Sometimes a wound will produce so much exudate that regular dressings cannot handle the amount of fluid. Typical examples of this are venous leg ulcers with a large surface area, especially when there also is a lot of inflammation ( dermatitis). This can lead to a vicious circle where aggressive exudate attacks the peri-wound area causing the wound surface to increase quickly. The exudate must be rapidly transferred away from the wound and surrounding skin and locked into the core of the dressing. For this, we need dressings with extra absorptive and retention properties, so-called superabsorbent dressings. These dressings do not solve all our issues with venous leg ulcers with high amounts of exudate. To control the exudate problem, it is essential to use compression therapy and elevation of the affected extremities. Even when using a superabsorbent dressing, the exudate amount may be so high that you have to change the dressing several times a day!
While it is not unusual for leg ulcers to have much exudate, this is less common for many other ulcer types. Deep pressure injuries over the sacrum or gluteal areas can, on occasion, have much exudate. When this is the case, you should always have a high level of suspicion of osteomyelitis ( infection of the bone) present.
Superabsorbent dressing work in many ways, like a modern single-use diaper. Have you ever touched the inner surface of such a diaper and were surprised about how dry the inner surface was despite the diaper being saturated with urine? That is because modern diapers are excellent at absorbing moisture and locking it within the core of the material so that the inner layer remains dry. This is essential to protect the baby's bottom from rashes and sores.
Since we just mentioned diapers - we have sometimes had to use diapers in the initial phases of treating huge venous ulcers where the exudate amount was too high to handle for most dressings! A diaper can, in other words, become an emergency solution for treating complicated venous ulcers!
In Tanzania, for example, a 60 diaper pack (Huggies Size 4) costs about 18 US Dollars at the online pharmacy dawa.co.tz - that means a diaper costs 30 cents. The prices will differ a lot depending on which country you live in and where you buy the diapers, but around 30 cents is probably where the price level is, although we are sure that you can buy them even cheaper. For large wounds, you may use a whole diaper. If the ulcer is smaller and you have nothing else as a good absorbent agent, you may have to resolve to cut the diaper into smaller pieces. This will still be better than using cotton gauze as your absorbent dressing. However, if you have ever cut up a baby's diaper, you will know that the layers fall apart, so you will have to strengthen the edges with tape. If you have to improvise because of minimal resources, you could even sow the edges with a sewing machine. Note that an intact diaper is designed not to leak fluid from the edges - if you improvise like above and sew the edges together, this will not be leakproof. If the diaper dressing is saturated with liquid, it will leak out at the edges! Homemade diaper dressings need to be changed more often to prevent moisture-related skin damage. If you are using compression, the exudate amount should gradually decrease within 7-10 days, and you can go over to using a more conventional dressing. Women's hygiene pads can make excellent superabsorbent dressings for smaller wounds. These are available cheaply in most parts of Africa.
Figure 1 A good superabsorbent dressing should have the capability to absorb its own weight manifold and at the same time retain the fluid in the core of the dressing. The inner layer of the dressing ( the surface touching the wound bed and surrounding skin) should remain dry even when the dressing is saturated. The image above shows how much the dressing (Xtrasorb) swells after absorbing much fluid. copyright: Integra Life Sciences
Some superabsorbent dressings have excellent absorption capabilities, and some can absorb as much as 40 x of their own weight. Be aware that even though a dressing may be able to absorb much fluid this does not necessarily mean that it is good at retaining the fluid. Some superabsorbent dressings become surprisingly moist at the inner layer once they are saturated.
Of all the different types of dressings in wound care, superabsorbent dressings are a category where the properties of the product differ a lot from one to another. There are significant differences in absorption and retention properties and how well they handle viscous fluids. Furthermore, they differ in how well they perform when placed under a compression bandage. A compression bandage will inadvertently squeeze on the superabsorbent dressing. If the dressing has poorer retention capabilities, moisture will be squeezed towards the inner layer and can cause peri-wound maceration. Cheap superabsorbents also tend to sag. With sagging, we mean that once the dressing is saturated, then forces of gravity will cause the saturated parts of the dressing to wander downwards. If you have to use a diaper as a superabsorbent alternative, you will see sagging if it has absorbed a lot of fluids. There are also differences in shapes. Some superabsorbent dressings have a shape that makes them perfect for wrapping around a leg. Others may be soft to conform well to tricky areas like under the armpits or in inguinal folds. Lastly, some superabsorbent dressings also have antimicrobial properties, like Sorbact Superabsorbent or Polymem Max.
Figure 2 Most superabsorbent dressings have four or more layers. The inner layer ( towards the wound) is usually a soft contact layer. Next is a wicking layer that transports fluid from the wound towards the center of the dressing. The super absorbent core is the middle of the dressing, where fluids are locked. On the outside is a protective backing that allows for some evaporation while at the same time repelling any liquids or microorganisms. The outer backing should also prevent strike through - this means that wound exudate cannot penetrate the outer layer no matter how saturated the dressing is. In the image above, Tegaderm Superabsorbent is used as an example. copyright: 3M
Some product alternatives for superabsorbent dressings
Mesorb is a more simple superabsorbent dressing that does not retain moisture as well as more expensive dressings. However, we find it to be a useful alternative when we have a situation where we need to change a dressing several times daily. Using an expensive dressing in such cases would be very costly. It does not perform very well under compression therapy, but this may be adequate for a shorter period of time.
Tegaderm foam comes with and without adhesive borders. It is also available as a roll. It can be used under compression therapy
Xtrasorb is similar in appearance to Mextra. It comes with and without adhesive borders. It is also available as a superabsorbent foam. It can be used under compression therapy
A soft superabsorbent dressing that performs well under compression therapy. It comes in sizes up to 20x30 cm.
Sorbion® sachet/Sorbion® sachet multistar (Cutimed® Sorbion)
Sorbion Sachet superabsorbents come in various shapes and make them ideal for placement on, for example, heels and elbows. Sorbion Sachet XL comes in a size up to 45 x 45 cm, which is useful for large leg ulcers. It can be used under compression therapy. Sorbion Drainage dressings are specifically designed to absorb around tubes and catheters. Note that these products are marketed under the name Cutimed Sorbion in some countries.
Eclypse® Super Absorber Dressings
Eclypse Super Absorbent dressings come in various shapes. Eclypse Boot is, for example, ideal for large leg ulcers. Eclypse Contour has an irregular shape and is useful for application in difficult areas like under armpits. Eclypse products can be used under compression therapy.
Dry Max Extra is a thin and soft superabsorbent dressing. It comes in sizes up to 37 x 56 cm.
Curea has a slightly different approach than most of the other producers. For the exudative phase, they recommend Curea P1 superabsorbent dressings, for the granulation phase Curea P2 is recommended. All Curea products can be used under compression therapy
As mentioned earlier, Curea P2 is recommended by the manufacturer once the highly exudative phase is over and the wound goes over into the granulation phase.
curea® P1 duo active
This superabsorbent contains active charcoal. Depending on which side you place on the wound, the dressing has different properties. If you place the white side on the wound, the dressing has superabsorbent and smell-reducing properties. if you place the grey side (charcoal side) on the wound the dressing has superabsorbent and antimicrobial properties. It can be used under compression therapy
PolyMem® Max / PolyMem® Max Silver
Polymem Max is the superabsorbent version of regular Polymem. It has good absorbent capabilities but not as high as some other dressings listed here. Also, its retention abilities are less. However, it is a very useful dressing once the wound produces less exudate. Polymem products contain a surfactant that aids in the removal of fibrin and dead tissue. It also comes with a silver version for wounds with high bacterial burden. Polymem Max can be used under compression therapy.
Sorbact products have a unique technology to trap microorganisms in the mesh of the dressing. The dressing has very good absorption/retention and works well under compression therapy.
Links to videos about some of the products shown above
If you are interested in learning more about some of the superabsorbent dressing discussed earlier, we have provided links to several videos about these.