy.


METHODS
Researchers were blinded to which cats received a TDF patch (25 microg/h) 18 to 24 hours prior to surgery or an i.m. injection of butorphanol (0.2 mg/kg (0.09 mg/lb]) at the time of sedation, immediately following extubation, and at 4-hour intervals thereafter for 12 hours. Clinical variables, plasma cortisol concentration, and pain scores were evaluated and recorded 24 hours prior to surgery, at extubation, and 2, 4, 8, 12, 24, 36, and 48 hours after surgery.


RESULTS
The TDF group had a lower pain score than the butorphanol group only at 8 hours after surgery. Both groups had significantly lower mean plasma cortisol concentrations 0, 24, 36, and 48 hours after surgery, compared with mean plasma cortisol concentrations prior to surgery. No significant differences in appetite or response to handling the feet were observed between the 2 groups.


CONCLUSIONS
Our data did not reveal a difference in pain relief between administration of TDF and butorphanol. Plasma cortisol concentrations were not different between groups. Fentanyl appeared to provide equivalent analgesia to butorphanol in cats undergoing onychectomy. The primary advantage of using a TDF patch is that repeated injections are not required.
Gellasch
Kelly L
KL
Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
Kruse-Elliott
Kris T
KT
Osmond
Christian S
CS
Shih
Andre N C
AN
Bjorling
Dale E
DE
D000279:Administration, Cutaneous; D000698:Analgesia / Q000295:instrumentation / Q000379:methods / Q000662:veterinary; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D002077:Butorphanol / Q000008:administration & dosage*; D002415:Cats / Q000502:physiology* / Q000601:surgery; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage*; D006724:Hoof and Claw / Q000601:surgery*; D006854:Hydrocortisone / Q000097:blood; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D010147:Pain Measurement / Q000662:veterinary; D010149:Postoperative Pain / Q000188:drug therapy / Q000662:veterinary*; D011446:Prospective Studies; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D002077:Butorphanol; D005283:Fentanyl; D006854:Hydrocortisone