Small Animal Wounds: Initial Approach Flashcards
what are the 3 stages of wound healing
- inflammatory stage
- debridement stage
- maturation stage
what occurs in the repair stage
granulation tissue forms
what occurs in the maturation stage
wound contraction, remodelling
what stages are managed with dressings
inflammatory, debridement, repair
what occurs in the inflammation stage
- hemorrhage + clot formation: scaffold for repair
- increase blood flow: increase oxygenation, source of inflammatory cells
what are the cells in the inflammatory stage
neutrophils which control the bacteria infection by phagocytosis
die and sit in the wound as dead white cells
what occurs in the debridement stage
- the neutrophils phagocytose bacteria and then die
- macrophage stakes over
- exudate
what is the major cell type of the debridement stage
macrophages
what are the functions of macrophages in the debridement stage (3)
- phagocytosis of debris
- proteases digest protein debris
- release cytokines to drive the cellular response
what is the exudate made up of in the debridement stage
sloughing of tissue, cells (dead neutrophils) and bacteria
what occurs in the repair stage (2)
- granulation tissue forms
- epithelialization
how does granulation tissue form (3)
- macrophages promote fibroplasia and angiogenesis
- vessels migrate into fibrin clot
- collagen matrix is laid down
how does epithelialization occur
migration between eschar and granulation tissue
why is granulation tissue important
framework for wound to epithelialize
reorganizes to increase wound strength and contraction
what is healthy granulation tissue
- highly resistant to infection
- lattice for scar formation
- nutrient and oxygen supply –> red, flat, epithelializing
what is unhealthy granulation tissue
- pale
- not progressing
- usually due to necrotic debris or infection
what factors promote epithelialization
- absence of infection
- absence of necrotic debris
- oxygen at wound surface (vessels)
- moist wound environment
- healthy granulation bed
what is the maturation phase (3)
- scar contracts
- collagen remodels increasing strength
- continues for weeks and months
what are local factors that impede wound healing
- foreign material in wound
- infection (including infected biofilm)
- surface trauma (inadequate bandaging)
- desiccation (failure to keep wound covered)
what are host factors that can delay healing (5)
- debility (geriatric patient)
- endocrine disease: cushings, diabetes mellitus
- metabolic disease: uremia
- hypoalbuminemia
- exogenous steroids
what things can be done to promote wound healing (5)
- removal of non-viable tissue (debride)
- control infection
- promote good blood supply
- maintain moist surface (keep covered)
- prevent surface trauma (dress properly)
what is the endpoint of initial wound management
granulation tissue with epithelialization
what is primary wound closure
immediate closure of healthy wounds (free of necrotic debris, free of infection)
ex. surgical wounds, some traumatic wounds (<6 hours)
what is delayed primary closure
ex. dog bite injury
closure after bacteria and debris have been eliminated but before granulation starts
what is secondary closure
closure once granulation tissue has formed
healthy granulation implies no infection or necrotic debris
ex. degloving injuries
what is second intention helaing
granulation, epithelialization and contraction
what are examples of open wound management
traumatic, contaminated wound not suitable for primary closure
so manage to the point of granulation formation, then close the wound in any way you want
what is phase 1 of open wound management
initial assessment and preparation
debridement
what is phase 2 of open wound management
encouraging active granulation
what are the 3 layers of bandages
- contact layer
- intermediary
- tertiary
what is the purpose of contact layer
controls wound environment
what is the intermediary layer
pads to prevent trauma and absorbs excess fluid
what is tertiary layer
secures dressing in place
what is the difference between adherent and non-adherent layer
adherent: debrides wound surface, used in initial stages, speeds debridement phase
non-adherent: protects surface, promotes granulation, cover surgical wounds
what is the difference between adherent and adhesive layers
many non-adherent dressings have an adhesive backing to stick to skin
these adhesives are inactivated by moisture so the dressing doesn’t adhere to the wound surface
how do you prevent further contamination of the wound (3)
- use clean or aseptic technique
- cover wound with sterile dressing
- clip widely –> pack wound sterile KY jelly to trap hair
how else can you remove contaminants from the wound
lavage with sterile saline/isotonic crystalloid
moderate pressure
how is the initial debridement done
sharp dissection and scraping with the blade
rub with dry swab
what tissue should you remove when debriding
- devitalized tissue
- contaminated tissue
- redundant compromised tissue
how does debridement help the wound
speeds up the inflammatory phase
what is devitalized tissue
white, green, black
doesn’t bleed when nicked
loss of skin pliability
thinning of skin
what is the best method for debriding
sharp (scapel) because it causes the least secondary injury
what are wet to dry dressings
rarely used as causes injury
adheres to wound over 12-24 hours
rips top layer of wound away
is on-going debridement necessary
active debridement causes injury
initial is good to remove detritus and dead tissue
on-going can be counterproductive
dressings encouring granulation promote sloughing of tissue
what are the aims of dressings (5)
- non-adherent contact layer
- moist wound environment
- no surface trauma
- promotes granulation formation
- initiate epithelialization
what are foam dressings
absorbent, non-adherent, semi-occlusive keeps wound moist
promote granulation
what is hydrogel
fits irregular wounds well and maintain moisture and encourage natural sloughing
what is the funciton of the intermediary layer
hold contact layer in place
absorb exudate passing through the contact layer
provide padding and support
what is the purpose of the tertiary layer
hold intermediary layer in place
protect from environment contamination
apply pressure to dressing
how would you apply dressing to a difficult area
tie-over bolus: suture anchor loops in skin, apply dressing, weave tape through suture anchors
when are antibiotics indicated
most traumatic or open wounds intially
what are topical wound dressings
- silver dressings
- manuka honey
- hydrochlorous acid
- PHMB/betaine
why are silver dressings used
bactericidal
what are manuka honey dressings used (5)
- antibacterial
- encourage sloughing
- moist wound environment
- osmotic effect
- accelerate wound healing
why should the biofilm reduction be a priority
organized matrix by bacteria that coats wounds
delayed healing
what products can be used to manage the biofilm
- hypochlorous acid: disinfectant
- PHMB/betaine: betaine disrupts the biofim, PHMB kills bacteria
what are wet-to-dry dressing
adherent dressing
how long are wet-to-dry dressings left on
48-72 hours
when are wet-to-dry dressings used
when wound is exudative
what is the contact layer of wet-to-dry dressings
moistened swabs ideal
what are the secondary layer in wet-to-dry dressings
swabs
dry, sterile, absorbent
how do you change a wet-to-dry dressing
don’t moisten or will lose adherent action
painful so anesthesia
causes trauma and bleeding
how often do you change wet-to-dry dressings
every 24 hours
typically 12-24 hours
before dressing is saturated and before strike through
