title: Use of electrical stimulation to monitor lumbosacral epidural and intrathecal needle placement in rabbits.
abstract: OBJECTIVE
  To determine the minimal electric threshold of neurostimulation dorsally and ventrally to the interarcuate ligament in the lumbosacral area necessary to cause muscle contraction of the hind limb or tail and determine whether a continuous electrical stimulation applied to an insulated needle during lumbosacral epidural needle placement could be used to distinguish the epidural from the intrathecal space in rabbits.
  
  
  METHODS
  24 New Zealand white rabbits.
  
  
  METHODS
  Rabbits received iohexol (0.2 mL/kg) either dorsally (group 1) or ventrally to the interarcuate ligament in the lumbosacral area (groups 2 and 3). Correct placement of the needle was determined by use of the loss of resistance to injection technique (group 2) or a continuous electrical stimulation (group 3) and confirmed by examination of the iohexol distribution pattern on radiographs.
  
  
  RESULTS
  In all rabbits of group 1, iohexol was injected in the lumbosacral area, outside the epidural space. In groups 2 and 3, iohexol was injected intrathecally. No pure iohexol epidural migration of iohexol was observed. Mean ± SD minimal electric threshold to elicit a motor response was 1.2 ± 0.3 mA, 0.3 ± 0.1 mA, and 0.3 ± 0.1 mA in groups 1, 2, and 3, respectively.
  
  
  CONCLUSIONS
  Neurostimulation was a useful technique to determine correct intrathecal needle placement in rabbits but failed to detect the lumbosacral epidural space when the common technique, used in dogs and cats for the lumbosacral epidural approach, was used.
authors: Anesthesiology Department, University of Buenos Aires, Argentina, Buenos Aires, Argentina. potero@fvet.uba.ar
authors: Pablo E
authors: PE
authors: Otero
authors: Diego A
authors: DA
authors: Portela
authors: Javier A
authors: JA
authors: Brinkyer
authors: Lisa
authors: L
authors: Tarragona
authors: Andrea S
authors: AS
authors: Zaccagnini
authors: Santiago E
authors: SE
authors: Fuensalida
authors: Martín R
authors: MR
authors: Ceballos
mesh_terms: D000767:Anesthesia, Epidural / Q000662:veterinary; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage / Q000494:pharmacology; D004558:Electric Stimulation / Q000295:instrumentation*; D005260:Female; D007268:Injections, Epidural / Q000662:veterinary*; D007472:Iohexol / Q000008:administration & dosage / Q000494:pharmacology; D008161:Lumbosacral Region / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology; D011817:Rabbits / Q000502:physiology*
chemical_list: D003287:Contrast Media; D007472:Iohexol