Minimum Effective Local Anesthetic Volume of 0.5% Levobupivacaine Required for Ultrasound Guided Superior Trunk Block for Shoulder Surgery
Overview
- Phase
- Not Applicable
- Intervention
- 0.5% levobupivacaine
- Conditions
- Musculoskeletal Diseases or Conditions
- Sponsor
- Chinese University of Hong Kong
- Enrollment
- 25
- Locations
- 1
- Primary Endpoint
- Changes of sensory & motor blockade (Readiness for surgery) of the upper extremity
- Status
- Recruiting
- Last Updated
- last year
Overview
Brief 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.
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.
Investigators
Prof Manoj K Karmakar
Professor
Chinese University of Hong Kong
Eligibility Criteria
Inclusion Criteria
- •American Society of Anesthesiologists (ASA) physical status I-III scheduled to undergo elective upper shoulder arthroscopic rotator cuff repair procedure
Exclusion Criteria
- •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.
Arms & Interventions
Levobupivacaine
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.
Intervention: 0.5% levobupivacaine
Outcomes
Primary Outcomes
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).
Secondary Outcomes
- Discomfort score(assess once before surgery)
- Changes of motor blockade of the upper extremity(within 45 minutes after the block at 5 minutes interval)
- Paresthesia(during the period of undergoing the nerve block)
- Percentage changes of the Diaphragmatic function(Baseline (before block) and at 30 minutes after block)
- Changes of the Extensiveness of Diaphragmatic function(calculated after block)
- Changes of sensory block of the upper extremity(within 45 minutes after the block at 5 minutes interval)
- Block performance time(assess once before surgery)
- Complications(during the nerve block till the end of surgery)