Which type of wet dressing is used for dry gangrene?

The treatment approaches for dry gangrene and wet gangrene are completely different. Dry gangrene is caused by tissue ischemia and necrosis; after the water evaporates, the tissue dries and hardens, resembling a black, hard shell adhering to the skin. In the absence of infection, exudation, and significant surrounding redness and swelling, the primary goal for this type of gangrene is to keep it dry, not to moisten it. Using moist dressings may actually soften the dry scab, allowing the necrotic tissue and bacteria that were originally sealed inside to spread. 

How is dry gangrene treated?

For dry gangrene with poor blood supply and unclear infection boundaries, dry therapy is clinically recommended. Iodine solution is a commonly used option; iodine-containing dressings can accelerate the formation of demarcation in necrotic tissue, helping to determine which parts should be excised and which can be preserved. For dressings, gauze dressings containing paraffin or similar substances, as well as basic absorbent dressings, can be used. These dressings do not actively add moisture to the wound; they simply provide a relatively stable environment, keeping the eschar dry and allowing the body to naturally define the demarcation.

When can we use wet dressings? 

Dry gangrene doesn't mean that wet dressings can never be used; the key is timing. When local blood supply improves, the demarcation becomes clear, and necrotic tissue begins to loosen, it's necessary to switch from dry therapy to wet therapy. At this point, the purpose of using wet dressings is to soften the eschar, promote autolytic debridement, and allow the body to digest the inactive tissue itself. 

Hydrogel dressings are suitable for the debridement phase of dry gangrene. Hydrogels have a water content of approximately 80%, and when applied to the eschar, they continuously release moisture, gradually softening the hardened necrotic tissue. After softening, the adhesion of the eschar decreases, and during dressing changes, a portion can be gently removed with a cotton swab or tweezers—much gentler than forcibly tearing it off. Hydrocolloid dressings can also be used for wet or mixed gangrene, but they are not recommended for dry gangrene without infection, as they can easily cause maceration of the surrounding skin.

One important detail to note is that the hydrogel is only suitable for use on necrotic tissue and should not be applied to the surrounding normal skin, otherwise the healthy skin will be soaked and damaged. When applying, use a cotton swab to apply a thin layer, covering only the black scab, leaving a small safety margin at the edges. Cover the outside with a layer of dry gauze or polyurethane foam dressing, but avoid using highly absorbent dressings. This is because the hydrogel needs to remain moist to function; highly absorbent dressings will draw moisture away, causing the gel to dry and become ineffective.

What types of dressings should not be used?

There are several dressings that should absolutely not be used on dry gangrene. Alginate dressings should never be used on dry wounds. They are specifically designed for wounds with a lot of exudate, and when used on dry scabs, they will stick, harden, and tear off like glue, pulling the scab and the underlying tissue off together. Foam dressings are also not recommended for dry gangrene without infection. These dressings are designed to absorb exudate; dry scabs do not need to absorb anything, and applying foam dressings is nothing more than a waste of money.

An even more important nursing principle :

Whether or not to use a moist dressing to soften dry gangrene depends on whether blood supply has improved. If softening of the dry scab is started before arterial ischemia is resolved, the exposed wound will lack blood supply, hindering healing and potentially leading to new necrosis. Therefore, before considering any moist dressing, check the dorsalis pedis artery pulse and perform an ankle-brachial index to ensure sufficient blood supply to the extremities. If blood supply is insufficient, address the vascular issue first; dressings can be used later. Dressings are merely an auxiliary tool and do not address the underlying ischemia. For more information on Innomed® Silver Ion Dressing Foam, refer to the Previous Articles. If you have customized needs, you are welcome to contact us; You Wholeheartedly. At long-term medical, we transform this data by innovating and developing products that make life easier for those who need loving care.

Editor: kiki Jia