Wounds 3 Flashcards
Wound healing - traditional method
- Traditional method was to “leave it open to the air to dry out”
- Scabs protect the healing wound from ingress of dirt and micro‐organisms
- Thought that bacteria died through dehydration, thus infection minimised
- Migrating polymorphonuclear leucocytes can’t get through dry tissue
- New epithelium forms below wound surface
- Scarring increased
Properties of Dressings
Dressings should ensure that the wound remains:
• Moist with exudate but not macerated
• Free of clinical infection and excessive slough
• Free of toxic chemicals, particles or fibres released by the dressing
• At the optimum temperature for healing to take place
• Undisturbed by frequent or unnecessary dressing changes
• At an optimum pH value
Types of dressing
- Hydrocolloid
- Foam
- Alginate
- Hydrogel
- Tulle
- Absorbent
• Hydrocolloids
Useful for fragile wounds - only need one dressing, have a hydrophobic backing which is vapour permeable, shower-proof
- Microgranular suspension of natural or synthetic polymers (e.g. gelatin, pectin) in adhesive matrix (e.g polyisobutylene)
- Granules semi‐hydrated and hydrophilic
- Adhesive matrix hydrophobic
- Slowly absorb fluid from wound, forming cohesive or hydrophilic gel
- can be cut and layered
- 2mm - 5mm thick, firm
Foams
• Absorbent polyurethane with other compenents: – Hydrocellular foams – Hydropolymer foams – Soft silicone foams – Foam + silver – Foam + charcoal
Alginates
• Seaweed based
• Alginicacid: polymer containing
– Mannuronic acid
– Guluronic acid
• Mannuronic rich alginates form soft flexible gels – Can be rinsed away
• Guluronic rich alginates form firm gels – Can be removed in one piece
• Highly absorbent
- come as dry sheets or ribbons
Hydrogels
• Gels with high water content
– Flat gels (sheets)
– Tubes / containers
• Need a secondary dressing
- add moisture to wound (useful for dead dry tissue to remove it)
Tulles
• Medicated or non‐medicated • Knitted polyester – Low adherence – Open weave – Allow wounds to dry out – Not ideal dressing
- oldest dressing type (knitted)
- skin graft usually taken from thigh or stomach
Vapour permeable films
- Sterile
- Thin
- Conformable
- Hypoallergenic
- Vapour‐permeable
- Adhesive coated
- May have absorbent backing
Absorbent dressings
• Low adherence primary dressing
– Viscose and rayon absorbent pad with adhesive border
– E.g. Mepore, Primapore
Or
– Plastic film faced dressing • Perforated polyester film contact layer • Absorbent cotton pad • Hydrophobic backing – E.g. Melolin
Surgical absorbent dressings
• Conventional dry dressings – Absorbent Cotton BP – Gauze – Lint ( good for fragile dry healthy) – Only on dry wounds!
Moist wound healing
- Moist wound healing first expostulated during WWII
- Winter’s study with pig(s) in 1962 demonstrated increased epithelialisation in moist environment
- Only on superficial wounds, but research was adopted by dressings manufacturers
- Moist conditions allow epidermal cells to migrate to surface of wound, reducing scarring
Useful for fragile wounds - only need one dressing, have a hydrophobic backing which is vapour permeable, shower-proof
Hydrocolloid dressing
Which dressing become more saturated than hydrocolloids
foams
Which foam dressing is used for skin draft or burn
Soft silicone foams
Which foam dressing is used for antibacterial
Foam + silver
Which foam dressing is used for antiodour for fungus
Foam + charcoal
- useless for epithelising wounds or dry wounds, only useful for damp or wet wounds
Alginates
primary dressings so will need another dressing on top (eg mepore)
Alginates
which dressings remove excess moisture but leave wound moist enough so they do not dry out
- alginates, hydrocolloids and foams
which dressing is useful for dead dry tissue to remove it
hydrogel
generally used as secondary dressing but can also be used as a primary dressing
Vapour permeable films
