Compartment syndrome is basically an increased pressure in the intramuscular compartment which results in decreased blood supply to the muscles and tissues in that space which can lead to necrosis and infection
It can be of two types –
Acute compartment syndrome is a medical emergency. It is usually caused by a severe injury. Without treatment, it can lead to permanent muscle damage.
Chronic compartment syndrome, is usually not a medical emergency. It is most often caused by athletic exertion.
Understanding Compartment syndrome
Due to the increased pressure in the compartments the fascia cannot stretch and hence the blood supply is paralysed to the nerves and small vessels. Therefore, if the pressure is not released quickly the permanent tissue necrosis may result.
Causes of Acute compartment syndrome
1. Trauma – fracture – most common cause
2. Muscle bruise due to fall
3. Re-established blood flow after blocked circulation
4. Anabolic steroid use
5. Constricting bandages
6. Snake bites
7. Soft tissue infection
8. Prolonged immobilisation
Normal tissue pressure ranges between 0 and 10 mmHg. If the pressure increases more than 20mm Hg the capillary blood flow maybe compromised. Muscle and nerve fibers are at risk for ischemic necrosis at pressures >30 to 40mmHg.
Pressure difference (Delta Pressure)
It is the difference between diastolic and Compartmental Pressure
Delta= Diastolic BP – Intracompartmental pressure
Value less than 30 is significant and can cause significant damage. After 4 hours of schema usually the injury is irreversible and permanent damage can occur.
Complications of Compartment syndrome
1. Ischaemic gangrene
3. Renal failure
Clinical presentation and characteristic features of presentation
6 P’s of compartment syndrome
1. Pain – Pain on passive stretching is the most significant sign of a compartment syndrome. This basically is due to stretching the nerves and the tissues when mobilised
2. Pallor – Pale limb to reduced blood supply
3. Perishingly cold
5. Paralysis – Function loss
6. Paraesthesia – Tingling and numbness due to nerve damage
Clinical suspicion is the best diagnosis. History of trauma or some of the causative factors listed above coupled with examination findings is usually enough to warrant no other investigation and do timely intervention.
Pressure measuring devices like the Stryker STIC device are useful to measure the compartmental pressure however determining pressure differences as the Delta pressure as described above is even more useful.
Urgent fasciotomy (Delta pressure <20 – absolute indication, <30 – relative indication)
Plastic surgery input – It is practical to involve the plastics and micro vascular teams as well
It is also very important to tell the patient what is expected from the outcome. Some patients may also need psychological counselling.