wound healing Flashcards
in what order do cells arrive at wound
PMNs, Macrophages, Lymphocytes, Fibroblasts
which growth factor can be applied medically?
PDGF
what grows during the proliferative phase of healing
provisional matrix of fibrin, angiogenesis driven by hypoxia, collagen depostion in final matrix
what happens to collagen composition during remodeling phase
content levels off. Continues to be synthesis and degradation
rate of epithelialization depends largely on ___. Occurs starting at ___
health of underlying tissue (healthy dermal bed). Always heal from edges
three main causes of scar
tension, inflammation (elderly=prettier scars), genetics (AA-keloid, Asian-hypertrophic scar
hypertrophic scar vs keloid
hypertrophic- never extends beyond original borders, Keloid- grows beyond boundaries
what can be done in surgery to prevent scarring
avoid cautery, careful with forceps, proper sutur
how is open wound healing different?
spatial separation of events: leading edge has inflamm, behind is proliferation, behind is scar and remodeling
where is wound contraction more likely
loose-skinned areas (not lower extremities)
four most likely causes of problem wounds
age, ischemia, eschemia-reperfusion injury, colonization (BIOFILM)
affect of aging on healing
less inflammation makes it more difficult to heal. decreased proliferation. Decreased ability to survive stressors like hypoxia and toxins. weaker scars due to less collagen
Can most old people heal most wounds
yes. Aging shows up when ischemia or infection is superimposed on injury
How do you ensure maximal perfusion of wound and why
wounds are always hypoxic. elevate to avoid edema, offload, debride, pain control, stay warm
best way to avoid reperfusion injury
offloading
area of tissue supplied by a given artery
angiosome
bioburden
sum of metabolic demand placed on wound by bacteria
How does biofilm affect healing? How long does it take to develop
freezes wound healing progress in state of low grade inflammation. As little as a day
how does amount of exudate change management
you have to select dressing that will keep wound moist but not too moist.
why do diabetic foot wounds not heal. What can help?
decreased compensatory angiogenesis. (less VEGF, eNOS). Offloading is essential
VAC or Negative pressure wound therapy: uses
to decrease edema, to improve perfusion, remove exudae, bring wound together. NOT to fully close wound
what can be used for broad-specturm antimicrobial stuff
silver
