wound management Flashcards
what are the stages of wound healing ?
Inflammatory phase
Debridement phase
Repair
Maturation/remodeling phase
- I Demand Rossies Memorize*
Can more than one phase of wound healing occur at a time ?
yes
what is the lag phase of wound healing?
the first 3-5 days because inflammation and debridement predominate
what phase of wound healing is characterized by the release of cytokines and growth factors ?
inflammatory phase
what are the characteristics of the inflammatory phase ?
- release of growth factors and cytokines
- increased permeability of local blood vessels
- recruitment of circulatory cells
- activation of neutrophils, lymphocytes, fibroblasts and macrophages
what is the first response to any injury ?
hemorrhage
what initiates the debridement phase?
WBCs leaking from blood vessels into wounds
what happens after hemorrhage occurs?
- vasoconstriction
- fibrin clot
- vasodilation
- leukocyte response
- platelets for coagulation
what helps control hemorrhage?
the fibrin clot
how long does vasodilation last?
~ 5 days
what is the order of leukocyte response?
- neutrophils
- macrophages
- T-lymphocytes
how long is the debridement phase?
2-5 days
what is the job of neutrophils in the debridement phase?
prevent infection and phagocytize organisms & debris
how are monocytes stimulated in the debridement phase?
the degeneration of neutrophils releases enzymes that facilitate breakdown of bacteria and extracellular debris and that stimulates monocytes
what leukocyte is essential for wound healing ?
monocytes
- neutrophils and lymphocytes are not essential
what do macrophages do in the debridement phase?
- secrete collagenases
- remove necrotic tissue, bacteria and foreign material
- secrete chemotactic and growth factors
- recruit mesenchymal cells, stimulate angiogenesis & modulate matrix production in wounds
how long does the repair phase last?
5 days to 2-4 weeks
what happens in the repair phase?
- macrophages stimulate fibroblast and DNA proliferation - capillaries infiltrate the wound behind fibroblasts which leads to angiogenesis
- the combo of fibroblasts, new capillaries and fibrous tissue lead to the development of granulation tissue
what does the granulation tissue do?
fills defects and protects wounds
true or false.
granulation tissue is a good barrier to infection.
true
how fast is granulation tissue formed at each wound edge daily?
0.4 to 1 mm/day
what are the special fibroblasts used in wound contraction ?
myofibroblasts
do sutured wounds need granulation tissue to epithelialize?
no, can begin in 24-48 hours because of this
what guides the migration of epithelial cells?
collagen fibers
what is contact inhibition?
contact on all sides with other epithelial cells inhibits further cell migration
does epithelialization occur faster in a dry or moist environment ?
moist environment
true or false.
epithelialization will occur slower in nonviable tissue than in more viable tissue
FALSE, will NOT occur in nonviable tissue
wet to dry bandages debride newly formed epithelium which causes what?
delayed re-epithelialization
true or false.
wound contraction, granulation and epithelialization all occur simultaneously.
true
what is the rate of wound contraction ?
0.6 - 0.8 mm/day
how many days until wounds appear smaller post injury?
5-9 days
when does wound maturation begin?
once adequate levels of collagen are reached
true or false.
scars eventually become as strong as normal tissue.
false, normal tissue strength is never regained
what is the golden period?
within 0-6 hours of wounding, minimal contamination so insufficient microbial replication to cause an infection
what is a class 1 wound?
within 0-6 hours old wound, minimal contamination or tissue damage
what is a class 2 wound?
within 6-12 hours old wound
what is a class 3 wound?
over 12 hours old wound, microbial replication at a critical level allowing infection
what is a primary closure?
- 1st intention healing
- wound is clipped, cleaned and suture closed IMMEDIATELY
- mostly used for class 1 wounds and sometimes class 2
what is a delayed primary closure ?
appositional closure BEFORE granulation tissue develops, done within 3-5 days of wounding
what is secondary closure?
appositional closure AFTER granulation tissue has developed, more than 3-5 days after wounding
what is second intention healing?
healing by contraction/epithelialization
true or false.
second intention healing involves surgery once tissue granulates in.
FALSE, no surgery involved
true or false.
second intention healing is common and uses open wound management.
true
should we complete a PE and stabilize before we close wounds?
yes! treat life threatening problems first
is it okay to use local anesthesia and pain meds for wound evaluation ?
yes, they are painful even if stable
true of false.
placing a protective bandage on all wounds that enter the hospital can help prevent nosocomial infections.
true, truncal wounds may be harder to cover but can secure with tape
when clipping wounds , why is it important to clip a wide area?
there can be extensive bite wounds we may not be able to see under the fur
where should we scrub for wound repair?
around the wound
true or false.
scrub the area around the wound with alcohol before repairing it.
FALSE, NEVER use alcohol on open tissue, it can damage it
true or false.
we can use any kind of chlorohex scrub for the wound
false! there is a cytotoxic and a non-cytotoxic version of chlorohex. The 2% solution is cytotoxic so don’t use that
what is the preferred lavage solution?
sterile isotonic saline or a balanced electrolyte solution (LRS)
what is important to remember if we use antibiotics or antiseptics in the lavage solution ?
we have to dilute them properly, they may damage tissue
why do we lavage wounds instead of using sponges to clean the wounds?
using a sponge to scrub the wound leads to tissue damage and that can effect the ability of the wound to resist infection
what are some examples of lavage solutions?
- LRS
- normal saline - 0.9% NaCl
- 0.05% chlorhexidine solution
- 0.1% povidone-iodine solution
can we use tap water to clean wounds?
its not ideal because it can be cytotoxic, can use in the initial stages of severely contaminated wounds, it is less detrimental than using sterile or distilled water
which should be used around the eye, chlorhexidine or iodine ?
iodine! chlorhex is toxic to cornea
what is the ideal pressure for wound irrigation?
7-8 psi
what equipment should we use to lavage a wound ?
- standard recommendation is a 35 ml syringe with an 18g needle
- 1 L bag with pressure cuff
how can we achieve the gold standard of 7-8 psi while lavaging a wound?
Using a 1 L bag with a pressure cuff at 300 mmHg, using a syringe and needle generates too much pressure
true or false.
minimally contaminated wounds less than 6-8 hours old can be clean and closed without culture or antibiotics.
true
when should we get samples from for a wound culture ?
during initial wound exploration or during initial debridement
- initial debridement is more preferred
what antibiotic can you use to treat wounds empirically ?
amoxi-clav
when should you use fluoroquinolones and aminoglycosides for antibiotics with wounds ?
only if a culture is performed
should we debride wounds we use topical antimicrobials on ?
yes, debridement allows antimicrobial access to the bacteria
what topical antimicrobial is effective against psuedomonas?
silver sulfadiazine
what is a disadvantage of using zinc bacitracin ?
it can retard wound contraction
what are methods of debridement?
- surgical excision
- autolytic mechanisms
- enzymes
- wet to dry bandages
- biosurgical methods
what is a danger of using surgical debridement?
removing an excessive amount of viable tissue
what is layered surgical debridement ?
removing tissue in layers beginning at surface and progressing deeper, can be done with sharp dissection, cautery or laser
what is en bloc surgical debridement?
- entire wound is excised at same time
when can en bloc debridement be used?
when there is sufficient healthy tissue surrounding the wound
what form of debridement is highly selective for devitalized tissue ?
autolytic
what is autolytic debridement?
creation of moist environment to allow endogenous enzymes to dissolve non-viable tissue
what is an example of biosurgical debridement?
using maggots to debride wounds
what is the most common form of debridement ?
layered debridement
when should we delay the closure of a wound?
when there is any question to the level of contamination, potential for deep tissue injury, tissue viability or vascular compromise
you are NEVER wrong to delay the closure of an open wound
what growth factors are produced from macrophages?
- basic fibroblast growth factor (BFGF)
- epidermal growth factor (EGF)
- platelet derived growth factor (PDGF)
- transforming growth factor (TGF)
