Minimum Effective Local Anaesthetic Volume of a 1:1 Mixture of 2% Lidocaine With 5ug/ml of Epinephrine and 0.5% Levobupivacaine Required for Ultrasound Guided Selective Trunk Block: A Dose Finding Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Musculoskeletal Diseases or Conditions
- Sponsor
- Chinese University of Hong Kong
- Enrollment
- 25
- Locations
- 1
- Primary Endpoint
- Readiness for surgery
- Status
- Completed
- Last Updated
- 4 years ago
Overview
Brief Summary
The objective of this study is to identify the minimum effective dosage of a mixture of two local anaesthetic drugs called 'levobupivacaine' and 'lignocaine with epinephrine" used to produce an effective ultrasound guided selective trunk block for surgical anaesthesia of the upper limb.
Detailed Description
Ultrasound is widely used for brachial plexus block (BPB) 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. Since majority of the innervation to the upper extremity, including the shoulder, arises from the three trunks (superior, middle and inferior) of the brachial plexus, so targeted injections of the individual trunks of the brachial plexus under ultrasound guidance will produce surgical anaesthesia of the entire upper extremity (C5-T1). Principal Investigator refers to this novel technique "selective trunk block" (SeTB) and the preliminary experience with SeTB for surgical anaesthesia of the entire upper extremity has been very encouraging. Currently there are no data describing an optimal dose or volume of local anaesthetic for SeTB. The aim of this study is to identify the minimum dosage of 1:1 mixture of 'levobupivacaine' and "lignocaine with epinephrine" required to produce effective surgical anaesthesia in at least 90% of patients presented for upper limb surgery.
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 extremity surgery involving 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 drugs
- •history of bleeding tendency or with evidence of coagulopathy
- •pre-existing neurological deficit
- •pre-existing neuromuscular disease.
Outcomes
Primary Outcomes
Readiness for surgery
Time Frame: within 45 minutes after the block at 5 minutes interval
Overall sensory score of NRS =\<30 (NRS: 0-100; 100=normal sensation, 0=no sensation) and Qualitative sensory score =1 for each nerve; and motor scores \>=1 (3 point scale: 0=no block, 1=paresis, 2=paralysis) in all nerves tested. Overall the maximum composite sensory-motor score achievable is 20 points (2 points for each 5 sensory nerves tested and 2 points for each 5 motor nerves tested).
Changes of sensory block of the upper extremity
Time Frame: within 45 minutes after the block at 5 minutes interval
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, 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). A 3-point qualitative sensory score (0=no block, 1=analgesia/ patient can feel touch but not cold, and 2=anaesthesia / patient cannot feel touch) will be used. 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 and Qualitative sensory score =1 .
Changes of motor blockade of the upper extremity
Time Frame: within 45 minutes after the block at 5 minutes interval
motor blockade will be graded using a 3-point scale: 0=no block, 1=paresis and 2=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.
Secondary Outcomes
- Changes of the Diaphragmatic function(Baseline (before block) and at 30 minutes after block)