The following soft signs are much less useful in predicting or ruling out major vascular injuries that require intervention. The arterial pressure index is useful in detecting patients with major vascular injury with pulses that appear normal. Systolic blood pressure in the affected extremity is divided by systolic pressure in the normal extremity. Ankle - brachial indices may also be employed. Ultrasound is an as yet unreliable but very promising noninvasive technique for investigating injuries with a high-risk mechanism or location but without any obvious indication for surgical management.
Ultrasound examination is extremely operator-dependent.
Dye load and renal function are important prestudy considerations. Dislocations of the elbow and knee should be promptly reduced to relieve tension on neurovascular structures. Control hemorrhage with direct pressure. Once the patient has been stabilized, it is imperative that peripheral vascular injuries are identified and that normal circulation is restored, as rapidly as possible. Do not apply clamps or hemostats to vascular structure, since this may make repair more difficult.