Clinical Trial Details
— Status: Recruiting
Administrative data
NCT number |
NCT05809258 |
Other study ID # |
061/2023 |
Secondary ID |
|
Status |
Recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
August 7, 2023 |
Est. completion date |
May 2025 |
Study information
Verified date |
November 2023 |
Source |
Sultan Qaboos University |
Contact |
Jyoti Burad, MD, EDIC |
Phone |
+96899578636 |
Email |
jyotiburad[@]yahoo.com |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This study compares the analgesic efficacy of supraclavicular brachial plexus nerve block to
axillary nerve block techniques in adults undergoing AV fistula creation. Both these
techniques will be done under ultrasound guidance, using the same local anesthetic drug. 120
patients will be included in this study, 60 patients for each technique. This study will help
us know better regional anesthesia techniques, the additional need for analgesia/anesthesia,
and the recovery rate following either of the blocks for AV fistula surgery. An interim
analysis will be done after recruiting 50% of cases (30 cases) in both arms.
Description:
Introduction An AV fistula creation is generally performed at the antecubital fossa under
regional anesthesia. General anesthesia is associated with increased cardiorespiratory
complications in patients with end-stage renal disease. Thus, in such patients, RA, such as a
brachial plexus block (BPB), is favored for AVF creation. In this study comparison between
two well-established and frequently used approaches of brachial plexus block: supraclavicular
and axillary, will be compared.
The supraclavicular block is one of several approaches used for the brachial plexus block.
The block is performed at the level of the brachial plexus trunks, where almost the entire
sensory, motor, and sympathetic innervation of the upper extremity is carried in just three
nerve structures confined to a very small surface area. Indications for the supraclavicular
block include elbow, forearm, and hand surgeries.
The axillary block technique is relatively easy to approach and simple to perform and may be
associated with a lower risk of complications than supraclavicular BPB. The supraclavicular
has a slightly wider area of coverage and a supposedly higher rate of complications compared
to the axillary approach when performed with a traditional approach without ultrasound
guidance. Using ultrasound should reduce the rate of complications for both blocks. No
randomized control study has compared the efficacy of both blocks for AV Fistula creation
with ultrasound guidance. This study aims to determine a better anesthesia technique for AV
fistula creation in terms of anesthesia efficacy, complications, and recovery.
Method
Study type: Randomized, Controlled, observer-blinded non-inferiority trial, with two parallel
arms.
Blinding: The observer, Anesthetist 2, and data analyst will be blinded. But the patient and
the block performer both will know the block group.
Randomization: The statistician will generate the block randomization sequence, and the file
will be handed over to the principal investigator. The file will be accessed during
randomization, and group allocation will be obtained and conveyed to the block performer
(Anesthetist 1). The remaining will be kept securely with the principal investigator. The
patient will be randomized into groups A (supraclavicular nerve block) and B (axillary nerve
block). The randomization sequence will be kept locked with a password-protected file.
Crossover: Nil Study duration: Prospective for 18-24 months, depending on the case
recruitment rate.
Number of groups: 2 Sample size: 120 cases, 60 in each group. Assessment: The patient will be
assessed intraoperatively at 10 minutes after the block and every 5 minutes. The final
assessment of block adequacy will be done 30 minutes after the block, and a decision will be
taken on adequacy. The next assessment will be at two hours and 30 minutes after time 0 and
will continue every hour till complete recovery of the block in PACU and ward.
Target follow-up duration: The patient will be followed till complete recovery of muscle
power of the upper limb.
Eligibility Study Population: all adult>18 years old patients posted for AV fistula creation
in the antecubital fossa.
Inclusion Criteria:
- Age >18 years old
- Patients undergoing AV fistula creation in the antecubital fossa
Exclusion Criteria:
- Patient Refusal
- Hemodynamically unstable patient
- Local infection over the insertion site
- Coagulopathy
- Known allergy to Local Anaesthetic medications.
- Grossly abnormal anatomy
- Severe chronic airways disease
Primary Outcome:
• Requirement of additional analgesics intraoperatively or block failure (conversion to
general anesthesia)
Secondary outcome:
- Time of motor recovery of block
- Rate of complications
- Comparison of change in brachial artery diameter at the elbow before and after block
Study population:
Sample size The estimated sample size is 120 (60 in each group). The estimation was based on
the success rate reported in the literature (95%), the non-inferiority margin between
supraclavicular and axillary brachial plexus block to be < 10%. The power was set at 80%, and
the alpha error was set at 5%. The allocation ratio was 1:1. The software used for the sample
size calculation is nMaster 2.0 sample size calculator.
Method:
Patients will be posted for surgery in the operating room list. An appropriate population, as
per eligibility criteria, will be approached. An explanation of the study will be done in
comprehensive language. The patient's rights will be explained to the patient/relatives.
Informed consent will be taken on the consent form. As per the departmental schedule and
protocol, a separate anesthetist will do the pre-anesthetic checkups. On the day of surgery,
the patient will be premedicated per standard institutional guidelines; the intravenous
cannula will be inserted in the ward. On arrival of the patients to the operative theatre,
ASA monitors will be attached (ECG, non-invasive blood pressure, and SpO2). The patient will
be positioned for the block, and the largest brachial artery diameter will be recorded with
the help of the ultrasound. This will be done before attempting block, at the start and end
of surgery. Following the study protocol, the block will be given as per randomization by one
of the expert anesthesia consultants (Anesthetist 1). The supraclavicular and axillary block
sites will be dressed for all patients to avoid disclosing the technique to Anesthetist 2 and
the assessors. An independent observer will record all the timings and procedure details. At
the end of the procedure, the patient will be shifted to PACU (Post-Anesthesia Care Unit).
Assessment of the block: The block assessment will start after 10 minutes of finishing the
block (Time 0) and will be repeated every 5 minutes until the start of surgery. If the
anesthesia state is not achieved within 30 minutes of the block, rescue analgesia or general
anesthesia will be given. Rescue analgesia will be given when the block is incomplete (only
one segment/nerve dermatome will be spared). It will consist of Fentanyl 0.5 mics/kg aliquots
followed by local infiltration with 1% Lidocaine by the surgeon and Paracetamol 15 mg/kg in
the same sequence, one after another if previous rescue analgesia is not effective. General
anesthesia will be given if there is a complete block failure (defined as no block in more
than one nerve).
Assessment of the block intraoperatively: The muscle power will be checked by asking the
patient to flex and extend his forearm and adduct, abduct and oppose the thumb and all
fingers. Motor blockade of the musculocutaneous nerve will be checked by elbow flexion, ulnar
nerve by thumb adduction, radial by thumb abduction and median nerve by thumb opposition. The
power will be graded on a three-point scale: 0=no block, 1=paresis, and 2=paralysis. Whereas
sensory blockade will be assessed on another three-point scale with a cold test: 0=no block,
1=analgesia (can feel touch but not cold), and 2=anesthesia (cannot feel touch).
Assessment of the block postoperatively: The assessment will start two hours 30 minutes after
time 0 and will continue every hour till discharge or complete recovery of the block.
Possible Complications:
- Pneumothorax
- Horner syndrome
- Vascular puncture and Hematoma
- Diaphragmatic paralysis
- Local anesthetic systematic toxicity (LAST)
- Prolonged block recovery
Troubleshooting:
Pneumothorax: Because of the proximity of the pleura to the brachial plexus at the clavicle's
level, the lung's apex can be damaged. It is a rare complication; pneumothorax was a more
frequent complication of the supraclavicular block before ultrasound use, with a reported
incidence of 0.6% to 6.1%. Maintaining needle tip visibility at all times during needle
advancement is critical while performing US-guided block., An urgent chest radiograph (CXR)
will be requested if the pleura is punctured, and supplemental oxygen will be delivered. A
general surgeon will insert a chest tube under local anaesthesia and connect to suction at a
negative pressure of 20 cm H2O. A repeat CXR will be done to confirm the correct position of
the chest tube and re-expansion of the lung. The chest tube will be removed a few days later
upon the resolution of symptoms.
Horner's syndrome may correspond to the diffusion of local anaesthetics in prevertebral
spaces, ultimately involving the sympathetic nerves and communicating with cervical nerve
trunks. It results from paralysis of the ipsilateral sympathetic cervical chain (stellate
ganglion) caused by surgery, drugs (mainly high concentrations of local anaesthetics), local
compression (hematoma or tumour), or inadequate perioperative positioning of the patient. It
appears after the block with a specific triad (ptosis, miosis, and exophthalmos) and quickly
disappears without any sequelae. Horner's syndrome may be described as an unpleasant side
effect because it has no clinical consequences, and if it occurs, patients should be
reassured and monitored closely.
Vascular puncture and Hematoma: These are not commonly encountered with ultrasound guidance.
Bleeding can be controlled by pressure, conservative treatment and surgical exploration if
needed. Especially if a hematoma forms, it should be removed promptly. Comprehensive
knowledge of anatomy and skills is crucial to avoid nerve injuries, so the blocks will be
performed by experts and US-guided in this study.
Diaphragmatic paralysis: the phrenic nerve lies in front of the anterior scalene muscle, and
local anaesthetic injected around the proximal, i.e., interscalene, part of the plexus can,
therefore, easily affect the phrenic nerve. Treatment is conservative and usually resolves
within a few days to weeks. Ultrasonography was chosen to demonstrate diaphragmatic movement
as it reliably shows the paradoxical movement of the diaphragm in the event of paralysis.
LAST: It is rare as the blocks are usually US-guided, and drugs are given in smaller amounts
than the toxic levels and given with frequent aspirations to prevent injecting into blood
vessels.
The following actions will be taken when managing local anaesthetic toxicity:
- Stop the local anaesthetic injection.
- Institute basic life support and call for assistance.
- Secure the airway, ventilate with 100% oxygen, and gain intravenous access.
- Seizures can be managed with a benzodiazepine or anaesthetic induction agent.
- If a cardiac arrest has occurred, commence advanced life support.
- Note that arrhythmias are often refractory, and resuscitation should be prolonged.
- Treatment with IntraLipid: An initial dose of 20% lipid emulsion at 1.5 ml/kg or a 100
ml bolus can be administered over a few minutes. This can be repeated after 5 minutes
two or more times for persistent hemodynamic instability. The bolus(es) should
immediately be followed by a continuous infusion at 0.25-0.5 ml/kg/min. The infusion
should run for a minimum of 10 minutes after the return of hemodynamic stability.
However, there are documented reports of recurrent systemic toxicity even after this.
For this reason, patients should be admitted for at least 12 hours for observation and
additional doses of intralipid as needed for rebound symptoms or hemodynamic compromise.
Prolonged block recovery: This is not expected as the medication injected is fixed, and the
drugs will be injected under ultrasound vision around nerves. If it occurs, 24 hours period
will be given for observation. And if it still doesn't recover, then neurological advice will
be sought.
Data collection:
This prospective study would entail the collection of the following patient-specific data:
Demographic Data: Age, gender, ASA grading, comorbidities, surgery
Lab Data: Routine blood investigations like complete blood count and coagulation profile.
Anesthesia and block details: Type of airway device, hemodynamic, block details: block name,
normal/abnormal anatomy, local anaesthetics injected; rescue analgesics needed, motor
assessment and complications at 30 minutes after arrival and before discharge from PACU,
postoperatively in Ward at every hour till muscle power recovery and after discharge at home
on day 2 and 5.
One assigned co-investigator will enter the recorded patient data with a code and no name
into the password-protected master chart.