Efficacy of the Anesthetic Blockade of the Saphenous and Lateral Cutaneous Femoral Nerves Employing Surface Anatomical Landmarks in Dogs
Introduction
The advantages of nerve stimulation and ultrasound to guide peripheral nerve blockade have been described in dogs (Echeverry et al. 2010). However, there are some factors that could limit the use of these guided techniques.
Objective
To evaluate the efficacy of the anesthetic blockade of the saphenous (SN) and lateral cutaneous femoral nerves (LCFN) employing a blind technique based in surface anatomical landmarks and loss of resistance for their neuro-location.
Methods
Five experimental dogs sedated with acepromazine (0.03 mg kg-1) were employed. Lidocaine (2%) was administered (0,3 ml kg-1) close to the target nerves on the right pelvic limb. The accuracy of the blockade was determined assessing the desensitization of the dermatomes corresponding to these nerves, with a secured mosquito clamp, every 5 minutes during a period of 30 minutes. Sensory response was evaluated by a discontinuous subjective scale (0–2). A week later, procedures were repeated on the other limb.
Results
SN was blocked in 7/10 (70%) cases in an average time of 7 minutes. LCFN was blocked in all cases 10/10 (100%) in an average time of 10 minutes. No complications were observed in any of the dogs, and the recovery from the blocks was uneventful.
Conclusions
The blind approaches described in this study could be considered as a cheap, effective, and safe method to block the SN and the LCFN nerves in the dog.