A calcium alginate dressing is a topical wound dressing made with the ingredient alginate, also called algin, which is a highly-absorbent substance that is extracted from the cell walls of brown seaweed. This type of dressing is used for dermal wounds that produce exudate, meaning that they ooze bodily fluids such as blood, plasma, mucus or pus. For these kinds of wounds, a calcium alginate dressing is often preferable over other dressings because it is easier to remove, causes less pain and promotes faster healing. These dressings have been utilized in wound care for more than 50 years and are used for certain kinds of burns, venous ulcers, pressure ulcers, diabetic foot ulcers and some cavity wounds as well as various other wounds. The dressings are available in fibrous, non-woven sheets for shallow wounds, and in a rope-like form for deep wounds.
Alginate fibers can absorb up to 20 times their own weight in fluid, and the calcium alginate dressing itself turns into a viscous, gel-like substance as this absorption takes place. This produces a moist, sterile environment that promotes healing and minimizes bacterial infection in the wound. These dressings also promote wound healing by helping with debridement, meaning the removal of infected, dead or damaged tissue that can otherwise interfere with healing and cause pain and further infection.
For both shallow and deep wounds that ooze large or medium amounts of bodily fluids, a calcium alginate dressing often works better than regular dressings such as saline soaked gauze. Other dressings might stick to an oozing wound, but the moistness of this type of dressing makes it more comfortable for the patient while it is on, and makes it easier and less painful to change or remove. Some calcium alginate dressings can even be washed off with saline rather than pulled off the wound, making removal even easier.
Calcium alginate dressings come in two forms: sheets and ropes. The sheets are available in various sizes and are used for shallow wounds; they are either applied directly or soaked in a saline solution before application. The rope or ribbon shaped dressings are recommended for deep wounds, and are packed into the wound itself. This type of dressing should be changed every day and is not recommended for wounds that are dry and produce little fluid because its absorbency might cause dryness and scabbing. Side-effects of these dressings are very unusual and can usually be avoided by proper wound care and careful removal of the dressing.