Trauma - Week 9 - Crush / Compartment Syndrome /Hangings

Crush _____: a direct injury resulting from a crush

Crush ______: the systemic manifestation of muscle cell damage resulting from pressure or crushing

Crush Syndrome: Causes

• Severe Crush Injury

• Immobility on a rigid surface for >1 hour

Crush Syndrome Pathophysiology

A combination of ______ ____ & ______ will cause muscle death within 1 hour

• mechanic force

• gravitational force

• ischemia

• hypoxia

• any intramuscular force which acts continually above the diastolic blood pressure causes this

______ _______

"when an extremely high pressure builds up in a closed fascia space"

usually rapid

Occurs when capillary blood perfusion is

decreased => prevents adequate circulation to
the necessary areas => compromises tissue viability

Limb Compartment Syndrome Causes

• Fractures: open or closed

  comminuted increases risk

  Management of #

• Vascular/Iatrogenic

  Extravasation

  (fluid leakage)

• Soft Tissue Injury

  Crush

  Burns

• Hypertension

  Worsens all causes

Compartment Syndrome: Mechanism

Issue is _____ return

initial problem is _____, heamorrhgae or external compression

raises compartment pressure

Cyclic Mechanism

Raised compartment pressure = compression of small ____ > worsening venous return, oedema, and compartment pressure

Eventually, Arteriolar compression occurs > muscle and nerve ______ results

Compartment Syndrome: Crush Injury

• Normal muscle compartment pressure is:

  <15mmHg

• Pressure >30mmHg produces muscle ischemia

• irreversible muscle damage after 6 hours

• hypertensive patietns are more at risk than patients with hypotension because they naturally have a lower diastolic pressure

• Irreversible nerve damage after 4 hours

Answer explanation

HYPOtensive patients are more at risk than patients with HYPERtension because they naturally have a lower diastolic pressure

Hyperkalemia

is a common effect of both Crush / Compartment Syndrome

• TRUE

• FALSE

Compartment Syndrome: Management

• Emergency Fasciotomy

• Treating cause

  (reducing blood pressure, improving perfusion)

• High flow oxygen

Hyperkalemia is a big factor as it causes cardiotoxicity.

How does it come about?

• Injured Cells >Stretched sarcolemma

• Sarcolemma becomes permiable and leaks contents out

• contents leaked out into circulation:

  myoglobin, uratem phosophate (nephrotoxic) and potassium (causes Hypokalemia)