Treatment of experimental frostbite with intra-arterial sympathetic blocking drugs.

A number of experimental and clinical studies have shown that early regional surgical sympathectomy decreases tissue loss following frostbite, presumably by relieving vasospasm and increasing blood flow. This study was performed to determine if a decrease in tissue loss following a standard cold injury could be obtained following a regional "medical sympathectomy" achieved by the intra-arterial administration of sympathetic blocking drugs. A standard cold injury was produced in rabbits and the animals were divided into nine treatment groups. Various treatment modalities were evaluated, including rapid rewarming, intra-arterial reserpine and tolazoline, and intravenous low molecular weight dextran. In the slowly rewarmed animals, the usual clinic situation, the regional intra-arterial administration of reserpine and tolazoline significantly reduced tissue loss, equalling the results obtained in the rapidly rewarmed group. These results indicate that the early achievement of a regional "medical sympathectomy" may be of benefit in reducing tissue loss following frostbite in patients, especially in those in whom rapid rewarming cannot be performed.