Definition
A.A surgical emergency, which refers to a build-up of pressure within a muscle compartment (surrounded by a closed fascia) leading to a decline in tissue perfusion in the injured extremity; causes permanent damage to muscle and nerves.
B.A serious complication typically resulting from a crush injury to a large bone. There is an increase in closed compartmental pressure causing ischemic changes and diminished microcirculation within the soft tissues.
Incidence
A.The average annual overall incidence of acute compartment syndrome (ACS) is 3.1 cases per 100,000 people.
B.Due to relatively larger muscle mass in men, ACS is more prevalent in men compared to women.
C.Tibial fractures caused by trauma account for approximately 75% of ACS cases; blunt soft tissue injury is the second-leading cause.
D.The most common sites of ACS are (in descending order of prevalence): Calf, forearm, thigh, upper arm, hand, and foot.
Pathogenesis
A.ACS develops when the intracompartmental pressure (ICP) exceeds venous capillary pressure.
B.Arteriovenous pressure gradient theory.
1.Ischemia begins when local blood flow cannot meet the metabolic demands of surrounding affected tissue.
2.As compartment pressure rises, venous outflow is reduced and venous pressure rises, leading to a decrease in the arteriovenous pressure gradient.
3.Without intervention, due to arteriolar compression, microcirculation is compromised, and blood is shunted away from intracompartmental tissues, which ultimately reduces tissue perfusion.
4.Inadequate tissue perfusion and oxygenation results in soft tissue ischemia, cellular necrosis, anoxia, and irreversible death of the cells.
C.Anatomy of the lower leg.
1.There are four compartments in the lower leg: Anterior, lateral, superficial posterior, and deep posterior.
2.Each individual compartment encloses specific muscles, nerves, arteries, veins, and bones.
Predisposing Factors
A.Trauma-related closed tibial shaft fracture is the major contributing factor to ACS and accounts for one-third of all ACS cases.
B.List of traumatic and nontraumatic ACS etiologies.
1.Vascular: Reperfusion therapy, arterial puncture or injury, hemorrhage, and deep vein thrombosis.
2.Soft tissue: Crush injury, contusion, fall, direct blow, burn, and snake bite.
3.Latrogenic: Drugs such as anticoagulants, bleeding disorders, circumferential wraps, casts or splints, constrictive dressings, tourniquets, long leg brace, extravasations of drugs and fluids, prolonged lithotomy positioning, viral myositis, and diabetic muscle infarction.
Subjective Data
A.Common complaints/symptoms.
1.The cardinal symptom of ACS is pain out-of-proportion.
2.Persistent burning pain at rest.
3.Pain reproduced with passive stretch of the affected muscle compartment.
B.Common/typical scenario.
1.Massive swelling of the limb with firm and tense feeling on deep palpation.
2.Reduced two-point discrimination or vibration sense.
3.Loss of light touch sensation.
C.Family and social history.
1.Family and social history are noncontributory, as the cause of ACS is typically related to injury or surgery.
D.Review of systems.
1.Pain out of proportion to injury is often an early and sensitive sign of ACS.
a.Most patients at risk for ACS have sustained trauma, fracture, or injury to the nerve or soft tissue, which may be the source of pain.
b.The injured extremity becomes swollen and tense as ACS develops. Increasing ICP builds up on nerve fibers and injured components within the compartment.
c.Obtunded patients, patients emerging from anesthesia, or patients receiving nerve blocks may not accurately report pain.
d.In the late stages of ACS, pain may not be a subjective clinical finding, as pain receptors and nerve fibers are at high risk of ischemic necrosis and death.
2.Paresthesia.
a.Onset, which suggests the first signs of ischemic nerve dysfunction, is within approximately 30 minutes to 2 hours following injury.
Physical Examination
A.Paralysis is found in the late stages of ACS.
1.A higher ICP leads to ischemic neuronal tissues and nerve dysfunction and subsequent paresthesia, paresis, and, ultimately, complete paralysis.
2.Motor function may deteriorate within 4 hours of muscle tissue ischemia.
3.At 8 to 24 hours of ischemia, motor and sensory loss is irreversible.
B.Pulselessness is a late finding, which is a poor indicator of ACS.
1.As ICP rises, a loss of limb pulses indicates a decline in arterial perfusion.
C.Pallor.
1.Presence of pallor and longer capillary time in the injured limb indicates direct arterial injury.
D.Poikilothermia.
1.Presence of coolness or a change in the temperature in the affected extremity.
Diagnostic Tests
A.High index of clinical suspicion and the 6 Ps
cardinal symptoms: Pain, pallor, poikilothermia,
paresthesia, paralysis, and pulselessness.
B.Measuring limb ICP.
1.Stryker pressure monitoring device: A hand-held digital monitor for single tissue fluid pressure readings. To measure, the clinician injects 0.3 mL of saline solution into each of the four leg compartments (see Figure 14.1).
2.An ICP of 30 mmHg or above is considered a critical threshold for diagnosis of ACS, and, if ICP is elevated, emergent decompression should be considered.
3.Normal pressure of a tissue compartment falls between 0 and 8 mmHg in resting stage.
4.ICP should be measured in each compartment of interest but within 5 cm from the injured or fractured site.
C.Delta pressure.
1.Delta pressure is the difference between the diastolic pressure and the measured ICP.
2.Delta pressure of less than, or equal to, 30 mmHg is diagnostic of ACS.
FIGURE 14.1 Advanced practice provider (APP) monitoring for compartment syndrome.
Differential Diagnosis
A.Deep vein thrombosis.
B.Thrombophlebitis.
C.Cellulitis.
D.Necrotizing fasciitis.
E.Peripheral vascular injury.
F.Rhabdomyolysis.
G.Shin splints.
H.Stress fractures.
Evaluation and Management Plan
A.General plan.
1.Standard treatment: Emergent fasciotomy is a surgical limb-saving procedure to decompress the affected compartments and prevent critical limb ischemia.
a.Two types of surgical technique: Single or double incision.
i.Single-incision technique involves a single long incision made from the head of the fibula to the lateral malleolus.
ii.Double-incision technique is the most common fasciotomy method: Four-compartment technique incorporating two longitudinal anterolateral and posteromedial incisions.
2.In 48 to 72 hours, return to surgery is needed for reevaluation of muscle viability and wound debridement of nonviable tissues.
3.Once ACS is completely resolved within 7 to 10 days, the fasciotomy wound is left open for delayed primary closure or skin grafting.
4.To prevent bacterial colonization, improve circulation, and approximate wound edges, a negative pressure wound therapy is used for assisted closure of fasciotomy wounds.
5.Nonoperative treatment measures.
a.Loosening compression dressings, bi-valving
casts, and complete removal of splints and casts.
b.Elevation of the affected extremity to facilitate venous drainage, reduce edema, and maximize tissue perfusion.
B.Patient/family teaching points.
1.ACS is a surgical emergency that can develop quickly.
2.Permanent damage to muscles and nerves can occur within hours, which can necessitate amputation if not addressed immediately.
3.Keep the affected limb propped up on pillows so the limb is level with the heart.
4.Do not put any compressive bandages over the site.
C.Pharmacotherapy.
1.There is no pharmacological treatment for ACS, only surgery will reduce the pressure in the compartment.
D.Discharge instructions.
1.Seek care immediately if the pain or swelling does not improve, fever or rash develops, or the injured limb becomes cold or numb.
2.Contact the provider with questions or concerns.
Follow-Up
A.Follow-up is needed in 1 to 2 weeks for neurovascular examination, control of swelling, and wound check to ensure complete wound healing.
Consultation/Referral
A.Early consultation and collaboration with orthopedic or vascular surgery is critical for limb salvage and to prevent possible devastating complications, such as the following.