Principles of wound healing 1

Question 1

Give examples of accidental wounds

Answer 1

• Road traffic accident
• Flights/kicks
• Stick injuries
• Athletic activity

Question 2

Failure to use good surgical technique / manage wounds correctly can result in…?

Answer 2

• Delayed healing
• Prolonged discomfort
• Extra cost to the owner

Question 3

Wounds of which parts of the body are particularly important?

Answer 3

• Head
• Thorax
• Abdomen
• Joints
• Tendon sheaths

Question 4

What is the largest organ in the body?

Answer 4

Skin

Question 5

What are the 3 main components of skin their functions?

Answer 5

• Collagen fibres: provide strength
• Elastic fibres: elastic properties
• Ground substance

Question 6

What are the 4 layers of the epidermis?

Answer 6

• Stratum corneum
• Stratum granulosum
• Stratum spinosum
• Stratum basal

Question 7

What are the two layers of the dermis?

Answer 7

• Superficial papillary layer

- Deep reticular layer

Question 8

Give examples of other features found in the skin

Answer 8

• Sweat glands, sebaceous glands, hair
• Subcutis and cutaneous muscles
• Arteries, veins, lymphatics
• Nerves

Question 9

Explain tension lines in the skin

Answer 9

• Normal tension in the skin exists due to elastic fibres in the dermis
• Skin edges retract when an incision is made along these lines
• Less retraction of wound edges and tension when incision made parallel to them

Question 10

What is the ultimate aim of wound healing?

Answer 10

To restore normal form, structure and function

Question 11

Give the 8 cellular components of wound healing

Answer 11

• Platelets
• Neutrophils
• Monocytes
• Macrophages
• Endothelial cells
• Fibroblasts
• Myofibroblasts
• Keratinocytes

Question 12

Collagen is found in which phase/s of wound healing?

Answer 12

Repair and maturation/remodelling

Question 13

What are the roles of growth factors in wound healing?

Answer 13

• proteins that bind to cell surface receptors

- results in activation of cellular proliferation and/or differentiation

Question 14

What are the roles of cytokines and chemokines in wound healing?

Answer 14

Small signalling proteins secreted by cells

• Cytokines: growth, differentiation and activation functions
• Chemokines: cytokines with a particular chemotactic function

Question 15

What are the 3 phases of wound healing?

Answer 15

• Lag/inflammatory phase
• Repair/proliferative phase
• Remodelling phase

Question 16

What are the characteristics of the inflammatory/lag phase?

Answer 16

• Tissue disruption initiates haemostasis & inflammation
• Transient vasoconstriction: occlusion of injured vessels
• Vasodilation after several minutes: Heat, redness and swelling
• Fibrin seal created: acts as a meshwork
• Platelets aggregate and release chemoattractants, growth factors & proteases
• Removal of wound contaminants and dead tissue

Question 17

Neutrophils are seen at a wound how long after injury?

Answer 17

Within 24-48 hours

Question 18

What is the role of macrophages in the lag phase?

Answer 18

• Debride wound of devitalised collagen and fibrin clots

- Essential for further secretion of signalling molecules

Question 19

What is the Primary leukocyte in the wound at 48-96h?

Answer 19

Macrophage

Question 20

What is the name given to the formation of new blood vessels?

Answer 20

Angiogenesis

Question 21

What are the aims of the proliferative phase of wound healing?

Answer 21

• Permanent wound closure

- Replace lost tisse

Question 22

What are the characteristics of the proliferative phase?

Answer 22

• Angiogenesis
• Fibroplasia and granulation tissue formation
• Epithelialisation
• Contraction

Question 23

The duration of the proliferative phase is dependant on?

Answer 23

Wound size & location, age & health of individual

Question 24

What are the characteristics of the remodelling phase?

Answer 24

• Slow increases in tissue strength up to 80%

- Remodelling and strengthening of collagen - orientation and crosslinking

Question 25

Can wound healing be accelerated?

Answer 25

There is no way to definitively accelerate wound repair

Question 26

Give examples of local factors that can impair wound healing

Answer 26

• wound perfusion
• tissue viability
• wound fluid accumulation
• infection
• movement

Question 27

Give examples of systemic factors that can impair wound healing

Answer 27

• immunology
• oncology
• systemic conditions: obesity, malnutrition, diabetes mellitus
• Thermal injuries

Question 28

What factors need to be discussed with an owner so that can make informed decisions regarding surgery?

Answer 28

• Why surgery is/may be required
• Risks
• Cost
• Aftercare
• Prognosis
• Informed consent

Question 29

How can you prepare yourself before a surgical procedure?

Answer 29

Be aware of your approach, environment, common complications and how to avoid them and what to do when they occur

Question 30

What are the 4 steps of preparing a patient for surgery?

Answer 30

• Preoperative medications
• Clipping
• Aseptic preparation
• Draping

Question 31

What are the 4 steps of preparing a surgeon for surgery?

Answer 31

• Theatre attire
• Scrubbing
• Gowning
• Gloving

Question 32

What are the main 4 postoperative steps?

Answer 32

• Analgesia, antimicrobial and other required medications
• Update the owner
• Recording of surgery and costing
• Appropriate monitoring & recording of postoperative progress

Question 33

What postoperative information needs to be discussed with an owner?

Answer 33

• Ongoing medications
• Timing of rechecks
• What is normal
• When to contact the practice