PBL 1

Question 1

describe the Jackson model of burns?

Answer 1

in the centre of the burn we have the coagulation zone with the stasis zone around that and then the hyperaemia zone around that

Question 2

what is the zone of coagulation in a burn?

Answer 2

the point of maximum damage where there is irreversible tissue loss due to necrosis

Question 3

what is the stasis zone of a burn?

Answer 3

where we get decreased perfusion and if not reversed this can become complete necrosis

Question 4

what is the zone of hyperaemia in a burn?

Answer 4

where tissue perfusion is increased

Question 5

what can cause a burn?

Answer 5

fire, heat, chemicals, electricity and radiation

Question 6

describe a superficial/first degree burn?

Answer 6

damage is caused only to the epidermis

the skin is red, dry with no blisters. it should have brisk capillary refill and is mildly painful

Question 7

whats an example of a first degree burn?

Answer 7

sunburn

Question 8

describe the pathophysiology of a second degree burn?

Answer 8

damage caused to the epidermis and papillary dermis

Question 9

what does the skin look like on a second degree burn?

Answer 9

red, moist, blistered swollen and very painful

Question 10

why do burns cause pain?

Answer 10

the release of pro-inflammatory cytokines stimulate sensory nerve endings

Question 11

why can burns result in hypotension?

Answer 11

because cytokines increase vascular permeability, causing fluid to leak out and cause interstitial oedema

Question 12

why do we get blanching and erythema of the skin in burns?

Answer 12

because cytokines cause vasodilation

Question 13

what are blisters?

Answer 13

the accumulation of fluid in an area

Question 14

what do second degree burns look moist?

Answer 14

because we get the formation of blisters which burst

Question 15

what is damaged in third degree burns?

Answer 15

the epidermis, dermis and hypodermis

so all blood vessels and nociceptors

Question 16

what does the skin look lik in third degree burns?

Answer 16

dry, non-blanching, charred, patchy in colour (white-> brown), dry leathery texture

Question 17

why do third degree burns have little or no pain?

Answer 17

because damage is caused to sensory nerve fibres and nociceptors leading to hypoaesthesia

Question 18

why can we get hypotensive from 3rd degree burns?

Answer 18

because any blood vessels which havnt been completely destroyed react to cytokines and this causes increased vascular permeability = oedema

Question 19

what is damaged in fourth degree burns?

Answer 19

all layers of the ski and even some muscles, tendons and bone

Question 20

what do fourth dgeree burns look like?

Answer 20

brown, dry, charred

Question 21

can you feel any pain with fourth degree burns?

Answer 21

NOTHING

Question 22

how do we measure the total body surface area burned?

Answer 22

using the rule of nines

Question 23

outline the rule of nines?

Answer 23

front + back of head = 9%
front + back of arm and hand = 9%
chest + stomach = 9%
upper back = 9%
lower back = 9%
front and back of 1 leg + foot = 18%
genital area = 1%

Question 24

how much a total body surface area must be burnt for it to be considered a major injury and require hospitalization?

Answer 24

children- 10%

adults 15-20%

Question 25

at what total body surface area of burns should you worry about hypovolemic shock?

Answer 25

over 15%

Question 26

what is hypovolemic shock?

Answer 26

an emergency condition in which severe blood/other fluid loss makes the heart unable to pump enough blood to the body

Question 27

when should you go to hospital with a burn?

Answer 27

if the burn is larger than the hand
if the burn is on the face. hand, buttox, feet or over a major joint
causes white or charred skin
forms blisters
all chemical/electrical burns
when the person appears to be in shock
if the person is pregannt
if the person is over 60 or under 5
if the person has a medical condition or a weakened immune system

Question 28

outline first aid of a burn?

Answer 28

stop the burning process
remove any clothing or jewellery nearby
dont remove anything stuck to the burn
keep the burn cool with running water for 20 minutes
keep the person warm to prevent hypothermia
cover burn with clingfilm
treat pain 
sit upright if face or eyes are burnt

Question 29

how often should you change the dressing on a burn?

Answer 29

every day with clean hands

Question 30

which burns may need skin grafts?

Answer 30

second, third or fourth degree burns

Question 31

how do superficial wounds heal?

Answer 31

the epidermis can regenerate from the stratum basale

Question 32

what are the stages for healing deeper wounds?

Answer 32

haemostasis
inflammation
proliferation
remodelling

Question 33

what happens in the haemostasis phase of wound healing?

Answer 33

vasoconstriction, platelets adhere to sub-endothelium, fibrin stands form a mesh, coagulation of blood and formation of a thrombus

Question 34

what happens in the inflammatory phase of wound healing?

Answer 34

damaged cells and pathogens are removed from the wound area

swelling, heat, pain and redness

Question 35

what happens in the proliferative phase of wound healing?

Answer 35

angiogensis, fibroplasia (fibroplasts contract wound and collagen is laid down), epithelialisation (keratinocytes laid down)

Question 36

what happens in the remodelling phase of wound healing?

Answer 36

collagen is remodelled from type 3 to type 1 and is re-aligned along tension lines with cross-linking
unneeded cells are removed by apoptosis