Advanced Trauma Life Support ATLS Student Course Manual 2018

LIMB-THREATENING INJURIES 159
casts can also have vascular compromise Promptly
release splints, casts, and any other circumferential
dressings upon any sign of vascular compromise, and
then reassess vascular supply.
Compartment Syndrome
Compartment syndrome develops when increased
pressure within a musculofascial compartment causes
ischemia and subsequent necrosis. This increased
pressure may be caused by an increase in compartment
content (e.g., bleeding into the compartment or swelling
after revascularization of an ischemic extremity) or a
decrease in the compartment size (e.g., a constrictive
dressing). Compartment syndrome can occur wherever
muscle is contained within a closed fascial space.
Remember, the skin acts as a restricting layer in certain
circumstances. Common areas for compartment
syndrome include the lower leg, forearm, foot, hand,
gluteal region, and thigh (n FIGURE 8-7).
Delayed recognition and treatment of compartment
syndrome is catastrophic and can result in neurologic
deficit, muscle necrosis, ischemic contracture, infection,
delayed healing of fractures, and possible amputation.
Assessment
Any injury to an extremity can cause compartment
syndrome. However, certain injuries or activities are
considered high risk, including
••
Tibia and forearm fractures
Anterior
compartment
••
Injuries immobilized in tight dressings or casts
••
Severe crush injury to muscle
••
Localized, prolonged external pressure to
an extremity
••
Increased capillary permeability secondary to
reperfusion of ischemic muscle
••
Burns
••
Excessive exercise
n BOX 8-1 details the signs and symptoms of compartment
syndrome. Early diagnosis is the key to successful
treatment of acute compartment syndrome. A high
degree of awareness is important, especially if the
patient has an altered sensorium and is unable to
respond appropriately to pain. The absence of a
palpable distal pulse is an uncommon or late finding
and is not necessary to diagnose compartment
syndrome. Capillary refill times are also unreliable
for diagnosing compartment syndrome. Weakness or
paralysis of the involved muscles in the affected limb
is a late sign and indicates nerve or muscle damage.
Clinical diagnosis is based on the history of injury and
physical signs, coupled with a high index of suspicion.
If pulse abnormalities are present, the possibility of a
proximal vascular injury must be considered.
Measurement of intracompartmental pressure can
be helpful in diagnosing suspected compartment
syndrome. Tissue pressures of greater than 30 mm
Hg suggest decreased capillary blood flow, which can
result in muscle and nerve damage from anoxia. Blood
pressure is also important: The lower the systemic
pressure, the lower the compartment pressure that
causes a compartment syndrome.
Compartment syndrome is a clinical diagnosis.
Pressure measurements are only an adjunct to aid
in its diagnosis.
Lateral
compartment
Fibula
Superficial posterior
compartment
Tibia
Deep posterior
compartment
Nerves and
blood vessels
box 8-1 signs and symptoms of
compartment syndrome
• Pain greater than expected and out of proportion to
the stimulus or injury
• Pain on passive stretch of the affected muscle
• Tense swelling of the affected compartment
• Paresthesias or altered sensation distal to the
affected compartment
n FIGURE 8-7 Compartment Syndrome. This condition develops
when increased pressure within a compartment causes ischemia and
subsequent necrosis. The illustration of a cross section of the lower
leg shows the anatomy and relations of the four musculofasical
compartments.
Management
Compartment syndrome is a time- and pressuredependent
condition. The higher the compartment
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