lack of funding

The investigators propose to test the hypothesis that when placing a perineural catheter for a continuous peripheral nerve block, injecting the initial local anesthetic bolus via the insertion needle results in a faster-onset sensory block than injecting the initial bolus via the perineural catheter. The study results will help define the optimal local anesthetic bolus introduction technique-needle versus catheter-for peripheral nerve blocks when placing a perineural catheter.

Specific Aim: The investigators propose to test the hypothesis that when placing a perineural catheter for a continuous peripheral nerve block, injecting the initial local anesthetic bolus via the insertion needle results in a faster-onset sensory block than injecting the initial bolus via the perineural catheter. The study results will help define the optimal local anesthetic bolus introduction technique-needle versus catheter-for peripheral nerve blocks when placing a perineural catheter.

Inclusion Criteria:

• age ≥ 18 years
• willing to have bilateral infraclavicular blocks/catheters placed

Exclusion Criteria:

• current daily analgesic use
• opioid use within the previous 4 weeks
• any neuro-muscular deficit of either upper extremity
• body mass index > 30 kg/m2
• weight < 50 kg [100 lbs]
• pregnancy
• incarceration