Evaluation of the Minimum Effective Concentration of Bupivacaine (EC50) in Femoral Block for Analgesia by Ultrasound After Knee Surgery

Study Overview
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Brief Summary
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The purpose of the study is to determine the minimum effective concentration of bupivacaine (EC50) in femoral block for analgesia by ultrasound after knee surgery.

Detailed Description
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45 patients classified as ASA P1 or P2 aged between 18 and 65 candidates for elective knee operation via arthroscopy were included in the study. All patients received femoral nerve block guided by ultrasound with bupivacaine, 22 ml. The first patient at a concentration of 0.25%. The other patients with higher or lower concentrations if the first patient has pain> 3 or <3 on visual analogic scale respectively after awakening of surgical anesthesia. For surgical anesthesia each patient will undergo general anesthesia. At the end of the surgical procedure and anesthetic awakening patients will be evaluated for analgesia by verbal numeric scale. The modified Dixon method was used to find the EC50 and EC95 of bupivacaine for analgesia of femoral nerve block guided by ultrasound. Concentration still correlated with motor block and side effects.

Official Title
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Evaluation of the Minimum Effective Concentration of Bupivacaine (EC50) in Femoral Block for Analgesia by Ultrasound After Knee Surgery

Conditions
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Knee Surgery, Postoperative Pain

Intervention / Treatment
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* Drug: Bupivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients to undergo knee surgery Exclusion Criteria: patients with coagulopathy pregnant infection at the puncture site chronic pain

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Femoral block, ultrasound, bupivacaine<br> | Drug: Bupivacaine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Scores on the Visual Analog Scale | 45 patients classified as ASA P1 or P2 aged between 18 and 65 candidates for elective knee operation via arthroscopy were included in the study. All patients received femoral nerve block guided by ultrasound with bupivacaine, 22 ml. The first patient at a concentration of 0.25%. The other patients with higher or lower concentrations if the first patient has pain> 3 or <3 on visual analogic scale respectively after awakening of surgical anesthesia. For surgical anesthesia each patient will undergo general anesthesia. At the end of the surgical procedure and anesthetic awakening patients will be evaluated for analgesia by verbal numeric scale. The modified Dixon method was used to find the EC50 and EC95 of bupivacaine for analgesia of femoral nerve block guided by ultrasound. Concentration still correlated with motor block and side effects. | two years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Knee surgery, Femoral block, Bupivacaine, Ultrasound