10/4 Wound Healing
debridement
-removal of foreign material and dead or contaminated tissue from and around a traumatic or infected lesion in order to expose healthy tissue and optimize healing 2 step approach 1. initial phase-removing burden of necrotic tissue (surgery) 2. maintenance phase- keep the wound free of necrotic tissue (dressing,enzymes, etc.)
surgical factors that affect wound healing
-the length and direction of the incision -dissection technique -tissue handling -hemostasis -maintaining moisture in tissue -removal of necrotic tissue and foreign materials
inflammatory phase
1-4 days post injury clinical inflammation, presents as erythema, swelling and warmth often associated with pain, the classic signs of inflammation: pain, heat, redness, tumor, and loss of function
4 phase of wound healing
1. hemostasis (clotting with fibrin and platelets) 2. inflammation (all the cells come in with growth factors to promote cell growth) 3. proliferative phase that will involve blood cells (fibroblasts, collagen, epithelial cells and endothelial cells) 4. finally, tensile strength is provided by collagen.
abrasions
1st degree burns- the skin peels off leaving abrasive skin. Very important to rub/brush the wound to prevent traumatic tattooing by dirt and gravel
Avulsion
Atrial avulsions/partial avulsions total-tissue is completely torn from teh body with no point of attachment partial- when the torn tissues are still well vascularized and viable, the tissue is gently cleansed and irrigated and the flap is reattached to its anatomical position with a few sutures.
contusions
BRUISE
Hemostasis: the fibrin clot
We need to kick start the wound closure process
4 types of things that can happen after tissue injury
acute wounds: can repair themselves or can be repaired in an orderly and timly process chronic wound: when the body does not progress accordingly and can not repair themselves (wound is present for more than 30 days...ex. pressure ulcers, venous stasis ulcers, diabetic foot ulcers)
remodeling phase
around thirty days, you see the tensile strength start to go up. remodelling occurs even when the wound is closed. Around day 45...you have about 85 percent of the previous tensile strength.
exudate of chronic wounds
compression continues to be one the more common methods of exudate management negative pressure devices and vacuum-assisted devices, are now being used to improve wound healing drains- are important in preventing exudate from accumulating in wound site.
biofilms
dense communities of bacteria commonly adherent to a surface or each other, are now recognized as significant contributor to wound infections
myofibroblast
fibroblast like cells within the granulation tissue that eventually exhibit features of smooth muscle cells such as actin filament bundles these cells ae responsible for force generation and their presence is a general feature of tissues undergoing contraction
inflammation is shorter if it's a primary intention vs. secondary in wounds closed by secondary or teritary intention, continues until epithelialization is complete
have a nice day
5 types of wounds
laceration abrasions contusion avulsion puncture
diabetic wounds have impaired efferocytosis
meaning they can't clear the apoptotic cells
How do we kick start the wound closure process
the cocktail of growth factors released from platelet degranuation kick starts the wound closure process -it provides chemotactic cues to recruit circulating inflammatory cells to the wound site (MCP-1 and IL-8) -initiates the tissue movements of reepithelialization and connective tissue contractions (KGP) -stimulates the characteristics wound angiogenic response (VEGF)
how wounds heal primary intention secondary intention third intentions
third intention (tertiary wound healing or delayed primary closure) -often used for infected wounds where bacterial count contraindicates primary closure -wound edges are approximated within 3-4 days and tensile strength develops as with primary closure.
4 types of chronic wounds
venous ulcers arterial ulcers diabetic ulcers pressure ulcers