Superabsorbent dressings have an extra fluid-handling capacity. They are designed to be used on wounds of varying aetiologies that produce moderate to high volumes of wound fluid (known as exudate).
Superabsorbents vary in the way they absorb and retain fluid and how they function under compression. Some superabsorbents can lock fluid inside the dressing. This may contain bacteria and proteases, which can be harmful to the wound and surrounding skin (periwound area). Due to their enhanced fluid-handling capacity and absorbency, they are designed for longer wear times and to reduce maceration.
They may have multiple layers, which can include a wound contact layer, an inner core containing fibres, powders, crystals or gelling agents to increase fluid absorption and retention properties, and some have a fluid repellent backing layer to prevent strikethrough. Some superabsorbent dressings absorb via osmosis, others through a capillary action while retaining a moist wound interface.
Non-adherent superabsorbent dressings require a secondary bandage, while others have adhesive borders to keep them in place.
Instructions for use on each superabsorbent dressings should be followed, as the fluid absorbed and use under compression varies from product to product.
There are many superabsorbent products available, how do I select the right one?
Each patient and their wound has different requirements that need to be considered when choosing the correct type of product. Dressing selection should consider the volume of exudate being produced and skin sensitivities. The following questions can help with dressing selection.
How much exudate is the wound producing?
If the wound is producing moderate-to-high volumes of exudate, a superabsorbent product may be required. If the wound has fluctuating volumes of exudate (i.e. low to high), or a heterogeneous healing process (mixed wond bed), a superabsorbent dressing with a built-in atraumatic contact layer may be more suitable. Moisture management is essential, both to maintain a moist wound healing environment and to protect the periwound skin from maceration.
Methods for assessing exudate have been suggested by Falanga (2000), Bates-Jensen (wound assessment tool) (Bates-Jensen, 2007) and a proposed national wound assessment form (Fletcher, 2010). The latter uses the term ‘wound moisture level’ rather than exudate, and is based on the World Union of Wound Healing Societies (WUWHS) document on exudate (WUWHS, 2007). Clinicians should also refer to their local policy on exudate assessment.
What kind of wounds can a superabsorbent be used on?
Superabsorbents can be used on a variety of wounds, including:
- Pressure ulcers
- Venous ulcers
- Diabetic foot ulcers
- Arterial and neuropathic ulcers
- Post-operative wounds
- Traumatic wounds
- First and second-degree burns (with caution)
- Oncology wounds (with caution)
- Donor sites.
How does a superabsorbent stay in place on the wound?
There are various types of superabsorbent dressings. Some that are designed to adhere to the wound and others that need to be held in place by a secondary product, e.g. tape, film dressing or bandage. These dressings are suitable for use on fragile skin, where adhesive dressings may result in skin damage.
Alternatively, bordered/adherent superabsorbents have an adhesive backing so that they stick directly to the skin without needing to be held in place by other products.
The appropriate dressing should be chosen, considering the patient history and skin condition.
Does the patient have fragile skin?
It is advisable to use a superabsorbent dressing either with a built in atraumatic contact layer or a separate contact layer to avoid any adhesion to the wound/periwound skin. Ideally, the dressing should be secured with a bandage or elastic stockinette to prevent skin damage.
Is the dressing going to be used under compression?
Some superabsorbents absorb and retain exudate under compression bandages and hosiery. It is important to check the manufacturer’s instructions to make sure that the dressing is suitable for use in this instance. Superabsorbent dressings should not be used over the top of compression.
Is antimicrobial action needed?
Some superabsorbent dressings 'lock and bind' microorganisms within the dressing. Studies have suggested that superabsorbents can impede the growth of microorganisms, particularly gram-negative and gram-positive bacteria, as well as yeasts (Wiegand et al, 2011). Wiegand et al concluded that the positive effects of superabsorbents suggest that they should be specifically useful for wound cleansing.
Where is the wound? Is it in a place that is difficult to dress?
Wound sites such as the sacrum, heel or toes can be difficult to dress. Some superabsorbent dressings have been specifically designed/shaped to fit on such anatomical areas, whereas others can be cut to fit.
Note: it is important to consider the manufacturers’ instructions before cutting a dressing.
Selecting a superabsorbent dressing
Selection of a superabsorbent dressing should be guided by:
- Volume and viscosity of exudate
- Is the wound infected
- Does the patient have sensitive/fragile skin
- Condition of skin, e.g. macerated, excoriated
- Location of wound
- Use under compression therapy.
Although cost-effectiveness is important, choosing the cheapest superabsorbent dressing is not necessarily the best thing to do, as dressing choice should always be guided by the patient’s needs. If a dressing fails to perform well, more frequent dressing changes will be needed incurring greater nursing time and associated costs.
Patient choice and preference should always be considered. This helps to build up a good nursing–patient relationship and is in line with national policy.
These will vary for each dressing, but include:
- Fluid-handling capacity
- Fluid retention
- Composition, e.g. hypoallergenic or containing glues/adhesives
- Secondary dressing required, or self-adherent
- Antimicrobial or locks in bacteria
- Can be used under compression
- Wear time.
Bates-Jensen B (1997) The pressure sore status tool a few thousand assessments later. Adv Wound Care 10(5): 65–73
Falanga V (2000) Classifications for wound bed preparation and stimulation of chronic wounds. Wound Rep Regen 8(5): 347–52
Fletcher J (2010) Development of a new wound assessment form. Wounds UK 6(1): 92–9
World Union of Wound Healing Societies (2007) Principles of Best Practice: Wound Exudate and the Role of Dressings. A Consensus Document. http://www.woundsinternational.com/pdf/content_42.pdf
Wiegand C, Abel M, Ruth P, Hipler UC (2011) Superabsorbent polymer-containing wound dressings have a beneficial effect on wound healing by reducing PMN elastase concentration and inhibiting microbial growth. J Materials Sci Materials Med 22(11): 2583–90