EMed

Acute Compartment Syndrome (ACS)

Background

Acute compartment syndrome (ACS) is a painful condition caused by ↑pressure within a closed osteofascial compartment.

  • Acute or chronic
  • Surgical emergency (nerve and soft tissue ischaemia develop rapidly)
  • High mortality (47% after ACS of the thigh)
  • Leg, forearm but also hand, foot, buttocks, orbit & abdomen
  • M:F = 10:1
  • Typical = young ♂ high energy trauma with tibial shaft #.1,2,3

Aetiology

Compartment syndrome results when increased pressure within one of the body's anatomical compartments results in insufficient blood supply to the tissues and leads to ischaemic necrosis of the tissues. Nerve symptoms such as paraesthesia and tingling begin as early as 30 minutes from the onset of ischaemia and irreversible damage may occur as early as 12 hours post onset.

Causes include

  • Fractures 75%(open & closed)
  • Soft tissue (e.g. crush) injuries = 23% of ACS cases
  • Isolated vascular injuries
  • Anticoagulation Rx & bleeding disorders (even low impact)
  • Radial artery angiography (arterial trauma and spasm)
  • Iatrogenic e.g. extravasation of IV fluids
  • Burns
  • Immobilisation
  • Snake bites
  • Soft tissue infection
  • Extreme exertion
  • Prolonged tourniquet application.1.

Clinical = 5Ps

  • Pain: Severe and disproportionate to injury, worsened by passive stretch of compartment muscles. May be absent in later stages due to necrosis of the nerves
  • Paraesthesia: tingling, numbness & ↓ two point discrimination sense indicate nerve ischaemia
  • Pallor: loss of pulses is a late feature
  • Paralysis: indicates muscle ischaemia
  • Pressure ↑: intra-compartment pressures >30 mmHg of diastolic blood pressure is indicative of compartment syndrome. Pressure for 6 to 8 hours can result in irreversible soft tissue damage. In ↓BP patients, compartmental pressure of 20 mmHg warrants intervention.1

Diagnosis

  • Do not delay if any suspicion
  • Call for senior help
  • Beware risks (above), particularly fractures in young patients
  • Although pain (ischaemic) is characteristically the index sign, clinical findings in isolation have been proven to have inadequate diagnostic performance [BestBets]
  • Intra compartmental pressure monitoring is recommended for patients at high risk, given the documented high estimated sensitivity (94%) and specificity (98%) for the diagnosis of ACS when using a slit catheter technique and a differential pressure threshold of 30 mmHg for more than 2 hours

Delta Pressure= [Diastolic pressure] - [Compartment pressure]

  • Normal < 10 mmHg
  • Pressure <20 mmHg can be tolerated without significant damage
  • Delta pressure <30 mmHg is a better indicator of compartment syndrome than absolute compartment pressure.2

Techniques for measurement of intra-compartment pressure

  1. Invasive: Slit catheter technique
  2. Non-invasive: Infrared spectroscopy (NIRS), Laser Doppler flowmetry

Points of measuring intra-compartment pressures of leg

  1. Anterior compartment: 1cm lateral to anterior border of tibia. Insert needle perpendicular to skin
  2. Deep posterior compartment: just posterior to medial border of tibia. Advance needle perpendicular to the skin towards the fibula
  3. Lateral compartment: just anterior to the posterior border of fibula
  4. Superficial posterior compartment: middle of calf
  5. In suspected compartment syndrome, the pressure should be measured as close to the fracture site as is practicable [BestBets]

Abdominal compartment syndrome

  • ↑intra-abdominal pressure >25 mmHg associated with new organ failure
  • Primary - cause is abdominal e.g. peritonitis, pancreatitis, trauma etc
  • Secondary - cause lies outside abdomino-pelvic cavity e.g. extra-abdominal sepsis, burns, dialysis...
  • High index of suspicion is needed to diagnose this early
  • Increased morbidity and mortality
  • Decompressive laparotomy is the gold standard treatment with non-operative options including paracentesis and pharmacological paralysis in selected cases.4,5

Management of ACS

  • Principles of ATLS apply then detailed 2° survey
  • Adequate analgesia and hydration
  • Close monitoring of urinary output
  • Remove any casts or dressings and closely examine. Keep limb at heart level (not elevated) to maximise profusion
  • Fasciotomy with incision large enough to open all compartments. Usually GA but consider conscious sedation

CUH referrals - compartmemnt synd

  • Upper limb without fracture ⇒ plastics
  • Upper limb with fracture ⇒ ortho
  • Lower limb ⇒ ortho
  • Details on "referrals" and "VTAC" pages

References / links

1. Via AG, Oliva F, Spoliti M, Maffulli N. Acute compartment syndrome. Muscles, ligaments and tendons journal. 2015 Jan;5(1):18.

2. Duckworth AD, McQueen MM. The diagnosis of acute compartment syndrome: a critical analysis review. JBJS reviews. 2017 Dec 1;5(12):e1.

3. McCallum E, Keren S, Lapira M, Norris JH. Orbital compartment syndrome: an update with review of the literature. Clinical Ophthalmology (Auckland, NZ). 2019;13:2189.

4. Maluso P, Sarani B. Abdominal compartment hypertension and abdominal compartment syndrome. Principles of Adult Surgical Critical Care. 2016:233-40.

5. Popescu GA, Bara T, Rad P. Abdominal compartment syndrome as a multidisciplinary challenge. A literature review. The Journal of Critical Care Medicine. 2018 Oct 1;4(4):114-9.

BestBets - Positioning of compartment pressure monitors in lower limb fractures.

BestBets - Diagnostic utility of clinical signs and symptoms in the diagnosis of compartment syndrome of the lower limb.

Content by Dr Aniqa Bano, Dr Íomhar O' Sullivan 17/02/2021. Last review Dr ÍOS 21/06/21.