week70 wound dressing Flashcards
what is the main infor for wound dressing?
§ Wounds may have different appearance based on the stage of healing
including necrotic, sloughy, granulating or epithelising.
§ They may also be infected or having malodours.
§ Different types wound dressing are used for different types of wounds
§ There are over 3000 types of wound dressing in the market
§ They come in form of square pad, sheets, rolls and packing strips
-§ Wound dressing could be a passive product
§ Examples of passive products include gauze, lint, and cotton wool
§ The main purpose is to keep the wound clean and dry by allowing
evaporation of the wound exudate
§ Maintaining a warm moist wound environment provided by the exudate is
important to encourage rapid wound healing
§ Excessive exudate could lead to maceration of surrounding healthy tis
-§ Advanced wound dressing offer alternative solution to that of passive products
§ They can control the environment for wound healing
§ Some dressing can absorb wound exudate (foam dressing)
§ Other dressing can maintain a moist healing environment (Hydrocolloids and
alginate dressing)
§ Other dressing donates moisture to rehydrate the dead tissue (Hydrogel
dressing)
§ Wet-to-dry dressing mostly used to remove necrotic tissuesue
what are examples of traditional wound dressings?
Available as gauze, lint, cotton wools or natural/synthetic bandages.
what are setbacks for traditional wound dressing?
Traditional wound dressing
8
There are several drawbacks to traditional wound dressings
§ Excessive evaporation could lead to desiccation of the wound (dry – necrotic)
§ Frequent change of the dressing is required to prevent tissue maceration
§ Gauze dressing tend to adhere to the wound as the exudate dries out and
therefore painful to remove and may re-injure the tissue
§ Non-transparent, therefore, it becomes difficult to assess the wound without
removing the dressing
§ They are not suitable for chronic wounds or burn wounds
what are advnaces in wound dressing that have occured?
§ They are designed to control the environment for wound healing
This will be achieved by one of the following
§ Absorb wound exudate (foam and alginate)
§ Donate moisture for wound rehydration (hydrogels)
§ Maintain hydration and moisture ( hydrocolloids)
what are film dressings?
Advanced wound dressing / examples / Film dressing 11
§ These are vapour permeable/semi permeable
§ Flexible, sterile sheets of clear polyurethane with adhesive coating on one side
(acrylic adhesive)
§ They are non-absorbent highly permeable to water vapour and gases but not to
liquid or microorganism
§ Good for visual observation/assessment of the wound
§ They are highly flexible and comfortable (knee, elbow, sacral area)
§ Maintain moist environment but not suitable for infected/heavy exudating wounds
what are foam dressings?
Composed of polymeric materials polyurethane
§ Manufactured to contain air-bubbles / spaces embedded within the dressing
absorbs fluid – so they are absorbent dressing
§ They are generally occlusive or semi occlusive
§ Permeable to water vapour and gases
§ Non-adherent dressing and are opaque – secondary dressing is needed to affix
§ Available in Sheet form: has a hydrophilic side in contact with the wound- absorb secretions and a hydrophobic side to provide a moist environment
§ Available in Spreadable form: are used to fill in cavities and more irregular
defect sites
what are alginate dressings?
§ They are produced from calcium and sodium salt of alginic acid (brown
seaweeds)
§ They form a protective film of gel to maintain occlusive and non-adherent moist
healing environment
§ They interact with exudate through partial ion exchange between sodium ions in
the dressing and calcium ions from the wound exudate
§ They are easy to remove without pain
§ They are highly absorbent, highly permeable and nonocclusive, often require
secondary dressing
They are excellent to fill in wound cavities
§ Made of polysaccharide fibre contains alginic acids from various seaweeds
§ The fibre materials absorb ulcer exudate to form a highly absorbent hydrophilic
gels, provide a moist environment and support ulcer healing
§ Alginate dressings are biodegradable and indicated for moderate to heavy
exuding ulcer
§ They should be changed at least once daily
§ Available in sheet, rope and gel forms (cavity filling)
what are hydrogels?
§ These are made of a 3D matrix of hydrophilic polymers, such as carboxymethylcellulose (Intrasite gel®) or polyethylene oxide (Vigilon®), combined
with a high (usually more than 90%) water content or glycerin
§ Available as sheets, gels or impregnated gauze
§ They absorb minimal fluid but able to donate moisture to dry wounds
§ They feel cool upon application and may reduce wound pain
§ They may dehydrate easily and since they are non-adhesive secondary dressing
is required
Applied mainly in two situations:
§ Since hydrogel dressings maintain a moist wound environment, they may be
used for clean, red ulcers.
§ Applied to ulcer that present white or yellowish slough on their surface (hydrated
moist condition enable separtion of necrotic tissue and induces process of
autolytic debridement.
what are hydrocolloids?
§ They are occlusive and semi-occlusive dressing – provide moist environment
§ Contains colloidal gel forming materials such as hydrocolloid hydrophilic
particles (sodium carboxy methyl cellulose), gelatin, pectin or alginate
§ They are impermeable to water vapour and oxygen and bacteria
§ They have strong adhesive backing
§ They absorb exudate slowly by swelling into a gel-like mass
§ Hydrocolloids available in spreadable and sheet form
§ The sheet form is composed of an inner hydrocolloid lining and an external
hydrophobic coating (usually polyurethane)
§ When applied on ulcer, the hydrocolloid interact with the ulcer fluid and form a
yellow mass – forming a moist environment
§ Hydrocolloid absorbs necrotic materials and ulcer’s fluid (the presence of these
substances diminish proliferative capacity of keratinocytes
§ The sheet form is impermeable to gases, water and bacteria
§ The sheet form is adhesive
what are bioactive dressings?
§ Dressing that contains active substances to promote wound healing
§ They main contain biopolymers with role in natural would healing process such
as collagen, hyaluronic acid, chitosan, alginate, elastin
§ They may also contain growth factors
§ There unique type which combines growth factors, polymers and cells – these
are called skin substitutes
what are tissue engineered dressings?
These are new type of dressing which can contain biodegradable films
§ They may be formulated from natural polymers like collagen or synthetic
polymers
§ Living cells are seeded onto these polymers (scaffold) to support new tissue
formation
§ Their mechanical properties are often similar to the native tissue
§ The polymers gradually degrade and replaces with new tissue formation
