Burns

Question 1

burns definition

Answer 1

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

Question 2

aetiology of burns

Answer 2

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

Question 3

RF for burns

Answer 3

young children and elderly most at risk

they suffer higher mortality

Question 4

epidemiology of burns

Answer 4

common

>12000 admissions in Eng and Wales /yr

Question 5

presenting symptoms of burns (history)

Answer 5

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)

Question 6

Answer 6

1st degree burn

Question 7

Answer 7

2nd degree burn

Question 8

Answer 8

3rd degree burn

Question 9

Answer 9

4th degree burn

Question 10

signs of burns

Answer 10

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

Question 11

partial thickness burn:

Answer 11

subdivided into superficial and deep

red and oedematous skin in a superficial burn

blistering and mottling in deep dermal burns

both painful

Question 12

full thickness burns

Answer 12

destriction of epidermis and dermis

charred leathery eschar, firm, painless with loss of sensation

Question 13

size of burn

Answer 13

% 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

Question 14

pathology of superficial parcial burns

Answer 14

damage to epidermis

healing within 7days

subsequent peeling of dead skin

Question 15

patholgy of deep partial burns

Answer 15

extend into dermis

sweat and sebaceous glands are spared

healing occurs by epithelial regrowth over 3weeks

usually w/o scarring unless infection develops

Question 16

pathology of full thickness burns

Answer 16

complete destruction of all skin layers

requires skin grafting

or healing will occur by scarring and contractures

Question 17

investigations for burns

Answer 17

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

Question 18

electrical burns

Answer 18

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

Question 19

chemical burn

Answer 19

acids - may penetrate deeply down to bone

alkali can cause deep dermal/full thickness burns

HCl can chelate with Ca ions = poor nerve conduction

Question 20

paediatric burn

Answer 20

inform social services

pullover burn - burn from pulled over hot drink

immersion in hot bath - if no splashes, unlikely to be accidental

cigarette burn

Question 21

importance of burn depth

Answer 21

determines healing time/scarring

burns can evolve - particularly over the 1st 48hrs

Question 22

3 zones of injury

Answer 22

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