Does Interneural Local Anesthetic Spread at the Site of Sciatic Nerve Bifurcation Shorten Block Onset Time?

Not Applicable

Completed

• Conditions: Post Operative Analgesia; Sciatic Nerve Block; Regional Anesthesia
• Interventions: Procedure: Distal; Procedure: Interneural

• Registration Number: NCT01568476
• Lead Sponsor: University Health Network, Toronto

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2011-07
• Study First Submitted: 2012-03-06
• Study First Submitted QC: 2012-03-29
• Study First Posted: 2012-04-02
• Primary Completion: 2013-06
• Study Completion: 2013-06
• Status Verified: 2017-12
• Last Update Submitted: 2017-12-01
• Last Update Posted: 2017-12-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 88

Inclusion Criteria

• ASA physical status I-III
• 18-85 years of age, inclusive
• 50-120 kg, inclusive
• 150 cm of height or greater

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Distal	Distal	Blockade of both terminal branches of Sciatic nerve separately, distal to bifurcation
Interneural	Interneural	sciatic nerve blockade at the site of bifurcation

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
Extent of longitudinal local anesthetic solution spread	starting at block administration till 5 minutes after complete injection
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)
Block success rate	starting after complete injection up to 45 minutes
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.

Trial Locations

Locations (1)

Toronto Western Hospital; 🇨🇦 Toronto, Ontario, Canada