Perineural Catheter Insertion Distance for Continuous Peripheral Nerve Blocks
Perineural Catheter Insertion Distance for Continuous Peripheral Nerve Blocks
This is a research study to determine if the effects of continuous peripheral nerve blocks
 are influenced by the distance of insertion past the needle tip of the perineural catheter.
Specific Aim: Research study to determine the relationships between perineural catheter
 insertion distance and subsequent continuous peripheral nerve block effects.

 Hypothesis: during ultrasound-guided perineural catheter placement, inserting the catheter
 0-1cm past the needle tip is associated with decreased postoperative pain compared with
 inserting the catheter 5-6cm past the needle tip.
Inclusion Criteria:

 -  undergoing surgery with a planned popliteal perineural catheter for postoperative
 analgesia

 -  age 18 years or older

 Exclusion Criteria:

 -  pregnancy

 -  inability to communicate with the investigators and hospital staff

 -  incarceration

 -  clinical neuropathy in the surgical extremity

 -  chronic high-dose opioid use

 -  history of opioid abuse