Burns
a) Define burns
b) Write the types of burns
c) Explain in detail the pathophysiology of burns
d) Discuss the emergency management of patient with 45% burns
Definition
Burns is defined as an injury caused by a transfer of energy from a heat source to the body. It may be thermal, electrical or chemical.
Pathophysiology
Tissue destruction results from coagulation, protein denaturation, or ionization of cellular contents.
Burns of 25% - local response - the loss of capillary integrity ands shift of fluid are localized to the burn itself - blisters, local swelling or oedema only in the area of injury.
More than 25 % → burn shock → tissue hypoperfusion and decreased cardiac output leading to organ hypofunction followed by a hyperdymamic and hypermetabolic phase
Cardiac output decreases before any significant change in blood volume is evident. Fluid is lost into the intercellular space → shock - sympathetic activity - catecholamines released - pulse rate increases - increase in peripheral resistance - further decrease in cardiac output. Needs prompt fluid resuscitation.
cell destruction → hyperkalemia. Hyponatremia occurs. Later on fluid shifts from the extracellular compartment to the intracellular compartment may cause hypokalemia
Anemia occurs due to red cell destruction; but plasma loss → increase in haematocrit Periodical blood transfusion needed to maintain Hb.
Abnormalities in coagulation, including a decrease in platelets (thrombocytopenia) and prolonged clotting and prothrombin time occur
Pulmonary response : hypoxia , carbon monoxide poisoning, Laryngeal edema may necessitate nasotracheal or endotracheal intubation.
Renal function : may be altered due to shock. Myoglobinuria, haemoglobinuria occur and may cause acute renal failure due to acute tubular necrosis.
D amage to skin - temperature regulation is affected - Early hypothermia - later hyperthermia even in the absence of infection.
The types of burns
Burns can be classified according to the depth of burns and the extent of body surface area (BSA) injured.
Depth :
Superficial partial thickness burns - epidermis destroyed, a portion of dermis may be injured
Deep partial thickness burns - destruction of epidermis and upper layers of dermis and deeper portions of dermis injured
Full thickness burns - total destruction of epidermis and dermis and in some cases underlying tissues as well
Patient with 45% burns :
Airway checked - if needed patient is intubated
O2 administered
If needed patient is put on ventilator and positive pressure breathing
Nasogastric tube inserted and paralytic ileus is combated
Morphine IV given
Burn shock is treated with IV fluids : -
Formula for 24 hour fluid requirement : 3ml/Kg/%BSA
Say the patient is around 60 Kg then 3 X 60 X 45 = 8100/24 hours
In the first 8 hours 4050 ml i.e. 126 drops/mt
In the next 16 hours 4050 ml ie 63 drops/mt
Simple antibiotics like ampicillin are started and maintained until a late stage when a tissue culture will guide a change of antibiotic.
