Multiple Bier blocks with labetalol for complex regional pain syndrome refractory to other treatments.

To the Editor: Although the Bier block has been used as a treatment for sympathetically-maintained pain (SMP) for many years, the selection of agents remains controversial. Different drug classes have been used, including alpha-adrenergic blockers (guanethidine, reserpine, bretylium), alpha-2 agonists (clonidine), nonsteroidal antiinflammatory agents (ketorolac, tenoxicam), local anesthetics (lidocaine, prilocaine), and NMDA antagonists (ketamine). To our knowledge the use of labetalol for Bier block has not been reported. We here report a case of complex regional pain syndrome (CRPS) that did not respond to a standard Bier block with bretylium and lidocaine, but responded for 7 years to multiple Bier blocks with labetalol and lidocaine.