Ultrasound Description of the Sciatic Nerve

Study Overview
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Brief Summary
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Sciatic nerve blocks are frequently used for anesthesia or analgesia for surgery of the lower legs. Currently, if ultrasound is used to find the sciatic nerve, the leg must be raised to locate the nerve with the ultrasound probe on the back of the thigh. In pediatric surgery, the patients are anesthetized (asleep) before the block is given. It is difficult for one person to administer the sciatic nerve block using this method. We would like to identify the sciatic nerve using ultrasound on the side of the thigh and its location to the adjacent structures.

Detailed Description
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The sciatic nerve block is frequently used for anesthesia or analgesia for surgery of the lower extremities. Ultrasound-guided sciatic nerve blocks performed at the lateral mid-femoral level have been successfully described with subjects in the supine position and the lower limb elevated in order to accommodate the ultrasound probe against the posterior aspect of the thigh. In the pediatric setting in which nerve blocks are commonly performed with the patient anesthetized rather than awake, we find this technique to be unwieldy as a single-operator technique. Using a more ergonomic approach that has not been previously described, we plan to identify and describe the sciatic nerve with the ultrasound positioned against the lateral aspect of the thigh. We hope to describe the appearance of the sciatic nerve and its location in relation to adjacent anatomic structures using this modified approach. This a prospective cross-sectional study of 40 pediatric subjects 11-17 years of age. Three ultrasound images of the sciatic nerve will be obtained via the lateral mid-thigh approach in 40 pediatric patients scheduled to undergo sciatic nerve block - the first image prior to placement of the block, the second after the nerve is located by the stimulating needle and the third after the injection of local anesthetic.

Official Title
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Anatomical Description of the Sciatic Nerve Via a Lateral Mid-Thigh Approach Using Ultrasound

Conditions
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Sciatic Nerve AH, Peripheral Nerves US

Intervention / Treatment
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* Other: Observation of the Sciatic Nerve


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males or females 11 to 17 years old. Patients undergoing lower extremity surgery who are scheduled to have a sciatic nerve block as part of the anesthetic. Parental/guardian permission (verbal consent) and child assent. Note: if you record ANY PHI, you will need to obtain written consent since HIPAA requires written authorization for use of PHI. Exclusion Criteria: None

Ages Eligible for Study
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Minimum Age: 11 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 1<br>Pediatric Patients of ages 11-17 | Other: Observation of the Sciatic Nerve<br>* Ultrasound will be used to determine the location of the Sciatic Nerve using a lateral mid-thigh approach.<br>* Other names: Peripheral Nerve Blocks;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary objective is to describe the appearance of the sciatic nerve and its location in relation to adjacent anatomic structures using ultrasound from the lateral mid-thigh position. |  | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A secondary objective is to describe correlations between any of the measured variables and the patient's mid-thigh circumference or weight. |  | 10 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Sciatic Nerve, Peripheral Nerve Block, Lower extremity surgery, Local Anesthesia, Ultrasound guided nerve blocks