US Guided Axillary Block With Only One Injection

A Prospective, Randomized Comparison Between Single and Double Injection Ultrasound-Guided Axillary Brachial Plexus Block

The investigators conducted this prospective, randomized, observer-blinded, non-inferiority trial to compare single perivascular injection to double injection (musculocutaneous nerve and perivascular injection) US guided axillary brachial plexus block.

The investigators have been challenged by the question of whether all a single injection may be enough to successfully perform a axillary plexus block.

Three hundred and twenty patients undergoing elective hand surgery under axillary brachial plexus block will be enrolled into this prospective, randomized, observer-blinded non inferiority trial. Using a computer-generated sequence of random numbers and sealed envelope technique, the patients included will randomly be allocated to receive either single or double injection ultrasound-guided axillary block. The block will be performed with the in-plane technique using a 22 gauge, 50 mm needle and a high frequency linear probe.

In the 2 injection group, the needle will initially be advanced toward musculocutaneous nerve and 7 ml of LA (lidocaine 1.5% with epinephrine 5µg/ml) will be deposited around the nerve. The needle will be then advanced until the tip will be positioned just dorsal to the artery and 28 ml of (lidocaine 1.5% with epinephrine 5µg/ml) will be deposited in this location. In the single injection group using the same LA, and 35 ml will be deposited dorsal the artery.

Inclusion Criteria:

• 18-75 year of age, ASA physical status I-III, BMI 25 to 35 Kg/m2

Exclusion Criteria:

• non consents patients, any contraindication to brachial plexus anesthesia (local anesthetic allergy, local infection and coagulopathy), preexisting neuropathy, hepatic or renal failure, pregnancy and surgery in the axillary region.