The electric neurostimulator was used as an adequate mean for the confirmation of the correct placement of the tip of the insulated needles in the lumbosacral epidural space through small electric stimulations causing muscle contractions by using an intravenous catheter needle instead of an electric neurostimulation insulated needle. Forty dogs were selected based on the need for an epidural block for orthopedic, abdominal or retroumbilical surgical procedures. Electrical stimuli were applied from 1.5 to 0.5mA during a gradual introduction of the needle into the lumbosacral vertebral canal. Responses that were considered as indicative of the correct placement of the needle and stimulation of the cauda equina were muscle contractions in the pelvic limbs, tail or anus. An association of lidocaine, bupivacaine and tramadol was then administered. Adequate epidural anesthesia was confirmed through relaxation of the anal sphincter, absence of patellar and flexor reflexes and analgesia of the abdominal surgical area. The authors were able to conclude that the method used was effective to confirm the correct needle placement in the epidural space during regional anesthesia in dogs.
dog; anesthesia; electrical stimulation; extradural