Motor-Sparing Femoral Nerve Block Dose

Phase 4

Terminated

• Conditions: Osteoarthritis, Knee; Knee Injuries
• Interventions: Drug: Same Bupivacaine Concentration; Drug: Lower Bupivacaine Concentration

• Registration Number: NCT02909257
• Lead Sponsor: University of Chile

Brief Summary

Femoral nerve blocks are commonly used to provide pain control for total knee replacement, anterior cruciate ligament (ACL) reconstruction. Commonly employed local anesthetic concentrations result in motor block of the quadriceps and constitute an inherent risk factor for patient fall.

The aim of this study is to determine the minimum effective concentration of bupivacaine in 90 % of patients (MEC90) required for a motor-sparing, successful sensory block of the femoral nerve.

Detailed Description

With the approval of Ethics Committee of the University of Chile Clinical Hospital, approximately 60 patients undergoing ACL repair or TKR will be recruited. All blocks will be conducted preoperatively in an induction room.Dose assignation will be done using an up-and-down sequential method, where the dose of each subsequent patient depends on the response of the previous patient, called the Biased Coin Design.

The assignment of each subsequent concentration will be based on the response of the previous patient.As soon as we recruit 45 patients with random dose assignment, we will terminate the enrollment procedure.

The injectate will be prepared and administered by a research assistant using syringes connected to the block needle. The operator and the patient will be blinded to the concentration injected.

Study Timeline

• Study Start: 2016-09
• Study First Submitted: 2016-09-19
• Study First Submitted QC: 2016-09-20
• Study First Posted: 2016-09-21
• Primary Completion: 2017-12
• Study Completion: 2017-12
• Status Verified: 2020-05
• Last Update Submitted: 2020-05-13
• Last Update Posted: 2020-05-14

Recruitment & Eligibility

• Status: TERMINATED
• Sex: All
• Target Recruitment: 31

Inclusion Criteria

• Age between 18 and 75 years
• American Society of Anesthesiologists classification 1-3
• Body mass index between 20 and 35

Exclusion Criteria

• Adults who are unable to give their own consent
• Pre-existing neuropathy (assessed by history and physical examination)
• Coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets≤ 100, International Normalized Ratio≥ 1.4 or partial prothrombin time ≥ 50)
• Renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100)
• Hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100)
• Allergy to LA
• Pregnancy
• Prior surgery in the inguinal region
• Chronic pain syndromes requiring opioid intake at home

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
same dose	Same Bupivacaine Concentration	patient is exposed to the same previously successful dose
lower dose	Lower Bupivacaine Concentration	patient is exposed to a lower concentration dose

Primary Outcome Measures

Name	Time	Method
Minimum Bupivacaine Analgesic concentration preserving quadriceps strength analgesia	5 months

Trial Locations

Locations (1)

Hospital Clinico Universidad de Chile; 🇨🇱 Santiago, Metropolitan, Chile