Wound Healing

Question 1

What are cytokines?

Answer 1

Small signalling proteins with growth, differentiation and activation functions

Question 2

What is TGF-α and which cells produce it?

Answer 2

Transforming growth factor-α, produced by macrophages, keratinocytes and T-lymphocytes

Question 3

Neutrophils reach a wound after how long?

What do they do?

Answer 3

24-48hrs
Kill bacteria
Usually short-lived

Question 4

What is the function of monocytes at the site of a wound?

When are they present?

Answer 4

Mature to macrophages (TGF-b)
Assist in debriding the wound of devitalised collagen and fibrin clots
Essential for further secretion of signalling molecules
Primary leukocyte in the wound at 48-96 hrs

Question 5

A wound will reach what % of its original strength after 3 months?

Answer 5

80% maximum

Question 6

Give some examples of open and closed wounds

Answer 6

Open: burn, laceration, degloving, puncture, surgical incision
Closed: contusion (bruise), haematoma, hygroma

Question 7

How do abrasions and erosions heal?

Answer 7

Heal primarily by mitotic division. Epithelial cells fill the defect without involvement of inflammatory cells, capillaries or contractile elements.

Question 8

What conditions must be met for a wound to undergo first intention (primary closure) healing?

Answer 8

1. Minimal bacterial contamination
2. All devitalised tissues, foreign bodies and blood clots have been removed through debridement
3. No dead space/haematomas/ischaemia (closure of dead space, ensure good blood supply)

Question 9

What is first intention healing/primary closure?

Answer 9

Wound is closed immediately and completely using strict aseptic technique.
Skin sutures/staples are used to appose wound edges.
Surgery.

Question 10

What is second intention healing?

Answer 10

Occurs when a wound cannot heal by first intention:
-Infection
-Severe soft tissue damage
Regular wound care required: dressings, bandages, debridement

Question 11

What is third intention healing/delayed primary closure?

Answer 11

Wound is treated initially as an open wound
-Allows tissue debridement
-Reduces bacterial contamination
Wound is then closed and allowed to heal by primary intention

Question 12

When are skin sutures removed after surgery?

Answer 12

10-14 days

Question 13

Give some factors that may affect wound healing

Answer 13

Reduced wound O2 tension (hypovolaemia)
Metabolic disease (uraemia)
Iatrogenic factors (corticosteroids, cytotoxic/radiation therapy, antiseptics)
Infection
Insufficient macro/micro nutrients (zinc and vitamin C deficiency)
Dehydration of wound surface

Question 14

What is the purpose of non-adherent dressings?

Answer 14

Aim to allow excess exudate to drain while keeping wound moist

Question 15

When would calcium anginate (non-adherent) dressings be used?
How long are they used for? How are they removed?

Answer 15

Indicated for non-infected wounds with moderate to heavy exudation
Applied for up to 7 days then removed by lavage

Question 16

Why are silver dressings used as primary (adherent) dressing layers?

Answer 16

Release silver ions into the wound bed, which are bacteriocidal against a range of pathogens

Question 17

Give the functions of the secondary dressing layer

Answer 17

Absorbs excess fluid from wound
Secures primary layer 
Obliterates dead space 
Protects wound 
Eg softban

Question 18

Give the functions of the tertiary dressing layer

Answer 18

Secures rest of dressing
Keeps dressing clean and dry
Ensures not too tight

Question 19

When would you choose a non-adherent dressing?

Answer 19

For wounds in the repair phase, when a healthy granulation bed has developed

Question 20

What are growth factors?

Answer 20

Proteins that bind to cell surface receptors

Results in activation of cellular proliferation and/or differentiation