The goal of this study is to determine if pre-operative placement of the continuous peripheral nerve block by an anesthesiologist using ultrasound technology is more effective than a continuous peripheral nerve block placed during the surgery by a surgeon for patients undergoing a limb amputation

We wish to determine the most effective site for the continuous infusion of local anesthetic for patients undergoing amputation of a limb. The information we obtain from this study will help to decide the most effective manner to provide pain relief for patients in the future. The primary outcome of interest is post-operative pain relief as measured by the amount of pain-relieving medications (opioids) required by patients prior to discharge home. The secondary outcomes of interest will be pain-relieving medications (opioid) requirements during the operation, length of stay in the hospital, time required for mobility, and patient satisfaction- measured by a survey given while in hospital and 3 months later.

Inclusion Criteria:

• undergoing a below knee amputation
• 16 years of age or older
• regional anesthetic will be used as part of the surgery

Exclusion Criteria:

• pregnant
• allergic to local anesthetic or ultrasound jelly
• a contraindication to having a peripheral nerve block catheter