wound healing and reconstruction Flashcards
what is an abrasion
- loss of epidermis and maybe some dermis
- not full tickness
- due to blunt trauma/shearing
what is an avulsion
- tearing of tissues from attachments but usually left as flap
- on limbs: degloving
what is an incision
- Created by a sharp object
- minimal trauma
- all surgical wounds
what is a laceration
- similar to incision but not controlled
- tearing of wound creating irregular defect
what is a puncture
- penetrating wound
- superficial damage may be minimal
- deep damage may be substantial (organs etc.)
what type of wound is this
abrasion
what type of wound is this
avulsion/laceration
what type of wounds are these
incisions
what type of wound is this
puncture
discuss vascular supply of the skin
- 3 layers of supply to all 3 layers of skin (deep, middle and superficial
- subdermal plexus is major netwrok supplying blood from direct cutaneous artery
- direct cutaneous artery branches off to supply skin
- if cut, patch of skin it was feeding will die
what are the 3 phases of wound healing
- inflammation/hemostasis
- fibroplasia
- maturation
what occurs during the inflammatory phase of wound healing and how can you tell you are looking at a wound in this phase
- transient vasoconstriction (prevet bleeding out) then vasodilation (to get as many clotting factors and inflam cells as possible to site)
- increased capillary permeability
- activation of intrinsic and extrinsic clotting cascade
- chemotaxis of inflammatory cells
- neutrophils called to site followed by macrophages (macros send signals for more cells to accumulate)
can tell: fresh blood, fresh edges, no granulation tissue
what occurs during the repair phase and how can you identify that you are looking at a wound in this stage
- fibroplasia
- cessation of inflammatory phase
- fibroblast migration (contact inhibition = cells meet eachother and signal to stop spreading and production of proteoglycans, collagen and elastin)
- wound contractions
- epithelialisation
Can tell: granulation tissue and pink epithelisation around edges
what occurs in the maturation/remodelling phase and how can you tell you are looking at a wound in this phase
- matrix synthesis and matrix degradation
- cross linking of collagen type 1 and 3
- inrease in tensile strength
- scar formation
- takes weeks to months
can tell: dry scab, no visible granulation tissue (or very little), scar
what species has slower wound healing
cats: granulation tissue forms slower and wound strength therefore less at same healing timeperiods
list systemic factors that negatively impact wound healing
- old age
- medications (steroids)
- radiation
- co-morbidities (cushings and diabetes)
- nutrition
list local factors that negatively affect wound healing
- seroma
- neoplasia
- foreign material
- self trauma
- necrostic tissue
- contamination infection
you are presented with a patient with a wound. what will you do first
assess the patient for other injuries
- always stabilise patient first, dont miss something more traumatic inside that can kill the patient by being distracted by the wound!!!
- TPR, imaging, bloodwork, history,
what things will you look for when assessing a wound
- level of contamination (soil/organic material within?)
- type of tissue affected (just skin? muscle? bone? tendon?)
- vascular compromise (are the tissues viable)
- foreign material (hair and sutures)
most animal wounds are contaminated. how do you distinguish contaminationf from infection
for a wound to be infected, the bacterial must be present in large amounts for period of time. contamination is considered as bacteria where it doesnt belong. it takes 6-12 hours for bacteria to divide and more than 12 hours for bacteria to invade the tissue
what factors influence bacterial contamination of a wound
- vascular supply (reduced ability to fight infection)
- devitalised tissue (increased bacteria growth)
- foreign body (reduced ability to fight infection)
- type of contamination (bite vs cut from glass?)
- type of bacteria
what are the goals of wound management
- promote healing
- convert contaminated into “clean”
- control infection
what are the principles of wound management
- clip hair to protect wound
- debride wound
- antimicrobial therapy
- open vs closed healing
discuss wound levage
- purpose to dilute bacteria and flush out FB
- encourages healing
- isotonic solutions are best (can use water but could kill good cells)
- always culture AFTER levage
what concentrations of chlorohexidine and iodine are appropriate for flushing wounds
- chlorohexidine 0.05%
- iondine 0.1-0.01%
how do you prepare a wet to dry dressing and what is its purpose
- moisten sterile swabs with sterile isotonic solution
- remove excess fluids
- place directly onto wound
- layer with dry sterile swabs
- debridement occurs by osmosis and the contaminated material will be drawn up toward dry gauze
- change daily until reach repair stage
what is a tie over bolus
- useful for hard to dress areas
- loop stay sutures around wound (nylon)
- umbilical tape criss crosses over gauze
what is primary closure
- immediate suture
- clean or clean-contaminated only
what is delayed primary closure
- clean-contaminated to contaminated wounds
- reduces incidence of infection
- closure after 3-5 days of wound management
what is secondary intention healing and what are the advantages/disadvantages
- no skin closure, leave wound and manage with bandages to heal on its own
- advantages: optimum wound drainage, local infection control and cheap
- disadvantages: poor cosmetic results, poor functional results if in a functional area, timely, results in thinner, fragile skin
what is proud flesh
exuberant (overgrowth) of granulation tissue
- particularly issue in horses
- must be cut off as will prevent epithelium from making contact
what are the advantages of a surgical drain
- remove fluid accumulation
- eliminate dead space
- increase healing capacity
- reduce tension from seroma formation
what are the disadvantages of surgical drains
- introduction of FB
- introduction of infection
- seroma always better than abscess!
list types of drains
- passive: penrose
- active:
what is the ideal healing envionment for advanced wound care
- a moist environment that isnt macerated
- free of infection and excessive debris
- free of toxic chemicals, particles or fibres
- warm - at the optimum temperature for healing
- leave new tissue undistrubed (minimise frequency of dressing changes)
- allow for adequate gas exchange
- dressing should be painless to apply and remove
- dressings should minimise contamination both to and from the wound
give examples of dressing that absorb moisture
- wet to dry
- alginates (made from seaweed)
- foam dressings (can also be used for dry wounds)
- hydrocolloid dressings (can also use on dry wounds)
what dressings maintain moisture
- hydrogels
- blister plaster
what are the principles of wound closure
- know your anatomy
- have a plan A, B and C
- always have good client communication
- clip and prepare larger area than anticipated
what are the issues with wound tension
- circulatory compromise
- reduced wound healing
- infection
- dehiscence
- skin necrosis
how do you minimise wound tension
- patient positioning
- undermining
- suture patterns
- relaxing incision
- advancement flaps
- techniques that provide additional skin
what is skin undermining and its benefits? how is it performed
- using blunt tipped metzenbaum scissors (or scalpel if scar tissue), blunt dissect under skin
- preserve direct cutaneous artery if possible
- gives you extra space to work with
what are walking sutures
- used after skin is undermined
- method of distributing skin tension
- method of advancing skins
- in areas where undermining and suture closure is sufficient for closure
- skin pulled forward in increments (great cumulative effect of multiple)
what are relaxing incisions
- either single or multiple incisions on either or one side of the wound to reduce tension
- enables the primary wound to be closed
- heal by secondary intention
what is a skin flap
- a section of skin elevated (usually local to the wound) and moved into the wound for coverage
- a skin flap retains its own blood supply
- as long as there is availible skin, a skin flap can be used anywhere
- 2 types: subdermal (random) plexus flap (may or may not include direct cutaneous artery) and axial pattern flap (will always include a direct cutaneous artery)
list complications of skin flaps
- partial thickness necrosis
- full thickness necrosis
- desensitisation and self trauma
