Effective low dosage of mepivacaine in ultrasound-guided axillary nerve block: a double-blinded, randomized clinical trial of efficacy in patients undergoing distal upper extremity surgery.
STUDY OBJECTIVE
To evaluate two low-dose volumes (20 mL or 30 mL) of 1.5% mepivacaine solution used for ultrasound-guided axillary blockade for outpatients undergoing distal upper limb surgery.


DESIGN
Prospective, double-blinded randomized study.


SETTING
Outpatient surgical setting of a university-affiliated hospital.


PATIENTS
64 adult, ASA physical status 1, 2, and 3 patients, aged 28-46 years, scheduled for upper limb surgery.


INTERVENTIONS
Patients were randomized to two groups to receive either 20 mL of 1.5% mepivacaine solution (n=31) or 30 mL of 1.5% mepivacaine solution (n=33) for ultrasound-guided axillary plexus blockade.


MEASUREMENTS
Block duration, proportion of surgical and functional successful blocks, onset of sensory and motor blockade measured from 0 to 30 minutes following final needle extraction, total amount of preoperative sedative (midazolam), and intraoperative propofol administered were recorded.


MAIN RESULTS
Following axillary plexus blockade, neither patient group showed any statistically significant difference in the percentage of functionally successful blockade (30 mL, 100%: 20 mL, 97%; P = 0.48), surgically successful blockade (30 mL, 100%; 20 mL, 94%; P = 0.23), cumulative sensory or motor blockade surgical time, block performance time, preoperative midazolam use, or intraoperative propofol use.


CONCLUSION
Low volumes (30 mL or 20 mL) of 1.5% mepivacaine provides satisfactory anesthesia for ambulatory distal upper limb surgery with no significant difference in clinical outcomes.
['Perov|Samuel|S|', 'Patel|Pranav|P|', 'Kumar|Sanjeev|S|', 'McKelvey|George M|GM|', 'Chidiac|Elie|E|', 'Motlani|Faisal|F|']
D000328:Adult D000556:Ambulatory Surgical Procedures D000779:Anesthetics, Local D001917:Brachial Plexus D004305:Dose-Response Relationship, Drug D004311:Double-Blind Method D005260:Female D006801:Humans D008297:Male D008619:Mepivacaine D008875:Middle Aged D009407:Nerve Block D011446:Prospective Studies D013997:Time Factors D018084:Ultrasonography, Interventional D034941:Upper Extremity
Mepivacaine Ultrasound-guided Axillary plexus block Functional block Regional anesthesia Surgical block