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Completed

NCT Number: NCT03326609

Local Anesthetic Concentration and Nerve Block Duration

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.

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Key information

Conditions

Peripheral Nerve Block

Age range

18 year–99 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Nordsjællands Hospital

Hillerød, Danmark, 3400, Denmark

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male or female from and above 18 years of age
  • ASA classification ≤ II

Exclusion criteria

  • BMI below 18 kg/m2
  • Former surgery to the lower extremity in which intervention is planned and surgery which may have caused neural damage to the common peroneal nerve/affected the sensory distribution area of the common peroneal nerve
  • Peripheral nerve disease
  • Allergy to LA
  • Pregnancy or breastfeeding
  • Enrolment in other investigational drug studies or recent clinical trials that may interfere with this study
  • Habitual use of any kind of analgesic treatment
  • Anatomic abnormalities preventing successful US-guided peripheral nerve catheter insertion

Treatment and study plan

Ropivacaine

Drug

Perineural injection using a peripheral nerve block catheter and a constant infusion rate (10mL/h)

Other names: Isotonic saline (natriumchloride)

Primary outcomes

  1. Duration of sensory nerve block

    Time frame: 1-24 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 outcomes

  1. Duration of motor nerve block

    Time frame: 1-24 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.

Other outcomes

  1. Length of neural exposure to local anesthetic

    Time frame: 10 minutes

    Ultrasound-guided measurement of the perineural spread of local anesthetic. From the most distal to the most proximal point. Measured in millimetres.

  2. Onset of sensory nerve block

    Time frame: 10-180 minutes

    Insensitivity towards cold. Testing will start 10 minutes after end of LA infusion and continue every 5 minutes until onset is apparent.

  3. Onset of motor nerve block

    Time frame: 10-180 minutes

    Paresis or paralysis of ankle dorsiflexion. Testing will start 10 minutes after end of LA infusion and continue every 5 minutes until onset of sensory nerve block is apparent.

  4. Degree of sensory nerve block

    Time frame: 1-24 hours

    Grading system using a 4-level scale and compared to the contralateral leg: 1) normal; 2) different; 3) warmth; 4) no sensation. 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.

  5. Degree of motor nerve block

    Time frame: 1-24 hours

    Grading system using a 3-level scale and compared to the contralateral leg: 1) normal; 2) paresis; 3) paralysis. 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.

Sponsors and collaborators

Lead sponsor

Nordsjaellands Hospital

Other

Collaborators

  • Innovation Fund Denmark

Registry information

Official study title

Local Anesthetic Concentration and Nerve Block Duration: A Randomized, Blinded Study in Healthy Volunteers

Important dates

Study start
2017
Primary completion
2017
Study completion
2018
First posted
Oct 31, 2017
Registry last updated
Jan 8, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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