Wound healing

Question 1

Abrasion

Answer 1

• Loss of epidermis and some dermis
  
  • Blunt trauma/shearing

Question 2

Avulsion

Answer 2

• Tearing of tissues from attachments
  
  • on limbs- degloving injury

Question 3

Incision

Answer 3

• Created by a sharp object
  
  • minimal trauma

Question 4

Laceration

Answer 4

Tearing of wound creating irregular defect

Question 5

Puncture

Answer 5

• Penetrating wound
  
  • Superficial damage may be minimal
  • deep damage may be substantial

Question 6

Vascular supply to the skin

Answer 6

• Epidermis, dermis and the hypodermis are vascularised
  
  • there is a 3 layer supply being the deep, middle, superficial

Subdermal plexus
Direct cutaneous artery

Question 7

What are the phases of wound healing

Answer 7

1. Injury
2. Haemostasis and inflammation
3. fibroplasia
4. maturation

Question 8

What is the role of vasoconstriction in inflammation?

Answer 8

• Increased capillary permeability
• activation of intrinsic and extrinsic clotting cascade
• Chemotaxis of inflammatory cells
• Neutrophils → macrophages

Question 9

Outline the repair phase of wound healing

Answer 9

Fibroplasia
Cessation of inflammatory phase
Fibroblast migration - contact inhibition - produced and secreted proteoglycans, collagen and elastin

Question 10

What happens in the remodelling phase of wound healing?

Answer 10

Maturation
Matrix synthesis and matrix degradation
Cross-linking of collagen
Increase in tensile strength
takes weeks to months

Question 11

How long does the maturation phase last and what is the % pre-wound strength at each stage?

Answer 11

2 weeks0 20% strength
5 weeks- 50% strength
10 weeks- 80% wound strength

Question 12

Why does maturation stage take longer in dogs than cats?

Answer 12

at 7 days wound strength is half in cats as it would be in dogs
This is because granulation takes longer to form

Question 13

What systemic and general factors affect wound healing?

Answer 13

Older age
Radiation
Medication such as steroids
Co morbidities
Nutrition

Question 14

What local factors would affect wound healing?

Answer 14

Contamination infection
Seroma
Neoplasia
Foreign material
Self trauma, necrotic tissue?

Question 15

What should be assessed when managing a patient with wounds?

Answer 15

Other injuries
Life threatening complications
Ensure to stabilise
Assessment of wound- consider sedation/ local or general anaesthesia

Question 16

Why is bacterial contamination common animal wounds?

Answer 16

Normally traumatic so caused by what caused the trauma

Question 17

What is the golden period in relation to bacterial contamination?

Answer 17

6 hours
6-12 hours bacteria will divide
after 12 hours there will be bacterial invasion

Question 18

What factors will affect bacterial contamination?

Answer 18

Vascular supply
Devitalised tissue
FB
Type contamination
Type of bacteria

Question 19

What are the goals of wound management?

Answer 19

Promote healing
Convert contaminated into clean
Control infection

Question 20

What is the role of wound lavage?

Answer 20

• Dilute bacteria
• Mechanically remove FB
• Encourage healing

Question 21

What should be used for a wound lavage?

Answer 21

Harrtmans
20ml and 18 gauge syringe
Culture after lavage

Question 22

When should a wound be showered prior to lavage?

Answer 22

If the wound is purulent/contaminated/ large wound

Question 23

What is debridement?

Answer 23

• removal of foreign material as a surgical technique
  
  • surgical procedure
  • aseptic technique
  • sharp incision
  • remove necrotic material
  • Repeated debridement often necessary

Question 24

How should a debridement be carried out?

Answer 24

Moisten sterile swabs with sterile isotonic fluid - remove excess fluids
Act to draw away purulent and necrotic material
Need external protection

Question 25

How does a non surgical debridement work?

Answer 25

Debridement occurs by osmosis
Change daily until the repair phase

Question 26

What is a tie over bolus dressing?

Answer 26

• Useful for hard to dress areas
• Loop to stay sutures around wound
• Umbilical tape

Question 27

What are the 3 types of wound closure techniques?

Answer 27

Primary
Delayed primary - close 3-5 days later
Secondary intention healing

Question 28

What should be completed for primary closure?

Answer 28

Debridement
Lavage
Culture
Wet to dry dressings

Question 29

What occurs in secondary intention healing?

Answer 29

Granulation tissue
Wound contraction and epithelialisation

Question 30

Advantages of secondary intention healing

Answer 30

• Optimum wound drainage
• local infection control
• Cheap??

Question 31

What are the disadvantages of secondary intention healing?

Answer 31

• Cosmetic results
• poor functional results
• time and expense
• Thin fragile skin

Question 32

What is the role of the surgical drain?

Answer 32

Remove fluid accumulation
Eliminate dead space

overused as prophylactic means of fluid drainage

Question 33

What are the advantages and disadvantages of surgical drains?

Answer 33

Passive drains
Active drains

Question 34

What are the important practices when using pentose drains?

Answer 34

Always cover as they have risle of ascending infection
Monitor the drainage for removal.

Question 35

What are examples of passive drains?

Answer 35

Penrose drain
Latex rubber tube
Gravity
Capillary action
Needs large SA

Question 36

What problems can arise due to wound healing tension?

Answer 36

Circulatory compromise
Reduced wound healing
Infection
Dihiscence
Skin necrosis

Question 37

How does patient positioning affect the wound tension?

Answer 37

Skin trapped by the animals own weight
Elevation of area in front or behind
Chain mastectomies
Release leg ties for inguinal region

Question 38

How should areas with panniculus be undermined?

Answer 38

Undermine below

Question 39

How should areas without panniculus be undermined?

Answer 39

Undermine deep fascia