title: Intravenous regional guanethidine in the treatment of reflex sympathetic dystrophy/causalgia: a randomized, double-blind study. Guanethidine Study Group.
abstract: This double-blind, randomized, multicenter study was designed to determine the short-term and long-term efficacy of intravenous regional block with guanethidine in patients with reflex sympathetic dystrophy (RSD)/causalgia. Sixty patients were enrolled to receive four intravenous regional blocks at 4-day intervals with either guanethidine or placebo in 0.5% lidocaine. Each patient was randomized to receive either one, two, or four blocks with guanethidine. Follow-up visits were scheduled for 4 days, 1 mo, 3 mo, and 6 mo after their final block. At 4 days after the initial block, the group treated with placebo experienced a greater decrease in pain scores than those treated with guanethidine, although this difference was not statistically significant. On long-term followup there was no difference in pain scores between groups receiving one, two, or four guanethidine blocks. Overall, only 35% of patients experienced clinically significant relief on long-term followup even though all were treated early in the evolution of RSD.
authors.affiliation: Department of Anesthesiology, University of Texas Health Science Center at San Antonio 78284-7838, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ramamurthy
authors.forename: J
authors.initials: J
authors.lastname: Hoffman
mesh_terms: D000328:Adult; D002422:Causalgia / Q000628:therapy*; D004311:Double-Blind Method; D005260:Female; D006145:Guanethidine / Q000008:administration & dosage*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D009407:Nerve Block; D010147:Pain Measurement; D012019:Reflex Sympathetic Dystrophy / Q000628:therapy*; D013565:Sympatholytics / Q000008:administration & dosage*
chemical_list: D013565:Sympatholytics; D006145:Guanethidine