MedPath

Local Anesthetic Concentration and Nerve Block Duration

Phase 4
Completed
Conditions
Peripheral Nerve Block
Interventions
Registration Number
NCT03326609
Lead Sponsor
Nordsjaellands Hospital
Brief Summary

Background: Local anesthetic (LA) concentration and nerve block duration is sparsely described in a heterogenic study mass.

Aim: To investigate the effect of LA concentration on peripheral nerve block duration in healthy volunteers.

Methods: Randomization of 60 healthy volunteers who will receive 1 of 5 different volumes of LA (ropivacaine) using a constant dose.

Primary endpoint: Sensory nerve block defined by insensitivity towards cold.

Detailed Description

Background:

Important factors for a safe and successful nerve block include volume, dose and concentration of local anesthetic (LA). Knowing the duration of peripheral nerve blocks is important to prevent pain breakthrough. With the advancements in ultrasound (US)-guided nerve block techniques it has been possible to substantially reduce the amount of LA required to perform a successful nerve block. This has reduced the risk of systemic toxicity. However, lowering LA volume may reduce nerve block duration, but the extent of this is sparsely described in a heterogenic study mass.

Diluted and large volumes of LA seem to correlate with nerve block duration. Furthermore, increasing LA concentration seems to increase the level of motor block, but not the block duration. A long-lasting nerve block without dense motor block is preferable for optimized pain control and better opportunities to rehabilitate/ambulate.

Aim:

To investigate the effect of LA concentration on common peroneal nerve block duration in healthy volunteers.

Methods:

Randomization of 60 healthy volunteers who will receive 1 of 5 different volumes of LA (ropivacaine) using a constant dose (10mg).

Primary outcome: Duration of sensory nerve block defined by insensitivity towards cold.

Secondary outcome: Duration of motor nerve block defined by either paresis or paralysis.

Explorative outcomes: Degrees of sensory and motor nerve block; Onset times of sensory and motor nerve block; Length of neural exposure to LA.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
60
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Volume: 5 mLRopivacainePerineural injection of ropivacaine 10 mg, 5 mL. Concentration: Ropivacaine 2 mg/mL
Volume: 15 mLRopivacainePerineural injection of ropivacaine 10 mg, 15mL Concentration: Ropivacaine 0.67 mg/mL
Volume: 2.5 mLRopivacainePerineural injection of ropivacaine 10 mg, 2.5 mL. Concentration: Ropivacaine 4 mg/mL.
Volume: 20 mLRopivacainePerineural injection of ropivacaine 10 mg, 20mL Concentration: Ropivacaine 0.5 mg/mL
Volume: 10 mLRopivacainePerineural injection of ropivacaine 10 mg, 10 mL Concentration: Ropivacaine 1 mg/mL
Primary Outcome Measures
NameTimeMethod
Duration of sensory nerve block1-24 hours

Insensitivity towards cold. Testing will start after onset of sensory nerve block and will be done in intervals of 60 minutes hereafter and continue until return of normal sensation.

Secondary Outcome Measures
NameTimeMethod
Duration of motor nerve block1-24 hours

Paresis or paralysis of ankle dorsiflexion. Testing will start after onset of sensory nerve block and will be done in intervals of 60 minutes hereafter and continue until return of normal sensation.

Trial Locations

Locations (1)

Nordsjællands Hospital

🇩🇰

Hillerød, Danmark, Denmark

Nordsjællands Hospital
🇩🇰Hillerød, Danmark, Denmark

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