Section 5-1: Guidance on Dressing Selection - (Untitled Section)

Although wounds such as leg ulcers, pressure sores[Image-15K], burns and traumatic injuries have very different aetiologies, they can generally be classified into broad groups according to their physical condition and appearance. Such wound classification systems provide a useful starting point in the dressing selection process. (Table 27.) In is not intended that the recommendations in the following section should be followed in every case. It is envisaged rather that they should be used as a starting point in the dressing selection process. More detailed information on the selection of dressings and the use of specific product groups can be obtained from the references cited in the text of this booklet, copies of which can be obtained from the VFM unit.

Dry sloughy and necrotic wounds[Image-16K]

If the blood supply to an area of tissue is interrupted for an extended period by the application of excessive pressure, the tissue will eventually die. The devitalised tissue will then become dehydrated and the epidermis will eventually take on a black leathery appearance. As it dries, the epidermis contracts, causing pain in the surrounding area. This necrotic material must be removed if normal healing is to take place. If surgical debridement is not an option, some method of reversing the process of tissue dehydration is required in order to facilitate autolytic debridement. This may be achieved in two ways. A dressing may be chosen that prevents the loss of water vapour from the dead tissue, or a product with a high water content may be applied to the area to rehydrate the tissue directly. Those dressings in the Drug Tariff that may be used in this way for the treatment of dry necrotic wounds[Image-16K] are described below.

Dry sloughy or necrotic wounds[Image-16K] (cont) - treatment with hydrocolloid dressings

Hydrocolloid dressings consist of a self-adhesive gel-forming mass, generally based upon carboxymethycellulose, applied to a carrier such as a thin polyurethane film or foam sheet. In their intact state hydrocolloids are virtually impermeable to water vapour and therefore retain moisture and thus facilitate rehydration followed by autolytic debridement of devitalised tissue. Depending upon the size and depth of the wound this process may take anything from a few days to several weeks to complete.

Method of use

A suitably sized dressing is selected, applied over the necrotic area and left in place for 3-5 days. It is then removed and the wound examined. This process may be repeated as often as required until debridement is complete.

Indications

Hydrocolloid dressings are particularly useful for relatively small, shallow areas such as `black heels' which can be covered completely by a single piece of dressing but they can also be used with good effect upon more extensive wounds on the sacrum or the buttocks.

Figures in ( ) indicate expenditure for period July 1993 - June 1994

Dry sloughy or necrotic wounds[Image-16K] (cont) - treatment with hydrogel dressings

Hydrogels consists of insoluble polymers with hydrophilic sites which interact with aqueous solutions absorbing and retaining significant volumes of water. The only hydrogel dressing currently available upon prescription is Intrasite gel which contains approximately 1-2% carboxy-methylcellulose, 80% water, and 20% propylene glycol as a humectant and preservative. When applied to necrotic tissue, water is transferred directly from the gel to the tissue and thus facilitates rehydration and autolysis.

Method of use

A generous layer of gel is applied to the surface of the wound and covered with a Perforated Plastic Film dressing such as Release. If the wound is very dry a more occlusive covering may be used to reduce water vapour loss and prevent the gel from drying out. A Semipermeable Adhesive Film such as Cutifilm may be used for this purpose. On very dry wounds it is usual to change the dressing at least once per day.

Indications

Intrasite is particularly useful for cavity wounds, particularly where a degree of undermining is present, and in other situations where the use of hydrocolloid sheets would be inappropriate.

Moist sloughy or necrotic wounds[Image-16K]

Wounds such as leg ulcers and pressures sores sometimes develop a thick coating of viscous yellow slough. This acts as a potential source of infection and may delay healing unless it is removed mechanically or by some other means. The recommended products to facilitate debridement are described briefly below;

In addition to the above, products made from polysaccharide beads and certain pharmaceutical preparations are also marketed for this indication. These are also described below. Moist sloughy wounds[Image-16K] (cont) - treatment with hydrocolloid dressings Hydrocolloid dressings consist of an adhesive mass which typically contains carboxymethycellulose, applied to a carrier such as a thin polyurethane film or foam sheet. In their intact state hydrocolloids are virtually impermeable to water vapour and therefore retain moisture and thus facilitate rehydration followed by autolytic debridement of devitalised tissue. If applied to an exuding wound, they have the ability to absorb liquid and form a gel, the nature of which depends upon the product selected, The moist conditions which exist beneath the dressing facilitate debridement followed by granulation tissue formation. Depending upon the size and depth of the wound this process may take anything from a few days to several weeks to complete.

Method of use

A suitably sized dressing is selected, applied over the sloughy area and left in place for 3-5 days. It is then removed and the condition of the wound examined. This process may be repeated as often as required until debridement is complete.

Indications

Hydrocolloid dressings are particularly useful for relatively small, relatively sloughy areas which can be covered completely by a single piece of dressing but they can also be used with good effect upon more extensive wounds on the sacrum or buttocks.

Figures in ( ) indicate expenditure for period July 1993 - June 1994All Wales expenditure on hydrocolloid dressings during the period of the study was £856,891.

Moist sloughy wounds[Image-16K] (cont) - treatment with hydrogel dressings

Hydrogels consists of insoluble polymers with hydrophilic sites which interact with aqueous solutions absorbing and retaining significant volumes of water. The only hydrogel dressing currently available upon prescription is Intrasite gel which contains approximately 1-2% carboxy-methylcellulose, 80% water, and 20% propylene glycol as a humectant and preservative. When applied to sloughy tissue, water is transferred directly from the gel to the tissue and thus facilitates rehydration and autolysis.

Method of use

A generous layer of gel is applied to the surface of the wound and covered with a Perforated Plastic Film dressing such as Release. Alternatively, a more occlusive covering may be used to reduce water vapour loss and prevent the gel from drying out. A Semipermeable Adhesive Film such as Cutifilm may be used for this purpose. It is usual to change gel dressings at least once per day.

Indications

Intrasite is useful for cavity wounds, particularly where a degree of undermining is present, and in other situations where the use of hydrocolloid sheets would be inappropriate

Figures in ( ) indicate expenditure for period July 1993 - June 1994

Moist sloughy wounds[Image-16K] (cont) - treatment with alginate dressings

Alginate dressings consist principally of the calcium salt of alginic acid, a polysaccharide derived from seaweed. Calcium alginate is insoluble in water but in the presence of sodium ions from wound exudate, a partial ion exchange reaction takes place resulting in the production of sodium alginate which forms a hydrophilic gel on the wound surface. This helps to keep the surface of the wound moist and thus facilitate autolysis and eventually wound healing. The physical and chemical properties of the dressings depend upon the botanical source of the seaweed which in turn determines relative concentration and arrangement of the mannuronic and guluronic monomers which together make up alginic acid. The gelling characteristics are also influenced by the relative concentrations of calcium and sodium ions present in the dressing. Five alginate dressings are available on the Drug Tariff. Most contain a high concentration of calcium alginate formed into textile fibres, but one product, Comfeel Alginate Dressing, rich in guluronic acid, is made by a freeze drying process and is therefore a fibre free mass of calcium alginate supported on a nylon mesh net. Sorbsan consists primarily of fibres of calcium alginate rich in mannuronic acid. Kaltostat is produced from fibres containing a mixture of calcium/sodium alginate rich in guluronic acid. Tegagel is chemically similar to Sorbsan but the fibres have been hydroentangled, so that it more closely resembles Kaltostat in appearance. Kaltogel, a new addition to the Tariff, is also rich in mannuronic acid but also contains 20% sodium alginate to facilitate rapid gelling. similar to Sorbsan.

Figures in ( ) indicate expenditure for period July 1993-June 1994.

Moist sloughy wounds[Image-16K] (cont) - treatment with polysaccharide bead dressings

The polysaccharide bead dressings, Debrisan and Iodosorb, which are marketed for the treatment of sloughy wounds[Image-16K], are available in several different forms such as pastes which are intended to overcome the handling problems associated with the use of the free flowing spheres. Although Debrisan was one of the first `modern' debriding agents, its has now been largely replaced by Intrasite gel which is cheaper and easier to use.

Moist sloughy wounds[Image-16K] (cont) - treatment with pharmaceutical preparations.

Traditionally, a number of pharmaceutical preparations been used to debride wounds. Much controversy surrounds the use of some of these materials, particularly those containing hydrogen peroxide and sodium hypochlorite. Most wound care experts recommend that they no longer be used because they are claimed to delay wound healing and may also cause adverse effects upon the surrounding skin. Nevertheless, some practitioners still believe that their short term use may be justified for the cleansing of particularly dirty or sloughy wounds[Image-16K]. The continued use of enzymatic debriding agents is similarly questioned, for although they have been shown to have some benefit in the treatment of wounds containing semi-liquid slough and purulent exudate, they are ineffective against wounds containing deep hard necroses. The pharmaceutical preparations offered for wound debridement are shown below.

Superficial granulating wounds[Image-16K]

If a wound involves a significant loss of dermal tissue, healing cannot occur unless the this damage is first repaired by the production of collagen-rich granulation tissue. During this process, particularly in the early stages, it is not unusual for the wound to produce significant quantities of serous fluid or exudate, the management of which may present considerable practical problems to the practitioner. As healing progresses, however, exudate production may diminish to the point at which a relatively impermeable dressing is required to ensure that the wound remains moist and in the optimum condition for rapid healing to take place. A range of dressing materials are available for this purpose, the choice of which will be determined by the site and nature of the wound as shown below.

Superficial granulating wounds[Image-16K] (cont) - treatment with foam dressings

Allevyn is a highly absorbent dressing made from a hydrophilic polyurethane foam layer about 3 mm thick sandwiched between a low-adherent net facing layer and a polyurethane film backing. The dressing is highly absorbent and is useful for the management of most moderate-heavily exuding wounds. Allevyn adhesive consists of a piece of Allevyn foam which is bonded to a piece of polyurethane foam to form an island dressing the surface of which is coated with adhesive. Lyofoam consists of an open-cell hydrophobic polyurethane foam sheet, one surface of which has been heat treated to collapse the cells of the foam to allow it to take up blood or wound exudate by capillarity. Although the absorbency of Lyofoam is limited, it is very permeable to water vapour and may therefore be used on moderately exuding wounds. Tielle is a sophisticated island dressing consisting of a piece of polyurethane film/foam, located in the centre of an adhesive moisture vapour permeable, polyurethane membrane. The dressing is highly permeable to moisture vapour which makes it suitable for application to moderately exuding wounds despite its limited absorbent capacity.

Method of use

A suitably sized piece of dressing is chosen, applied to the wound and held in place with tape or a bandage as appropriate. Allevyn adhesive and Tielle clearly do not require the use of a secondary dressing. Unlike most absorbent dressings, Lyofoam transmits absorbed fluid laterally across the face of the dressing rather than from front to back. For this reason, a size of Lyofoam should always be selected which overlaps the edges of the wound by about 2-3 cm.

Indications

The Allevyn range can be used in the management of most heavily exuding wounds including leg ulcers, traumatic wounds, minor burns[Image-16K], donor sites[Image-16K] and malignant wounds. Lyofoam has been used for a similar range of applications when exudate production is reduced. Tielle may be used for most moderately exuding wounds because of its high MVTR.

Superficial granulating wounds[Image-16K] (cont) - treatment with alginate dressings

Five alginate dressings are available on the Drug Tariff. Most consist of calcium alginate formed into textile fibres. Sorbsan consists primarily of fibres of calcium alginate rich in mannuronic acid. Kaltostat is produced from fibres of calcium/sodium (80:20) alginate rich in guluronic acid. Tegagel is chemically similar to Sorbsan but more closely resembles Kaltostat in appearance. Kaltogel, a new addition to the Tariff, is also rich in mannuronic acid but also contains 20% sodium alginate to facilitate rapid gelling. Comfeel Alginate Dressing, rich in guluronic acid, is made by a freeze drying process and is therefore a fibre-free mass of calcium alginate which is supported on a nylon mesh net.

Method of use

A suitable size of dressing is chosen and applied to the surface of the wound. It is usually recommended that a Kaltostat is cut to the size and shape of the wound but this is not usual for the other products. The dressing is then covered with a secondary dressing such as a perforated plastic film or semipermeable film depending upon the amount of exudate that is anticipated. The chemical and physical properties of the alginate dressings are very different and this has implications for the selection and method of use of the products concerned. Sorbsan and Kaltogel are soluble in 0.9% sodium chloride solution and are therefore easily removed from the wound by irrigation. Tegagel and Kaltostat are less soluble and therefore may be removed from the wound intact as may the Comfeel product and Kaltogel - provided it is not saturated with saline.

Indications

Alginate dressings may be used for the treatment of most exuding wounds such asleg ulcers[Image-16K], minor burns[Image-16K], donor sites[Image-16K], surgical wounds, pressure sores[Image-15K] and malignant wounds. They also have haemostatic properties, and one product, Kaltostat, has a product licence for this application.

Superficial granulating wounds[Image-16K] (cont) - treatment with hydrocolloid dressings

Three hydrocolloid dressings are listed in the Drug Tariff, and these vary significantly in their composition and physical characteristics. The products differ in price, but in the absence of hard published data on their relative clinical effectiveness, it is not possible to make any recommendation on preferred usage. In the presence of wound exudate, the dressings absorb liquid and form a gel, the precise nature of which is determined by the product selected.

Method of use

The dressings are very easy to use. An appropriate size product is chosen, the backing removed and the dressing applied over the wound ensuring an overlap of about 2 cm all around to avoid leakage. The dressing may be left in place for a maximum of 5-7 days depending upon the nature of the wound.

Indications

Hydrocolloids are generally indicated for use in light-moderately exuding wounds including pressure sores[Image-15K], minor burns[Image-16K] and traumatic injuries. Also used extensively in the management of leg ulcers where they appear to have advantages in the treatment of wounds that fail to respond to compression therapy alone. Because hydrocolloid dressings do not cause pain on removal, they are particularly useful in paediatric wound care for the management of both acute and chronic wounds.

Superficial granulating wounds[Image-16K] (cont) - treatment with low-adherent dressings

Low-adherent wound contact layers are used as interface layers to prevent a secondary absorbent dressing from adhering to the surface of a wound and causing trauma on removal. They are available both plain and impregnated with soft paraffin which may also contain an antibacterial agent. Most wound care experts would agree, however, that medicated products should be avoided unless there is clear evidence of clinical wound infection present. The most widely used low adherent dressings are now Knitted Viscose Primary Dressing BP, more familiarly known as NA Dressing or Tricotex, is a simple knitted fabric that is claimed to have limited adherence properties. This dressing is commonly used as the initial layer of the Four Layer Bandage system. For many applications, NA Dressing and Tricotex have largely replaced the paraffin gauze dressings (tulles), which, despite their greasy nature and description of `low-adherent dressings', often become firmly attached to the surface of a wound causing pain or discomfort upon removal.

Cavity wounds

Cavity wounds are formed when significant damage to the dermis has occurred. Cavity wounds may be open and `boat-shaped' or may involve significant undermining of the surrounding tissue. In extreme cases this can result in the formation of a flask-shaped wound with a narrow opening leading into a chamber beneath the skin. Such wounds, like sinuses[Image-15K], can be very difficult to heal without surgical intervention. Unfortunately, at the present time, there are no cavity wound dressings available on the Drug Tariff and therefore the products available to treatment these often extensive complex wounds are very limited. Traditionally cavity wounds have been packed with absorbent fabric such as ribbon gauze, often soaked in hypochlorite or proflavine solutions. This technique has now largely fallen out of favour and most hospital-based practitioners now tend to use alginate ribbon or rope. As neither of these materials are available on the Tariff, the sheet forms of alginate dressings are commonly used for larger open wounds, cut into strips if required. For narrow wounds or sinuses[Image-15K] Intrasite gel is sometimes used.

Cavity wounds - treatment with alginate dressings

Five alginate dressings are available on the Drug Tariff. Most consist of calcium alginate formed into textile fibres. Sorbsan consists primarily of fibres of calcium alginate rich in mannuronic acid. Kaltostat is produced from fibres of calcium/sodium (80:20) alginate rich in guluronic acid. Tegagel is chemically similar to Sorbsan but more closely resembles Kaltostat in appearance. Kaltogel, a new addition to the Tariff, is also rich in mannuronic acid but also contains 20% sodium alginate to facilitate rapid gelling. Comfeel Alginate Dressing, rich in guluronic acid, is made by a freeze drying process and is therefore a fibre-free mass of calcium alginate which is supported on a nylon mesh net.

Method of use

Alginate dressings may be used for the treatment of most cavity wounds providing that they can be easily inserted and removed. (It may be necessary to cut them into strips for some applications). The chemical and physical properties of the alginate dressings are very different and this has implications for the selection and method of use of the products concerned. Sorbsan and Kaltogel are soluble in 0.9% sodium chloride solution and are therefore easily removed from a wound cavity by irrigation with saline. Tegagel and Kaltostat are less soluble in saline and therefore must be removed from the wound intact using a forceps or gloved hand. The Comfeel product maintains its integrity because of the nylon mesh carrier and is also removed in one piece.

Indications

Alginates can be used for the treatment of most cavity wounds including abscesses, surgical wounds and pressure sores[Image-15K].

Epithelialising wounds

Epithelialisation is the final stage in the healing process and takes place when epithelial cells from the margin of the wound or hair follicles in the dermis proliferate and grow over the surface of exposed granulation tissue. At this stage of the healing cycle, the wound tends to be relatively dry and therefore a dressing is required which conserves moisture and prevents the exposed tissue from drying out. Although a number of different products can be used, most favoured are materials which form a moisture retaining protective covering over the wound surface.

Epithelialising/lightly exuding wounds (cont) - treatment with semipermeable films

There are currently four adhesive film dressings available on the Tariff. They are all made from a thin sheet of polyurethane coated with a layer of acrylic adhesive. The dressings are permeable to moisture vapour and gases but impermeable to liquids. They therefore provide protection to the wound but prevent it from becoming macerated .

Method of use

Although the physical properties of the films from which the dressings are constructed are broadly comparable, major differences exist in the application systems that have been developed for them. Users often express a strong preference for a particular brand of film dressing because they have become familiar with its method of use Basically, however, a suitably sized dressing is selected, the backing removed and the polyurethane film applied over the wound, taking care not to apply it under tension which could cause damage to the surrounding skin.

Indications

Film dressings have a wide range of applications. Their use has been reported in burns, donor sites[Image-16K], surgical wounds and superficial pressure sores[Image-15K]. They are also used as secondary dressings in combination with alginates and hydrogels.

Epithelialising wounds (cont) - treatment with perforated plastic film dressings

These dressings are designed to combine a degree of absorbence with low-adherence for the management of lightly exuding superficial wounds. They consist of an absorbent fibrous fleece covered with a plastic film containing a series of small holes arranged in a uniform pattern. The plastic film is intended to prevent the dressing adhering to the surface of the wound and the holes are present to allow the passage of exudate through to the absorbent layer.

Method of use

A suitably sized dressing is selected and held in place over the wound using tape or a bandage as appropriate. The ability of these dressings to absorb exudate is limited, and for more heavily exuding wounds they are sometimes covered with a second absorbent pad. In these situations the absorbency of the dressing is less important than its low-adherent properties.

Indications

Perforated film absorbent dressings are widely used in the treatment of superficial wounds such cuts and grazes and are frequently applied in combination with hydrogels or alginates for more heavily exuding wounds.

Epithelialising wounds (cont) - treatment with hydrocolloid sheets

Three hydrocolloid dressings are listed in the Drug Tariff, and these vary significantly in their composition and physical characteristics. The products differ in price, but in the absence of hard published data on their relative clinical effectiveness, it is not possible to make any recommendation on preferred usage. In the presence of wound exudate, the dressings absorb liquid and form a gel, the precise nature of which is determined by the product selected.

Method of use

The dressings are very easy to use. An appropriate size product is chosen, the backing removed and the dressing applied over the wound ensuring an overlap of about 2 cm all around to avoid leakage. The dressing may be left in place for a maximum of 5-7 days depending upon the nature of the wound.

Indications

Hydrocolloids are generally indicated for use in light-moderately exuding wounds including pressure sores[Image-15K], minor burns[Image-16K] and traumatic injuries but they can also be used for lightly exuding wounds if required. It has been observed that wounds dressed with hydrocolloid dressings sometimes tend to over-granulate. If this is noted a change to more permeable dressing such as a semipermeable film may be indicated

Epithelialising exuding wounds (cont) - treatment with foam dressings

Of the five polyurethane foam dressing included in the Drug Tariff the products recommended for lightly exuding wounds are Lyofoam and Spyrosorb. The remaining products are generally used for more heavily exuding wounds Lyofoam consists of an open-cell polyurethane foam sheet, one surface of which has been heat treated to collapse the cells of the foam and allow it to take up blood or wound exudate by capillarity. It is used in the management of a variety of different wound types including leg ulcers, traumatic wounds,minor burns[Image-16K] , and donor sites[Image-16K] Spyrosorb is thin sheet of polyurethane foam coated with adhesive. The dressing which is very conformable, has limited absorbent capacity but is highly permeable to moisture vapour. It is used for dressing relatively shallow/lightly exuding wounds or wounds in the final stages of healing.

Method of use

A suitably sized dressing is chosen, applied to the wound and held in place with tape or a bandage as appropriate. Unlike most absorbent dressings, Lyofoam transmits absorbed fluid laterally across the face of the dressing rather than from front to back. For this reason, a size of Lyofoam should always be selected which overlaps the edges of the wound by about 2-3 cm. Spyrosorb being adhesive does not require a secondary dressing.

Indications

Lyofoam and Spyrosorb may be used for most lightly exuding wounds in the final stages of healing.

Infected or malodorous wounds

Wounds which contain large numbers of pathogenic bacteria may become clinically infected which will delay healing and may even lead to a life-threatening systemic infection. An appropriate form of topical treatment used as an adjunct to systemic antibiotics is likely to be of value in this situation. Other wounds, often those which contain significant quantities of slough or necrotic material, may become heavily colonised with proteolytic bacteria the metabolic processes of which can result in the formation of extremely unpleasant odours. This often occurs in pressure sores[Image-15K] and malignant wounds but it is also not uncommon in leg ulcers. There are two ways of dealing with this problem. Either a dressing containing activated charcoal can be applied to absorb the odour, or an appropriate treatment administered to kill the organisms that are responsible for causing the infection. At the present time, activated charcoal dressings are not reimbursable and are therefore not available to most practitioners in the community. The only alternative, therefore, is to use some form of medicated dressing or topical application until the infection is brought under control. Once the infection has been eradicated a change to an alternative dressing is probably indicated.

Infected/malodorous wound (cont) - treatment with medicated tulles

Paraffin gauze dressings containing antibiotics such as sodium fusidate and framycetin have the potential to cause sensitivity reactions and the development of resistant strains of micro-organisms. For this reason they should be avoided unless they are specifically indicated following microbiological investigations. Dressings such as Bactigras and Serotulle which contain an antiseptic, chlorhexidine, instead of an antibiotic are generally considered to be free of these disadvantages. Laboratory tests suggest that the chlorhexidine is not readily released from the hydrophobic paraffin base and therefore the antibacterial activity of these dressings is likely to be limited. Inadine contains povidone iodine in polyethylene glycol which is hydrophilic and therefore better able to liberate the antimicrobial agent into wound exudate in order to exert a bactericidal effect.

Method of use

A suitably sized dressing is applied to the wound and covered with a secondary dressing such as a perforated plastic film held in place with tape or a bandage as appropriate. Depending upon the condition of the wound the dressing should be changed every 24-48 hours until the infection is brought under control.

Indications

Medicated paraffin gauze-type dressings are used in the treatment of wounds such as ulcers where clinical infection has been identified. If cellulitis is also present, consideration should also be given to the use of systemic antibiotics.

Infected/malodorous wound (cont) - treatment with polysaccharide bead dressings.

Both the Debrisan and Iodosorb range are sold for the treatment of sloughy or infected wounds[Image-16K] but the Iodosorb products which contain elemental iodine have a clear theoretical advantage over non-medicated Debrisan in the treatment of infected wounds[Image-16K].

Method of use

Iodosorb ointment can be applied directly to a wound or placed upon the surface of a dressing which is then applied as normal. Iodoflex consists of a layer of Iodosorb ointment sandwiched between two pieces of gauze. Once a suitable size dressing has been selected, one piece of gauze is removed and the dressing is applied to the wound and covered with a secondary dressing such as a perforated plastic film.

Indications

Iodosorb ointment is indicated for the treatment of small infected cavity wounds whilst Iodoflex is most suitable for larger shallowinfected wounds[Image-16K] such as leg ulcers.

Infected/malodorous wound (cont) - treatment with pharmaceutical preparations.

The antibacterial agents that may be used topically to prevent or combat wound infection are identified below. Antibiotic powders are used mainly in the treatment of infections in superficial wounds although some are also indicated for larger wounds. These products contain neomycin that is known to cause skin sensitisation and there is also a theoretical risk that their application can also lead to the emergence of resistant strains of bacteria. Antibiotic powders should therefore probably be avoided or used with extreme caution. Silver sulphadiazine cream, e.g. Flammazine, is used extensively in specialist centres for the treatment of extensive burns. Because the cream is active against a wide range of pathogenic organisms, including Pseudomonas sp., it is also of value in the treatment of infected leg ulcers and other wounds. Preparations containing the antibiotic metronidazole, e.g. Metrotop, are effective against the potentially pathogenic anaerobic bacteria often found in necrotic tissue. As such it is very useful agent for combating the odour produced by malignant or sloughy wounds[Image-16K]. Povidone iodine preparations are sometimes used in the treatment of infected wounds. Like other antiseptics, however, their use should be discontinued once the infection is brought under control, for povidone iodine may have an adverse effect upon wound healing.

Infected/malodorous wound (cont) - treatment with alginate dressings

A certain amount of anecdotal evidence is available to suggest that at least one alginate dressing, Sorbsan, may be of some value in the treatment of infected and necrotic wounds[Image-16K] although this has not been confirmed in a randomised controlled clinical trial. The reasons for this observed effect are not understood but it is possible that the activity may be associated with the gel-forming abilities of this particular dressing. If used in the treatment of infected wounds[Image-16K] the dressing should be changed regularly, at least every 48 hours.