Circumferential Spread of Anesthetic and Success in Sciatic Nerve Blockade

University Health Network, Toronto

Status: Completed

Conditions: Sciatic Nerve Blockade for Foot/Ankle Surgery

Treatments: Procedure: Non-circumferential spread of local anesthetic; Procedure: Circumferential spread of local anesthetic

Study type: Interventional

Funder types: Other

Identifiers

NCT00802581

08-0728-B

Details and patient eligibility

About

Current practices when performing any peripheral nerve block may or may not involve ensuring circumferential spread of local anesthetic around the nerve. Ensuring circumferential spread can involve several redirections of the needle above and below the nerve, and potentially could result in either more discomfort for the patient or an increased chance of inadvertent direct trauma to the nerve. Not ensuring spread around the nerve may result in a slower and less complete blockade. The investigators suspect that by ensuring complete spread around the nerve, the speed of block onset would be quicker because it avoids the loss due to diffusion time.

Enrollment: 64 patients

Sex: All

Ages: 18 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. English-speaking
2. ASA physical status I-III
3. 18-85 years of age, inclusive
4. 50-110 kg, inclusive
5. 150 cm of height or grater
6. Scheduled for elective foot or ankle surgery

Exclusion criteria

1. Contraindications to sciatic nerve block (e.g., allergy to local anesthetics, coagulopathy, malignancy or infection in the popliteal area)
2. Significant peripheral neuropathy or neurologic disorder affecting the lower extremity
3. Pregnancy
4. Contraindications to, allergies to, and/or past adverse reactions to study medications (local anesthetics, opioid analgesics)
5. History of alcohol or drug dependency/abuse
6. History of long term opioid intake
7. History of significant psychiatric conditions that may affect patient assessment

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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64 participants in 2 patient groups

1

Experimental group

Description:

Ensuring circumferential spread of local anesthetic around the sciatic nerve.

Treatment:

Procedure: Circumferential spread of local anesthetic

2

Active Comparator group

Description:

Single shot injection of local anesthetic near the sciatic nerve will be performed, without ensuring circumferential spread.

Treatment:

Procedure: Non-circumferential spread of local anesthetic