L2: Wound Healing in Horses Flashcards
What are the 3 phases of wound healing?
- Acute Inflammation
- Cellular Proliferation
- Matrix synthesis and remodelling
What is involved in the acute inflammatory phase?
- Vascular response: vascoconstriction (narrowing of blood vessels) in first 5 - 10 mins.
- Vasodilation (dilation of blood vessels) for diapedsis of cells, fluids and proteins to occur.
- Clot formation
What is the role of the Neutrophil during wound healing?
Acute Inflammatory Phase.
- First line of defence
- Phagocytosis
- Destruction of debris and removal of bacteria
- Source of pro-inflammatory
What is the role of the macrophage during Acute Inflammatory Phase?
- Debridement
- Mesenchymal cell recruitment
- Express cytokines (pro inflammatory and growth factors)
What is involved in cellular proliferation?
Growth of new tissue.
- Fibroplasia: fibroblasts grow and form a new, provisional extracellular matrix by excreting collagen and fibronectin.
- Angiogenesis: Vascular endothelial cells form new blood vessels.
- Epithelialisation: epithelial cells migrate across the new tissue to form a barrier between the wound and the environment.
What is involved in Matrix Synthesis and Remodelling?
Type III collagen, which is prevalent during proliferation, is replaced by type I collagen. Originally disorganized collagen fibers are rearranged, cross-linked, and aligned along tension lines.
Name and describe the 4 types of wound classification
Clean: non-infected, no break in sterile technique, no inflammation
Clean-Contaminated: GI or resp tracts entered without spillage, urinary tract entered with no infection noted, minor break in sterile technique
Contaminated: major break in technique, gross spillage from GIT, fresh traumatic wound (<4hr old)
Dirty: Acute bacterial inflammation encountered, traumatic wound with retained devitalised tissue, foreign bodies, faecal contamination, delayed treatment (>4hr old)
What is the difference between horses and ponies in wound healing?
Ponies have a shorter and stronger inflamm process and heal faster due to greater contractiong because of increased TGF-beta, where as horses have a faster granulation tissue formation but are subject to persistant inflamm.
What are some factors affecting wound healing?
Wound location
Synovial involvment
Bone/tendon involvement
Foreign body
Movement
Blood supply
What are some immobilasation techniques?
Bandage
Splint
Cast
Why should we only use a weak chlorex or iodine solution?
Strong solution will kill all cells trying to heal the wound
PROUD FLESH
What is it?
Treatment options?
Excessve granulation, no nerve supply, highly vascular tissue.
Treatment options include ruling out sequestrum and foreign bodies, trim level to skin (bleeds alot when granulation tissue is cut), immobilisation, control infection, confine horse, some may need biopsy.
DEGLOVING INJURY
What is it?
Factors to consider?
How to assess vascular supply?
Treatment Options
What is it? section of skin is completely torn off the underlying tissue, severing its blood supply
Factors to consider? Age of injury, contamination, blood loss, vascular supply to distal limb, bone exposed, extensor tendon laceration
How to assess vascular supply? clinical examination, fluroescein dye (5g IV), doppler ultrasound, scintigraphy
Treatment Options: Lavage and debridement, primary/secondary closure, immobilisation, antibiotics.
HEEL BULB LACERATION
Structures involved?
Treatment options
Structures involved? digital vessels and nerves, synovial structures, collateral cartilidge, coronary band, collateral ligaments.
Treatment options: Assess contamination, check synovial involvement, local anaesesthia, tourniquet, debride and lavage, suture, foot cast application.
AXILLARY WOUND
What is it?
Risks involved?
Treatment options
What is it? Damage to the space near the armpit
Risks involved? Can be life threatening, subcutaneous emphysemea, pneumothorax, pneumomediastinum, URT obstruction.
Treatment options: Drain chest to take air out if needed, pack wound, suture, antibiotics, confinement, anti inflamms.
