Wound Healing Flashcards
what are the stages of wound healing
Inflammation (0-3 days)
Vasodilatation and increased capillary permeability allow inflammatory cells
to enter the wound, leading to oedema.
Neutrophils enter the tissues to debride and kill bacteria, followed by
macrophages to phagocytose the debris and orchestrate fibroblast migration
Proliferation (3 days - 3 weeks)
Fibroblasts migrate in to synthesise collagen, with myofibroblasts secreting
actin-containing products to cause wound contraction.
Angiogenesis is stimulated by hypoxia, and also the cytokines secreted by
neutrophils and macrophages. This creates granulation tissue
Remodelling (3 weeks to 1 year)
Re-orientation and maturation of collagen fibres to increase wound strength.
what is granulation tissue
combination of capillary loops and myofibroblasts which allows infiltration of inflammatory cells to promote healing
what is primary intention healing
where there is close apposition of clean wound edges
thrombosis in blood vessels prevents haematoma formation
coagulated blood forms a suface scab to keep the wound clean
fibrin frameworks are extended over which capillaries proliferate and secrete collagen into the fibrin network
elastic network of the dermis cant be replaced
what is secondary intention healing
takes place in wounds where the skin edges cannot be clearly opposed
phagocytosis clears the wound and granulation tissue fills the deficit
epithelial regeneration covers the surface
there is a greater loss of tissue
what are factors that affect wound healing
age diabetes nutrition smoking HGH levels infection inflammatory conditions - e.g. RA
when can you close a wound
tidy wounds (minimal skin loss) can be closed within 12 hours
what is delayed closure of a wound and when it is indicated
Delayed closure is indicated if the wound is untidy (large skin loss,necrosis or crush injuries) they are more than six hours old or heavily
contaminated, where the wound will be dressed and inspected daily for further
necrosis or inflammation.
The wound will then be closed at 48-72 hours if it is
satisfactory.
what are the typical indications of inflammation
Calor (heat)
Rubor (erythema)
Tumour (swelling)
Dolor {pain)
Function laesa (loss of function)how should you manage an infected surgical wound
Depending on the severity of the wound infection, the patient may need no
treatment, oral / IV antibiotics alone, or re-intervention on the ward / in theatre to
open, drain, debride, rinse and pack the wound. Cultures are always recommended.
