Compartment Syndrome (PCL 12)

Compartment Syndrome - Penny and Ben

Definition: compression of nerves and blood vessels within a compartment of the body (confined space surrounded by fascia), which can lead to impaired blood flow, muscle damage and nerve damage.

Pathophysiology: since fascia does not expand, swelling within a compartment can lead to increased pressure in the compartment, causing compression of muscle, nerves and blood vessels. If the pressure is high enough, blood flow may be blocked and permanent damage may occur. If the pressure lasts long enough, the limb may die.

When the pressure in the compartment exceeds the pressue in the capillaries, the capillaries will collapse and can no longer deliver oxygen and nutrients to the muscles and nerves within the compartment, and they will start to die in a matter of hours.

Causes: compartment syndrome is caused by increased pressure in the compartment, which may be due to a) increased fluid content or b) decreased compartment size.

• Swelling from a high-trauma injury such as a car crash or surgery
• Swelling from repetitive activities such as runing may cause chronic compartment syndrome
• Burns
• Fractures
• Hemorrhage
• Tight bandages or casts
• Use of creatinine monohydrate by athletes to build muscle

Signs and Symptoms
Severe pain, especially when the muscle is stretched, and out of proportion to the injury, which does not respond to pain medication.
Tingling or burning sensation in the muscle (parasthesia)
Muscle feeling tight or full
Paralysis = cell death has already begun

Diagnosis

• Measurement of compartment pressure ( >30 mm Hg suggests compartment syndrome)
• Lab Studies
• CT to look at the bones
• Vascular pathologies can be evaluated with arterial and venous Doppler ultrasonography
• Magnetic resonance imaging (MRI) to see muscle tears

Treatment

• Physical rehabilitation that decreases activity or load acting on affected compartment
• Aquatic exercises can improve mobility and strength
• Massage and stretching exercises also have been shown to be effective
• For worse compartment syndromes, a fasciotomy is performed

Complications

• Irreversible tissue ischemia can develop in the acute setting → permanent muscle and nerve damage, along with chronic pain, may occur.
• Peroneal nerve palsy, in particular, may develop.
• Muscle contractures may be observed.
• Infection is a major issue after fasciotomy and in some cases becomes chronic. Patients, especially those with multiple traumatic injuries--> can lead to death through metabolic complications
• Calcific myonecrosis - latent formation of a dystrophic calcified mass occurring almost exclusively in the lower limb

References
http://www.emedicine.com/EMERG/topic739.htm
http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/001224.htm
http://orthoinfo.aaos.org/topic.cfm?topic=a00204