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The Effect of PPB Using 10, 20 and 30 ml of Lidocaine, Study on Volunteers

Phase 4
Completed
Conditions
Knee Arthritis
Anesthesia, Local
Post Surgical Pain
Interventions
Drug: Popliteal Plexus Block with 10 ml
Drug: Popliteal Plexus Block with 20 ml
Drug: Popliteal Plexus Block with 30 ml
Drug: Femoral Nerve Block
Drug: Sciatic Nerve Block
Registration Number
NCT05464862
Lead Sponsor
Charlotte Runge
Brief Summary

The aim of this study is to evaluate the Popliteal Plexus Block (PPB) effect on motor nerve branches of the sciatic and femoral nerve, when using different volumes of local anesthetics for PPB.

The hypothesis is that increasing the volume of anesthetics used for PPB will spread to the sciatic nerve leading to a reduced muscle strength in the lower leg and decreased nerve conduction velocity in the nerve to gastrocnemius muscle (the tibial nerve) and the nerve to anterior tibial muscle (the deep fibular nerve).

The effects will be evaluated by maximum voluntary isometric contraction (MVIC) of the lower leg muscles and by recordings of the compound muscle action potential (cMAP) of the gastrocnemius and tibialis anterior muscles - a motor nerve conduction study.

In addition, evaluation of PPBs effect on the femoral nerve is done by MVIC of the quadriceps femoris muscle, cMAP of the vastus medialis and vastus lateralis muscles and by a sensory nerve conduction study of the saphenous nerve.

Detailed Description

A total number of 40 volunteers will be enrolled in the study. Each volunteer will receive two peripheral nerve blocks (one in each leg) on the day of participation. This will result in 80 peripheral nerve blocks. The types of nerve blocks given to each leg on each volunteer will depend on randomization.

The 80 nerve blocks are divided into five groups specified by type of nerve block, volume of anesthetic used, and respective numbers of legs used in the group. The groups and specifications are listed here:

Groups name, type of peripheral nerve block, study medication dosage and number of legs in the group:

* Group A: PPB with 10 ml of lidocaine 1%, 20 legs.

* Group B: PPB with 20 ml of lidocaine 1%, 20 legs.

* Group C: PPB with 30 ml of lidocaine 1%, 20 legs.

* Group FNB: FNB with 20 ml of lidocaine 1%, 10 legs.

* Group SNB: SNB with 20 ml of lidocaine 1%, 10 legs.

Group FNB of SNB are performed unblinded and works as active comparatives for model control, in order to establish reference points for when a nerve is considered affected.

Prior to nerve block procedure , pre block assessments are obtained in the following order:

* Sensory test of the saphenous nerve.

* MVIC by ankle plantarflexion.

* MVIC by ankle dorsiflexion.

* MVIC by knee extension.

* Compound muscle action potential (cMAP) recordings in the following order:

* Nerve to vastus medialis muscle

* Nerve to vastus lateralis muscle

* Nerve to tibialis anterior muscle

* Nerve to gastrocnemius muscle

60 minutes after the block performance, post block assessments are done. Values are obtained in the same order as for the pre block assessments.

A peripheral intravenous line is inserted prior to the procedure of the peripheral nerve block is performed. At the discretion of the anesthetist, up to 20 mg Propofol IV may be provided to ease the patient during the nerve block procedure. The volunteer is monitored with continuous electrocardiography and pulse oximetry for the first 30 minutes after block performance and clinically hereafter. Final check by an investigator to ensure the volunteer is ready to go home. If the muscle strength is reduced, the volunteer will not be sent home before the ability to walk safely with crutches is ensured.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
40
Inclusion Criteria
  • ASA 1-2
  • Ability to give their written informed consent to participating in the study after having fully understood the contents of the study
Exclusion Criteria
  • Subjects who cannot cooperate with the study.
  • Subjects who cannot understand or speak Danish.
  • Subjects with allergy to the medicines used in the study.
  • Subjects suffering from alcohol and/or drug abuse - based on the investigator's opinion.
  • Pathology or previous major surgery to the lower limb.
  • Intake of any analgesics 24 hours prior to baseline measurements.
  • BMI > 35
  • Active signs of infection in the cutaneous area of injection
  • Subjects diagnosed with epilepsy, neurologic diseases, severe hypoxia or respiratory depression, hypovolemia, shock, bradycardia or Wolff-Parkinson-Whites syndrome
  • Subjects with a positive pregnancy test**
  • Subjects diagnosed with cardiovascular disease or heart failure
  • Subjects diagnosed with partial or complete cardiac block
  • Subjects in daily treatment with class III antiarrhythmics (e.g. amiodarone)
  • Subjects in daily treatment with drugs that are structurally related to local analgesics or class IB antiarrhythmics
  • Subjects diagnosed with severe liver disease or reduced kidney function

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Group APopliteal Plexus Block with 10 mlPopliteal Plexus Block given with 10 ml of Lidocaine Hydrochloride 10 mg/ml
Groups BPopliteal Plexus Block with 20 mlPopliteal Plexus Block given with 20 ml of Lidocaine Hydrochloride 10 mg/ml
Group CPopliteal Plexus Block with 30 mlPopliteal Plexus Block given with 30 ml of Lidocaine Hydrochloride 10 mg/ml
Group FNBFemoral Nerve BlockFemoral Nerve Block given with 20 ml of Lidocaine Hydrochloride 10 mg/ml
Groups SNBSciatic Nerve BlockSciatic Nerve Block given with 20 ml og Lidocaine Hydrochloride 10 mg/ml
Primary Outcome Measures
NameTimeMethod
MVIC (Maximum Voluntary Isometric Contraction) ankle plantarflexionMeasured pre block and at 45 minutes post block

Difference between group A, B and C in post block MVIC by ankle plantarflexion, expressed as percentage change of the pre block value. MVIC is measured using a handheld dynamometer.

MVIC ankle dorsiflexionMeasured pre block and at 45 minutes post block

Difference between group A, B and C in post block MVIC by ankle dorsiflexion, expressed as a percentage change of the pre block value. MVIC is measured using a handheld dynamometer.

Secondary Outcome Measures
NameTimeMethod
MVIC knee extensionMeasured pre block and at 45 minutes post block

Difference between group A, B and C in post block MVIC by knee extension, expressed as a percentage change of the pre block value. MVIC is measured using a handheld dynamometer.

cMAP (compoud motor action potention) gatrocnemiusMeasured pre block and at 45 minutes post block

Difference between group A, B and C, in the number of volunteers with affected cMAP of the gastrocnemius muscle, defined as sufficient change from pre block to post block. Cut-off value for sufficient change is determined by SNB group. cMAP is recorded using a motor nerve conduction study.

cMAP tibialis anteriorMeasured pre block and at 45 minutes post block

Difference between group A, B and C, in the number of volunteers with affected cMAP of the tibialis anterior muscle, defined as sufficient change from pre block to post block. Cut-off value for sufficient change is determined by SNB group. cMAP is recorded using a motor nerve conduction study.

cMAP vastus medialisMeasured pre block and at 45 minutes post block

Difference between group A, B and C, in the number of volunteers with affected cMAP of the vastus medialis muscle, defined as sufficient change from pre block to post block. Cut-off value for sufficient change is determined by FNB group. cMAP is recorded using a motor nerve conduction study.

cMAP vastus lateralisMeasured pre block and at 45 minutes post block

Difference between group A, B and C, in the number of volunteers with affected cMAP of the vastus lateralis muscle, defined as sufficient change from pre block to post block. Cut-off value for sufficient change is determined by FNB group. cMAP is recorded using a motor nerve conduction study.

Saphenus senory testMeasured pre block and at 45 minutes post block

Difference between group A, B and C in the number of volunteers with an affected sensory of the saphenous nerve, defined as change, from pre block to post block, in the volunteers ability to discriminate cold in the cutaneous area innervated by the medial crural cutaneous branches of saphenous nerve.

Trial Locations

Locations (1)

Elective Surgery Center at Silkeborg Regional Hospital

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Silkeborg, Region Midt, Denmark

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