Efficacy of 5-day continuous lidocaine infusion for the treatment of refractory complex regional pain syndrome.

OBJECTIVE Chronic regional pain syndrome (CRPS) is a severe pain condition that usually results from an injury or surgical procedure. The pain in CRPS often spreads from the site of injury, and with time becomes refractory to conventional therapy. The present study was undertaken to evaluate the effects of 5-day continuous intravenous lidocaine treatment in patients afflicted with CRPS. METHODS Intravenous lidocaine was administered in an escalating dose schedule to 49 severely affected CRPS patients in a monitored setting over 5 days. Evaluation of pain parameters and other signs and symptoms of CRPS were obtained during the infusion and at 1, 3, and 6 months following therapy. RESULTS The majority of patients demonstrated a significant decrease in pain parameters and other symptoms and signs of CRPS. The pain reduction lasted an average of 3 months. Lidocaine may be particularly effective for thermal and mechanical allodynia. Less clinically significant effects were documented on the motor aspects of the syndrome. DISCUSSION Intravenous lidocaine administration titrated to 5 mg/L demonstrated: 1) a significant decrease in mechanical and thermal allodynia for three months, 2) lessened associated inflammatory components of CRPS, and 3) only minimal side effects and no severe complications.