Clinical trial NCT01568476: Does Interneural Local Anesthetic Spread at the Site of Sciatic Nerve Bifurcation Shorten Block Onset Time?
Official title: Does Interneural Local Anesthetic Spread at the Site of Sciatic Nerve Bifurcation Shorten Block Onset Time?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Post Operative Analgesia
Regional Anesthesia
Sciatic Nerve Block
Keywords: Regional anesthesia
Sciatic nerve block
foot surgery
ankle surgery
Interneural local anesthetic
Lead sponsor: University Health Network, Toronto
Sponsor class: OTHER
First posted: 2012-04-02
Enrollment: 88
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

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.


Eligibility criteria: 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

Primary outcomes:
measure: Block onset Time
timeFrame: every 5 minutes up to 45 minutes of the block or until surgery starts
Secondary outcomes:
measure: Extent of longitudinal local anesthetic solution spread
timeFrame: starting at block administration till 5 minutes after complete injection
measure: Nerve diameter prior to and following injection
timeFrame: starting at block administration till 5 minutes after complete injection
measure: Block procedure time
timeFrame: starting at block administration till complete injection(up to 10 minutes)
measure: Number of skin punctures required.
timeFrame: starting at first attempt of block administration till complete injection(up to 10 minutes)
measure: Block success rate
timeFrame: starting after complete injection up to 45 minutes
measure: Incidence of block-related complications
timeFrame: immediately , at 24 hours and Post operative day 7
measure: Postoperative pain
timeFrame: starting at patient's arrival at post-anesthetic care unit till 120 minutes
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Toronto Western Hospital
state: Ontario
Study officials:
affiliation: University of Toronto
name: Anahi Perlas, MD, FRCPC
role: PRINCIPAL_INVESTIGATOR
References: