Compartment syndrome

• Compartment syndrome is a surgical emergency characterised by increased pressure within a closed space.

  • Usually encountered in limb injuries such as tibial or forearm fractures, crush injuries, reperfusion injury or restrictive casts and dressings
  • Requires urgent intervention as delay can lead to necrosis
  • Upper and lower limbs are most commonly affected - can also affect the abdomen or any other muscle compartment
• Pathophysiology:

  • Each limb compartment is covered by fascia and contains muscles, blood vessels and nerves - normal pressure is 12-18mmHg
  • Blood flows from a high-pressure arterial system to a low-pressure venous system - homeostatic pressure gradient
  • Injury, bleeding or swelling affects the capillary perfusion pressure
  • Causes the build up and subsequent extravasation of fluid out of the capillaries which further increases the pressure within a closed myofascial compartment
  • Distribution of oxygen and nutrients, and the removal of carbon dioxide is disrupted - muscle ischaemia and necrosis
• Risk factors:

  • Major surgical procedures
  • Blunt trauma
  • Burns
  • Reperfusion injury
  • Crush injury
  • Fractures
  • Tight casts
  • Ongoing intra-abdominal bleeding
  • Penetrating trauma e.g. vascular injury
  • Malignancy
• Typical symptoms of compartment syndrome include:

  • Disproportionate pain that increases with time
  • Paraesthesia
  • Paresis

  At later stages, patients may also develop:

  • Muscle contracture
  • Complete loss of sensation
  • Limb pallor
• Typical clinical findings associated with compartment syndrome include:

  • Pain out of proportion to the clinical findings, particularly during passive stretching (passive dorsiflexion)
  • The limb may be tense on palpation and difficult to mobilise
  • Numbness and paralysis (later stages)
• Investigations:

  • While compartment syndrome is diagnosed clinically, intra-compartmental pressure monitoring using a needle connected to a transducer can be performed
  • A difference between the diastolic blood pressure and the compartment pressure of less than 30 mmHg implies an increased risk of compartment syndrome.
  • An absolute intra-compartmental pressure of > 40 mmHg with clinical signs is diagnostic of acute compartment syndrome.
• Management:

  • Surgical decompression through emergency fasciotomy - opening the fascial compartment affected to relieve the pressure - should be done within 1 hour of diagnosis
  • Removal of any circumferential casts or bandages
  • Maintenance of blood pressure
• Abdominal compartment syndrome:

  • Abdomen has normal pressure of 0-5mmhg
  • Abdominal wall can expand to a certain extent beyond which compliance is not possible
  • Can lead to multi-organ failure and death
  • Causes - retroperitoneal bleeding, reperfusion injury and bowel obstruction
  • Diagnosis: intra-abdominal pressure >20mmHg with evidence of multi-organ failure
  • The gold standard for monitoring intra-abdominal pressure is via a transducer connected to a urinary bladder catheter
  • Abdominal compartment syndrome is treated by surgical decompression in the form of a laparotomy.
• If prompt intervention is not performed, patients may develop irreversible neurovascular damage of the affected limb.

  Other complications of compartment syndrome include:

  • Neurological dysfunction
  • Muscle/joint contracture
  • Infection
  • Amputation
  • Long term disability