The Retroclavicular Approach for Regional Anesthesia of the Upper Limb in Patients With BMI ≥ 30 kg/m2 : A Descriptive Study
The Retroclavicular Approach for Regional Anesthesia of the Upper Limb in Patients With BMI ≥ 30 kg/m2 : A Descriptive Study
The goal of this study is to determine the success rate of the retroclavicular approach for the anesthesia of the upper limb in the obese patient population (BMI ≥ 30 kg/m2)
Classic infraclavicular approach of the brachial plexus involves a needle puncture below the clavicle and advancing the needle with a 45-60 degree angle from cephalad to caudad. The aim is to advanced the block needle posterior to the axillary artery and to deposit the local anesthetic at that point, near the posterior cord. A "U" shaped spread around the artery should ensure distribution around all three cords. Ultrasound guidance is highly recommended and neurostimulation is optional.
The retroclavicular approach is a variant to this classical technique. Ultrasound probe is positioned initially below the clavicle in a manner similar to the classic approach but is then rotated in a clockwise fashion (right arm) or counter-clockwise fashion (left arm) for about 25-35 degrees. The puncture site is just behind the clavicle at the most lateral point available. If initial entry point is optimal, needle direction is then parallel to ultrasound probe. The final aim and position of block needle is identical to classical approach. Entry point ensures a parallel alignment of the needle and the ultrasound beam, thus enabling almost perfect visualization of both artery, cords and block needle. This is turn optimizes safety, rapidity of technique, efficiency and efficacy.
It is recognized that regional anesthesia is more difficult to perform in obese patients. Anatomic landmarks are harder to localize in this population and ultrasound guidance is more difficult because of the attenuation of the ultrasound beam by adipose tissue. The complication rate of regional techniques is also reported to be higher in the obese patient population.
Since the retroclavicular variant of the infraclavicular approach for the anesthesia of the brachial plexus offers a better needle visualisation, we believe that this technique can be used successfully in the obese patient population with a low complication rate.
Inclusion Criteria:
Exclusion Criteria: