Changes in human forearm blood flow after intravenous regional sympathetic blockade with guanethidine.

The effect of intravenous regional sympathetic blockade with guanethidine on total forearm blood flow and on muscle and skin blood flow in the forearm was studied in healthy humans, using venous occlusion plethysmography, 133Xe-clearance technique and skin temperature recordings. The total blood flow tripled in response to the blockade and the rise persisted for 2-3 days. The increase in blood flow was confined to the skin, with no demonstrable steal effect on muscle blood flow. The observations imply that this type of sympathetic blockade may be of therapeutic value in some vascular disorders of the hand, and as supportive treatment in vascular surgery on the extremities.