Minimum Effective Volume of Bupivacaine for Retroclavicular Approach Brachial Plexus Block
Minimum Effective Volume of Bupivacaine for Retroclavicular Approach Brachial Plexus Block
In this study, the primary objective was to estimate the minimum effective volume of bupivacaine 0.5% resulting in successful block in 90% of patients (MEV90) for ultrasound-guided retroclavicular approach to infraclavicular brachial plexus block.
A "biased coin up-and-down sequential design" will be applied to assess the minimum effective volume in 90% of patients for the retroclavicular brachial plexus block. The first subject received 25 ml 0.5% bupivacaine . Each subsequent patient received a dose that depended on the response of the previous one. If the previous block is successful, the block will be performed either by a reduction of the volume by 2.5 ml with a probability ß = 0.11 or by a same dose of the previous one with a probability 1-ß = 0.89 in the next patient.
Inclusion Criteria:
Exclusion Criteria: