Burns Flashcards
state some different types of burns
scalds thermal electrical chemical radiation
what is a scald?
a wet burn
- from boiling water for example
what is a thermal burn?
a dry burn
- flame
what does the extent of a electrical burn depend on?
voltage
contact time
resistance of electricity (water- skin moisture would decrease the resistance)
what model describes a burn?
Jackson burn model
what are the three zones of a jackson burn model?
coagulation zone
stasis zone
hyperaemia zone
what happens at the coagulation zone?
location of primary injury
results in coagulation of cellular proteins and causes the cells to die
infarction
what happens in the stasis zone?
tissue can potentially recover
ischaemia
what causes hyperaemia around the injury site?
release of inflammatory mediators
what happens to the vascular supply around a burn?
vasodilation and increased capillary permeability
- loss of fluid and proteins (exudate)
- hypoperfusion due to loss of oncotic pressure
- cell death and oedema
what intervention should be done to prevent vascular system failure?
early IV fluids to reverse hypovoleamia
what happens to the renal system after a burn?
hypovoleomia from vascular failure and dehydration causes a drop in BP and hence vasoconstriction at the renal tubules by the juxtaglomerular cells which produce renin (ACE system)
reduced renal perfusion
haemolysis and muscle breakdown (due to suppression of anabolic hormones) results in further kidney failure
what happens to the metabolic system after a burn?
body responds by secreting the stress hormones cortisol, glucagon and various catecholamines.
There is a suppression or resistance to anabolic hormones such as insulin and growth hormone, which leads to a profound catabolic state, resulting in muscle protein breakdown.
This mobilises building blocks such as amino acids to help begin repair burnt tissue.
what happens to the immune system after a burn?
Release of cortisol depresses the persons immune system
Burn wound infection is problematic because it delays healing, encourages scarring and may result in bacteraemia, sepsis or multiple-organ dysfunction
infection is the leading cause for burn patients
what happens to the respiratory system after a burn?
associated with the acute respiratory distress syndrome (ARDS)
what is the gatsric ulcer thatt burns patients can get called?
curlings ulcer
acute gastric erosion resulting as a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis (sloughing) of the gastric mucosa.
what prophylaxis should be given to prevent curlings ulcer?
PPI
what questions should be asked in a history about a burn?
Time of the injury
Mechanism
First aid treatment received
If the affected area was immersed in water, how long was it for?
Was any analgesia taken?
When was the patient last immunised against tetanus?
Does the patient have any relevant PMH, especially diabetes
or takes any relevant drugs, such as steroids or warfarin?
or is allergic to dressings or antibiotics?
how long should a burn be held under cold water?
20 mins
what are the three stages of basic first aid for a burn?
stop the burning process
run under cold water fro 20 mins
cover burn with plastic to keep it clean
what mneumonic is used to remember the secondary survey?
AMPLE
A - Allergies M - Medications P - Past illness L - Last meal E - Events/Environment related to injury
what are the two determinants of the seriousness of a burn?
depth
total body surface area
what are the three different depths of burns?
Superficial
Partial thickness, or deep dermal, and
Full thickness
what is a hallmark sign of partial thickness burns?
greatly diminished capillary refill time
what does a full thickness burn look like?
dense white, waxy or even charred appearance
does full thickness burns have any senstaion ?
no - all nerves endings are destroyed
what is coagulation of dead skin of a full thickness burn called?
eschar
with what TBSA of burn is resusciation fluids advised?
Resuscitation fluids are recommended if the %TBSA is >10% in children or >15% in adults
are adults and children given the same maintenance fluids?
no
what formula is used to calculate maintenance fluids in adults?
parklands
4ml x TBSA x weight
first 1/2 in first 8hrs
what formula is used to calculate maintenance fluids in children?
parklands
2ml x TBSA x weight
first 1/2 in first 8hrs
normal (0.9%) saline +/- 5% dextrose
100ml/kg up to 10kg
50ml/kg from 10-20kg
20ml/kg above 20kg
For maintenance in a child the “4, 2, 1” rule should be applied:
4ml per hour for every kg of the first 10kg weight
2ml per hour for every kg of the second 10kg weight
1ml per hour for every kg of weight over 20kg weight
why are children given dextrose for burns?
small hepatic glycogen reserves, which can be exhausted quickly and sometimes require the change from RL/Hartmann’s solution to dextrose 5% in RL solution to prevent life-threatening hypoglycemia.
what should the rate of urine output be in patients with burns?
approximately 1 mL/kg/h
- require catheter to measure output
state some symptoms and signs of inhalation injuries ?
Symptoms of inhalation injury include: Shortness of breath/dyspnoea Wheezing and brassy cough Hoarse voice Signs to look for include:
Soot in respiratory and oral secretions Burns around the mouth and face Stridor Altered consciousness Increased respiratory rate and effort of ventilation
what two gases are important to consider for inhalation injury?
carbon monoxide and hydrogen cyanide
what does CO look like?
Carbon monoxide (CO) is a colourless and odourless gas which diffuses rapidly into the blood stream and combines with haemoglobin, with a 240 times higher affinity than oxygen, to produce carboxyhaemoglobin, which then shifts the oxygen dissociation curve to the left.
what is the management of inhalation injury?
Give humidified oxygen at 15 litres per minute via a non-re-breathing mask.
Monitor sats continuously!
Call for help of your senior and an anaesthetist, as airway oedema may develop rapidly and mechanical ventilatory support may be needed!
Remember that patients with concomitant inhalation injury require greater quantities of fluid for resuscitation than patients with pure cutaneous burns
when is immediate surgery preformed ?
burns to the eyelids or circumferential burn
when is early surgery preformed ?
non-viable tissue and skin grafting
when is late surgery preformed ?
contractures and post-burn reconstruction
what is a Tangential excision
serves to preserve uninjured tissue in order to maximise cosmesis and function.
The major complication with this technique is the excessive blood loss associated with it.
Tissue resistance of increases in the order of:
nerve, vessels, muscles, skin, tendon, fat and bone
with chemical burns, what are the differences between acids and alkali burns?
Acids - causing a coagulative necrosis (like thermal burns).
Alkalis - causing a liquefactive necrosis.
whats of chemical burns affect the extent of injury?
toxicity and quantity, concentration, temperature of the chemical and the surface area exposed, duration of contact, ease of absorption and systemic effects of the particular chemical.
state some common acids and alkalis that cause chemical burns
Sulphuric, nitric and hydrochloric acid
Sodium and potassium hydroxide
what affect does Hydrofluoric acid have ?
hydrogen ions cause skin injury and fluoride ions bind to calcium and lead to severe hypocalaemia which may lead to arrhythmias and cardiac arrest
what % of the population is burned every year?
0.5%
what % of people burned will require hospital ?
10%
what should be measured to determine carbon monoxide poisoning ?
carboxyhaemoglobin levels
what is the surgery called where the burnt tissue is released to help with blood supply ?
Escharotomy
