Burns & Wounds Flashcards
Epidermis
Outlayer, No nerve endings, dead cells
first line of defence
allows release of salts and water
Dermis
Sensory receptors, nerve endings, sweat glands
tough, elastic connective tissue
aids in thermoregulation
has macrophages & lymphocytes that assist in inflammatory response
has hair follicles
Hypodermis
subcutaneous fat & insulation
important in protection against injury
the layers are present everywhere but the thickness varies depending on location, age and health
characteristics of 1st degree burns
epidermis layer
mild to moderate
dry
red
no blistering
heals in 3-10 days
characteristics of 2nd degree burns
epidermis and part of the dermis
can be superficial partial or deep partial
painful
blistering
moist
may be blistering
characteristics of 3rd degree burns
subcutaneous tissue
may involve muscle or bone
can be waxy or yellow
pain free due to nerve damage
usually requires a skin graft
characteristics of 4th degree burns
epidermis and dermis
extending to muscle or bone
common in electrical burns
Definition of burn
An injury caused by energy transfer to the body’s tissues causing an inflammatory response. The source of energy can be thermal, chemical, electrical or radiation.
Pathophysiology of burns: Local Response
Destroys cells
Jackson’s thermal wound theory: zone of coagulation, zone of stasis and zone of hyperaemia.
Inflammatory response: redness, swelling, pain and heat
Local Response: zone of coagulation
central zone where most damage occurs
necrosis of cells
tissue is non viable
Local response: zone of stasis
surrounds critically injured area
cells are ischaemic
Local Response: Zone of hyperaemia
increased blood flow
should recover in 7-10 days
What do local and systemic responses to thermal trauma lead to?
oedema and the accumulation of vascular fluid
Emergent phase of burn shock
brief initial decrease of blood flow to the area of injury follow by arteriolar vasodilation.
Fluid shift phase of burn shock
release of vasoactive substances from burned tissues causes increased capillary permeability = IV fluid loss and wound oedema
Sunburn treatment
Analgesia, hydration, soothing creams & avoid the sun
characteristics of frost nip
irritation of skin
redness
numbing
characteristics of superficial frostbite
skin feels warm
fluid filled blisters may appear
characteristics of deep frostbite
numbness
joints/muscles may no longer work
large blisters appear
area turns black and hard
Skin Function: protection against infection
- skins forms a barrier against pathogens
- stratum cornuem cells interlock and resist pathogen penetration - rupturing this compromises the body’s ability to fight against infection
- the cells beneath the stratum corneum (stratum basale) divide and create new cells
- epidermic cells constantly die due to lack of nourishment
Skin Function: Protection against dehydration
keratin and oily sebum from sebaceous glands help to waterproof the skin and prevent water loss
Skin Function: Thermoregulation
Cold: vasoconstriction, shivering, hairs lie flat
Hot: vasodilation, sweating, hairs stand up
Skin Function: collection of sensory information
free nerve endings detect pain
Meissner’s corpuscle = touch receptor
Pacinian Corpuscle = pressure receptor
Name the 4 thermoregulatory mechanisms and what they mean + include examples
Radiation: Heat loss in the form of infrared rays (erection of hairs, flushes appearance)
Conduction: Heat Transfer from body’s core to the surface (holding a cold glass)
Convection: Heat transfer to the free air layers by the heart pumping blood through the body (using a fan)
Evaporation: water lost through skin or sweat glands (sweating)
What is the importance of thermoregulation?
low temps = reduced kinetic energy for molecules so slower chemical reactions
high temps = enzymes denature
Which part of the brain is heavily involved in thermoregulation?
Hypothalamus
Inflammatory Response: Local Response
(9 points)
- Mast cells are produced (such as histamine)
- histamine causes blood vessels to leak
- blood plasma leaks into interstitial spaces
- swelling and clotting occurs
- increased blood flow to the area
- immune cells are activated which attracts leukocytes
- mixture of leukocytes and fluid is called exudate
- swelling and exudate puts pressure on pain receptors
- Body temp rises to increase metabolism and immunity
Inflammatory Response: Systemic Response
(8 points)
- Damage occurs to the sodium potassium pump
- sodium is lost due to damage of the skin
- plasma leaks into interstitial space and potassium follows
- blood in the vessels becomes more concentrated and viscous
- less blood flow to the kidneys but blood pressure is higher
- Effect on GI tract = less blood flow, bicarb and mucosal production is lost, acidity increases, ulcers occur, metabolic acidosis could also occur
- Catecholamine’s are produced (including cortisol) - affecting the immune system negatively- putting the body into a hyper metabolic state
- HR and RR increase - blood pressure falls
Considerations when conducting a burns assessment
time of injury, mechanism, is it in a confined space, was it non accidental
Serial Halving burns assessment overview
is the burn greater than half of the patient’s body surface, between a quarter and half, between an eighth and a quarter or less than an eighth.
Rule of Palms burns assessment overview
estimating the burn by comparing the surface area of the burn to the area of the palm (excluding the fingers). The area of the palm is around 0.5% of the total body surface area
Rule of 9s burns assessment overview
Divides body into percentages - multiples of 9
Lund and Browder Chart burns assessment overview
divides the body into proportions based on age
Considerations with using morphine as analgesia for burns
it is a vasodilator and is metabolised faster when burns are present so titrate the dose.
