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

• Sponsor: University Health Network, Toronto (Other)
• Overall Status: Completed
• CT.gov ID: NCT01568476
• Collaborator: (none)
• Enrollment: 88
• Location: 1
• Arms: 2
• Duration (Months): 23
• Patients Per Site Per Month: 3.8

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Post Operative Analgesia; Regional Anesthesia; Sciatic Nerve Block	Procedure: Distal; Procedure: Interneural	N/A

Study Design

• Study Type: Interventional
• Actual Enrollment: 88 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: Double (Participant, Investigator)
• Primary Purpose: Other
• Official Title: Does Interneural Local Anesthetic Spread at the Site of Sciatic Nerve Bifurcation Shorten Block Onset Time?
• Study Start Date: Jul 1, 2011
• Actual Primary Completion Date: Jun 1, 2013
• Actual Study Completion Date: Jun 1, 2013

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Distal Blockade of both terminal branches of Sciatic nerve separately, distal to bifurcation	Procedure: Distal; Blockade of both terminal branches of Sciatic nerve separately, distal to bifurcation
Active Comparator: Interneural sciatic nerve blockade at the site of bifurcation	Procedure: Interneural; Sciatic nerve blockade at the site of bifurcation

Outcome Measures

Primary Outcome Measures

1. 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

1. Extent of longitudinal local anesthetic solution spread [starting at block administration till 5 minutes after complete injection]

2. Nerve diameter prior to and following injection [starting at block administration till 5 minutes after complete injection]

3. Block procedure time [starting at block administration till complete injection(up to 10 minutes)]

4. Number of skin punctures required. [starting at first attempt of block administration till complete injection(up to 10 minutes)]

5. Block success rate [starting after complete injection up to 45 minutes]

6. 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

7. 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.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years to 85 Years
• Sexes Eligible for Study: All
• Accepts 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

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Toronto Western Hospital	Toronto	Ontario	Canada	M5T 2S8

Sponsors and Collaborators

• University Health Network, Toronto

Investigators

• Principal Investigator: Anahi Perlas, MD, FRCPC, University of Toronto

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

• Responsible Party: University Health Network, Toronto
• ClinicalTrials.gov Identifier: NCT01568476
• Other Study ID Numbers: 11-0059-A
• First Posted: Apr 2, 2012
• Last Update Posted: Dec 5, 2017
• Last Verified: Dec 1, 2017

• Keywords provided by University Health Network, Toronto: Regional anesthesia; Sciatic nerve block; foot surgery; ankle surgery; Interneural local anesthetic

Study Results

No Results Posted as of Dec 5, 2017