Pages

Tuesday, 3 April 2018

Crush Syndrome

                           Crush Syndrome

     Crush Syndrome (also called Traumatic rhabdomyolysis or Bywater's Syndrome) is a medical condition characterized by major shock and renal failure after a crushing injury to skeletal muscle. Crush injury is compression fo extremities or other parts of the body that causes muscle swelling and/ or neurological disturbances in the affected areas of the body, while crush syndrome is localized crush injury with systemic manifestations. Cases occur commonly in catastrophes such as earthquakes, to victims that have been trapped under fallen or moving masonry. 
     Victims of crushing damage present some of the greatest challenges in field medicine, and may be among the few situations where a physician is needed in the field. The most drastic response to cruising under massive objects may be field amputation. Even if it is possible to extricate the patient without amputation, appropriate physiological preparation is mandatory, where permissive hypotension is the standard for prehospital care, fluid loading is the requirement in crush syndrome. 

Pathophysiology:
    Seigo Minami, a Japanese physician, first reported the crush syndrome in 1923. He studied the pathology of three soldiers who died in World War I from insufficiency of the kidney. The renal changes were due to methemoglobin infarction, resulting from the destruction of muscles, which is also seen in persons who are buried alive. The progressive acute renal failure is because of acute tubular necrosis. the syndrome was later described by British Physician Eric Bywaters in patients during the 1941 London Blitz. It is a reperfusion injury that appears after the release of the crushing pressure. The mechanism is believed to be the release into the bloodstream of muscle breakdown products notably myoglobin, potassium, and phosphorus, that are the products of rhabdomyolysis (the breakdown of skeletal muscle damaged by ischemic conditions). The specific action on the kidneys is not understood completely but may be due partly to nephrotoxic metabolites of myoglobin. 

 The most devastating systemic effects can occur when the crushing pressure is suddenly released, without proper preparation of the patent, causing reperfusion syndrome. In addition to tissue directly suffering the crush mechanism, the downstream tissue is subject to the ischemia-reperfusion injury of the appendicular musculoskeletal system, without proper preparation, the patient, with pain control, may be cheerful before extrication, but die shortly thereafter. This sudden decompensation is called the "smiling death". 

   These systemic effects are caused by a traumatic rhabdomyolysis. As muscle cells die, they absorb sodium, water, and calcium, the rhabdomyolysis releases potassium, myoglobin, phosphate, thromboplastin, creatine and creatine kinase. 
Monitor for the classic 5Ps: Pain, Pallor, Parasthesias, Pain with passive movement, and Pulselessness. 

Treatment:
 Due to the risk of crush syndrome, current recommendation to lay first-aiders is to not release victims of crush injury who have been trapped for more than 15 min. Treatment consists of not releasing the Tourniquet and fluid overloading the patient. If the pressure is released during first aid then the fluid is restricted and an input-output chart for the patient is maintained, and proteins are decreases in the diet. 

 The Australian Resuscitation Council recommended in March 2001 that first-aiders in Australia, where safe to do so, release the crushing pressure as soon as possible, avoid using a tourniquet and continually monitor the vital signs of the patient. St. John Ambulance Australia, first responders are trained in the same manner. 

Field Mangement:
 As mentioned permissive hypotension is unwise. Especially if the crushing weight is on the patient more than 4 hours, but often if it persists more than one hour, careful fluid overload is wise, as well as the administration of intravenous sodium bicarbonate. 
If the patient cannot be fluid loaded, this may be an indication for a Tourniquet to be applied. 



No comments:

Post a Comment