wound healing and reconstruction

Question 1

what is an abrasion

Answer 1

• loss of epidermis and maybe some dermis
• not full tickness
• due to blunt trauma/shearing

Question 2

what is an avulsion

Answer 2

• tearing of tissues from attachments but usually left as flap
• on limbs: degloving

Question 3

what is an incision

Answer 3

• Created by a sharp object
• minimal trauma
• all surgical wounds

Question 4

what is a laceration

Answer 4

• similar to incision but not controlled
• tearing of wound creating irregular defect

Question 5

what is a puncture

Answer 5

• penetrating wound
• superficial damage may be minimal
• deep damage may be substantial (organs etc.)

Question 6

what type of wound is this

Answer 6

abrasion

Question 7

what type of wound is this

Answer 7

avulsion/laceration

Question 8

what type of wounds are these

Answer 8

incisions

Question 9

what type of wound is this

Answer 9

puncture

Question 10

discuss vascular supply of the skin

Answer 10

• 3 layers of supply to all 3 layers of skin (deep, middle and superficial
• subdermal plexus is major netwrok supplying blood from direct cutaneous artery
• direct cutaneous artery branches off to supply skin
• if cut, patch of skin it was feeding will die

Question 11

what are the 3 phases of wound healing

Answer 11

• inflammation/hemostasis
• fibroplasia
• maturation

Question 12

what occurs during the inflammatory phase of wound healing and how can you tell you are looking at a wound in this phase

Answer 12

• transient vasoconstriction (prevet bleeding out) then vasodilation (to get as many clotting factors and inflam cells as possible to site)
• increased capillary permeability
• activation of intrinsic and extrinsic clotting cascade
• chemotaxis of inflammatory cells
• neutrophils called to site followed by macrophages (macros send signals for more cells to accumulate)

can tell: fresh blood, fresh edges, no granulation tissue

Question 13

what occurs during the repair phase and how can you identify that you are looking at a wound in this stage

Answer 13

• fibroplasia
• cessation of inflammatory phase
• fibroblast migration (contact inhibition = cells meet eachother and signal to stop spreading and production of proteoglycans, collagen and elastin)
• wound contractions
• epithelialisation

Can tell: granulation tissue and pink epithelisation around edges

Question 14

what occurs in the maturation/remodelling phase and how can you tell you are looking at a wound in this phase

Answer 14

• matrix synthesis and matrix degradation
• cross linking of collagen type 1 and 3
• inrease in tensile strength
• scar formation
• takes weeks to months

can tell: dry scab, no visible granulation tissue (or very little), scar

Question 15

what species has slower wound healing

Answer 15

cats: granulation tissue forms slower and wound strength therefore less at same healing timeperiods

Question 16

list systemic factors that negatively impact wound healing

Answer 16

• old age
• medications (steroids)
• radiation
• co-morbidities (cushings and diabetes)
• nutrition

Question 17

list local factors that negatively affect wound healing

Answer 17

• seroma
• neoplasia
• foreign material
• self trauma
• necrostic tissue
• contamination infection

Question 18

you are presented with a patient with a wound. what will you do first

Answer 18

assess the patient for other injuries
- always stabilise patient first, dont miss something more traumatic inside that can kill the patient by being distracted by the wound!!!
- TPR, imaging, bloodwork, history,

Question 19

what things will you look for when assessing a wound

Answer 19

• level of contamination (soil/organic material within?)
• type of tissue affected (just skin? muscle? bone? tendon?)
• vascular compromise (are the tissues viable)
• foreign material (hair and sutures)

Question 20

most animal wounds are contaminated. how do you distinguish contaminationf from infection

Answer 20

for a wound to be infected, the bacterial must be present in large amounts for period of time. contamination is considered as bacteria where it doesnt belong. it takes 6-12 hours for bacteria to divide and more than 12 hours for bacteria to invade the tissue

Question 21

what factors influence bacterial contamination of a wound

Answer 21

• vascular supply (reduced ability to fight infection)
• devitalised tissue (increased bacteria growth)
• foreign body (reduced ability to fight infection)
• type of contamination (bite vs cut from glass?)
• type of bacteria

Question 22

what are the goals of wound management

Answer 22

• promote healing
• convert contaminated into “clean”
• control infection

Question 23

what are the principles of wound management

Answer 23

• clip hair to protect wound
• debride wound
• antimicrobial therapy
• open vs closed healing

Question 24

discuss wound levage

Answer 24

• purpose to dilute bacteria and flush out FB
• encourages healing
• isotonic solutions are best (can use water but could kill good cells)
• always culture AFTER levage

Question 25

what concentrations of chlorohexidine and iodine are appropriate for flushing wounds

Answer 25

- chlorohexidine 0.05% - iondine 0.1-0.01%

Question 26

how do you prepare a wet to dry dressing and what is its purpose

Answer 26

1. moisten sterile swabs with sterile isotonic solution 2. remove excess fluids 3. place directly onto wound 4. layer with dry sterile swabs 5. debridement occurs by osmosis and the contaminated material will be drawn up toward dry gauze 6. change daily until reach repair stage

Question 27

what is a tie over bolus

Answer 27

- useful for hard to dress areas - loop stay sutures around wound (nylon) - umbilical tape criss crosses over gauze

Question 28

what is primary closure

Answer 28

- immediate suture - clean or clean-contaminated only

Question 29

what is delayed primary closure

Answer 29

- clean-contaminated to contaminated wounds - reduces incidence of infection - closure after 3-5 days of wound management

Question 30

what is secondary intention healing and what are the advantages/disadvantages

Answer 30

- no skin closure, leave wound and manage with bandages to heal on its own - advantages: optimum wound drainage, local infection control and cheap - disadvantages: poor cosmetic results, poor functional results if in a functional area, timely, results in thinner, fragile skin

Question 31

what is proud flesh

Answer 31

exuberant (overgrowth) of granulation tissue - particularly issue in horses - must be cut off as will prevent epithelium from making contact

Question 32

what are the advantages of a surgical drain

Answer 32

- remove fluid accumulation - eliminate dead space - increase healing capacity - reduce tension from seroma formation

Question 33

what are the disadvantages of surgical drains

Answer 33

- introduction of FB - introduction of infection - seroma always better than abscess!

Question 34

list types of drains

Answer 34

- passive: penrose - active:

Question 35

what is the ideal healing envionment for advanced wound care

Answer 35

- a moist environment that isnt macerated - free of infection and excessive debris - free of toxic chemicals, particles or fibres - warm - at the optimum temperature for healing - leave new tissue undistrubed (minimise frequency of dressing changes) - allow for adequate gas exchange - dressing should be painless to apply and remove - dressings should minimise contamination both to and from the wound

Question 36

give examples of dressing that absorb moisture

Answer 36

- wet to dry - alginates (made from seaweed) - foam dressings (can also be used for dry wounds) - hydrocolloid dressings (can also use on dry wounds)

Question 37

what dressings maintain moisture

Answer 37

- hydrogels - blister plaster

Question 38

what are the principles of wound closure

Answer 38

- know your anatomy - have a plan A, B and C - always have good client communication - clip and prepare larger area than anticipated

Question 39

what are the issues with wound tension

Answer 39

- circulatory compromise - reduced wound healing - infection - dehiscence - skin necrosis

Question 40

how do you minimise wound tension

Answer 40

- patient positioning - undermining - suture patterns - relaxing incision - advancement flaps - techniques that provide additional skin

Question 41

what is skin undermining and its benefits? how is it performed

Answer 41

- using blunt tipped metzenbaum scissors (or scalpel if scar tissue), blunt dissect under skin - preserve direct cutaneous artery if possible - gives you extra space to work with

Question 42

what are walking sutures

Answer 42

- used after skin is undermined - method of distributing skin tension - method of advancing skins - in areas where undermining and suture closure is sufficient for closure - skin pulled forward in increments (great cumulative effect of multiple)

Question 43

what are relaxing incisions

Answer 43

- either single or multiple incisions on either or one side of the wound to reduce tension - enables the primary wound to be closed - heal by secondary intention

Question 44

what is a skin flap

Answer 44

- a section of skin elevated (usually local to the wound) and moved into the wound for coverage - a skin flap retains its own blood supply - as long as there is availible skin, a skin flap can be used anywhere - 2 types: subdermal (random) plexus flap (may or may not include direct cutaneous artery) and axial pattern flap (will always include a direct cutaneous artery)

Question 45

list complications of skin flaps

Answer 45

- partial thickness necrosis - full thickness necrosis - desensitisation and self trauma