Wound healing

Question 1

When does healing by primary intention occur?

Answer 1

Wounds with dermal edges that are close together (e.g. scalpel incision)

Question 2

What are the four stages of healing by primary intention?

Answer 2

Haemostasis (platelets and cytokines action forms a haematoma and causes vasoconstriction)

Inflammation (to remove any cell debris and pathogens)

Proliferation (cytokines drive proliferation of fibroblasts and formulation of granulation tissue)

Remodelling (collagen fibres deposited in wound to provide strength in region)

Question 3

What may happen wound is sutured too tightly?

Answer 3

Blood supply = compromised leading to tissue necrosis and wound breakdown

Question 4

What is healing by secondary intention?

Answer 4

Sides of wound are not opposed - healing must occur from bottom of wound upwards

Question 5

What are the four stages of healing by secondary intention?

Answer 5

Haemostasis = large fibrin mesh forms, filling wound

Inflammation = to remove cell debris (larger amount than in primary)

Proliferation = Granulation tissue at the bottom of the wound (grows up to the level of original epithelium - then epithelia can cover the wound)

Remodelling = wound contraction can occur

Question 6

Which cells are vital in secondary intention?

Answer 6

Myofibroblasts (modified smooth muscle cells - can contract)

Question 7

Which factors affect wound healing?

Answer 7

Local blood supply

Infection

Foreign material

Radiation damage

Increasing age

Co-morbidities (DM)

Nutritional deficiencies (especially vit C)

Obesity

Question 8

What are the basic principles for management of a wound?

Answer 8

Haemostasis (spontaneous / pressure, elevation, tourniquet, suturing)

Cleaning the wound (disinfect around wound with antiseptic, manually remove any foreign bodies, debride any devitalised tissue, irrigate wound with saline, abx doe signs of infection)

Analgesia (local anaesthetic and paracetamol - max level of lidocaine is 3mg/kg)

Skin closure (adhesive strips e.g. steri-strip, tissue adhesive glue e.g. indermil, sutures if greater than 5cm long or on locations prone to flexion, tension or wetting, staples for scalp wounds)

Dressing and follow-up advice (first layer of non-adherent e.g. saline-soaked gauze, followed by absorbent layer, followed by soft gauze tape to secure in place)

Question 9

What are some risk factors for wound infection?

Answer 9

Foreign body present

Heavily soiled wounds

Bites

Open fractures

Question 10

What prophylaxis may be needed in wounds?

Answer 10

Tetanus

Question 11

What advise after wound management?

Answer 11

Medical attention for signs of infection

Simple analgesia e.g. paracetamol

Keep wound as dry as possible