title: Evaluation of the local analgesic effect of ketamine in the palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses.
abstract: OBJECTIVE
  To evaluate the local analgesic effect of ketamine in a palmar digital nerve block at the base of the proximal sesamoid (abaxial sesamoid block) in horses.
  
  
  METHODS
  36 mature healthy Andalusian horses.
  
  
  METHODS
  Horses were randomly assigned to 4 groups of 9 horses each and received an abaxial sesamoid block in a randomly chosen forelimb with 1 of the following: saline (0.9% NaCl) solution, 1% ketamine solution, 2% ketamine solution, or 3% ketamine solution. To determine analgesia, the radiant heat lamp-hoof withdrawal model was used as a noxious thermal stimulus. Before each nerve block, baseline hoof withdrawal reflex latency (HWRL, time between lamp illumination and withdrawal of the hoof) was determined; after the nerve block, local analgesic effects were determined by measuring HWRL at 2 and 5 minutes after injection and then every 5 minutes for a total period of 1 hour.
  
  
  RESULTS
  Significant differences in HWRL were found between baseline values and values at 2 to 15 minutes following a nerve block with ketamine. Significant differences were found between HWRL values at every time point from 2 to 10 minutes following a nerve block with saline solution, compared with 1 or 2% ketamine solution. Similarly, significant differences were found between HWRL values at every time point from 2 to 15 minutes following a nerve block with saline solution, compared with 3% ketamine solution.
  
  
  CONCLUSIONS
  Abaxial sesamoid block with ketamine ensures adequate analgesia in horses with an onset of action of 2 minutes and a maximal duration of action of 15 minutes.
authors.affiliation: Departamento de Patología Animal II, Facultad de Veterinaria, Universidad Complutense, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: López-Sanromán
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Cruz
authors.forename: Martín
authors.initials: M
authors.lastname: Santos
authors.forename: Rubén A
authors.initials: RA
authors.lastname: Mazzini
authors.forename: Agustin
authors.initials: A
authors.lastname: Tabanera
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Tendillo
mesh_terms: D000772:Anesthesia, Local / Q000662:veterinary*; D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006724:Hoof and Claw / Q000187:drug effects* / Q000294:innervation*; D006736:Horses; D007649:Ketamine / Q000494:pharmacology*; D009407:Nerve Block / Q000662:veterinary*; D012018:Reflex / Q000187:drug effects; D012716:Sesamoid Bones / Q000187:drug effects* / Q000294:innervation*; D013997:Time Factors
chemical_list: D000779:Anesthetics, Local; D007649:Ketamine