Background and Objectives. Local, not systemic, complications associated with intravenous regional sympathetic block (IVRS) are very rare. The authors report the complication that occurred in a 70-year-old man who sustained an injury of the left thumb.

Methods. The second IVRS using reserpine and lidocaine, 1 week after the first IVRS, was performed for pain relief.

Results. About 1 hour after the operation, an entirely localized blister developed in the dorsolateral aspect of the thumb. The palmar side appeared viable 2 weeks after the operation, which guaranteed intact survival of the thumb, but 2 months later the patient reported that he had the thumb amputated at an outside hospital.

Conclusions. When IVRS is applied to the extremities with compromised vasculature, or with an altered neuroanatomy, unpredictable and counterproductive mishaps may occur.