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Completed

NCT Number: NCT03797235

The Impact of Nerve Cross Section Area on Sensory Block Onset

The study aims to describe a correlation between the nerve cross section and the sensory or motor block onset time. Therefore, different nerve cross sections with their Motor and sensory onset times are compared in order to find a correlation.

In the case of discovering a correlation, this could be translated into clinical practice, where a more tailored and individualized approach to performing peripheral nerve blocks would be possible, thus lowering the risks of adverse events occurring.

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Key information

Conditions

Regional Anesthesia

Age range

18 year–64 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Der Balgrist

Zurich, 8008, Switzerland

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • ASA I - II, both sexes
  • ≥ 18 years old
  • < 65 years old
  • Written informed consent as documented by signature

Exclusion criteria

  • Known allergy or hypersensitivity to a study drug or class of drug.
  • Severe coagulopathy.
  • History of alcohol abuse or the intake of psychotropic drugs.
  • Pregnancy.
  • Infection at the injection site or a systemic infection.
  • Fever of unknown origin.
  • Motor or sensory abnormalities in the arm.
  • Previous enrollment into the current study

Treatment and study plan

Dominant Arm

Procedure

The volume of local anesthetic used for the block of the ulnar and median nerve will be 5 times the estimated 95% effective dose (ED 95 ) of LA needed to block the nerve relative to the nerve cross-sectional area. The ED 95 for the ulnar nerve has been elucidated to be 0,11ml/mm2. The same ED 95 will be used for the median nerve.

Non-dominant arm

Procedure

The volume of local anesthetic used for the block of the ulnar and median nerve will be 5 times the estimated 95% effective dose (ED 95 ) of LA needed to block the nerve relative to the nerve cross-sectional area. The ED 95 for the ulnar nerve has been elucidated to be 0,11ml/mm2. The same ED 95 will be used for the median nerve.

Primary outcomes

  1. Correlation between nerve cross-section and time to complete sensory block of a nerve

    Time frame: Sensory evaluation will be carried out before the block and every 2 minutes after the start of the injection of LA until complete sensory loss to both cold and pinprick. Expected time frame: 10-60 minutes

    Correlation between the nerve cross-section in mm2 of both nerves (median and ulnar) measured with an ultrasound system and time in minutes from the moment the investigator starts injecting the local anesthetic (LA) around the respective nerves to complete sensory loss in the innervation area of the blocked nerve, assessed by response to light touch, pinprick and cold sensation. This correlation will be expressed in min/ mm2.

Secondary outcomes

  1. Correlation between nerve cross-section and time to complete motor block of a nerve

    Time frame: Motor evaluation will be carried out before the block and every 2 minutes after the start of the injection of LA until complete motor block. Expected time frame: 10-100 minutes

    The correlation between the nerve cross-section area in mm2 of both nerves (median and ulnar) measured with an ultrasound system and time in minutes from the start of the LA injection around the nerve median and ulnar nerves to the respective onset of the motor block, assessed with a numerical scale ranging from 0 to 5 (0-no muscle contraction visible, 5-normal muscle strength, maximal force against resistance and gravity). This correlation will be expressed in min/ mm2.

  2. Correlation between nerve cross-section and the duration of sensory nerve block

    Time frame: The evaluation of the duration of block will start one hour after the determined complete sensory loss and will be tested every 10 minutes until complete resolution of the sensory block. Expected time frame: 10-300 minutes

    The correlation between the nerve cross-section area in mm2 of both nerves (median and ulnar) measured with an ultrasound system and the duration of the respective sensory block in minutes, as reflected by the return of normal sensation in the innervation area of the respective nerve. This correlation will be expressed in min/ mm2.

  3. Correlation between the nerve cross-section and duration of motor nerve block

    Time frame: The evaluation of the duration of sensory block will start one hour after the determined complete motor loss and will be tested every 10 minutes until complete resolution of the motor block. Expected time frame: 10-300min

    The correlation between the nerve cross-section area in mm2 of both nerves (median and ulnar) measured with an ultrasound system and the duration of the respective motor block in minutes, as reflected by the return of normal muscle strength in the innervation area of the respective nerve. This correlation will be expressed in min/ mm2.

Sponsors and collaborators

Lead sponsor

Jose Aguirre

Other

Registry information

Official study title

The Impact of Nerve Cross Section Area on Sensory Block Onset. A Prospective, Monocentric Crossover Study on Volunteers

Important dates

Study start
2019
Primary completion
2019
Study completion
2019
First posted
Jan 9, 2019
Registry last updated
May 22, 2020

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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