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43 Cards in this Set
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- 3rd side (hint)
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Second intention healing
involveswhat 3 processes? |
Inflammation
Formation of granulation tissue Closure of the defect by the combined processes of – Epithelialisation – Wound contraction |
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Wound Healing involves a number of processes the
aims of which are: (3) |
To CLEAN the wound
·To COVER the wound ·To STRENGTHEN the wound |
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Describe the inflammatory phase.
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Wounding
• skin retraction • vasoconstriction - transient • blood clot formation Later - • vasodilatation • increased vessel permeability • migration of inflammatory cells into wound These processes all driven by cytokines |
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What is the debridement phase?
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• Neutrophils & monocytes appear in wound
• Monocytes become macrophages • Fibroblasts attracted into wound Inflammatory cells +fluid +dead tissue = pus |
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What is the repair phase?
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Fibroblast proliferation
Capillary infiltration Epithelial coverage |
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Describe fibroblasts!
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From undifferentiated mesenchymal cells in nearby
connective tissues • Appear by Day 3 • Predominant cell type by ≅ Day 10 • Collagen appears by Day 4/5 • Collagen production peaks by Week 2-3 • Wound strength continues after collagen production stops |
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Wht does granulation tissue consists of?
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Granulation Tissue:
• capillary loops • macrophages • fibroblasts |
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What are the 5 characteristics of granulation tissue.
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Granulation Tissue
• 1º wound cover • Resistant to infection • Substrate for epithelial migration • Source of fibroblasts for healing • Myofibroblasts – wound contraction |
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What are the 3 processes in the repair phase?
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Fibroblast proliferation
Capillary infiltration Epithelial coverage |
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What is wound contraction? By what 2 mechanism does it operate?
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Centripetal contraction of a full-thickness skin wound
• An essential part of Second Intention Healing • Independent of epithelialisation • The skin that surrounds the wound is advanced inwards, reducing the size of the open wound Mechanisms: • movement of fibroblasts in granulation tissue collagen • contraction of myofibroblasts within granulation tissue |
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What are the 4 Factors affecting wound contraction?
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1)Amount of skin surrounding wound
2)Attachment of skin to underlying tissue - trunk vs extremities - greyhound vs bassett hound - horse vs cat - thin vs obese 3) Pressure from bandages, splints inhibits wound contraction 4) Drugs – contraction inhibited by corticosteroids, silver sulphadiazine (‘Silvazine’), hydrocolloid dressings? |
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What is the difference in the wound healing in cats and dogs?
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Cats have different cutaneous vascular patterns , lower skin perfusion. Sutured wounds in cats have lower breaking strength at 7 days. In second intention healing, granulation tissue production slower than in dogs, tissue is paler and forms mostly at the edges then grows towards the centre.
Fluid pockets sometimes occur in feline wounds which are lined with collagen and filled with a transudate - which interfere with normal healing. |
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What stops contraction? (2)
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•Contact between epithelial edges (healing)
• tension opposing the centripetal movement (tension in surrounding skin) •When this occurs, contraction stops, the wound defect fills with collagen and the wound starts to expand again |
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What is contracture?
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IF THIS OCCURS IN AN AREA AROUND A JOINT, THE
TENSION + COLLAGEN DEPOSITION MAY INHIBIT NORMAL MOVEMENT POOR FUNCTION AND COSMESIS AS A RESULT OF WOUND HEALING |
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What are the Factors that influence wound healing?
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Nutrition
• Oxygen • Blood supply • Trauma • Foreign bodies • Free fluid in wound • Drugs • Infection • Age • Concurrent illness |
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Factors that influence wound healing >> Nutrition >> name 5 nutrients that affect it.
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Protein deficiency causes
reduced collagen production and wound tensile strength • Vitamin A can counter adverse effects of steroids • Vitamin E has steroid-like adverse effects • Vitamin C beneficial only if deficient • Zinc deficiency slows epithelialisation and collagen synthesis |
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What are the 3 factors of oxygen and blood that affect healing?
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Blood supply brings oxygen,
nutrients, inflammatory cells • Oxygen essential for collagen production • Poor blood supply predisposes to infection |
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How does surgical trauma affect wound healing? 4
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Surgical trauma causes –
• Devitalisation of tissues • increased tissue necrosis and fluid accumulation • increased risk of infection |
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How does the fluid affect wound healing?3 How do you prevent it?3
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Fluid accumulation within wound -
• Medium for bacterial growth • Dissects tissue layers apart • Uncomfortable and unsightly Prevent by - • Good haemostasis • Surgical closure of dead space • Post-operative drainage |
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Describe a drug that affect wound healing ? How does it ? 2
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• Steroids inhibit inflammatory
response and fibroplasia and neovascularisation if given before wounding or in first 3 days • Steroids inhibit epithelialisation & contraction irrespective of time of administration |
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How does infection affect wound healing? How do you prevent it 3
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Inhibits wound healing processes
All wounds are contaminated – only some become infected Infection prevented by • good surgical technique • good aseptic technique • good post-op wound care |
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How does age influence ?
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Healing processes slower in aged
patients – make adjustments to post-op management and reduce other risk factors eg: nutritional support |
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Concurrent illness factors that influence wound healing? 2
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• Diabetes
• Hyperadrenocorticism |
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Wound healing >>Four important processes.
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–Inflammation
–Fibroplasia –Epithelialisation –Wound contraction |
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Wound healing
>>Important cells: 4 |
–Fibroblasts/myofibroblasts
–Endothelial cells –Inflammatory cells (macrophages, PMN’s) –Epithelial cells |
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Principles of wound management>>? 4 (i.e what do you do when you first come across a wound case?
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First aid - restraint, haemostasis
Anaesthesia - local, general Assess - consider surgical exploration Manage - prepare - swab/culture - lavage/debri |
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4 Reasons for wound surgery
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Achieving a better cosmetic
or functional result Reduced healing time More rapid return to health and function Reduced discomfort and irritation to the patient |
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What are the 2 Problems in wound
management? |
1. Breakdown of a sutured wound
2.2. Failure of a wound to heal |
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1. Breakdown of a sutured wound:
caused by ...6 |
1. Breakdown of a sutured wound:
caused by: • Tension on wound • Inadequate blood supply • Infection • Haematoma/seroma formation • Excessive movement • Trauma - by patient or bandage |
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Failure of a wound to heal
caused by...... 6. |
Failure of a wound to heal
caused by: • Foreign body in wound • Tissue necrosis • Dead space • Infection • Denervation • XS granulation tissue (“proud flesh”) • Host factors/disease • Lack of available skin/wound tension |
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What are the 3 Principles of
wound management? |
1. Remove any barrier to healing
2. Create an environment that supports and encourages healing 3. Repair any underlying deficiency (nutrition, vascular or nerve supply) |
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What are the 3 steps in managing granulating wounds?
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Steps in managing
granulating wounds Debridement Cleaning Covering |
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Debridement, there is 3 type.
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Surgical
Chemical/Enzymatic Bandaging |
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What are 7 Aims of Debridement.
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Thoroughly explore wound
Remove dead, damaged & contaminated tissue Remove foreign bodies Stop haemorrhage Restore structural normality Provide drainage |
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Bandage debridement . & points
- what type of bandage? - why is bad? - what is the replacement regime? |
Most commonly used is wet-to-dry
Good first aid dressing Saline soaked gauze applied to wound Dressing adheres to wound surface as it dries out Painful to remove Cheap but must be changed at least daily Newer surface dressings preferred today (eg hydrogels) |
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Chemical debridement.
- when do you use it? - what is it used for? - give 2 examples. |
Useful when abundant soft tissue present
Useful for control of proud flesh Supposedly differentiate between necrotic and healthy tissue Care needed when dealing with shearing wounds on distal extremities Egs Lotagen, Debrisol, Otoderm (Hydrophilic agents such as dextranomer act similarly to hydrogels) |
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What are the 3 Principles (Aims) of
wound management? |
1. Remove any barrier to healing
2. Create an environment that supports and encourages healing 3. Repair any underlying deficiency (nutrition, vascular or nerve supply) |
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What are the Functions of dressings/bandages:? 5
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Maintain wound hydration
Maintain wound temperature Minimise self trauma Reduce contamination Immobilisation/patient comfort |
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What does bandages consists of?3
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Bandages consist of
Primary (contact) layer Secondary (intermediate) layer Tertiary (outer) layer |
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When are adherant and non- adherant bandages used?
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Adherent dressings
used in early (debridement) phase of wound management. Non-adherent dressings used in later (reparative) phase of wound management |
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Toxicity for ampicillin and amoxicillin
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Hypersensitivity reactions, ampicillin rash, pseudomembranous colitis
Mono Px (EBV) if given aminopen, will break into a rash |
HAPpy Aminopens
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Semi occlusive dressing. Give 4 examples
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Paraffin gauze dressings (Jelonet, Bactigras)
– Cellophane dressings (Melolin, Melolite) – Amorphous hydrogels (Intrasite gel) – Alginate dressings (Kaltostat) – Some foam dressings – Some hydrocolloids Most commonly used in veterinary practice |
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Describe 4 points about occlusive dressing
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Prevent exudate loss
Increase rate of epithelialisation in partial thickness wounds May increase rate of dermal repair Allow less frequent bandage changes |
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