The Minimum Effective Concentration of Ropivacaine in Ultrasound-guided Supraclavicular Block

Huazhong University of Science and Technology

Status: Completed

Conditions: Minimum Effective Concentration of Local Anesthetic

Treatments: Other: brachial plexus block

Study type: Interventional

Funder types: Other

Identifiers

NCT02286336

2014-64

Details and patient eligibility

About

The aim of this study is to determine the minimum effective concentration of local anesthetic (ropivacaine 40mL) required to produce an effective double-injection USG-SCB for surgical anesthesia in 90% of patients (MEC90) in young group (18-40 years) and in middle aged group (40-65 years) of patients scheduled for elective surgery of one upper limb distal to the shoulder.

Full description

The study is based on biased coin design, and the concentration of LA for the next patient is determined by the result of the last one. In the case of block failure, the concentration will be increased by 0.025%. Conversely, block success will result in either a reduction in concentration by 0.025% (probability 11%) or no change in concentration (probability 89%). A blinded assistant will assess sensory and motor blockade in each nerve territory ( the median, radial, ulnar and musculocutaneous nerves) at 10-min intervals up to 30 min after completion of the block. Finally, MEC90 is calculated by isotonic regression.

Enrollment: 102 patients

Sex: All

Ages: 18 to 65 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. age between 18 and 65 years
2. ASA 1-3
3. body mass index between 18 and 35kg/m2

Exclusion criteria

1. inability to consent to the study
2. pregnancy
3. allergy to local anesthetics
4. preexisting neuropathy or coagulopathy
5. prior surgery in the supraclavicular region

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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102 participants in 2 patient groups

middle aged group

Experimental group

Description:

brachial plexus block with ropivacaine 40ml, MEC90 for USG-SCB

Treatment:

Other: brachial plexus block

young group

Active Comparator group

Description:

brachial plexus block with ropivacaine 40ml, MEC90 for USG-SCB

Treatment:

Other: brachial plexus block