Remarkably, the body’s respond to physical injury is poorly understood. For example uncontrolled bleeding accounts for death in a third of trauma patients who make it to hospital and in more than half of the people who die at the scene of an accident.
Correcting the loss of blood is fundamental in understanding the body’s response and subsequent methods of treatment.
This is a controversial area but some important lessons have been learned from developments by the military.
In recent years research has turned away from the type of infusion that replaces lost blood to prevention, early identification and treatment of the body’s response that bizarrely, increases the likelihood of death.
This response is referred to as the ‘lethal triad’ or ‘triad of death’. The acidity of the blood increases (acidosis), the body temperature drops (hypothermia) and blood clotting is impaired.
In an accident, massive haemorrhage leads to restricted blood flow to the body’s organs, resulting in low oxygen levels in the tissues.
This triggers the accumulation of lactic acid and the start of the lethal triad.
The body is unable to maintain its normal temperature, made worse by the environment, the older the age of the person and the possible infusion of cold, intravenous fluids by the emergency team to restore lost blood.
Acidosis and hypothermia affect the third element of the triad, the function and production of natural substances that lead to the blood’s inability to form clots.
The disastrous effects of major blood loss are therefore enhanced.
Trauma is the main cause of death in the first four decades of life and a leading cause of disability.
The emergency care and treatment for victims of major injury has improved in the last few years partly as a result of the coordination of trauma services but also the establishment of major trauma centres.
These developments have ensured consistently higher standards of care leading to reduced mortality rates of around 10 per cent and reducing the estimated £3.5bn annual economic cost of trauma.
Trauma care providers including ambulance trusts, specialist hospitals, and rehabilitation units have developed appropriate changes to save more lives and reduce long-term disability.