Clinical findings fairly specific for vascular injury ("hard signs"):
(1) absence or decrease in distal pulses
(2) unexplained hypotension or anemia (with bleeding into thigh, etc.)
(3) pallor or coolness distal to injury
(4) pulsatile bleeding
(5) an expanding or pulsatile hematoma
(6) audible bruit or palpable thrill over the wound
Clinical findings less specific for vascular injury but still worth pursuing ("soft signs"):
(7) isolated peripheral nerve deficit (since the blood vessels travel with nerves)
(8) a wound in close proximity to a neurovascular bundle
(9) pulses in the affected limb diminished relative to pulses in the opposite unaffected limb
(10) prolonged capillary refill distal to the injury
(11) a nonpulsatile hematoma
(12) pain, paresthesias or paralysis distal to injury
Problems with relying solely upon the clinical examination to detect vascular trauma:
(1) Hypotension may cause pulses to be weak. It also will reduce bleeding from an injured vessel and other findings associated with vascular injury.
(2) Other causes (constrictive dressings, hypothermia, pre-existing vascular disease) may explain weak pulses in the injured limb.
(3) An unconscious or intoxicated patient cannot report symptoms and are unable to cooperate in the examination.
(4) An artery with a small injury may not have a reduced pulse, at least initially.
(5) Physical examination is insensitive to a number of vascular injuries that can only be detected using arteriography or other imaging studies.
A patient with a penetrating injury who has an indeterminate or negative examination should be re-examined frequently and a high index of suspicion should be maintained.
