Wound healing Flashcards
Define abrasion
Loss of epidermis and some dermis
Define avulsion
Tearing of tissues from attachments eg on the limbs, degloving
Define incision
Created by sharp object with minimal trauma
Define laceration
Tearing of wound creating irregular defect
Define puncture
Penetrating wound: Superficial damage may be minimal, Deep damage may be substantial
What are the three stages of wound healing?
The inflammatory phase
Vasoconstriction and then dilation as increased capillary permeability and platelet aggregation
The repair phase
Fibroblast migration and secretion of proteoglycans, collagen and elastin
Wound contraction and contact inhibition.
The remodelling phase
Maturation and cross linking of collagen. Increase in tensile strength.
At 5 weeks the wound will be at …….% of its original strength
50%
When assessing the type of wound what should we think about?
Degree of tissue damage
Depth of wound
Vital structures (bones, joints, nerves, tendons)
‘Tip of the iceberg’ (e.g. bite wounds)
When assessing wound age what should we consider?
Are we within the GOLDEN PERIOD (6 - 8 hours) before wound is contaminated or infected
When assessing the level of contamination what should we consider?
Foreign material
Bacterial inoculum (bite vs. clean glass)
When we initially see the wound to prevent further contamination we clip the hair (with KY jelly), debride the tissue, issue some antimicrobial therapy and think about closing it up.
Why would we lavage a wound?
We can lavage wounds as a way of diluting the bacteria and encourage healing. Isotonic solutions are best (administer with a 20ml syringe and an 18G needle) – culture after the lavage.
What factors will influence the golden period?
Vascular supply (reduced ability to fight infection)
Devitalised tissue (increased bacterial growth)
Type of contamination: soil better than organic debris, clean glass cut vs bite wound
Type of bacteria
How can we do non-surgical debridement?
Use of wet to dry sterile swabs
Use of dry to dry swabs
Both act to draw away purulent and necrotic material
What is primary closure oF a wound?
Immediate suture
Clean or clean-contaminated
What is delayed primary closure?
Clean-contaminated to contaminated wounds
Reduces incidence of infection
Closure after 3-5 days
What are the advantages and disadvantages of primary wound closure?
Advantages
o optimum wound drainage
o local infection control
o Cheap (?)
Disadvantages
o cosmetic results
o poor functional results
o time / expense
What are passive drains and how do they work?
Penrose drain which is alatex rubber tube
gravity – place dependently and works by capillary action so needs large surface area
Do not exit wound directly
Always cover to reduce risk of ascending infection
When should you remove a drain?
Drain removal should be as soon as possible as all drains produce an FB reaction and hence produce fluid, usually removed in 1-5 days
What is the natural progression of a would from necrotic to epithelialisation?
Necrotic –> sloughy –> granulating –> epithelialising
What is the ideal healing environment?
A moist environment - but not macerated
Free of infection and excessive debris
Free of toxic chemicals, particles or fibres
Warm - at the optimum temperature for healing
Leave new tissue undisturbed (minimise the frequency of dressing changes)
Allow for adequate gas exchange (oxygenation)
Dressing should be painless to apply & remove
Dressings should minimise contamination both to and from the wound
What is alginate dressing and when is it useful?
Made from seaweed, alginate dressings are available as sterile pads, ribbons, or ropes. These non-occlusive dressings are non-adherent and promote autolytic debridement to soften and remove necrotic tissue. Stimulates granulation tissue
What are foam dressings and when are they useful?
Foam dressings are absorbent, sponge-like polymer dressings. In addition to providing thermal insulation, they help create a moist wound environment.
What are would fillers and when are they useful?
Used to fill deep wounds, some wound fillers add moisture to the wound bed whereas others absorb drainage. Made of various materials, wound fillers are available as pastes, granules, strands, powders, beads, and gels.
What are contact layer dressings and when are they useful?
Made with a water or glycerin base, hydrogel dressings hydrate wounds and soften necrotic tissue. Because they contain a large percentage of water, these dressings provide limited absorption. Hydrogel dressings are available as a flexible sheet or a gel. Although hydrogel dressings are good for hydrating wounds, they must be used with care as they can also macerate the surrounding skin
When are antimicrobial dressings useful?
Although hydrogel dressings are good for hydrating wounds, they must be used with care as they can also macerate the surrounding skin.
Covidien Antimicrobial Dressings (AMD) contain polyhexamethylene biguanide (PHMB) which binds/disrupts phospholipid outer membrane causing cell death – effective against MRSA, gram +ve, gram -ve Inc. Pseudomonas spp.
The honey needs a manuka factor of what to be effective as an antibacterial?
+12
The osmotic action of the honey draws fluid out but the antibacterial activity prevents bacterial growth.
Why does honey have debridement properties?
Honey also has good debridement properties due to its low pH (approx. 3.7) which helps to draw up fluid from the wound area and may be an alternative to hydrogels where infection is an issue.
How can maggots be used in wound healing?
Stage 1 larvae only eat liquid protein so provide accurate and efficient debridement
What is Silver sulphadiazine used for?
Excellent antibacterial and antifungal activity with no known resistance
Effective against gram negative organisms for example Pseudomonas spp
Effective against MRSA
What are walking sutures used for?
Walking sutures are used after skin has been undermined as a method of distributing skin tension. The skin is pulled forward in increments so there is a cumulative effect of multiple walking sutures paced in rows not more than 2-3cm apart. The skin dimples eventually disappear and circulatory compromise and pockets of serosa need to be managed
What are relaxin incisions?
Relaxing incisions are cuts made parallel to the wound to undermine the bipedicle flap
Can use two large relaxing incisions either side of the wound
Multiple relaxing incisions can also be made, they are staggered and provide not as much advancement as the single incision, they also increase risk of circulatory compromise.
What are the two types of tissue flap? What are their pros/cons?
Vascularised
Resistance to infection, any tissue bed, may withstand radiation therapy, rapid healing (single procedure)
Non-vascularised
technically relatively simple, covers large tissue defects, requires vascular tissue bed, poor resistance to infection or radiation
What are pinch grafts?
A small punched hole of granulated tissue is taken out and a section of healthy tissue is inserted
