Burns Flashcards
burns definition
Burns are very common injuries, predominantly to the skin and superficial tissues, caused by heat from hot liquids, flame, or contact with heated objects, electrical current, or chemicals
coagulative destruction of the skin or mucous membrane
aetiology of burns
caused by heat, liquid, chemical or irradiation and UV light, electrical
thermal damage occurs above 48degrees C, contact flame radiation
extent of necrosis is related to the temp and duration of the contact
RF for burns
young children and elderly most at risk
they suffer higher mortality
epidemiology of burns
common
>12000 admissions in Eng and Wales /yr
presenting symptoms of burns (history)
circumstances of burn
note time, temp and length of contact
consider risk of inhalation of smoke and toxic gas poisening (CO)
dry, painful, no blisters, red burns (1st degree - epidermis)
wet, blistered, blanch on pressure, painful burns (2nd degree - epidermis and dermis)
dry, red, doesnt blanch well, and insenate burns (3rd degree - epidermis and dermis and damahe to appendages)
burns affecting subcutaneous tissue, tendon or bone, black and white, leathery, charred skin, no sensation (4th degree)
1st degree burn
2nd degree burn
3rd degree burn
4th degree burn
signs of burns
look for signs of inhalation injury or airway compromise:
- stridor
- SOB
- hoarse voice
- soot in nose/mouth
- singed nose hairs
- carbonaceous sputum
- flame burns on face
examine site and depth and distribution of burn
partial thickness burn:
subdivided into superficial and deep
red and oedematous skin in a superficial burn
blistering and mottling in deep dermal burns
both painful
full thickness burns
destriction of epidermis and dermis
charred leathery eschar, firm, painless with loss of sensation
size of burn
% body SA and calculated by Wallace’s rule of 9s: arm/head 9%, anterior or posterior trunk 18%, leg 18%, palm 1%, perineum 1%
or Lund-Browder chart
important because influences the size of the inflammatory response (vasodilation, increased vascular permeability) and so fluid shift from the intravascular volume
ignore erythema
pathology of superficial parcial burns
damage to epidermis
healing within 7days
subsequent peeling of dead skin
patholgy of deep partial burns
extend into dermis
sweat and sebaceous glands are spared
healing occurs by epithelial regrowth over 3weeks
usually w/o scarring unless infection develops
pathology of full thickness burns
complete destruction of all skin layers
requires skin grafting
or healing will occur by scarring and contractures
investigations for burns
bloods
- SatO2, ABG and carboxyhaemoglobin if inhalation injury
- FBC
- UE
- G&S or cross match - in severe
electrical burns
- serum CK
- urine myoglobin for muscle damage
- ECG
electrical burns
low tension burns <1000V are usually small but full thickness
high tension burns >1000V usually have an entry and exit wound - get burning from the inside out, compartment syndrome
current passes along the path of least resistance eg bv, fascia, muscle
extent of tissue destruction can be underestimated
high tension burns can be associated with cardiac arrhythmias
myonecrosis and myoglobinuria can occir - cause muscle death
lightning strike - Lichtenberg figures
chemical burn
acids - may penetrate deeply down to bone
alkali can cause deep dermal/full thickness burns
HCl can chelate with Ca ions = poor nerve conduction
paediatric burn
inform social services
pullover burn - burn from pulled over hot drink
immersion in hot bath - if no splashes, unlikely to be accidental
cigarette burn
importance of burn depth
determines healing time/scarring
burns can evolve - particularly over the 1st 48hrs
3 zones of injury
zone of coagulation - irreversible tissue damage, max contact
zone of stasis - intermediate zone, can go either way - goof fluid resus and perfusion means likely to go to hyperaemia zone rather than coagulation.
zone of hyperaemia - recovery zone
