title: Evaluation of thoracic epidural analgesia induced by lidocaine, ketamine, or both administered via a lumbosacral approach in dogs.
abstract: OBJECTIVE
  To determine the analgesic and systemic effects of thoracic epidural administration of ketamine, lidocaine, or both in conscious dogs.
  
  
  METHODS
  6 adult mixed-breed dogs.
  
  
  METHODS
  Each dog received 2% lidocaine hydrochloride without epinephrine (3.8 mg/kg), 5% ketamine hydrochloride (3.0 mg/kg), or both in randomized order with ≥ 1 week between treatments. Drugs were administered in a total volume of 0.25 mL/kg through a thoracic epidural catheter implanted via the lumbosacral approach. Heart rate, blood pressure, respiratory rate, rectal temperature, analgesia, sedation, and ataxia were determined before treatment (baseline [time 0]) and at 5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 150, and 180 minutes after administration.
  
  
  RESULTS
  The main areas of analgesia for the 3 treatments were the thorax and forelimbs bilaterally. Median duration of analgesia was shorter after administration of ketamine (30 minutes) than after administration of lidocaine (40 minutes) and lidocaine plus ketamine (90 minutes). All treatments caused moderate motor blockade, and only the ketamine and lidocaine plus ketamine treatments caused mild sedation. Significant decreases in systolic and mean arterial blood pressure were observed only with the lidocaine plus ketamine treatment.
  
  
  CONCLUSIONS
  Thoracic epidural administration of lidocaine plus ketamine resulted in longer duration of analgesia of the thorax and forelimbs bilaterally in conscious dogs, compared with administration of ketamine or lidocaine alone. Additional studies are needed to determine whether this technique adequately relieves postoperative pain after thoracic surgical procedures and whether it causes respiratory depression in dogs.
authors: Department of Veterinary Medicine, Surgery and Anesthesiology, Faculty of Veterinary Medicine and Animal Science, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil. derossi@nin.ufms.br
authors: Rafael
authors: R
authors: DeRossi
authors: Fabrício O
authors: FO
authors: Frazílio
authors: Paulo H A
authors: PH
authors: Jardim
authors: Alessandro R C
authors: AR
authors: Martins
authors: Rafaella
authors: R
authors: Schmidt
authors: João M
authors: JM
authors: Negrini-Neto
mesh_terms: D015360:Analgesia, Epidural / Q000379:methods* / Q000662:veterinary; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure; D002404:Catheterization / Q000295:instrumentation / Q000662:veterinary; D004285:Dogs / Q000378:metabolism*; D004359:Drug Therapy, Combination / Q000662:veterinary; D005260:Female; D005552:Forelimb / Q000503:physiopathology; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology*; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D008161:Lumbosacral Region; D008297:Male; D011897:Random Allocation; D013909:Thorax / Q000503:physiopathology; D013997:Time Factors
chemical_list: D000700:Analgesics; D000779:Anesthetics, Local; D007649:Ketamine; D008012:Lidocaine