Post Operative Analgesia, Regional Anesthesia, Sciatic Nerve Block
Conditions
Keywords
Regional anesthesia, Sciatic nerve block, foot surgery, ankle surgery, Interneural local anesthetic
Brief summary
Following foot and ankle surgery, ultrasound-guided sciatic nerve block (SNB) at the popliteal fossa decreases post-operative pain and opioid consumption. At the popliteal fossa, the sciatic nerve bifurcates to form the Common Peroneal Nerve (CPN) and Tibial Nerve (TN). Studies have shown that when both branches are blocked separately distal to the bifurcation site, block onset time is reduced by 30%. Through clinical observation, the investigators found that onset time is further shortened when ultrasound-guided SNB is performed at the site of bifurcation. This is because the local anesthetic spreads interneurally. The purpose of this study is to compare the block onset time of an ultrasound-guided sciatic nerve block at the site of nerve bifurcation with the blockade of each terminal nerve separately (TN and CPN) distal to sciatic nerve bifurcation.
Interventions
PROCEDUREDistal
Blockade of both terminal branches of Sciatic nerve separately, distal to bifurcation
PROCEDUREInterneural
Sciatic nerve blockade at the site of bifurcation
Sponsors
University Health Network, Toronto
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* ASA physical status I-III * 18-85 years of age, inclusive * 50-120 kg, inclusive * 150 cm of height or greater
Exclusion criteria
* Contraindications to sciatic nerve block (e.g., allergy to local anesthetics, coagulopathy, malignancy or infection in the popliteal area) * Significant peripheral neuropathy or neurological disorder affecting the lower extremity * Pregnancy * History of alcohol or drug dependency/abuse * History of significant psychiatric conditions that may affect patient assessment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Block onset Time | every 5 minutes up to 45 minutes of the block or until surgery starts | We aim to compare the block onset time of an ultrasound-guided sciatic nerve block at the site of nerve bifurcation resulting in interneural spread of local anesthetic with that of blockade of each terminal nerve separately (TN and CPN), distal to sciatic nerve bifurcation. We hypothesize that sciatic nerve blockade at the site of bifurcation with interneural local anesthetic spread within a common epineural sheath results in shorter onset time compared to blockade of each terminal nerve distal to sciatic nerve bifurcation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Nerve diameter prior to and following injection | starting at block administration till 5 minutes after complete injection | — |
| Block procedure time | starting at block administration till complete injection(up to 10 minutes) | — |
| Number of skin punctures required. | starting at first attempt of block administration till complete injection(up to 10 minutes) | — |
| Extent of longitudinal local anesthetic solution spread | starting at block administration till 5 minutes after complete injection | — |
| Incidence of block-related complications | immediately , at 24 hours and Post operative day 7 | Incidence of block-related complications (vascular puncture, hematoma formation, intravascular injection and post-operative neurologic deficit) will be documented, but due to the very low incidence in all block-related complications, this study is not powered to show a difference in safety |
| Postoperative pain | starting at patient's arrival at post-anesthetic care unit till 120 minutes | Postoperative pain: Postoperative pain using a verbal rating score (0-10, where 0= no pain, 10=excruciating pain) at 0, 30, 60, 90 and 120 min upon admission to post-anesthetic care unit. |
| Block success rate | starting after complete injection up to 45 minutes | — |
Countries
Canada
Outcome results
None listed