The goal of this study is to demonstrate that the novel retroclavicular approach is a safe, fast and effective technique for ultrasound-guided brachial plexus anesthesia.
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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
50
Retroclavicular approach ultrasound guided regional anesthesia
Centre Hospitalier Universitaire de Sherbrooke
Sherbrooke, Quebec, Canada
Success Rate of the Block
Success is defined as complete sensory loss in the distribution of the radial, median, ulnar, musculocutaneous, and medial cutaneous nerves of the forearm and hand.
Time frame: Assessed 30 minutes after block completion
Surgical success rate
Success rate is defined as avoidance of rescue analgesic technique. These techniques are defined as: adding local anesthetic locally by surgeon, rescue intravenous narcotics in excess of 1 microgram per kilogram of patient weight, need for general anesthesia, rescue distal neural blockage by anesthesiologist. Data presented will be the need or not of a rescue analgesic technique
Time frame: Defined at the beginning of surgery until the end of surgery
Technique duration
Number of seconds needed to complete the block, from time of local skin anesthesia until regional block needle removal (local skin anesthesia plus injection of mepivacaine)
Time frame: Time required in seconds for the retroclavicular block technique completion, assessed during block performance
Needle visualization
Using the Likert standardized scale, two evaluators will individually quantify the ease of needle visualization using the video footage recorded by the ultrasound machine from all the retroclavicular blocks. Likert scale for visualization, is defined as: 1:very bad, 2: bad, 3: adequate, 4:good, 5: very good. No units are attached to this scale
Time frame: Assessed after study completion, once all 50 patients will have been completed. Assessment will take place in the weeks following study completion
Patient discomfort
Using a Visual Analog Scale (VAS), patients will quantify the discomfort they experienced during the block. This assessment will take place in the minutes following mepivacaine injection and block needle withdrawal. The VAS scale is rated from 1-10, 1 being almost no pain and 10 being the worst pain ever. Assessment will be done by an independent person, not taking part in the study. The VAS has no units attached to it.
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Time frame: Assessed immediately after the block
Patient satisfaction
Using a VAS, patients will quantify their satisfaction with the retroclavicular technique throughout the study period.
Time frame: Assessed 48 hours after the block
Sensitive Block Progression
Progress of the sensory block in the distribution of the radial, median, ulnar, musculocutaneous, and medial cutaneous nerves of the forearm and hand at 10, 20 and 30 minutes after block completion (mepivacaine injection). The scale used is: 0:no sensitive block, 1:analgesia, 2:anesthesia. No units are attached to this scale.
Time frame: Assessed 10, 20, 30 minutes after the block
Motor Block Progression
Progress of the motor block in the distribution of the radial, median, ulnar, musculocutaneous nerves of the forearm and hand at 10, 20, and 30 minutes after block completion (mepivacaine injection). The scale used is: 0: no motor block, 1: paresis, 2: paralysis. No units are attached to this scale
Time frame: Assessed 10, 20, 30 minutes after the block
Complication Rate
With a phone call to the patient at 48 hours after injection of mepivacaine, complications will be searched for (pain at puncture site, paresthesia or paresis in the operated arm, signs of infection at puncture site such as redness or purulent discharge). Response is classified as YES or NO. No units attached to this scale. If patient reports paresthesia or paresis, further questioning over the phone will determine which nerve or cord is involved.
Time frame: Assessed 48 hours after the block
Duration of the Block's Effects
Duration of the block will be evaluated using 3 criteria: patient's subjective opinion of when the block receded (time of the day), time at which first oral analgesia is taken, and time of first onset of pain. Units involved is time (for example "3 pm".)
Time frame: Assessed 48 hours after the block
Use of narcotic for tourniquet pain
If at any point during the surgery, patient complains of tourniquet pain, this will be noted as well as the analgesia given. Units is time of pain ("3 pm") and analgesia given ("micrograms of fentanyl").
Time frame: Assessed throughout the surgery
Rate of Neurostimulation Usage
At the discretion of the anesthesiologist performing the block, neurostimulation can be used to supplement ultrasound guidance. This will be recorded as a YES or NO (neurostimulation used or not). No units attached to this rate.
Time frame: Assessed during the block