Clinical trial NCT05464862: The Effect of PPB Using 10, 20 and 30 ml of Lidocaine, Study on Volunteers
Official title: The Effect of the Popliteal Plexus Block on the Motor Function of the Leg - a Randomized, Controlled, Blinded Study in Volunteers
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Knee Arthritis
Anesthesia, Local
Post Surgical Pain
Lead sponsor: Regionshospitalet Silkeborg
Sponsor class: OTHER
Collaborators: name: Danish Society of Anesthesiology and Intensive Care Medicine
name: University of Aarhus
name: The Danish Rheumatism Association
First posted: 2022-07-19
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Maximum age (years): 64
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A randomization list is computed by the REDCap administrator from Aarhus University and imported in REDCap.The anesthesiologist and the assistant performing all the nerve blocks, are the only one with access to REDCaps randomization module, where the randomization procedure is made prior to the nerve block procedure.

The randomization list will assign each volunteer to one of six combinations, deciding which type of peripheral nerve block is used for each their leg. One leg equal one observation. The combinations ensure that observations are obtained in even numbers from right and left legs and that the total dose of perineural used lidocaine does not exceed 400 mg per volunteer.

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

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.

Eligibility criteria: 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

Primary outcomes:
measure: MVIC (Maximum Voluntary Isometric Contraction) ankle plantarflexion
timeFrame: Measured pre block and at 45 minutes post block
measure: MVIC ankle dorsiflexion
timeFrame: Measured pre block and at 45 minutes post block
Secondary outcomes:
measure: MVIC knee extension
timeFrame: Measured pre block and at 45 minutes post block
measure: cMAP (compoud motor action potention) gatrocnemius
timeFrame: Measured pre block and at 45 minutes post block
measure: cMAP tibialis anterior
timeFrame: Measured pre block and at 45 minutes post block
measure: cMAP vastus medialis
timeFrame: Measured pre block and at 45 minutes post block
measure: cMAP vastus lateralis
timeFrame: Measured pre block and at 45 minutes post block
measure: Saphenus senory test
timeFrame: Measured pre block and at 45 minutes post block
Other outcomes:
Locations:
city: Silkeborg
country: Denmark
facility: Elective Surgery Center at Silkeborg Regional Hospital
state: Region Midt
Study officials:
affiliation: Aarhus Universitet (Aarhus)
name: Johan Sørensen, MD
role: PRINCIPAL_INVESTIGATOR
References: