Crush syndrome

Question 1

What is crush syndrome?

Answer 1

Spectrum of conditions characterised by skeletal muscle injury/ rhabdomyolysis

Question 2

Causes of crush syndrome

Answer 2

Direct injuries/ severe burns causing muscle damage

Compartment syndromes

Entrapment/ self crushing e.g. when drunk and lying on hard surface

Metabolic disorders

Exertional: grand mal fitting, rave dancing (esp. when on E/ cocaine)

Question 3

Clinical features of crush syndrome

Answer 3

Depend on cause but

Muscle pain, tenderness and swelling - these may not be apparent at time of admission

Commonly confused with DVT in the lower limbs

Question 4

Investigations for crush syndrome

Answer 4

Increased creatine phosphokinase reflects muscle damage

70% have myoglobulinuria and pigmented, granular casts (dipsticks don’t differentiate between Hb and myoglobin)

Question 5

Management of crush syndrome

Answer 5

Compartment syndrome: refer to orthopods

Systemic complications: hyperkalaemia can occur following revascularisation - correct

Question 6

Why does acute renal failure occur in crush syndrome?

Answer 6

Following revascularisation, fluid leaks into damaged areas which decreases circulating volume

Intracellular muscle components enter the circulation and myoglobin can block renal tubules