Wounds 3 - wound healing

What is the term used to describe natural healing?

Primary intention

What wounds are usually healed by primary intention?

Clean surgical wounds, recent traumatic wounds, minor injuries that have been stitched/glued

What is an example of a wound allowed to heal by primary intention?

Very pink wound due to increase in vascular epithelia production, sealed, sterile environment

What is the first stage in healing by primary intention?

• Acute inflammation within a few mins of injury and lasts 3 days

• Platelets flow into wound and thromboplastin liberated

• Vasodilation results in serum release into wound

• Plasma release increases capillary permeability and serum released into the wound

• Serum contains neutrophils and macrophages which clean the wound

What cells are responsible for synthesising collagen in wounds?

Fibroblasts

What are the steps in stage 2 of healing by primary intention?

• Fibroblasts synthesise collagen

• Scabs form within a few hours from WBCs and collagen and sits on top, forming a seal

• Within 2-3 days epithelial cells grow across the wound under the scab

• Healing completes within 2-3 weeks and full epithelsiation occurs

What process does healing by primary intention mimic?

Epithelisation

What is the term to describe the healing used when the wound is too large or dirty for closure?

Secondary intention

What is used to treat a healing environment in secondary intention?

Dressings

What are the 4 stages in secondary intention?

Necrosis (not always there), granulation, vascularisation, epithelisation

What wounds are healed by secondary intention?

Debicutous ulcers, large wounds/dirty wounds

What is the term to describe dead tissue?

Necrosis

What is the term to describe dry, necrotic tissue that is hard and black?

Eschar

What is the term used to describe wet necrotic tissue that is slimy, yellow and looks like it can be lifted out but is stuck down?

Slough

What must happen to necrotic tissue to allow healing to occur?

Must be debrided/removed

What is an example of necrotic tissue in a diabetic foot?

Eshar = fully black, slough in the middle of the wound, has clean edges so may be beginning to heal

What is the term to describe the formation of a new tissue bed?

Granulation

What are the steps that occur in granulation?

• Inflammation

• Infiltration with erythrocytes, leukocytes and platelets

• Endothelial cells appear as capillary beds and appear pink/speccled

• Growth factors generated with promote capillary formation

What is the term to describe a wound being wet for too long/too much moisture that leads to skin breakdown?

Maceration

What is a diagram to show granulation occurring?

Red tissue here is good as it shows it is healthy, macerated white tissue around the outside is an issue though

When does epithelialisation occur?

Once the wound cavity has filled with granulation tissue

What happens in epithelisation?

Epithelium around wound edges become activate and begins to grow across the wound, begins to contract noticeably and will eventually meet at a point

What is a diagram to show epithelialisation?

Epithelial starts to migrate, light pink wound

What is the term to describe the growth of skin cells over a wound as the final stage of healing by secondary intention?

Epithelialisation

What is the term to describe the fluid that leaks out of vessels during inflammation of wound healing?

Exudate