Noninvasive vascular studies in management of rattlesnake envenomations to extremities

Twenty-five consecutive patients suffering rattlesnake envenomation to an extremity underwent noninvasive vascular arterial studies using contralateral extremities as controls. All but one received antivenin, and none underwent early surgical decompression. Pulse volume amplitudes in the envenomated extremities, reflecting pulsatile arterial blood flow, were increased in 24 of 25 patients (P less than .02) in spite of edema and discoloration. Ischemia requiring surgical procedures developed in three of seven patients with decreased skin temperatures, as compared to none of 18 with increased or mixed skin temperatures on the envenomated extremity (P less than .02). One of 24 survivors suffered a functional deficit. Most victims of rattlesnake bites have increased arterial pulsatile blood flow in an envenomated extremity and do well with medical therapy. Noninvasive arterial studies help select those who are more likely to require special surgical intervention.