Principles of wound healing 1 Flashcards
Give examples of accidental wounds
- Road traffic accident
- Flights/kicks
- Stick injuries
- Athletic activity
Failure to use good surgical technique / manage wounds correctly can result in…?
- Delayed healing
- Prolonged discomfort
- Extra cost to the owner
Wounds of which parts of the body are particularly important?
- Head
- Thorax
- Abdomen
- Joints
- Tendon sheaths
What is the largest organ in the body?
Skin
What are the 3 main components of skin their functions?
- Collagen fibres: provide strength
- Elastic fibres: elastic properties
- Ground substance
What are the 4 layers of the epidermis?
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basal
What are the two layers of the dermis?
- Superficial papillary layer
- Deep reticular layer
Give examples of other features found in the skin
- Sweat glands, sebaceous glands, hair
- Subcutis and cutaneous muscles
- Arteries, veins, lymphatics
- Nerves
Explain tension lines in the skin
- Normal tension in the skin exists due to elastic fibres in the dermis
- Skin edges retract when an incision is made along these lines
- Less retraction of wound edges and tension when incision made parallel to them
What is the ultimate aim of wound healing?
To restore normal form, structure and function
Give the 8 cellular components of wound healing
- Platelets
- Neutrophils
- Monocytes
- Macrophages
- Endothelial cells
- Fibroblasts
- Myofibroblasts
- Keratinocytes
Collagen is found in which phase/s of wound healing?
Repair and maturation/remodelling
What are the roles of growth factors in wound healing?
- proteins that bind to cell surface receptors
- results in activation of cellular proliferation and/or differentiation
What are the roles of cytokines and chemokines in wound healing?
Small signalling proteins secreted by cells
- Cytokines: growth, differentiation and activation functions
- Chemokines: cytokines with a particular chemotactic function
What are the 3 phases of wound healing?
- Lag/inflammatory phase
- Repair/proliferative phase
- Remodelling phase
What are the characteristics of the inflammatory/lag phase?
- Tissue disruption initiates haemostasis & inflammation
- Transient vasoconstriction: occlusion of injured vessels
- Vasodilation after several minutes: Heat, redness and swelling
- Fibrin seal created: acts as a meshwork
- Platelets aggregate and release chemoattractants, growth factors & proteases
- Removal of wound contaminants and dead tissue
Neutrophils are seen at a wound how long after injury?
Within 24-48 hours
What is the role of macrophages in the lag phase?
- Debride wound of devitalised collagen and fibrin clots
- Essential for further secretion of signalling molecules
What is the Primary leukocyte in the wound at 48-96h?
Macrophage
What is the name given to the formation of new blood vessels?
Angiogenesis
What are the aims of the proliferative phase of wound healing?
- Permanent wound closure
- Replace lost tisse
What are the characteristics of the proliferative phase?
- Angiogenesis
- Fibroplasia and granulation tissue formation
- Epithelialisation
- Contraction
The duration of the proliferative phase is dependant on?
Wound size & location, age & health of individual
What are the characteristics of the remodelling phase?
- Slow increases in tissue strength up to 80%
- Remodelling and strengthening of collagen - orientation and crosslinking
Can wound healing be accelerated?
There is no way to definitively accelerate wound repair
Give examples of local factors that can impair wound healing
- wound perfusion
- tissue viability
- wound fluid accumulation
- infection
- movement
Give examples of systemic factors that can impair wound healing
- immunology
- oncology
- systemic conditions: obesity, malnutrition, diabetes mellitus
- Thermal injuries
What factors need to be discussed with an owner so that can make informed decisions regarding surgery?
- Why surgery is/may be required
- Risks
- Cost
- Aftercare
- Prognosis
- Informed consent
How can you prepare yourself before a surgical procedure?
Be aware of your approach, environment, common complications and how to avoid them and what to do when they occur
What are the 4 steps of preparing a patient for surgery?
- Preoperative medications
- Clipping
- Aseptic preparation
- Draping
What are the 4 steps of preparing a surgeon for surgery?
- Theatre attire
- Scrubbing
- Gowning
- Gloving
What are the main 4 postoperative steps?
- Analgesia, antimicrobial and other required medications
- Update the owner
- Recording of surgery and costing
- Appropriate monitoring & recording of postoperative progress
What postoperative information needs to be discussed with an owner?
- Ongoing medications
- Timing of rechecks
- What is normal
- When to contact the practice
