buprenorphine and Femoral-Fractures

Management of pain in research swine used for studies involving painful procedures is a considerable challenge. Here we assessed whether a regional anesthesia method is effective for pain control of hindlimb injuries in pigs used for research in bone fracture healing. For this randomized controlled study, we administered regional anesthesia before an experimental femoral injury was produced. Using ultrasound guidance, we placed sterile infusion catheters near the sciatic and femoral nerves and administered local anesthetic (bupivacaine) for the first 24 h after surgery. We evaluated various behavioral and physiologic parameters to test the hypothesis that this regional anesthesia would provide superior analgesia compared with systemic analgesia alone. We also collected blood samples to evaluate serum levels of cortisol and fentanyl postoperatively. At the end of the study period, we collected sciatic and femoral nerves and surrounding soft tissues for histopathologic evaluation. Treatment pigs had lower subjective pain scores than did control animals. Control pigs had a longer time to first feed consumption and required additional analgesia earlier in the postoperative period than did treatment pigs. Ultrasound-guided regional anesthesia is a viable and effective adjunct to systemic analgesics for providing pain control in swine with experimental femoral fractures.

Topics: Analgesics; Anesthetics, Local; Animals; Bupivacaine; Buprenorphine; Catheters; Female; Femoral Fractures; Femoral Nerve; Fentanyl; Pain, Postoperative; Sciatic Nerve; Swine; Ultrasonography

Adequate pain management is essential for ethical and scientific reasons in animal experiments and should completely cover the period of expected pain without the need for frequent re-application. However, current depot formulations of Buprenorphine are only available in the USA and have limited duration of action. Recently, a new microparticulate Buprenorphine formulation (BUP-Depot) for sustained release has been developed as a potential future alternative to standard formulations available in Europe. Pharmacokinetics indicate a possible effectiveness for about 72 h. Here, we investigated whether the administration of the BUP-Depot ensures continuous and sufficient analgesia in two mouse fracture models (femoral osteotomy) and could, therefore, serve as a potent alternative to the application of Tramadol via the drinking water. Both protocols were examined for analgesic effectiveness, side effects on experimental readout, and effects on fracture healing outcomes in male and female C57BL/6N mice. The BUP-Depot provided effective analgesia for 72 h, comparable to the effectiveness of Tramadol in the drinking water. Fracture healing outcome was not different between analgesic regimes. The availability of a Buprenorphine depot formulation for rodents in Europe would be a beneficial addition for extended pain relief in mice, thereby increasing animal welfare.

Topics: Agnosia; Analgesia; Animals; Buprenorphine; Disease Models, Animal; Drinking Water; Female; Femoral Fractures; Male; Mice; Mice, Inbred C57BL; Pain; Pain Management; Tramadol

A four-month-old, entire male guinea pig was presented for surgical repair of a closed oblique femoral fracture. Analgesia was provided with 30 µg/kg buprenorphine intramuscularly (im) four times a day and 0 · 3 mg/kg meloxicam subcutaneously once a day. The following day, anaesthesia was induced and maintained with 100 µg/kg medetomidine im, 20 mg/kg ketamine im, 30 µg/kg buprenorphine im and isoflurane in oxygen. Femoral and sciatic nerve blocks were performed with bupivacaine. The fracture was reduced and aligned using an intramedullary 1 · 4 mm K-wire and a 3 metric polydioxanone cerclage. Three weeks postoperatively remodelling and callus formation was documented, with no evidence of complications. Complete union was present 14 weeks postoperatively.

Topics: Anesthesia; Anesthetics, Combined; Animals; Bone Wires; Bupivacaine; Buprenorphine; Femoral Fractures; Femoral Nerve; Fracture Fixation, Intramedullary; Guinea Pigs; Humans; Isoflurane; Ketamine; Male; Medetomidine; Nerve Block; Sciatic Nerve