Module 6 - Vascular Disorders Flashcards
What is a non-healing wound
Any wound that takes longer than 3 weeks to heal and has not responded to conventional therapies. Examples include non healing surgical wounds; diabetic ulcers; arterial, venous, mixed ulcers; pressure ulcers.
Why are non healing wounds significant
Cost (direct & indirect) - resources required to manage such wounds
Lifestyle impact for those with NHW
Uncertainty, fear
Whats the difference between acute and chronic wounds
Acute wounds have a limited pro-inflammatory stimulus
Chronic wounds have a prolonged pro- inflammatory stimulus
Persistent pro-inflammatory stimuli include for chronic wounds:
Ischaemia ( or other underlying disease process)
Bacterial contamination / colonisation
Repeated trauma
What are matrix metaloproteinases (MMPs)
MMP’s are enzymes sub-classified in the metalloendopeptidase family. One of their roles is to degrade extracellular matrix components following trauma, which in turn assists in wound debridement and consequently facilitates cell migration.
What is the MMP activity in chronic wounds
Elevated pro-inflammatory response
Protease activity elevated
Growth factor activity decreased
TIMP activity increased
Importantly senescent cells do not have receptors and therefore will not bind with growth factors
What is the role of MMP in tissue repair?
Inflammatory phase: produced by macrophages, keratinocytes and fibroblasts to assist in removal of damaged & denatured extracellular matrix components
Remodelling phase: assist in remodelling
TIMP (tissue inhibitors of matrix metalloproteinases) increase while MMP’s decrease at the end of the inflammatory phase
Why is Removal of eschar & slough material
Debridement a good principle of wound care
Accelerates wound healing, decreases risk of infection, allows full assessment of the wound bed
What are the 4 mechanisms used for debridement
Sharp
autolytic
mechanical
enzymatic / chemical
What are the indications to use sharp debridement + how is it done
- Lge amounts of necrotic tissue
- When infection / sepsis present
Instruments used to remove nonviable tissue
E.g. sharp forceps / scalpels
What are the indications to use mechanical debridement + how is it done
Slough / minimal eschar
Large wounds
Removal of non viable tissue by physical forces e.g. wet to dry dressings (saline packs allowed to dry)
What are the indications to use autolytic debridement + how is it done
- Dry eschar
(vascular status needs confirming) - For those not requiring urgent debridement
Bodies own process – leukocytes & proteolytic enzymes digest
What are the indications to use chemical debridement + how is it done
- Smaller wounds
- When clients are not surgical candidates (at risk)
Application of prescriptive medicine to remove NV tissue
Why is moist wound healing a good principle of wound care?
- Wound fluid contains growth factors – stimulate connective tissue formation and epithelial migration
- Thought to accelerate healing by 40%
How is a moist wound achieved?
Achieved through wound exudate and product use
Be careful not to have too much moisture in base of wound can spill onto surrounding tissue (peri-wound skin) and cause maceration (water logging) which in turn affects the supply of nutrients and oxygen to the tissue (through micro circulation) and removal of waste products
Why is the maintenance of thermoregulation a principle of good wound care?
- Ideal wound temp is 370C
- Hypothermia / cold irrigating fluids causes vasoconstriction can lead to decreased oxygen to the tissues.
This can impair the production of growth factors, alter phagocytosis, and impair collagen deposits (all essential for healing) - Most contemporary wound dressings are designed to maintain ideal wound temp.
- If wound temp drops below 28 C then leucocyte activity may stop
Why is identifying and eliminating infection a principle of good wound care
- All open wounds are contaminated with bacteria, therefore they may be colonised, but not infected
- Chronic wounds can show much higher concentrations before becoming infective
What is erythema
is redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries
Why is the management of exudate a principle of good wound care
Generally agreed that a decrease in the amount of exudate means that healing is taking place
Excessive exudate results in maceration of surrounding tissue further degrading the wound