Principles of wound healing

Question 1

What are the phases of wound healing

Answer 1

Question 2

Describe phase 1 (haemostasis) of wound healing)

Answer 2

Question 3

Describe phase 2 (inflammatory) of wound healing)

Answer 3

• overlap with haemostasis
• occurs in first 72 hours after injury
• vasodilation (follows transient vasoconstriction during haemostasis)
• cytokines in fibrin clot attract white blood cells
  
  • initially neutrophils & then macrophages
• destruction of cells by phagocytosis helps “clean up” bacteria & devitalised tissue

Question 4

Describe phase 3 (proliferation/repair) of wound healing) part 1

Answer 4

• some overlap with inflammatory phase
• formation of granulation tissue
  
  • formed of macrophages, fibroblasts & new blood vessels (gives it red appearance)
• fibroblasts proliferate & produce new extracellular matrix, elastin & collagen

Question 5

Describe phase 3 (proliferation/repair) of wound healing) part 2

Answer 5

• formation of new epithelial tissue
• myofibroblasts cause wound contraction
• contact inhibition

Question 6

Describe phase 4 (maturation) of wound healing)

Answer 6

• remodelling
• type 3 (immature) collagen replayed by type 1 (mature) collagen
• cross linking of collagen
• change in components of extracellular matrix
• increase in tensile strength
• takes weeks to months

Question 7

What are some factors affecting wound healing

Answer 7

Question 8

What kind of wound is this?

Answer 8

Abrasion
- loss of epidermis and some dermis
- blunt trauma/shearing

Question 9

What kind of wound is this?

Answer 9

Avulsion
- tearing of tissues from attachments
- on limbs - degloving injuries

Question 10

What kind of wound is this?

Answer 10

Incision
- created by sharp object
- minimal trauma

Question 11

What kind of wound is this?

Answer 11

Laceration
- tearing wound creating irregular defect

Question 12

What kind of wound is this?

Answer 12

Puncture
- penetrating wound
- superficial damage may be minimal
- deep damage may be substantial

Question 13

Describe the skin vascular supply

Answer 13

Subdermal plexus
- terminal branches of direct cutaneous arteries
- within panniculus & subcutis
- important to protect during surgery

Question 14

Describe the fundamentals of wound management

Answer 14

First assess patient (other injuries, life-threatening complications, stabilise) and then the wound (consider sedation)

Question 15

What are the steps in wound assessment

Answer 15

Question 16

What is the golden period in wound age

Answer 16

6-8 hours
wound might be contaminated but not yet infected

Question 17

Describe wound lavage & debridement

Answer 17

Syringe & needle used to slightly increase pressure

Question 18

What are the 3 types of wound management

Answer 18

primary intention

second intention healing (takes time)

third intention (secondary closure)

Question 19

What are some factors that influence bacterial contamination of a wound

Answer 19

• vascular supply (reduced ability to fight infection)
• devitalised tissue (increased bacterial growth)
• FB (reduced ability to fight infection)
• type of contamination (soil better than organic debris, clean glass cut vs bite wound)
• type of bacteria

Question 20

What are the goals of wound management?

Answer 20

• promote healing
• convert contaminated into clean
• control infection