Analgesic comparison of systemic lidocaine, morphine or lidocaine plus morphine infusion in dogs undergoing fracture repair.
OBJECTIVE
To compare the postoperative analgesic effects of lidocaine, morphine and lidocaine plus morphine administered by constant rate infusion (CRI) and analyzing their effects on opioid requirements after orthopedic surgery in dogs.


METHODS
Twenty-four dogs underwent fracture repairs were premedicated with IM acepromazine (0.05 mg/kg) combined with morphine (0.3mg/kg). Anesthesia was induced with IV propofol (4 to 5 mg/ kg) and maintained with isoflurane. The dogs were randomly assigned to 3 groups and administered a CRI IV of lidocaine (T-L), morphine (T-M) or lidocaine plus morphine (T-LM) at the same doses. Postoperative analgesia was assessed for 24 hours using a Visual Analog Scale (VAS) and the Glasgow Composite Pain Scale (GCPS). Rescue analgesia was performed if the evaluation score exceeded 50% of the VAS and/or 33% of the GCPS.


RESULTS
The pain score and postoperative opioid requirements did not differ among the treatments. Rescue analgesia was administered to 1/8 dogs in the T-M and T-LM, and to 3/8 dogs in the T-L.


CONCLUSIONS
Lidocaine, morphine or lidocaine/morphine CRI may be efficacious techniques for pain management in the first 24 hours post-surgery. However, the two drugs administered together did not reduce the postoperative opioid requirement in dogs undergoing fracture repair. Key words: Anesthesia. Analgesics. Analgesics, Opioid. Lidocaine. Morphine. Dogs.
School of Veterinary Medicine, Oeste Paulista University, Presidente Prudente, SP, Brazil.
Isabela Picolo
IP
Guimarães Alves
Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine, UNOESTE, Presidente Prudente, SP, Brazil.
Gabriel
G
Montoro Nicácio
Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine, UNOESTE, Presidente Prudente, SP, Brazil.
Miriely Steim
MS
Diniz
Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine, UNOESTE, Presidente Prudente, SP, Brazil.
Thalita Leone
TL
Alves Rocha
Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine, UNOESTE, Presidente Prudente, SP, Brazil.
Glaucia
G
Prada Kanashiro
Department of Veterinary Surgery and Anesthesiology, School of Veterinary Medicine, UNOESTE, Presidente Prudente, SP, Brazil.
Renata
R
Navarro Cassu
D000698:Analgesia / Q000379:methods / Q000662:veterinary*; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D019162:Anesthetics, Combined / Q000008:administration & dosage*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D004285:Dogs; D004338:Drug Combinations; D005260:Female; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary*; D007262:Infusions, Intravenous; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement / Q000662:veterinary; D010149:Postoperative Pain / Q000188:drug therapy / Q000662:veterinary*; D015203:Reproducibility of Results; D013997:Time Factors; D016896:Treatment Outcome
D000701:Analgesics, Opioid; D019162:Anesthetics, Combined; D000779:Anesthetics, Local; D004338:Drug Combinations; D009020:Morphine; D008012:Lidocaine