Wound care

Sloughy pressure ulcer wound (Convatec)

In the early 1980s, very few dressings were available, apart from traditional dressings and paste bandages. The first representatives of modern wound management products were used in hospitals during the mid 1980s. These did not become available in primary care until 1988 when Inadine, Granuflex, Kaltostat and Sorbsan were added to the Drug Tariff. Up until 1995, further products were cautiously added following careful evaluation. Many primary care practitioners, eg, nurses, and wound care groups complained about the limited choice in the Drug Tariff.
From 1996, however, this considered approach appears to have been abandoned as an avalanche of new products have been added both to the Drug Tariff and to the list of preparations which can be prescribed by nurses, namely Part XVIIB of the Drug Tariff (see Table 1).¹ There is limited information available about these products, eg, of evidence of effectiveness of individual products or of comparative effectiveness. In fact, when added to the Drug Tariff, it is often difficult to find out basic details such as the name of the manufacturer of the product.

This review covers wound management products in the Drug Tariff (and some additional comments about miscellaneous products used in the community, such as antibiotics and antiseptics). Typical products in each group are considered with reference to their ideal characteristics (see Panel, right), advantages, disadvantages, effectiveness and use. Precise details of sizes, shapes and price of products can be found in the Approved List of Appliances in Part IXA of the Drug Tariff.¹ General information about individual products is available in the British National Formulary,² in the Formulary of Wound Management Products³ and from the Surgical Materials Testing Laboratory website.⁴

Characteristics of ideal dressing

• Maintains moist environment at the wound dressing interface
• Provides thermal insulation
• Low or non-adherent
• Requires infrequent changing
• Provides mechanical protection
• Free from particulate contaminants
• Safe to use (non-toxic, non-sensitising, non-allergenic)
• Conformable and mouldable
• Good absorption characteristics (for exuding wounds)
• Impermeable to micro-organisms
• Acceptable to the patient
• Cost effective
• Sterile
• Available in a suitable range of forms/sizes

Low-adherent dressings (Table 2) are the modern alternative to traditional dressings. Most dressings in this group are low-adherent rather than non-adherent, although N-A Ultra is claimed to be truly non-adherent. Most are suitable for use on dry wounds or on lightly exuding wounds. Mepitel, Mesorb and Mepore can be used on medium to heavy exuding wounds, although a secondary dressing may be required to absorb excess exudate.

Vapour-permeable adhesive films (formerly known as semi-permeable films) are sterile, thin, films (Table 3). Most of them are coated with hypoallergenic adhesive. They are the most flexible of the products as they can mould around elbows, heels and sacral areas. They differ in terms of vapour permeability, adhesiveness, conformability and extensibility. Films are variably transparent, depending on the product. They tend to cool the wound surface, which may not be desirable.
Excessive exudate may accumulate as a bubble under the film. In these circumstances, the film should be removed, the wound irrigated with normal saline and a new film applied.
Films are only considered suitable for relatively shallow wounds. Opsite Flexigrid (formerly Opsite) incorporates a grid system on the upper layer of the film which can be used for mapping wound size and producing a permanent record. Films are also used prophylactically to prevent pressure ulcers, as retention dressings, eg, for cannulas and for operative surgery as sterile drapes.

Hydrogel dressings (Table 4) contain a large proportion of water - often more than 70-90 per cent. Nu-Gel and Purilon are hydrogel/alginate combinations.
Hydrogels have many of the characteristics of an "ideal" dressing, eg, they promote moist healing, and are non-adherent. They can cool the surface of the wound and this is said to be the cause of the marked reduction in pain that is reported in patients using these dressings. Sometimes hydrogels are refrigerated to increase this effect.
Hydrogels are suitable for use on dry "sloughy" or necrotic wounds and for lightly exuding wounds. They are suitable for use for all stages of wound healing except for infected or heavily-exuding wounds. Most hydrogels require covering with a secondary dressing.
A recent innovation has been an extension to the range of gel formulations available - there are now six gels. They are an excellent alternative to chlorinated solutions such as Eusol for desloughing wounds. Intrasite gel sachet has been replaced by a user-friendly "applipak" dispenser in two sizes.

Applying Nu-Gel, one of the combination hydrogel/alginate products (Johnson & Johnson)

Hydrocolloid dressings (Table 5) are more complicated than hydrogels. They contain a variety of constituents such as methylcellulose, pectin, gelatin and polyisobutylene. Comfeel Plus is a hydrocolloid/alginate combination dressing. When in contact with wound exudate, hydrocolloids slowly absorb fluid, leading to a change in the physical state of the dressing and the formation of a gel covering the wound. Thus they are called "interactive" dressings. Hydrocolloids promote the formation of granulation tissue and provide pain relief by covering nerve endings with gel and exudate.
The selection of dressing is becoming more technical as semi-permeable, thin semi-permeable and fibrous forms of hydrocolloids are marketed, with or without adhesive borders. Depending on the choice of product, hydrocolloids are suitable for the treatment of acute and chronic wounds, for desloughing, and for light to medium or medium to heavy exuding wounds. They are not suitable for infected wounds.
Initially, dressings may need to be changed daily but, once the exudate has diminished, dressings may be left in place for up to seven days. Except for Aquacel (which is not waterproof), the dressings are waterproof and require no secondary dressings, and thus patients can bathe or shower.

Aquacel, a hydrocolloid dressing. This type of dressing changes physical state as it absorbs fluid from wound exudate (Convatec)

Polysaccharide dressings are listed in Table 6. Debrisan products are suitable for sloughy, exuding wound cavities. Debrisan consists of sterile, spherical beads of dextranomer which are not biodegradable. Rinsing away the soiled beads can be difficult and the advised method of application of the paste is cumbersome.
Iodosorb consists of hydrophilic beads of cadexomer impregnated with elemental iodine and is suitable for infected, exuding cavities. Cadexomer is a modified starch hydrogel which is biodegradable. Dressings should be changed frequently when saturated with exudate, indicated by a loss of colour of the iodine. The powder should be changed daily and the ointment three times per week. Iodoflex consists of sterile cadexomer iodine paste sandwiched in protective gauze and is changed two to three times per week or when there is a loss of colour.
Generally, ointments and pastes are more convenient to use than powders, beads or granules which can be difficult to contain within certain types of wounds.

Algisite M, Algosteril and Melgisorb are the most recent additions to this group (Table 7). Kaltogel is a quick gelling, calcium/sodium alginate with reduced lateral wicking. Seasorb was formerly called Comfeel:Seasorb and Tegagen was formerly called Tegagel.
A recent improvement in the Drug Tariff is the addition of alginate cavity dressings such as packing (Melgisorb, Sorbsan), rope (Algisite M, Algosteril, Kaltostat), ribbon (Sorbsan) and filler (Seasorb).
Alginate dressings are manufactured from different varieties of seaweed (used for many generations by sailors as dressings for wounds). Alginic acid consists of a polymer containing mannuronic and guluronic residues. Alginates rich in mannuronic acid (like Sorbsan) form soft, flexible gels, whereas those which are rich in guluronic acid (like Kaltostat) form firmer gels. Some dressings contain calcium alginate fibre (Sorbsan and Tegagen) and others contain sodium-calcium alginate fibre (Seasorb, Kaltogel and Kaltostat).
Alginates^5,6 are suitable for use on medium to heavy exuding wounds and cavities. They are not the dressings of choice for infected wounds and should not be applied to dry or drying wounds, eg, necrotic tissue. Most alginates (except Sorbsan Plus) require a secondary dressing.

Melgisorb cavity dressing— one of the newer alginate dressings (Mölnlycke)

Many new foams have recently been added to the Drug Tariff (Table 8). These products consist of polyurethane foam or polyurethane foam film, with or without adhesive borders. Most foams are suitable for use on light to medium exuding wounds, except Tielle Lite which is for lightly to non-exuding wounds. Many foams can be left in place for about seven days, depending on exudate volume. Foams are not recommended for dry, superficial wounds. Besides the usual range of sizes, anatomically shaped dressings are available for the sacrum (Allevyn, Lyofoam Extra, Tielle) and heel (Allevyn).
Allevyn cavity wound dressing is designed to overcome the problems associated with dressing deep wounds. It is available in two circular and two tubular shapes. The dressing can remain in place for up to five days and can be used in conjunction with a gel or paste to ensure that all contours of the wound are kept moist. Lyofoam can be used as a non-traumatic method of reducing hypergranulation tissue.⁷

Lyofoam Extra - a foam dressing. This type of product is generally suitable for use on light to medium exuding wounds (Seton)

Odour absorbing dressings (Table 9) are suitable for discharging, purulent and contaminated wounds complicated by bacterial infection and offensive odour. Most of the traditional deodorisers contain activated charcoal which reduces the concentration of offensive odour to low levels. The only activated charcoal product available in the Drug Tariff is Actisorb Plus. It also contains silver, which inhibits bacterial growth in the dressing.
Metrotop gel is a clear, colourless gel containing metronidazole 0.8 per cent w/v in an aqueous hypromellose base. Anabact contains metronidazole 0.75 per cent. They are licensed for the treatment of malodorous fungating tumours, gravitational ulcers and pressure sores, as they are active against anaerobic bacteria associated with the pungent smell. They are used once or twice daily as necessary. There is a possibility that the use of metronidazole topically may induce antibiotic resistance. Thus, in my view, topical use should be restricted to fungating, malodorous tumours until more experience is gained of their use. The switch from oral to topical metronidazole in the treatment of malodorous wounds seems to have occurred on the basis of few reliable data.⁸ Metronidazole gel has not been compared with tablets for efficacy, speed of action or patient preference.⁹
Note: Metrogel (Sandoz) and Rozex (Stafford-Miller) are licensed for treating acute inflammatory exacerbation of acne rosacea and not for deodorising wounds.
Sugar pastes are also very effective in deodorising wounds and are used in the community. The pastes are made from caster sugar, icing sugar (additive free), polyethylene glycol and hydrogen peroxide.¹⁰ Thin sugar paste can be instilled into wounds with small openings, using a syringe and quill. Thick sugar paste can be packed into wounds with large openings. Twice daily (or more frequent) packing of wounds is necessary. Sugar may exert its antibacterial effect by competing for the water present in the cells of bacteria.

Paste bandages (Table 10) are suitable for treating skin conditions, such as eczema and inflammation, associated with leg ulcers. They act as a buffer between fragile, inflamed skin and compression bandages and are able to absorb exudate and deslough wounds. However, many patients are sensitive to some of the constituents of paste bandages, such as parabens preservatives, so it is advisable to patch test the patient with a small strip of bandage over at least 48 hours. If used sensibly, these bandages still have a valuable part to play in skin and wound care.
Zinc paste bandages (Steripaste, Viscopaste PB7 and Zincaband) are protective, soothing applications for reddened, irritated skin. Steripaste has a preservative-free formulation. Zipzoc is rayon stocking impregnated with preservative free zinc ointment, which is not available in the community.
Ichthammol bandages (Ichthopaste, Icthaband) can be used to soothe irritated skin when tar is not tolerated. Coal tar bandages (Coltapaste, Tarband) are useful for their anti-inflammatory and mild antiseptic properties. Calaband (containing calamine) is emollient and soothes irritated fragile skin, while Quinaband contains both calamine and clioquinol and acts as an antibacterial and deodorant.
These traditional bandages have the advantage that they can be left in situ for one to two weeks before a dressing change is required. When used on legs, paste bandages are applied loosely from the base of the toes to below the knee or applied in short strips. They are not compression bandages but are usually applied between a wound contact dressing and a compression bandage (for venous ulceration).

Non-medicated tulle (Table 11) can be used for clean, superficial wounds, such as dermabrasion or partial thickness burns. Tulles contain different weights of paraffin per unit area and can be described as either light loaded (90-130g/m2 ,eg, Paranet) or normal loaded (175-220g/m2, eg, Jelonet). Paraffin reduces the adherence of the dressing to the wound. The dressings require frequent changes in order to avoid drying out and incorporation into granulation tissue. Secondary dressings are always required.

The medicated tulle dressings (Table 12) are often used inappropriately for infected, superficial wounds. Bactigras, Clorhexitulle and Serotulle are all similar, containing 0.5 per cent chlorhexidine. These dressings are suitable if the use of an antiseptic product is deemed necessary. The use of Fucidin Intertulle and Sofra-Tulle is declining in wound care as both products contain topical antibiotics (see below) and lanolin which carries the risk of skin sensitisation.

As a general rule, antibiotics (Table 13) should not be applied topically to wounds but should be given systemically. Plasmid transfer and induction of antibiotic resistance can be eliminated by restricting the use of topical antibiotics. Sensitivity reactions can cause considerable harm and delay healing. The precise place of Bactroban in wound management remains to be established.

Antibacterial products are listed in Table 14. Flamazine is a hydrophilic cream containing silver sulphadiazine 1 per cent which is very effective against pseudomonas. It has been used since 1968 for burns and is also used for other infected wounds where infection may prevent healing. It is mainly used under absorbent dressings, which are changed at least three times a week for leg ulcers. There is a possibility of leucopenia. Sensitivity reactions, caused by one of the excipients in the cream can occur but are uncommon. The two metronidazole products have already been described (see above).

Desloughing agents are listed in Table 16. A wound will not heal until the slough is removed but the use of many desloughing agents is controversial. Hydrogen peroxide and Aserbine have not been evaluated. Chlorinated solutions are still available and are used as Chlorasol, Dakin's, Eusol and Milton. They have been used as desloughing agents for over 100 years but recently their use has been questioned because of various adverse effects such as delayed healing, cell toxicity, irritancy and reduced capillary blood flow.^12,13
Modern practitioners prefer to use alternative products such as hydrogels, sugar paste, hydrocolloids, alginates or Debrisan products. These may not be as effective as traditional solutions in removing the slough but they are non-toxic and do not delay wound healing. There is also renewed interest in an old treatment - maggots or Larv E (see below).
Necrotic wounds are usually covered with black eschar or scabs, eg, a black heel and will not heal until the necrotic tissue is removed. Surgical debridement is a fast and efficient way of removing the necrosis and hydrocolloids are also effective because of their occlusive, rehydrating properties. Varidase removes the necrosis effectively. On debridement, a larger sloughy wound remains.

For many years, these products were not available for use in primary care. During the past 12 months, however, many products have been added to the Drug Tariff that can be used as components in a multi-layer bandaging system for use in the treatment of venous ulceration. Multi-layer bandaging "kits" are not prescribable as such. However, if prescribers wish to prescribe the individual components they are free to do so, and pharmacists are free to meet a prescription with a "kit", eg, Profore, System 4, Ultra Four, if the content of the kit exactly matches the components prescribed.
Typically, components of a multi-layer bandaging system are applied over a wound contact layer (primary dressing) and are as follows:

• First layer - natural orthopaedic wool layer which is used to absorb exudate and redistribute pressure around the ankle. Applied in a loose spiral, eg, Soffban, Softexe and Sohfast
• Second layer - a crepe bandage which increases absorbency and smoothes the orthopaedic wool layer. Applied in a spiral, eg, K-Lite, Setocrepe and Soff- crepe
• Third layer - a light compression bandage, eg, Elset, K-Plus and Litepress
• Fourth layer - an elastic, cohesive bandage which maintains the four layers in place, eg, Coban, Cohfast and Co-plus.

Multilayer compression bandaging (Ultra Four), used to treat venous ulceration (Robinson Healthcare Ltd)