Intertruncal versus classical approach to the ultrasound-guided supraclavicular brachial plexus block for upper extremity surgery: study protocol for a randomized non-inferiority trial

Abstract

Background Ultrasound-guided intertruncal approach (IA) to the supraclavicular block (SB) is recently proposed as a new approach for local anesthetic (LA) injection in terms of the classical approach (CA) at the level of the first rib. The CA-SB has been proven to result in satisfying sensorimotor block, but associate with a high risk of intraneural injection. The aim of this randomized non-inferiority study is to explore whether IA-SB can obtain similar block dynamics, as the CA-SB, but avoiding an intraneural injection during the whole nerve block procedure. Methods The total 122 patients undergoing elective upper extremity surgery will be randomly allocated to receive either an IA-SB or a CA-SB using a double-injection (DI) technique. In the IA-SB group, a portion of LA (15 mL) is injected accurately to the intertruncal plane between the middle and lower trunks under real-time ultrasound guidance; then, the remaining volume (10 mL) is carefully distributed to the other intertruncal plane between the upper and middle trunks. In the CA-SB group, the DI technique will be carried out as described in Tran’s study. The primary outcome is the percentage of patients with a complete sensory blockade at 20 min with a predefined non-inferiority margin of − 5%. The secondary outcomes include the sensory-motor blockade of all 4 terminal nerves, onset times of the individual nerves within 30 min, block-related variables, and adverse events. Discussion The results will provide sensory-motor blockade-related parameters and safety of the ultrasound-guided intertruncal approach to the supraclavicular block, thereby promoting clinical practice. Trial registration Chinese Clinical Trial Registry ChiCTR2000040199. Registered on 25 November 2020

Efficacy of intertruncal and corner-pocket approaches of ultrasound-guided supraclavicular block in terms of ulnar nerve blockade: A randomised controlled study

“…In the present study, the patient discomfort score was significantly higher in the intertruncal group. A single skin-prick -single injection technique used for the corner-pocket approach[ 4 5 ] requires less manipulation of the needle compared to a single-skin prick–dual-injection technique used for the intertruncal approach, where the hand needs more manipulations, resulting in more discomfort to the patient in the intertruncal group. Since, in the present study, single point injection of local anaesthetic solution at the corner pocket of SCA and the first rib was done, more volume and concentration of local anaesthetic near the lower trunk must have resulted in a significantly prolonged duration of sensory blockade in the ulnar nerve in the corner-pocket group compared to the intertruncal group.…”

“…The USG-guided corner-pocket approach of SCB, wherein the local anaesthetic is deposited between the lower trunk and the subclavian artery (SCA) by targeting the needle between the inferolateral side of SCA and the first rib, is considered to be effective in the prevention of ulnar nerve sparing. [ 4 ] Although local anaesthetic is deposited near the lower trunk in the corner-pocket approach, ulnar nerve sparing may occur in up to 30% patients. [ 5 ] In a recent technique of USG-guided SCB [ 2 ], which is a single-needle puncture, a dual-injection technique termed the intertruncal approach, the local anaesthetic is deposited in the investing adipose layers between the upper-middle trunk and the middle-lower trunks.…”