Unappreciated causes of ischemia in the leg.

Limb ischemia due to blunt trauma, dissecting hematoma, and cardiac dysfunction jeopardizes limbs and lives more than is generally appreciated. Delay in diagnosis after blunt trauma led to major amputation in 21 percent of our patients. Current principles avoid those hazards. Five patients presented with acute limb ischemia caused by dissecting hematoma of the aorta. Suspicion of that diagnosis is warranted in patients without a history of chronic vascular occlusive disease or cardiac disease, in young white males with Marfan characteristics, and in middle-aged hypertensive black males. Confirmation of the diagnosis requires urgent angiography. In selected cases, treatment with femorofemoral bypass will be limb- and life-saving. Ischemia due to low flow, which portends a dire prognosis, should be suspected in severely ill patients with a history of peripheral vascular disease. Analysis of cardiac and metabolic functions with the Automated Physiologic Profile system identified the cause of the low flow state in 10 patients, permitting precise management with specific therapy. A discernible improvement in circulatory status of the limb coincided with correction of the low flow states. Angiography and surgery were not necessary in 90 percent of this group, and should be avoided during low flow episodes.