[Pharmacological sympathetic block in complex regional pain syndrome]

The Complex Regional Pain Syndrome (CRPS) is a chronic pain state provoked by lesions of the soft tissues or of the bony tissues (type CRPS-I or reflex sympathetic dystrophy-RSD) or by lesions of the nerves (type CRPS-II or causalgia) with vegetative alterations (perspiration, vasomotory alterations) and trophic alterations (bony cutaneous atrophy, alopecia, articular contractures). The pharmacological block of the sympathetic nerves through a peripheral vein is inserted in the multidisciplinary approach that characterizes the therapy of this syndrome.

A retrospective survey was carried out on a group of 185 patients affected by RDS/CRPS with block of the sympathetic nerves through a peripheral vein with guanethidine. Superior limb: Inflation of the tourniquet till disappearance of the radial wrist. Cannulation of a peripheral vein with Butterfly needle n. 23. Guanethidine 10 mg, lidocaine 20 mg, sodic heparin 500 u.i, NaCl 0.9% 20 ml. Injection in 5 minutes. Permanence of the pneumatic tourniquet inflated above systolic blood pressure for 15 minutes. Deflation slowly. Inferior limb: Inflation of the tourniquet till disappearance of the pedidium wrist. Cannulation of a peripheral vein with Butterfly needle n. 23. Guanethidine 20 mg, lidocaine 40 mg, sodic heparin 1000 u.i, NaCl 0.9% 40 ml. Injection in 5 minutes. Permanence of the pneumatic tourniquet inflated above systolic blood pressure for 15 minutes. Deflation slowly.

The first stage (hyperemic) showed the highest incidence of remissions: (83, 33%). Even in the second stage (dystrophic) the answer to the therapy has been fundamentally positive: (53, 68%). In the third stage (atrophic) the results have been more modest: (8, 33%).

The block of sympathetic system with guanethidine is still an important method in the therapy of the CRPS; in fact it is surely less invading than the blocks of the stellate ganglion or of the lumbar sympathetic.