Acute compartment syndrome is a serious condition characterized by increased pressure within a closed muscle compartment, leading to compromised blood flow and potential tissue damage. Prompt recognition and treatment are crucial to prevent irreversible injury. This article provides a comprehensive overview of acute compartment syndrome, with a particular focus on its differential diagnosis, aiding healthcare professionals in accurate and timely management.
Introduction
Acute compartment syndrome (ACS) arises when elevated pressure within a confined osteofascial space impairs local circulation. This condition is considered a surgical emergency due to the risk of ischemia and necrosis if left untreated. Diagnosis is primarily clinical, although intracompartmental pressure (ICP) measurements above 30 mmHg can support the diagnosis. However, it’s important to note that a single normal ICP reading does not rule out ACS.
The leg is divided into four compartments by inelastic fascia: anterior, lateral, deep posterior, and superficial posterior. The anterior compartment of the leg is most frequently affected by compartment syndrome. This compartment houses the muscles responsible for toe extension and ankle dorsiflexion (tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius), the deep peroneal nerve, and the anterior tibial artery.
ACS can also occur in other locations, including the forearm, thigh, buttock, shoulder, hand, foot, and even the abdomen, although limb involvement is more common.[1, 2, 3, 4, 5]
It’s critical to consider ACS in patients with open fractures, as skin lacerations may not adequately relieve compartmental pressure. Studies indicate that ACS remains a risk, particularly in severe open fractures like Gustilo type 2 and 3 lesions involving proximal intra-articular tibia fractures.[6]
Etiology
ACS develops when the volume within a compartment increases or the compartment size decreases. While trauma, especially tibial fractures (the most frequent cause) and distal radius fractures, are common triggers (accounting for 75% of cases), ACS can also occur due to soft tissue injuries. Other predisposing factors include burns, vascular injuries, crush injuries, drug overdoses, reperfusion injuries, thrombosis, bleeding disorders, infections, constricting casts or splints, tight bandages, penetrating trauma, strenuous exercise, and improper surgical positioning.
In pediatric patients, supracondylar humerus fractures and forearm fractures (ulnar and radial) are frequently associated with compartment syndrome.[7, 8, 9, 10, 5, 11]
Epidemiology
The estimated incidence of ACS is 7.3 per 100,000 males and 0.7 per 100,000 females, with trauma being the predominant cause. Tibial shaft fractures carry a 1% to 10% risk of developing ACS.
ACS is more prevalent in males under 35 years old, potentially due to greater muscle mass within compartments and a higher likelihood of high-energy trauma exposure.
Individuals with bleeding disorders, such as hemophilia, have an elevated risk. Cases of ACS without preceding trauma have been reported in children with leukemia.[4, 5, 12, 13, 11, 14]
Patients who develop ACS without fractures are at a higher risk of complications and delayed diagnosis.[15]
Pathophysiology
ACS arises from a mismatch between the rigid fascial boundaries of muscle compartments and increasing pressure within. This pressure elevation disrupts the delicate balance between venous outflow and arterial inflow. Initially, increased compartmental pressure impedes venous outflow, leading to venous hypertension and increased capillary pressure. As pressure escalates, it can surpass arterial pressure, reducing arterial inflow and causing tissue ischemia. Prolonged ischemia can result in irreversible muscle and nerve necrosis.
Normal intracompartmental pressure is below 10 mmHg. ACS is typically diagnosed when ICP reaches or exceeds 30 mmHg. However, continuous or serial ICP monitoring is crucial because a single normal reading doesn’t exclude ACS.[16, 17, 18]
History and Physical Examination
ACS typically manifests within hours of the inciting event, but onset can be delayed up to 48 hours. The earliest physical sign is a tense or “wood-like” compartment upon palpation. Pain is a hallmark symptom, often described as severe and disproportionate to the injury. Initially, pain may only be elicited by passive stretching of the muscles within the compartment, but this finding may diminish in advanced stages. Patients may describe a burning sensation or a deep ache in the affected compartment. Paresthesia, hypoesthesia, or poorly localized muscle pain may also be present.
The classic “Five P’s” of ACS—pain, pulselessness, paresthesia, paralysis, and pallor—are often cited. However, pulselessness, paralysis, and pallor are late findings. Paresthesia is a more reliable early sign. The presence of a palpable pulse does not exclude ACS, as pulses can be preserved even in severely compromised extremities.
A thorough physical exam should assess the neurovascular status of the affected compartment:
- Skin: Inspect for lesions, swelling, and color changes.
- Palpation: Assess compartment temperature, tension, and tenderness.
- Pulses: Check distal pulses.
- Sensation: Evaluate two-point discrimination and light touch sensation.
- Motor Function: Assess muscle strength and function.
While clinical features are suggestive, they have limited sensitivity and specificity. Compartment pressure measurements can be a valuable adjunct to clinical assessment.[19, 20] Serial examinations are essential due to the potential for rapid progression.
Evaluation
ACS diagnosis is primarily clinical and requires urgent intervention. However, the following evaluations may be used to support and confirm the diagnosis:
- Radiographs: Obtain if fracture is suspected.
- Intracompartmental Pressure (ICP) Measurement: While not mandatory, ICP measurement aids diagnosis when clinical uncertainty exists.
- Manometer: Measures pressure by saline injection resistance.
- Slit Catheter: More accurate, allows continuous monitoring, recommended for measuring pressure in all compartments.
- Normal ICP: 0 to 8 mmHg.
- ICP > 30 mmHg: Indicates ACS and need for fasciotomy.[21]
- ICP 10-30 mmHg below diastolic BP: Suggests inadequate perfusion and potential ischemia.
- Delta Pressure: Diastolic blood pressure minus ICP. A delta pressure ≤ 30 mmHg is often used as an indication for fasciotomy.
- Doppler Ultrasound: To evaluate for vascular occlusion or thrombus.
- Creatine Phosphokinase (CPK): Elevated levels may indicate muscle breakdown (rhabdomyolysis).
- If rhabdomyolysis is suspected: Assess renal function, urine myoglobin, and urinalysis. Chemistry panel if rhabdomyolysis is confirmed.
- Preoperative studies: Complete blood count and coagulation studies are recommended at a minimum.[22, 23, 24, 25]
Treatment and Management
ACS is an emergency requiring immediate intervention. Delays in treatment can lead to limb loss.[26]
- Immediate Surgical Consultation
- Supplemental Oxygen
- Remove Constricting Dressings: Cast bivalving or removal, bandage loosening to reduce external pressure.
- Extremity Positioning: Maintain extremity at heart level to avoid hypoperfusion.
- Blood Pressure Management: Prevent hypotension, provide support if needed.
- Fasciotomy: Indicated if ICP ≥ 30 mmHg or delta pressure ≤ 30 mmHg.
For patients not meeting strict ACS criteria but at high risk or with ICP between 15-20 mmHg, serial ICP measurements are advised. ICPs of 20-30 mmHg warrant admission and surgical consultation. Surgical fasciotomy is mandatory for ICP > 30 mmHg or delta pressure < 30 mmHg.
Prompt diagnosis and fasciotomy are critical. Ideally, fasciotomy should be performed within six hours of injury. Fasciotomy after 36 hours is generally not recommended due to the likelihood of irreversible tissue damage and limited benefit.
If necrosis develops before fasciotomy, infection risk is high, potentially necessitating amputation. Debridement is crucial if infection occurs to prevent systemic complications.
Following fasciotomy and swelling reduction, skin grafting is often used for wound closure. Postoperatively, monitor for complications like infection, acute renal failure, and rhabdomyolysis.[2, 1, 27]
Differential Diagnosis
The differential diagnosis of acute compartment syndrome includes conditions that can mimic its signs and symptoms, particularly pain, swelling, and neurological deficits. Accurate differentiation is crucial for appropriate management. Key differential diagnoses include:
- Deep Vein Thrombosis (DVT): DVT can cause leg pain and swelling, but typically lacks the tenseness and pain on passive stretch characteristic of ACS. Doppler ultrasound is helpful in diagnosing DVT.
- Cellulitis: Infection of the skin and subcutaneous tissue can present with pain, swelling, erythema, and warmth. However, cellulitis usually lacks the severe pain out of proportion to the injury and the compartment tenseness seen in ACS. Fever and systemic signs of infection are more prominent in cellulitis.
- Gas Gangrene: A severe bacterial infection causing tissue necrosis and gas production. Gas gangrene is characterized by crepitus, severe pain, and systemic toxicity. It progresses rapidly and requires immediate surgical debridement and antibiotics.
- Phlegmasia Cerulean Dolens: A severe form of DVT causing massive venous outflow obstruction, leading to limb swelling, pain, and cyanosis. It can mimic ACS in its severity and limb-threatening nature. Doppler ultrasound is essential for diagnosis.
- Rhabdomyolysis: Muscle breakdown releasing myoglobin into the bloodstream. Rhabdomyolysis can cause muscle pain, weakness, and swelling. While it can occur concurrently with ACS or be a consequence of it, rhabdomyolysis itself can cause muscle pain and swelling that may be confused with ACS. Elevated CPK and urine myoglobin help differentiate rhabdomyolysis.
- Cnidaria Envenomation (e.g., Jellyfish Sting): Stings from jellyfish and similar marine creatures can cause intense local pain, swelling, and muscle spasms, potentially mimicking ACS in affected limbs. History of exposure and skin findings are key to diagnosis.
- Peripheral Vascular Injuries: Arterial occlusion or injury can cause limb pain, pallor, pulselessness, and paralysis, overlapping with some “P’s” of ACS. However, vascular injuries typically lack compartment tenseness. Vascular studies like angiography or Doppler are essential for diagnosis.
Differentiating ACS from these conditions relies on a thorough history, physical examination, and judicious use of diagnostic tools such as ICP measurement, Doppler ultrasound, and laboratory tests. Table 1 summarizes key differentiating features.
Table 1: Differential Diagnosis of Acute Compartment Syndrome
| Condition | Key Differentiating Features | Diagnostic Modalities |
|---|---|---|
| Deep Vein Thrombosis (DVT) | Lack of compartment tenseness, Doppler ultrasound positive | Doppler Ultrasound |
| Cellulitis | Erythema, warmth, fever, lack of compartment tenseness | Clinical exam, WBC count |
| Gas Gangrene | Crepitus, rapid progression, systemic toxicity | Clinical exam, imaging, Gram stain |
| Phlegmasia Cerulean Dolens | Massive swelling, cyanosis, Doppler ultrasound positive | Doppler Ultrasound |
| Rhabdomyolysis | Muscle weakness, elevated CPK, urine myoglobin | CPK, urine myoglobin, renal function tests |
| Cnidaria Envenomation | History of sting, skin findings, localized reaction | Clinical history and exam |
| Peripheral Vascular Injury | Pallor, pulselessness, lack of compartment tenseness | Doppler, Angiography |
Pertinent Studies and Ongoing Trials
Research continues to explore innovative approaches to compartment syndrome management. Ultrafiltration catheters are being investigated in clinical trials as a method to monitor the biochemical environment within muscle compartments in patients at risk of ACS, particularly those with tibial shaft fractures needing surgery. These catheters may offer insights into tissue changes and potentially guide treatment strategies. Further research is warranted to evaluate the therapeutic potential of ultrafiltration in ACS.[28]
Prognosis
Prognosis after ACS treatment is strongly linked to the timeliness of diagnosis and intervention. Fasciotomy within 6 hours of onset typically results in near-complete limb function recovery. Delays beyond 6 hours increase the risk of residual nerve damage. Fasciotomy performed within 12 hours is associated with normal limb function in approximately two-thirds of patients. Severely delayed cases may necessitate amputation.
Posterior compartment syndrome of the leg tends to have worse outcomes compared to anterior compartment syndrome due to challenges in achieving adequate decompression. Long-term sequelae in survivors can include persistent pain, Volkmann’s contracture, mild neurological deficits, and cosmetic deformities. Recurrent compartment syndrome can occur in athletes due to scar tissue. In rare instances, ACS can be fatal, often due to infection leading to sepsis and multiorgan failure.[29, 5, 30, 31]
Complications
Complications of ACS can be significant and long-lasting:
- Persistent Pain
- Contractures (e.g., Volkmann’s contracture)
- Rhabdomyolysis
- Nerve Damage (numbness, weakness)
- Infection
- Renal Failure
- Death [29, 5]
Postoperative and Rehabilitation Care
- Physical Therapy: Essential for regaining strength, function, and preventing contractures and stiffness.
- Wound Care: Meticulous care and monitoring for infection, ischemia, and gangrene are crucial after fasciotomy.
- Antibiotics: Administered if infection develops.
- Pain Management: Analgesics are necessary for pain control.
- Assistive Devices: Patients may require crutches or other ambulatory aids during healing.
- Occupational Therapy: Helps patients adapt to daily living activities and regain independence.[32, 33, 34]
Consultations
ACS management often requires a multidisciplinary team. Initial management is typically by general or orthopedic surgeons. Depending on complications, consultations may include:
- Infectious Disease Specialists
- Wound Care Specialists
- Physical Therapists
- Occupational Therapists
Deterrence and Patient Education
Patient education is vital. Individuals should seek prompt medical attention after traumatic injuries or if they experience extremity pain or swelling. For those undergoing fasciotomy, proper wound care instructions are paramount.
Pearls and Other Issues
When applying plaster casts, particularly after fracture reduction, uni-valving or bi-valving can reduce pressure by approximately 50%. However, it’s important to remember that as swelling subsides, casts can become loose, potentially compromising fracture reduction.
Enhancing Healthcare Team Outcomes
Optimal ACS management demands a well-coordinated interprofessional team including nurses, laboratory staff, pharmacists, and physicians from various specialties. Without this collaborative approach, morbidity and poor outcomes are more likely.
- Nurses: Often the first point of contact in the emergency department, nurses play a critical role in early recognition of ACS signs and symptoms, alerting the medical team, monitoring vital signs and pain, and preparing the patient for surgery. Postoperatively, ongoing monitoring and management of associated injuries and complications are essential nursing responsibilities.
- Pharmacists: Emergency department pharmacists contribute through medication reconciliation and pain management recommendations.
- Nurse Practitioners, Physician Assistants, and Physicians: Coordinate care, perform procedures, and educate patients and families about the condition and treatment plan.
Post-surgery, a holistic interprofessional approach involving surgical/orthopedic teams, nurses, physical and occupational therapists, pharmacists, and social workers optimizes patient outcomes in this complex condition.[35, 36]
Review Questions
Figure
Acute Compartment Syndrome Fasciotomy secondary to compartment syndrome of the deep leg compartment.
References
[List of references as in the original article]
Disclosures:
