Sensorimotor Block Dynamics and Hemidiaphragmatic Palsy: Selective Trunk Block vs Supraclavicular Brachial Plexus Block

Official title

Sensorimotor Block Dynamics and Hemidiaphragmatic Palsy: A Randomized Superiority Trial Comparing Selective Trunk Block and Supraclavicular Brachial Plexus Block

Overview

Ultrasound guided supraclavicular brachial plexus block (BPB) has been extensively studied and recommended as a sole anesthetic for upper extremity surgeries. The efficacy of ultrasound-guided (USG) SeTB for surgical anesthesia of the entire upper extremity and cadaver anatomic study evaluating the spread of the injectate after a simulated SeTB is further confirmed from the results of our previous research. Although the results in our previous study are encouraging, there is a paucity of data on sensorimotor blockade and incidence of hemidiaphragmatic palsy after a SeTB, and no data comparing SeTB with a supraclavicular BPB techniques which this study aims to evaluate. We hypothesise that USG SeTB is superior to supraclavicular BPB in anesthetising the entire upper extremity from the shoulder to hand.

Detailed description

Ultrasound guided supraclavicular brachial plexus block (BPB) has been extensively studied and recommended as a sole anesthetic for upper extremity surgeries. The supraclavicular BPB is often touted to be the 'spinal of the upper extremity' as it produces anesthesia of the entire upper extremity except for the T2 dermatome.

However, based on clinical experience, such a claim is grossly unsubstantiated. This is evident from the finding that supraclavicular BPB is associated with 2-36% inferior trunk or ulnar nerve sparing. In addition, since the suprascapular nerve takes off more proximally from the superior trunk and the supraclavicular BPB is performed distally at the supraclavicular fossa, the effect of supraclavicular BPB on the suprascapular nerve, which predominantly supply the shoulder and proximal humerus, is not known and has not been objectively documented.

Nonetheless, supraclavicular BPB has been successfully used for shoulder surgery albeit with a large local anesthetic (LA) volume (50-60 ml) or combined with interscalene BPB, a hybrid BPB technique using 30-50 ml LA volume, for proximal humerus fracture surgeries. But such high LA volume is invariably associated with potential complications in the high risk population and therefore not used in contemporary clinical practice.

Since all major nerves supplying the upper extremity, including suprascapular nerve, passes through the trunks of the brachial plexus, we proposed that by selectively identifying and blocking the three trunks of the brachial plexus with small doses of LA-selective trunk block (SeTB), it is feasible to produce anesthesia of the entire upper extremity, i.e., from shoulder to hand. This is further confirmed from the results of our research evaluating the efficacy of ultrasound-guided (USG) SeTB for surgical anesthesia of the entire upper extremity and cadaver anatomic study evaluating the spread of the injectate after a simulated SeTB. Although these are encouraging results, there is a paucity of data on the sensorimotor blockade and incidence of hemidiaphragmatic palsy comparing SeTB and supraclavicular BPB techniques which this study aims to evaluate. We hypothesize that USG SeTB is superior to supraclavicular BPB in anesthetizing the entire upper extremity from shoulder to hand.

Interventions

• Procedure Selective Trunk Block (SeTB)
  Patient will lie supine on the examination couch with the ipsilateral arm in the neutral position (adducted), neck slightly extended and the head turned slightly to the contralateral side. After local anesthetic (LA) infiltration (1-2 ml lidocaine 1%), the nerve block needle will be inserted and placed within the interscalene groove. Then, a 7 ml of a 1:1 mixture of lidocaine 2% with 1:200,000 epinephrine and levobupivacaine 0.5% will be slowly injected in aliquots. After that, the tip will be r
• Procedure Supraclavicular Brachial Plexus Block (SC BPB)
  Patient will lie supine on the examination couch with the ipsilateral arm in the neutral position (adducted), neck slightly extended and the head turned slightly to the contralateral side. Patient will receive a subcutaneous infiltration with 1-2 ml of 0.9% normal saline (NS) at the superior and middle trunk level after which the needle will be completely withdrawn. Then, a local anesthetic (LA) infiltration (1-2 ml lidocaine 1%) will then be performed at the supraclavicular fossa and the nerve

Primary outcome measures

• Readiness for surgery (Change of sensory and motor function from baseline to blockade) [Time frame: Within 45 minutes after the block at 5 minutes interval]
• Change of ipsilateral Hemidiaphragmatic (phrenic nerve) function from baseline to 30 minutes after SeTB [Time frame: Before and 30 minutes after SeTB]

Secondary outcome measures (9)

• Complete sensory block [Time frame: Within 45 minutes after the block at 5 minutes interval]
• Motor blockade [Time frame: Within 45 minutes after the block at 5 minutes interval]
• Any occurrence of paradoxical movement [Time frame: Within 45 minutes after the block]
• Block performance time [Time frame: Within 30 minutes after entering the procedure room]
• Any occurrence of paresthesia [Time frame: Immediately after the end of the block]
• Discomfort score [Time frame: Immediately after the end of the block]]
• Any occurrence of symptomatic dyspnea [Time frame: During and within 45 minutes after the block]
• Name and dosage of used rescue analgesia [Time frame: During surgery]
• Total amount of local anesthetic infiltration used [Time frame: During surgery]

Eligibility criteria

Inclusion criteria

• ASA 1-3 patients
• Undergoing elective or emergency upper extremity surgery involving anywhere from the proximal humerus to distal hand or surgery involving any combination of these regions

Exclusion criteria

• Patient refusal
• Pregnancy
• Skin infection at the site of block placement
• History of allergy to local anaesthetic (LA) drugs
• Bleeding tendency or with evidence of coagulopathy
• Pre-existing respiratory disease
• Neurological deficit or neuromuscular disease.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Hong Kong · 1 center

• Department of Anaesthesia & Intensive Care, Prince of Wales Hospital, Shatin, New Territor — Hong Kong

Identifiers

NCT: NCT05649644 · 2022.219 SeTB vs SC BPB_RCT

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗