An effective treatment protocol for intraarterial drug injection. Between 1972 and 1988, 48 patients with extremity ischemia after an intraarterial drug injection were treated with the following protocol: heparin, dextran 40, dexamethasone, elevation, and early mobilization of the extremity. A tissue ischemia score, derived by assessing the color, capillary refill, sensory function, and temperature of the extremity, was used to assess the ischemic injury. Each sign was scored either normal = 0 or abnormal = 1; then summed to provide the tissue ischemia score (range, 0 to 4). Twenty-four (50%) patients had an extremity tissue ischemia score less than or equal to 2. After treatment 22 of the 24 patients had a normal extremity, and 2 required limited digital amputations. In this group, outcome was comparable regardless of the time interval from intraarterial drug injection to treatment. Ten of 24 (50%) patients with an extremity tissue ischemia score greater than 2 had a normal extremity, 3 had a functional deficit, and 11 required digital amputations. Twelve of the 24 patients were treated within 24 hours and had a significantly superior outcome when compared to the 12 who were treated more than 24 hours after intraarterial drug injection (p less than 0.001, Fisher's exact test). The tissue ischemia score is a useful predictor of extremity outcome in patients with intraarterial drug injection. The outlined treatment protocol is effective in minimizing tissue injury caused by intraarterial drug injection. Institution of treatment within 24 hours of intraarterial drug injection is particularly important in patients who manifest severe ischemia. 