Equine wounds Flashcards
Classification of wounds
a) Mechanical injuries
b) Thermal injuries
c) Chemical injuries
a)
- Most common
- Grazes, abrasions, erosions
- Bruising, hematomas, contusions
- Puncture/penetrating wounds
- Lacerations/incised wounds
b)
- Rare
- Thermal burns
- Friction rubs
c)
- Acids: cause coagulation necrosis and protein precipitation
- Alkalis: cause liquefaction necrosis
Classification of wounds
a) Clean
b) Clean contaminated
c) Contaminated
d) Dirty
a)
- Elective/Surgical wounds created under aseptic conditions, primarily closed
- No break in technique or dirty space entered
b)
- GI, respiratory or urogenital tract (without urinary
infection) entered without significant contamination
- Or minor break in aseptic technique
c)
- Traumatic wounds = always contaminated
- elective procedure with major break in aeptic technique
d)
- > 1x10^5 bacteria
- Traumatic wound with devitalized tissues, FB, feces, chronic wound
Stages of wound healing
a) Inflammatory/debridement
b) Proliferative repair
c) Maturation/remodelling
a)
- haemostasis/acute inflammation
- Immediate, lasts days to weeks
- Neutrophils (remove damaged tissue and chemo attractants) and Macrophages (release O2 radicals, cytokines, tissue growth factors)
b)
- tissue formation
- day 3-14+
- angiogenesis, fibrous and granulation tissue formation
- collagen deposition
- epithelialisation
c)
- strengthening tissue
- ends in formation of scar tissue
Control of haemorrhage
- Horse can use ~5L without any real problems
- Pressure bandage
- Pressure with swab/hand
- Topical haemostatic agent
Preparing the wound
- Clip around area
- Clean/lavage with large volumes, moderate pressure (do not use soap solutions)
- Can use local anaesthetic directly on wound to desensitise
- use sterile gloves to palpate
- debride necrotic tissue, but any tissue that may be viable should be left
Wound closure
a) Primary closure
b) Delayed primary closure
c) Delayed secondary closure
a)
- clean wounds with minimal contamination
- minimal tissue loss
- best cosmetic result
b)
- up to 5 days, gives more time for contamination removal
- lavage and dress daily until healthy granulation bed present, then close
c)
- rarely performed due to lack of elasticity of skin
Second intention healing
- very common
- especially if contaminated tissue or large skin defects
- granulation then epithelialisation, wound will be exudative
- multiple bandage changes
Suture material used on equine skin
- prolene is least reactive, most commonly used
- can also use nylon, PDS, vicryl
- consider absorbable sutures
Factors affecting wound healing (5)
- Degree of contamination/infection (may need to debride further, broad spectrum antibiotics, allow drainage)
- Tension of skin edges (can cause dehiscence or necrosis at wound margin)
- Vascularity
- Dead space (allows fluid accumulation, use a penrose drain, mesh skin)
- Motion (commonly over joints, must box rest)
Bandaging
a) How often to change a bandage
b) Other materials to use
a)
- typically daily, then reduce it after a week
- depends per case
b)
- clean, dry, sutured wound won’t need anything
- no oil-based ointments, no caustic agents
- flamazine (antibacterial)
- manuka honey (infected wounds)
- topical antibiotics (rarely used, only for chronically infected wounds)
- corticosteroids (chronic wounds, use sparingly)
Bandaging
a) Primary layer
b) Secondary layer
c) Tertiary layer
a)
- wicks exudate
- cushions/protects
- promotes healing environment
b)
- absorbs excess exudate
- provides pressure and support
- reduces movement of wound edges
c)
- secures other components
- provides additional support and pressure
Considerations at
a) Heel bulb laceration
b) Coronary band laceration
a)
- must rule out coffin joint, DDFT and navicular bursa involvement
- primary or delayed primary closure best
- hoof cast reduces movement and allows faster healing
b)
- if coronary band misaligned will result in hoof wall defects
- also use hoof cast
Causes of chronic/non-healing wounds (5)
- excess movement
- large skin defect (may require skin graft)
- presence of foreign body/necrotic tissue (stake wounds, inadequately debrided, bone fragment remaining, bony sequestrum formation)
- excessive granulation (proud flesh)
- systemic disease of patient, quite severe (nutritional status, cushings/PPID)
Chronic/non-healing wounds
Proudflesh indications and predisposing factors
- When granulation tissue protrudes higher than wound edge, difficult for epithelium to grow over
- due to inefficient acute inflammatory phase and protracted chronic inflammatory response (too much granulation tissue)
- trim off tissue until a flat surface
- Predisposing: chronic inflammation, motion, bandages/casts, size of horse
Chronic/non-healing wound
Bony sequestrae cause
- following when initial injury traumatises bone or blood supply to the bone
- suspect when see a mature granulation bed but a cleft/cloaca
- may require surgical intervention
