Musculoskeletal Diseases or ConditionsNCT04941664
Minimum Effective Local Anesthetic Volume for Ultrasound Guided Superior Trunk Block
A study testing 0.5% levobupivacaine in people with Musculoskeletal Diseases or Conditions, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
The objective of this study is to identify the minimum effective dosage of a commonly used local anaesthetic drug "levobupivacaine" required to produce an effective ultrasound guided (USG) superior trunk block (STB) in at least 90% of patients for shoulder arthroscopic surgeries. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Musculoskeletal Diseases or Conditions
- What is being tested?
- 0.5% levobupivacaine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteHong Kong
- Study dates
- 19 Jan 2023to 31 Aug 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- American Society of Anesthesiologists (ASA) physical status I-III scheduled to undergo elective upper shoulder arthroscopic rotator cuff repair procedure
Who cannot join
- Patient refusal
- pregnancy
- skin infection at the site of block placement
- history of allergy to local anaesthetic drugs
- bleeding tendency or with evidence of coagulopathy
- pre-existing neurological deficit or neuromuscular disease.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site, 1 recruiting
- Recruiting
Department of Anaesthesia & Intensive Care, Prince of Wales Hospital
Shatin, New Territories
Winnie Samy, RN, BN, MSc, +85235052734, wsamy@cuhk.edu.hk
About this study
Official title: Minimum Effective Local Anesthetic Volume of 0.5% Levobupivacaine Required for Ultrasound Guided Superior Trunk Block for Shoulder Surgery
The objective of this study is to identify the minimum effective dosage of a commonly used local anaesthetic drug "levobupivacaine" required to produce an effective ultrasound guided (USG) superior trunk block (STB) in at least 90% of patients for shoulder arthroscopic surgeries.
Read the detailed description
Shoulder arthroscopic surgery is one of the most commonly performed procedures worldwide, and associated with significant postoperative pain. Currently, such surgery is performed either under general anaesthesia or under Interscalene brachial plexus block (ISBPB), which is a regional anaesthesia technique. However, ISBPB is associated with the highest incidence of hemi-diaphragmatic palsy of the operative side. Since majority of the innervation to the shoulder arises from or passes through the superior trunk of the brachial plexus, superior trunk block has been shown to have lesser impact on the phrenic nerve and it has been gaining popularity worldwide. Ultrasound is widely used for brachial plexus block and current evidence indicates that it is feasible to accurately identify majority of the main components of the brachial plexus above the clavicle, including the three trunks (superior, middle, and inferior trunks). However, there are no data describing an optimal volume of local anaesthetic for superior trunk block. The aim of this study is to identify the minimum effective dosage of a commonly used local anaesthetic drug "levobupivacaine" required to produce an effective ultrasound guided (USG) superior trunk block (STB) in at least 90% of patients for shoulder arthroscopic surgeries.
- Conditions
- Musculoskeletal Diseases or Conditions
- Being tested
- 0.5% levobupivacaine
- Keywords
- Superior Trunk nerve block
- Medical subject headings
- Musculoskeletal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
0.5% levobupivacaineDrug
Also called Peripheral nerve block
This study adopts a "Modified Narayana rule (MNR)", a sequential up-and-down pharmacodynamics method (UDM) to estimate the minimum effective local anesthetic volume of 90% (MELVA90) of cases of the aforementioned local anesthetic (LA), in order to produce the surgical anesthesia of the patients scheduled for shoulder surgeries. Based on the principal investigator's clinical experience, the initial volume of 8ml will be used. Depending on the success or failure of the superior trunk block, which is defined as the readiness for surgery at 30 minutes after the block, the volume for the next patient will be adjusted up or down by 2ml. The upper dose limit of the study to minimize the potential for local anesthetic systemic toxicity will be 16ml and the lower dose limit will be 4ml, which will be of no clinical importance.
| Study group | Role | What they receive |
|---|---|---|
| Levobupivacaine | Other | Superior trunk nerve block will be done under ultrasound guidance to patients scheduled for shoulder surgeries. Local anesthetic agent (0.5% levobupivacaine) 8ml will be injected at the superior trunk of the brachial plexus in order to produce surgical anesthesia or analgesia for shoulder surgeries. Receives: Drug: 0.5% levobupivacaine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes of sensory & motor blockade (Readiness for surgery) of the upper extremity
The first exact timing (in minutes) [Readiness for surgery] that an Overall sensory score =<30 (NRS: 0-100; 100=normal sensation, 0=no sensation) using ice test and a motor grade =<1 (3 point scale: 2=no block, 1=paresis, 0=paralysis) in the nerves (C5 to C6) tested that are supplied by superior trunk of brachial plexus. Sensation to coldness (ice) will be tested at C5 - Lateral (radial) side of the antecubital fossa (just proximal to elbow crease); C6 - Thumb, dorsal surface, proximal phalanx. Motor block will be graded using a 3-points scale: 2=no block, 1=paresis and 0=paralysis, and will be test at C5 - elbow flexors and C6 - wrist extensors. "Block failure" will be defined as inability to achieve "readiness for surgery" at 30 minutes after the completion of the block.
Measured: within 45 minutes after the block at 5 minutes interval
Minimum effective volume (ml) of local anesthetic agent
The lowest volume (in milliliters) of local anesthetic agent that can produce an effective superior trunk block for surgery. Effective superior trunk block is defined as an overall sensory score of NRS =<30 and a motor grade of =<1 during the assessment after the nerve block that can undergo surgery. Sensory assessment will be done by using ice (cold sensation) test in both dermatomes (C5, C6) and a motor grade of =<1 in both myotome (C5, C6) tested. Sensory block will be graded as 0 to 100 where 100 represents normal sensation and 0=no sensation to coldness (ice cube).
Measured: after nerve block till end of surgery
Secondary outcomes (8)
Changes of motor blockade of the upper extremity
Motor blockade will be graded using a 3-point scale: 2=no block, 1=paresis and 0=paralysis. Motor blockade of each individual nerve in the anaesthetized upper extremity will be evaluated by testing C5 - elbow flexors, C6 - Wrist extensors, C7 - Elbow extensors, C8 - Finger flexors to the middle finger, and T1 - small finger abductors. Onset of Motor block for each nerve will be defined as the time it took to achieve motor score =<1.
Measured: within 45 minutes after the block at 5 minutes interval
Changes of sensory block of the upper extremity
Sensation to coldness (ice) will be test at C5- lateral (radial) side of the antecubital fossa (just proximal to elbow crease), C6 - Thumb, dorsal surface, proximal phalanx, C7 - middle finger, dorsal surface, proximal phalanx, C8 - Little finger, dorsal surface, proximal phalanx, and T1 - medial (ulnar) side of the antecubital) fossa, just proximal to the medial epicondyle of the humerus. Sensory block, defined as loss of sensation to cold (ice), will be graded using a numeric rating scale (NRS: 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 NRS =<30.
Measured: within 45 minutes after the block at 5 minutes interval
Percentage changes of the Diaphragmatic function
Excursion of the ipsilateral 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 the 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 %) in diaphragmatic excursion measured before and 30 minutes after superior trunk block (STB).
Measured: Baseline (before block) and at 30 minutes after block
Changes of the Extensiveness of Diaphragmatic function
After obtaining the percentage changes of the diaphragmatic function, if the reduction in diaphragmatic excursion of more than 75%, or no movement, or paradoxical movement will be considered as complete paresis. Reduction in diaphragmatic excursion of both sigh and sniff test between 25% and 75% will be considered as partial paresis and diaphragmatic excursion of less than 25% will be considered as 'no paresis'.
Measured: calculated after block
Block performance time
The time taken from the start of the local anesthetic skin infiltration to the end of the injection of study drug for the nerve block.
Measured: assess once before surgery
Discomfort score
the degree of discomfort during the nerve block (NRS: 0-100; 0= no discomfort, 100 = very uncomfortable)
Measured: assess once before surgery
Paresthesia
Any incidence of paresthesia during the nerve block
Measured: during the period of undergoing the nerve block
Complications
Any complications during and right after the nerve block directly related to local anesthetic toxicity, vascular or pleural puncture,intraneural injection with nerve swelling.
Measured: during the nerve block till the end of surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jun 2021
- Study start19 Jan 2023
- Primary completion31 Mar 2027 (estimated)
- Study completion31 Aug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Musculoskeletal Diseases or ConditionsStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Prof Manoj K Karmakar, Chinese University of Hong Kong
- Investigators
- Manoj K Karmakar, MD, Principal investigator, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04941664
- Sponsor's protocol ID
- CREC.2021.184-T
- Status last verified
- Oct 2026
- First submitted
- 9 Jun 2021
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Minimum Effective Local Anesthetic Volume of 0.5% Levobupivacaine Required for Ultrasound Guided Superior Trunk Block for Shoulder Surgery
- ClinicalTrials.gov ID
- NCT04941664
- Acronym / sponsor ID
- CREC.2021.184-T
- Conditions
- Musculoskeletal Diseases or Conditions
- Keywords
- Superior Trunk nerve block
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 19 Jan 2023 (actual)
- Primary completion
- 31 Mar 2027 (estimated)
- Study completion
- 31 Aug 2027 (estimated)
- First posted
- 28 Jun 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The objective of this study is to identify the minimum effective dosage of a commonly used local anaesthetic drug "levobupivacaine" required to produce an effective ultrasound guided (USG) superior trunk block (STB) in at least 90% of patients for shoulder arthroscopic surgeries.
Detailed description
Shoulder arthroscopic surgery is one of the most commonly performed procedures worldwide, and associated with significant postoperative pain. Currently, such surgery is performed either under general anaesthesia or under Interscalene brachial plexus block (ISBPB), which is a regional anaesthesia technique. However, ISBPB is associated with the highest incidence of hemi-diaphragmatic palsy of the operative side. Since majority of the innervation to the shoulder arises from or passes through the superior trunk of the brachial plexus, superior trunk block has been shown to have lesser impact on the phrenic nerve and it has been gaining popularity worldwide. Ultrasound is widely used for brachial plexus block and current evidence indicates that it is feasible to accurately identify majority of the main components of the brachial plexus above the clavicle, including the three trunks (superior, middle, and inferior trunks). However, there are no data describing an optimal volume of local anaesthetic for superior trunk block. The aim of this study is to identify the minimum effective dosage of a commonly used local anaesthetic drug "levobupivacaine" required to produce an effective ultrasound guided (USG) superior trunk block (STB) in at least 90% of patients for shoulder arthroscopic surgeries.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Levobupivacaine | Other | Drug: 0.5% levobupivacaineSuperior trunk nerve block will be done under ultrasound guidance to patients scheduled for shoulder surgeries. Local anesthetic agent (0.5% levobupivacaine) 8ml will be injected at the superior trunk of the brachial plexus in order to produce surgical anesthesia or analgesia for shoulder surgeries. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- American Society of Anesthesiologists (ASA) physical status I-III scheduled to undergo elective upper shoulder arthroscopic rotator cuff repair procedure
Key exclusion criteria (6 listed)
- Patient refusal
- pregnancy
- skin infection at the site of block placement
- history of allergy to local anaesthetic drugs
- bleeding tendency or with evidence of coagulopathy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 0.5% levobupivacaineAlso: Peripheral nerve blockThis study adopts a "Modified Narayana rule (MNR)", a sequential up-and-down pharmacodynamics method (UDM) to estimate the minimum effective local anesthetic volume of 90% (MELVA90) of cases of the aforementioned local anesthetic (LA), in order to produce the surgical anesthesia of the patients scheduled for shoulder surgeries. Based on the principal investigator's clinical experience, the initial volume of 8ml will be used. Depending on the success or failure of the superior trunk block, which is defined as the readiness for surgery at 30 minutes after the block, the volume for the next patient will be adjusted up or down by 2ml. The upper dose limit of the study to minimize the potential for local anesthetic systemic toxicity will be 16ml and the lower dose limit will be 4ml, which will be of no clinical importance. | Drug | Levobupivacaine |
Primary outcome
Changes of sensory & motor blockade (Readiness for surgery) of the upper extremity
Time frame: within 45 minutes after the block at 5 minutes interval
The first exact timing (in minutes) [Readiness for surgery] that an Overall sensory score =<30 (NRS: 0-100; 100=normal sensation, 0=no sensation) using ice test and a motor grade =<1 (3 point scale: 2=no block, 1=paresis, 0=paralysis) in the nerves (C5 to C6) tested that are supplied by superior trunk of brachial plexus. Sensation to coldness (ice) will be tested at C5 - Lateral (radial) side of the antecubital fossa (just proximal to elbow crease); C6 - Thumb, dorsal surface, proximal phalanx. Motor block will be graded using a 3-points scale: 2=no block, 1=paresis and 0=paralysis, and will be test at C5 - elbow flexors and C6 - wrist extensors. "Block failure" will be defined as inability to achieve "readiness for surgery" at 30 minutes after the completion of the block.
Minimum effective volume (ml) of local anesthetic agent
Time frame: after nerve block till end of surgery
The lowest volume (in milliliters) of local anesthetic agent that can produce an effective superior trunk block for surgery. Effective superior trunk block is defined as an overall sensory score of NRS =<30 and a motor grade of =<1 during the assessment after the nerve block that can undergo surgery. Sensory assessment will be done by using ice (cold sensation) test in both dermatomes (C5, C6) and a motor grade of =<1 in both myotome (C5, C6) tested. Sensory block will be graded as 0 to 100 where 100 represents normal sensation and 0=no sensation to coldness (ice cube).
8 secondary outcomes
Changes of motor blockade of the upper extremity
Time frame: within 45 minutes after the block at 5 minutes interval
Changes of sensory block of the upper extremity
Time frame: within 45 minutes after the block at 5 minutes interval
Percentage changes of the Diaphragmatic function
Time frame: Baseline (before block) and at 30 minutes after block
Changes of the Extensiveness of Diaphragmatic function
Time frame: calculated after block
Block performance time
Time frame: assess once before surgery
Discomfort score
Time frame: assess once before surgery
Paresthesia
Time frame: during the period of undergoing the nerve block
Complications
Time frame: during the nerve block till the end of surgery
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Manoj K Karmakar, MD principal investigator
Chinese University of Hong Kong
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing 0.5% levobupivacaine in people with Musculoskeletal Diseases or Conditions, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ayla Wong, RN, BN (+85235056157, aylawong@cuhk.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes of sensory & motor blockade (Readiness for surgery) of the upper extremity (time frame: within 45 minutes after the block at 5 minutes interval). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Nov 2026.