Wound Healing Flashcards
What is the number 1 thing to do in wound healing?
Stabilize the patient
What are 3 common ways to control bleeding?
Bandage Clamp Ligate
What is the protocol for tetanus prophylaxis?
If vaccination hx: Tetanus toxoid If no vaccination hx: Tetanus toxoid AND Tetanus antitoxin
Why is sedation and a local block preferred in large animal?
Because GA is risky
What is the most commonly isolated bacteria in horses?
Strep
What NSAIDs do we not use in bovine, and why?
Phenylbutazone and aminoglycosides because they have a long residual.
What are the two common NSAIDs used in equine medicine?
Phenylbutazone and Banamine (Flunixin megalumine)
What is a clean wound?
Sterile incision
What is a clean/contaminated wound?
Surgical wound where hollow viscous is opened, but no contents spill out
What is a contaminated wound?
Opened hollow viscous with gross spillage.
What is an infected wound?
Has pus
What is the “golden period”?
Time after wound occurs where it can be closed with first intention.
How long is the golden period?
4-6 hours post injury
What is healing by primary intention?
Healing without fibroplasia (no scar) via suturing the wound.
Why do we give thiamine post-op?
To prevent polioencephalomalacia.
What are 3 major downsides to abx if they’re not needed?
Resistance, Cost, Kidney failure
What is a good suture patter for equine skin?
Vertical mattress because there is lots of tension.
When handling a wound, what are the first three steps (AFTER stabilizing the patient)?
Pack the wound Clip the area Lavage
When does debridement by the animal occur?
6 hours after wounding
What is delayed primary intention healing?
Delayed closure of a contaminated wound. Wound is left open until infection is under control, and then closure after 2-3 days (BEFORE fibroplasia begins)
What is second intention healing?
Wound heals via fibroplasia, contraction and epithelialization
What type of skin heals slower?
Tight skin
What is the goal of second intention healing?
To provide an optimal environment for wound healing
What are 2 ways we can stimulate granulation tissue?
Hydrotherapy (using a hose) Moist and irritant dressings
What 4 things does cold hydrotherapy cause?
Vasoconstriction Decreased metabolism Cutaneous anesthesia Cell death
What 3 things can heat hydrotherapy cause?
Vasodilation Increased metabolism Decreased pain
What are 4 inhibitors of granulation tissue?
Pressure Dry dressing Corticosteroid cream Caustic agents
What is the period of fibroplasia?
Days 4-16
What is wound contraction?
Wound edges pulled closer together to facilitate closure.
How long is the lag period in wound contraction?
Up to 9 days
What are 3 steps of epithelialization?
Mobilization Migration Mitosis
How is wound closure completed when healing by second intention?
Closure completed by epithelialization ONLY once contraction has stopped.
What are two differences between large and small animal wound healing?
Exuberant granulation tissue (pretty much only in equine) Slow healing on distal limbs
What causes exuberant granulation tissue/proud flesh?
Slow contraction and epithelialization dont cover the granulation tissue fast enough to stop it.
What are 3 major problems with proud flesh?
Cosmetically unappealing Can be heavy and cause lameness Bleed a lot if they get hit (very vascular)
What are the only two mammals to develop proudflesh?
Humans and equines
What promotes the formation of exuberant granulation tissue?
Treatment which arrests wound contraction and epithelialization
What is the number one reason to do skin grafting in large animals?
Proud flesh
How do you figure out blood volume of a horse?
8%BW (kgs) = blood volume in liters
Why must you thoroughly examine a heel bulb laceration?
Because you need to know if there is joint involvement.
What are 2 ways you can assess if there is joint involvement with a heel bulb laceration?
Arthrocentesis to look for WBCs and bacteria Inject saline, will either leak out (bad) or will not be able to put much in (good).
What is the prognosis with a heel bulb laceration?
If only skin and SQ, good prognosis If joint involved, guarded to poor
What is third intention wound healing?
You undermine the skin around the wound and then suture it closed.
What is the difference between delayed primary and third intention closure?
Third intention has fibroplasia
What is the purpose of a skin graft?
To provide dermal coverage and to stimulate epithelial edges of the wound to minimize risk of proud flesh.
What is a split thickness graft?
Portion of the dermis
What is a full thickness graft?
Epidermis plus dermis
What thickness of graft is ideal to use in a horse?
Full thickness (best cosmetic and hair growth)
What is a disadvantage of skin grafts on a horse?
Not a lot of donor skin.
What is a free graft?
No blood supply **Used in equine
What are 3 advantages of doing a pinch/punch graft?
Can do standing Equipment and skills are minimal Complete graft failure is rare
What is a disadvantage of a pinch/punch graft?
Scat hair growth (cosmetic)
What is a disadvantage of a sheet graft?
Must be done in a surgical theater with GA
What are the 3 donor sites for a pinch/punch graft?
Neck Ventral abdomen Pectoral region
What are 3 advantages of doing a mesh graft?
Small amount of skin can cover a larger surface Can cover awkward areas Allows for better drainage to prevent seromas/hematomas
What procedure is this?
Punch graft
What is going on here?
Punch graft
What is going on here and what equipment is being used?
Meshing with a dermatome.
What are 3 ways you can evaluate intenstinal viability in a case of eviceration?
Colour
Spontaneous motility
Thickness
What are 3 ancillary methods for determining intestinal viability in a case of evisceration? (6 total)
Fluorescein dye
Doppler
Ultrasound
Thermography
Histology
Surface oximetry
How much of the small intestine can be resected?
50%
