No abstract

Microscopic needles previously shown capable of transdermal delivery of drugs and proteins are demonstrated to be painless when pressed into the skin of human subjects.

Patients with reflex sympathetic dystrophy, who received transient pain relief from stellate ganglion blocks or lumbar sympathetic blocks and had abnormal isolated cold stress tests, were enrolled in a study to determine the efficacy of intravenous regional bretylium. Each patient received two control treatments (0.5% lidocaine) and two treatments with 0.5% lidocaine and bretylium 1.5 mg/kg in a randomized, double-blind fashion. A standard intravenous regional technique was used with a 300-mm Hg tourniquet pressure for 20 min. Patients kept a daily record of pain relief (0 = no relief, 100% = complete relief). A decrease in pain of more than 30% was considered clinically significant. Therefore, once the patient's pain relief was less than 30%, the next intravenous regional treatment was performed. Bretylium and lidocaine provided more than 30% pain relief for a mean of 20.0 (+/- 17.5) days, whereas lidocaine alone provided relief for only 2.7 (+/- 3.7) days (Mann-Whitney U-test, P less than 0.001). A mean temperature increase in the treated limb of +2.64 +/- 3.41 degrees C above the baseline temperature was noted after bretylium administration, whereas after control treatments the change was -0.086 +/- 1.30 degrees C (Mann-Whitney U-test, P less than 0.02). We conclude that the combination of bretylium and lidocaine is significantly more effective than lidocaine alone when an intravenous block is used to treat reflex sympathetic dystrophy.