Continuous Femoral Nerve Blocks: Relative Effects of Basal Infusion and Bolus Doses on Sensory and Motor Function

Continuous Femoral Nerve Blocks: Relative Effects of Basal Infusion and Bolus Doses on Sensory and Motor Function

This is a research study to determine if the way local anesthetic- or numbing medication- is delivered through a tiny tube next to the nerves that go to the thigh affects the strength and sensation in the thigh.

Specific Aim: Research study to test the null hypothesis that differing the delivery method (continuous basal infusion vs. repeated bolus doses) but providing an equal total dose of Ropivacaine has no impact on quadriceps muscle strength. These results will help define the optimal delivery method of local anesthetic used for continuous peripheral nerve blocks and help guide future research in this clinically relevant area.

Inclusion Criteria:

• 18 years of age or older
• willing to have bilateral femoral perineural catheters place with a subsequent ropivacaine infusion and motor/sensory testing for 9 hours
• willing to stay overnight in the UCSD GCRC/CTRI to allow dissipation of local anesthetic infusion effects by the following morning.

Exclusion Criteria:

• current daily analgesic use
• opioid use with in the previous 4 weeks
• any neuro-muscular deficit of either femoral nerves and/or quadriceps muscles
• pregnancy
• incarceration