Surgery - Wounds & Wound Healing

Question 1

What are the four stages of wound healing?

Answer 1

Haemostasis (immediate)
Inflammation (0-3 days)
Proliferation (3 days - 3wks)
Remodelling (3wks - 1yr)

Question 2

Describe haemostasis

Answer 2

Platelets aggregate in response to exposed collagen
-release inflammatory markers
-activate clotting & complement cascade
Haemostasis achieved by vasospasm & thrombus formation

Question 3

Describe inflammation

Answer 3

Vasodilatation & increased capillary permeability (oedema)
Neutrophils enter tissue –> debride & kill bacteria
Macrophages phagocytose debris & ensure fibroblast migration

Question 4

Describe proliferation

Answer 4

Fibroblasts synthesise collagen
Myofibroblasts cause wound contraction
Angiogenesis is stumlated by hypoxia & cytokines
-creates granulation tissue

Question 5

Describe remodelling

Answer 5

Re-orientation/maturation of collagen fibres

-increases wound strength

Question 6

What is granulation tissue?

Answer 6

Combination of capillary loops/myofibroblasts

• small, red foci that bleed easily (capillary loops)
• commonly seen when scab picked

Question 7

What is the purpose of granulation tissue in wound healing?

Answer 7

Capillary loops allow inflammatory cells to enter damaged tissue
-promote defence & healing

Question 8

What are the signs of infected granulation tissue?

Answer 8

Painful discharging
Erythematous
Swollen
Systemic features

Question 9

What is Epithelialisation?

Answer 9

Covering of denuded surface w/ epithelial tissue

-occurs from outer edges of wound after granulation

Question 10

When does healing by primary intention take place?

Answer 10

When there is close apposition of clean wound edges

Question 11

What are the stages of healing by primary intention?

Answer 11

Thrombosis in cut blood vessels prevents haematoma formation
Coagulated blood forms scab to keep wound clean
Fibrin forms weak framework b/w edges
-capillaries proliferate & secrete collagen
Elastic network of dermis cannot be replaced

Question 12

When does healing by secondary intention take place?

Answer 12

When skin edges cannot be clearly opposed

Question 13

What are the stages of healing by secondary intention?

Answer 13

Phagocytosis removes debris
Granulation tissue fills defect
Epithelial regeneration covers surface

Question 14

Which form of healing results in greater loss of tissue?

Answer 14

Healing by secondary intention

Question 15

What factors affect wound healing?

Answer 15

Age 
Diabetes
Nutrition
Smoking
HGH levels
Infection
Inflammatory condition (RA)

Question 16

What are ‘tidy’ wounds?

Answer 16

Lacerations, abrasions, wounds w/ min skin loss

-can be closed primarily if <12hrs old

Question 17

What are ‘untidy’ wounds?

Answer 17

Wounds w/ marginal necrosis, crush injuries or tearing injuries w/ skin loss
-require wound excision w/ removal of debris/dead tissue

Question 18

When is delayed closure indicated?

Answer 18

Wounds >6hrs old OR

Heavily contaminated

Question 19

What is the procedure of delayed closure?

Answer 19

Dressed & inspected daily further from necrosis & inflammation
-closed at 48hrs/72hrs

Question 20

What are the potential complications of abdominal wound closure?

Answer 20

Dehiscence

Herniation

Question 21

What are the important components of abdominal wound closure?

Answer 21

Mass closure (midline incision)
   -continuous fascial closure w/ single suture
   -1cm bites 1cm apart
Layered closure (other abdo incision)
Remove sutures at 10 days

Question 22

What are the signs of inflammation in a wound/around a suture?

Answer 22

Calor (heat)
Rubor (erythema)
Tumour (swelling)
Dolor (pain)
Function laesa (loss of function)

Question 23

What are the management options for an infected surgical wound?

Answer 23

No treatment
Oral/IV antibiotics
Re-intervention on ward/in theatre
   -open
   -drain
   -debride
   -rinse & pack wounds
Cultures