The lateral parasagittal in-plane is the current conventional approach in ultrasound-guided infraclavicular brachial plexus block. However this technique is less popular because brachial plexus at the infraclavicular level runs deeper compared to its course proximally, often give rise to impaired needle visualisation due to its steep angle of needle trajectory to the ultrasound beam. A new posterior parasagittal in-plane approach was introduced to improve needle visibility. This approach proved feasible from our case series hence the investigators would like to compare it with the conventional method in this study
This study compared the conventional lateral and posterior approach parasagittal in-plane ultrasound guided infraclavicular brachial plexus block for upper limb surgery. A cadaveric study was also performed to complement the findings. After obtaining approval from the Medical Ethics Committee, University Malaya Medical Centre (IRB reference no. 949.14 dated 17 October 2012), 46 patients undergoing upper limb surgery were prospectively recruited and randomized. A cadaveric dissection was also performed. DESIGN: Prospective randomized study SETTING: Single centre, University of Malaya Medical Centre, Kuala Lumpur, Malaysia; November 2012 to October 2013 INTERVENTION: Ultrasound guided, lateral or posterior parasagittal in-plane infraclavicular brachial plexus blocks were performed on patients, depending on randomization. All blocks were performed using 21G x 4 inch Stimuplex A (B Braun Medical) without nerve stimulation plus SonoSite M-Turbo with HFL38x/ 13-6 MHz linear transducer probe. A 25-ml local anaesthetic admixture \[Lignocaine 2% (100mg) plus Ropivacaine 0.75% (150mg)\] were injected to all patients. A total volume of normal saline 0.9% 25ml mixed with methylene blue (0.2ml) was used for cadaveric study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Masking
NONE
Enrollment
46
The needle insertion point was over the trapezius muscle sufficiently posterior to allow the needle to pass between the clavicle and the scapula in the direction of the axillary artery. The insertion point was strictly aligned with the long axis of the ultrasound beam i.e. in-plane technique.
The needle insertion point would be at the cephalad (lateral) aspect of the ultrasound probe, beneath the clavicle and medial to the coracoid process. The insertion point was strictly aligned with the long axis of the ultrasound beam i.e. in-plane technique.
Success rate (ability to proceed with surgery without the need for intravenous narcotics, general anaesthesia, rescue blocks or local infiltration by the surgeon)
Success rate - was equivalent to surgical anesthesia, defined as the ability to proceed with surgery without the need for intravenous narcotics, general anaesthesia, rescue blocks or local infiltration by the surgeon. The adequacy of block was determined during assessment of motor and sensory blockade at predetermined intervals, every 5 minutes until 30 minutes; Please refer to the study detailed description.
Time frame: participants will be followed up throughout the operation duration; as stated each operation has variable duration of operation time, average operation time 2 to 4 hours
Performance parameters
This is a composite outcome measure. The anaesthesia assistant would record the time required to perform the procedure as follow below description: (i)Imaging time (defined as the time interval between contact of the ultrasound probe with the patient and the acquisition of a satisfactory sonoanatomy - a complete round short-axis view of the axillary artery), (ii) Needling time (defined as the time interval between the start of the needle insertion and the end of local anaesthetic injection through the needle), (iii) Performance time (defined as the sum of imaging and needling times). This timing definition had been published in other journals (please refer our references - 3)
Time frame: participants will be followed up throughout the procedure (performing the blocks), average time for block perfomances 30 minutes
Safety aspects and potential complications; we measured by any incidence of paraesthesia, vascular puncture, Horner's syndrome, dyspnoea and symptoms suggestive of LA toxicity
This is a composite outcome measure. We measured safety aspects and potential complications by recording any incidence of paraesthesia and vascular puncture during block performances, any Horner's syndrome, dyspnoea and symptoms suggestive of local anaesthetic toxicity were routinely checked after the procedure and during surgery. To further enhance patient's safety, we would still follow up patient by phone call 1 week after the surgery
Time frame: Participants would be followed up throughout procedure (average duration 30 minutes), during operation (average duration 2 to 4 hours) and 1 week after the operation (via phone call)
adequacy of block for tourniquet application
The incidence of tourniquet pain; this would describe whether the block technique covers for tourniquet pain
Time frame: participants would be followed up throughout the operation duration whether they complained of pain at torniquet site during the operation duration; average duration of operation 2 - 4 hours
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