Intra-articular lidocaine plus bupivacaine in sheep undergoing stifle arthrotomy.
OBJECTIVE
To evaluate the effect of intra-articular (i.a.) lidocaine plus bupivacaine on post-operative pain in sheep undergoing stifle arthrotomy.


METHODS
Randomized controlled experimental trial.


METHODS
Sixteen adult Rambouillet-cross ewes.


METHODS
Sheep were randomly assigned to one of two treatment groups. The lidocaine/bupivacaine group (L/B, n=8) received i.a. lidocaine (40 mg (2 mL)) prior to incision and i.a. bupivacaine (10 mg (2 mL)) post-closure, while the control group (n=8) received no i.a. injections. i.a. local anesthetics were an addition to the standard analgesic protocol of phenylbutazone (1 g orally, every 24 hours for 5 days) and transdermal fentanyl (equivalent to 15 mg), initiated 24 hours prior to surgery. A stifle arthrotomy was performed with the purpose of creating a full-thickness articular cartilage defect. Two observers blinded to treatment assessed sheep for total pain score using a numeric ranking scale that included: comfort, movement, and flock behavior. The first observation (T=0) was obtained the evening of surgery (3-7 hours post-operatively); subsequent observations occurred every 12 hours for 72 hours. Nonparametric statistical tests were used to evaluate differences between groups for total pain score.


RESULTS
L/B sheep had significantly lower total pain scores at T=0 than control sheep (p<0.05). No significant differences between treatments were noted at any subsequent time periods. There were no differences attributable to the use of different observers.


CONCLUSIONS
i.a. lidocaine plus bupivacaine provided analgesia at 3-7 hours post-operatively. Use of i.a. lidocaine and bupivacaine is a simple, effective, yet inexpensive perioperative analgesic protocol for joint surgery in sheep.
Shafford
Heidi L
HL
Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Hellyer
Peter W
PW
Turner
A Simon
AS
D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D001182:Arthroscopy / Q000379:methods / Q000662:veterinary*; D002045:Bupivacaine / Q000008:administration & dosage*; D005260:Female; D007270:Injections, Intra-Articular / Q000662:veterinary; D008012:Lidocaine / Q000008:administration & dosage*; D010147:Pain Measurement / Q000662:veterinary; D010149:Postoperative Pain / Q000517:prevention & control / Q000662:veterinary*; D012756:Sheep / Q000502:physiology* / Q000601:surgery; D013264:Stifle / Q000601:surgery*
D000779:Anesthetics, Local; D008012:Lidocaine; D002045:Bupivacaine