Specific Aim 1: To determine if, compared with current and customary analgesia, the addition of multiple-day ambulatory continuous peripheral nerve blocks decrease the incidence and severity of post-amputation phantom limb and stump pain.
Hypothesis 1: Following upper or lower extremity amputation, the incidence of phantom limb and/or stump pain will be significantly decreased four weeks following multiple-day ambulatory continuous peripheral nerve blocks as compared with patients receiving standard-of-care treatment.
Hypothesis 2: Following upper or lower extremity amputation, the severity of phantom limb and/or stump pain will be significantly decreased four weeks following multiple-day ambulatory continuous peripheral nerve blocks as compared with patients receiving standard-of-care treatment (as measured on the 11-point numeric rating scale).