f Post graduate mcqs and discussion : CRUSH SYNDROME

Tuesday, April 3



It is due to crushing of muscles causing extravasation of blood and release of myohaemoglobin into the circulation leading to acute tubular necrosis and acute renal failure.


Mining and industrial accidents.
Air crash.

Initially tension increases in the muscle compartment commonly in the limb, which itself impedes the circulation and increases the ischaemic damage.

In 3 days, urine becomes discoloured and scanty, patient becomes restless, apathy and delirious with onset of uraemia. Crush syndrome is often life￾threatening.

Effects of crush syndrome

Renal failure
Disability with extensive tissue loss
Gas gangrene


Tension in the muscle compartment is relieved by placing multiple parallel deep incisions in the limb so as to prevent further damage.

Rheomacrodex, or mannitol is given to improve the urine output by improving the renal function.

Alkalisation of urine is done by giving sodium citrate or sodium bicarbonate. It increases the solubility of acid haematin in the urine and so promotes its excretion. Urinary pH should be above 6.5 until urine does not show any myoglobin. Mannitol-alkaline diuresis should be 8 litre/day.

Initial aggressive volume load using saline about 1-1.5 litres/ hour is ideal in these patients.

Haemodialysis is done sometimes as a life-saving procedure.

Other measures:

Oxygen therapy.
Blood transfusion.
Correction of severe hyperkalaemia.


Crush injury is one where a part of the body is being squeezed/ compressed between two high force or pressure systems. It causes extensive lacerations, bruising, compartment syndrome, crush syndrome, fractures, haemorrhage, etc. with extensive tissue destruction and devitalisation. Renal failure, hypovolaemic shock and sepsis are the most dreaded problems in crush injuries.