Burns Pathophysiology –When large parts of the body is burnt this will effect most other sytems of the body. This is why treatment of severe burns, as a paramedic, nurse or doctor requires continuous monitoring of other body systems, and treatment holistically, including replacement of electrolytes, plasma, and fluids.
These are the main body systems which are affected by severe burns.
Red bone marrow replaces red blood cells which is destroyed by the burnt skin. If the burns area is too large for the bone marrow to compensate for the loss in red blood cells, the patient will require blood transfusions to survive.
Burning of the skin will lead to an increase in capillary permeability, which causes an increase in blood vasculature – this then results in a decrease of blood pressure as well as live blood volume. This further decreases the blood flow and oxygenation to tissues, which then also results in oedema, shock and eventually death.
Anytime the body becomes hypermetabolic (which is does in the case of a burn), one first areas to be targeted is muscle mass.
Pain is primarily only felt in the partial-thickness burns, where as in full thick-ness burns the nerve cells are destroyed and the patient will feel nothing. As a result of the abnormal levels of circulating potasium ions (K+) such as high K+ due to cellular destruction and the efflux (outward flow) of potasium ions causing hyperkalaemia (high potasium) or hypokalaemia (low potasium) as a result of rapid K+ loss as a result of fluid in the burn, the nervous system transmission of messages, may work faster or slower than normal or not at all.
Airway obstruction caused by gross oedema of the throat. Also, these patients may have an increased respiratory rate as a result of pulmonary oedema (secondary to smoke inhalation) or increased respiratory rate as an attempt to compensate the increased metabolic rate.
Increased secretions of adrenaline and nor-adrenaline in response to the injury may lead to increased body temperature and increased cell metabolism.
Inflammation increases as a result of damaged tissue, which results in greater strain on the lymphatic system and pitting oedema.
Decreased response as a result of excessive strain on the lymphatic system and due to increased infection as a result of burns area removing the first line of infection defence.
Due to the potential hypovolaemic state in which a body with severe burns is likely to be in, their is a decrease in blood availability in the intestinal lining and liver. The intestinal lining automatically increases nutrients required to support metabolsim and repair of damaged cells.
The kidneys compensate for the increased fluid loss as a result of the burn area by decreasing urine output. The potential detriment of this change is the potential for kidney damage as a result of poor perfusion.