Selective Trunk Block: A Study to Evaluate Block Dynamics, Effects and Efficacy for Upper Limb Surgery

Selective Trunk Block: A Prospective Non-Randomized Study to Evaluate Block Dynamics, Effects on Ipsilateral Hemidiaphragmatic (Phrenic Nerve) Function and Efficacy for Upper Extremity Surgery

Brachial plexus block (BPB) is frequently used as the sole anesthetic technique for upper extremity surgery. The choice of technique often depends on the site of surgery because the extent of sensory-motor blockade after a BPB varies with the technique used. The investigator is not aware of any single BPB technique described to date that can consistently produce surgical anesthesia of the whole ipsilateral upper extremity. However, occasionally surgery entails that the whole upper extremity, i.e. from the shoulder to the elbow, or even the forearm, wrist or hands. This clinical challenge has been addressed previously using a combination of BPB techniques. The investigator has recently demonstrated that it is feasible to accurately identify majority of the main components of the brachial plexus above the clavicle, including the three trunks, using ultrasound imaging. Since majority of the innervation of the upper extremity, i.e. shoulder, arm, elbow, forearm, wrist and hand, originates from the three trunks of the brachial plexus, the investigator hypothesized that selectively blocking upper, middle, and inferior trunks of the brachial plexus will produce surgical anesthesia of the whole ipsilateral upper extremity. This study is a continuation of a previously approved study with title "Selective Trunk Brachial Plexus Block: A Prospective Non-Randomized Study of Intervention" [NCT04510259] after the amendment (study title, protocol and increased sample size) was rejected by local IRB and suggested to submit as a new protocol. The aim of this study is to assess a novel brachial plexus block technique, the selective trunk block (SeTB), and provide preliminary clinical evidence of its effectiveness in producing surgical anesthesia of the whole ipsilateral upper extremity.

Study Overview

• Status: Completed
• Conditions: Upper Extremity Problem
• Intervention / Treatment: Procedure: Selective Brachial Plexus Block

Detailed Description

Brachial plexus block (BPB) is frequently used as the sole anesthetic technique for upper extremity surgery. The choice of technique often depends on the site of surgery because the extent of sensory-motor blockade after a BPB varies with the technique used. The investigator is not aware of any single BPB technique described to date that can consistently produce surgical anesthesia of the whole ipsilateral upper extremity (shoulder to fingers). However, occasionally surgery entails that the whole upper extremity is anesthetized, i.e. from the shoulder to the elbow, or even the forearm, wrist or hands. This clinical challenge has been addressed previously using a combination of BPB (hybrid) techniques. The investigator has recently demonstrated that it is feasible to accurately identify majority of the individual components of the brachial plexus above the clavicle, including the three trunks, using ultrasound imaging. Since majority of the innervation of the upper extremity, i.e. shoulder, arm, elbow, forearm, wrist and hand, originates from or pass through the three trunks of the brachial plexus, the investigator hypothesized that selectively blocking the upper, middle, and inferior trunks of the brachial plexus will produce surgical anesthesia of the whole ipsilateral upper extremity, except for the area innervated by the intercostobrachial nerve (T2 - medial aspect of the upper arm). The investigator refers this novel technique as "selective trunk block" (SeTB). Currently there are no published data on block dynamics, safety or efficacy of SeTB. In addition, there may be a potential advantage that phrenic nerve can be spared, so this blockade will not affect the respiratory function as it is common to see phrenic nerve palsy after interscalene BPB (100%) and supraclavicular BPB (50-67%). This study is a continuation of a previously approved study with title "Selective Trunk Brachial Plexus Block: A Prospective Non-Randomized Study of Intervention" [NCT04510259] after the amendment (study title, protocol and increased sample size) was rejected by local IRB and suggested to submit as a new protocol. The aim of this study is to assess a novel brachial plexus block technique, the selective trunk block (SeTB), and provide preliminary clinical evidence of its effectiveness in producing surgical anesthesia of the whole ipsilateral upper extremity.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Kowloon
    • Shatin, Kowloon, Hong Kong
      • Department of Anaesthesia & Intensive Care, Prince of Wales Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• elective upper extremity surgery
• emergency upper extremity surgery

Exclusion Criteria:

• Patient refusal
• pregnancy
• local skin site infection
• allergy to local anesthetics
• bleeding tendency
• pre-existing neurological deficit
• pre-existing neuromuscular disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Selective Brachial plexus block; Selective brachial plexus block will be done under ultrasound guidance to patients scheduled for upper extremity surgeries. Local anesthetic agents (a mixture of 2% lidocaine with 1:200,000 epinephrine and 0.5% levobupivacaine in a total of 25ml) will be injected at the superior, middle, and inferior trunks of the brachial plexus in order to anesthetize the whole upper limb.

Procedure: Selective Brachial Plexus Block; It is one type of peripheral nerve blocks for upper extremity surgery. In this study, the block will be done under the ultrasound guidance and the local anesthetic agent (a mixture of 2% Xylocaine with 1:200,000 adrenaline and 0.5% Chirocaine in a total of 25ml) will be injected at the trunks of the brachial plexus in order to produce the surgical anesthesia of the whole upper extremity of the patients scheduled for upper limb surgeries.; Other Names: Drug

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes of sensory block of the upper extremity	Sensation to coldness (ice) will be tested at the median (lateral three and half digits on the palmar side), radial (dorsal side of hand), ulnar (medial one and a half digits), musculocutaneous (lateral side of the forearm) and axillary (skin over the lower deltoid) and graded using a verbal rating scale (VRS:0-100, 100=normal sensation, 0=no sensation). Onset of sensory block for each nerve will be defined as the time that it took to achieve a sensory block score of =<30.	within 45 minutes after the block at 5 minutes interval
Changes of motor block of the upper extremity	Motor blockade will be graded using a 3-points scale revising from previous study: 2=no block, 1=paresis and 0=paralysis. Motor blockade of each individual nerve in the anesthetized upper extremity will be evaluated by testing for opposition of thumb with the index finger (median nerve), wrist extension (radial nerve), thumb opposition with little finger (ulnar nerve), elbow flexion (musculocutaneous nerve) abduction of shoulder (axillary nerve), and external rotation of the arm with elbow flexed and simulate emptying a can motion and test for power against resistance (Suprascapular nerve). The onset of motor block for each nerve will be defined as motor grading at each nerve =<1. Complete block will be defined as a sensory and motor block score of '0' in all nerves functions.	within 45 minutes after the block at 5 minutes interval
Readiness for surgery	overall sensory scores =<30 (VRS: 0-100, 100=normal sensation, 0=no sensation) and motor score =<1 (3-points scale, 2=no block, 1=paresis, 0=paralysis) in all the nerves tested.	within 45 minutes after the block at 5 minutes interval

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes of the Diaphragmatic function	Excursion of the right hemidiaphragm will be measured by ultrasound machine in supine position via the anterior subcostal route. The movement of the diaphragm will be measured in centimetres. The range of diaphragmatic excursion will be recorded from the resting expiratory position to deep inspiration (sigh test) as will be range of diaphragmatic movement from resting expiratory position when quickly inspiring through the nose (sniff test). The decrease in diaphragmatic excursion will be calculated as the difference (in percentage) in diaphragmatic excursion measured before and 30 minutes after SeTB. Reduction in diaphragmatic excursion of more than 75% of baseline, or no movement, or paradoxical movement will be considered as complete paresis. Reduction in diaphragmatic excursion of between 25% and 75% will be considered as partial paresis and diaphragmatic excursion of less than 25% will be considered as 'no paresis'.	Baseline (before brachial plexus block) and at 30 minutes after block

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong

Publications and helpful links

General Publications

• Sivakumar RK, Samy W, Pakpirom J, Songthamwat B, Karmakar MK. Ultrasound-guided selective trunk block: Evaluation of ipsilateral sensorimotor block dynamics, hemidiaphragmatic function and efficacy for upper extremity surgery. A single-centre cohort study. Eur J Anaesthesiol. 2022 Oct 1;39(10):801-809. doi: 10.1097/EJA.0000000000001736. Epub 2022 Aug 11.

Study record dates

Study Major Dates

• Study Start (Actual): February 19, 2021
• Primary Completion (Actual): July 27, 2021
• Study Completion (Actual): July 27, 2021

Study Registration Dates

• First Submitted: February 9, 2021
• First Submitted That Met QC Criteria: February 9, 2021
• First Posted (Actual): February 12, 2021

Study Record Updates

• Last Update Posted (Actual): July 28, 2021
• Last Update Submitted That Met QC Criteria: July 27, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Keywords: Upper extremity; Brachial plexus block
• Other Study ID Numbers: Updated SeTB (CREC.2020.308)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No