Intravenous Regional Block
Indication: Complex regional pain syndromes
The intravenous regional block (Bier block) is another treatment modality commonly used for CRPS I. This procedure is achieved by the injection of local anesthetic and other medications such as bretylium into the vein of the affected limb. A high-pressure cuff is applied to the proximal part of the limb immediately before the injection and for about 20 to 30 minutes after to prevent loss of the medication into the systemic circulation. A variety of medications have been used in the Bier block, including guanathedine, labetalol, corticosteroids, clonidine and bretylium. However, only bretylium has been proved by a double blind, clinically controlled study to be effective for CRPS I. Bier block is the treatment of choice for early stage CRPS limited to one limb that does not respond to other conservative treatments.