This question submitted by Timothy Casias, MD

A 15-year-old, 50-kilogram female has history of Complex Regional Pain Syndrome in her right lower extremity for the last 5 years. She presents to the operative room for an open reduction and internal fixation of a displaced distal tibial shaft fracture after falling on ice and hitting her right lower leg on the curb during the winter.  She previously is quite disabled from CRPS and spends most of the time in a wheelchair.  The decision is to place a popliteal catheter for post-operative pain control.  The operation was uneventful, and she has good analgesia with the catheter running 0.2% ropivacaine at 6 ml/hr.   Approximately 36 hours after the operation, she has increasing, severe pain.  What is your biggest concern for this patient?