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