NCT02124005 - Evaluation of the Minimum Effective Concentration of Bupivacaine (EC50) in Femoral Block for Analgesia by Ultrasound After Knee Surgery | Crick

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

45

Conditions

Knee Surgery Postoperative Pain

Interventions

BupivacaineDRUG

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

Universidade Federal de São Paulo

São Paulo, São Paulo, Brazil

Outcomes

Primary Outcomes

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.

Time frame: two years