Wound healing is a complex process. Your body goes through several overlapping phases to repair injuries, including inflammation, proliferation (building new tissue), and remodeling (strengthening the new tissue).
Sometimes, a yellowish, tan, gray, green, or brown substance appears in the wound bed. This is called slough. It’s moist, stringy, and made of dead tissue (avascular).
If you’re dealing with a wound that has slough, it’s important to understand what it is and how to manage it. Effective wound care requires a good understanding of slough and the right strategies to encourage healing.
Understanding slough: Formation, composition, and characteristics
Slough can be an unpleasant sight, but it’s important to understand what it is and why it forms.
Formation of slough
Slough is part of the inflammatory phase of wound healing. It’s how your body clears away dead tissue and other debris from the wound.
However, chronic wounds often have a lot of slough because the healing process has stalled, frequently due to an underlying condition.
Composition of slough
Slough is made up of a variety of materials, including:
- Fibrin
- Leukocytes (white blood cells)
- Dead and living cells
- Microorganisms
- Proteinaceous material
Characteristics and appearance of wound slough
Slough can appear in a variety of colors, including yellow, tan, gray, green, or brown. Its texture can be moist, stringy, mucinous (like mucus), or amorphous (shapeless).
The color and consistency of slough can vary depending on factors like infection or dehydration. An infection may change the color to green or yellow, while dehydration can make it dry and crusty.
Slough vs. necrotic tissue and pus
Slough, necrotic tissue, and pus are all things you might see in or around a wound, but they’re very different, and it’s important to know the difference.
Slough vs. necrotic tissue (eschar)
Slough is moist and soft, whereas necrotic tissue, also known as eschar, is dry and hard. Eschar is usually black or brown, and slough can be a variety of colors.
Being able to tell the difference between the two is key because they require different treatments. You’ll need to use different debridement methods for each one.
Slough vs. pus
Slough is dead tissue, and pus is a sign of infection. Pus contains dead white blood cells and bacteria.
Slough may have a slight odor, but pus often has a strong, foul smell. Pus is usually thicker and more opaque than slough.
If pus is present, that means you’ll need to take steps to control the infection, possibly including antibiotics.
Why is slough bad for wound healing?
Slough is a problem because it gets in the way of wound healing. Here’s how:
- It raises the risk of infection. Slough is dead tissue, and bacteria love to feed on dead tissue. The more slough, the higher the chance of infection.
- It slows down healing. Wounds heal in stages. Slough interferes with the stage where the wound starts building new tissue.
- It makes it hard to see what’s going on. Slough covers the wound bed, so it’s hard to tell how deep the wound is and whether it’s getting better or worse.
Leaving slough in a wound can lead to:
- Longer healing times. If the wound can’t heal properly, it’s going to take longer to close.
- More problems. A slough-covered wound is more likely to get infected and develop other complications.
- Lower quality of life. A wound that won’t heal can be painful and limit your activities.
Also, slough encourages bacteria to form a biofilm, a slimy coating that’s hard to get rid of. This leads to ongoing inflammation, which also slows down the healing process.
Assessing Slough in Wound Beds
If you see slough in a wound, a thorough assessment is important. You’ll want to look at the slough’s color, texture, odor, and how much of it there is.
You can usually assess slough with a simple visual inspection. Wound measurement can also help you determine how much slough is present. Be sure to document all of the wound’s characteristics so you can track its progress over time.
Slough often needs to be removed for a wound to heal, but sometimes it can actually indicate progress. For example, a decrease in the amount of slough may mean the wound is improving. If you start to see granulation tissue (new connective tissue and blood vessels) underneath the slough, that can also be a positive sign.
Slough removal techniques: Debridement methods
Debridement is a fancy word for removing dead or damaged tissue from a wound so it can heal properly. Removing slough in a controlled way helps new tissue grow, lowers the chance of infection, and gets the wound ready to close.
Conservative sharp debridement
Conservative sharp debridement involves using tools like scalpels and scissors to cut away the slough. This gets rid of the slough quickly, but it needs to be done by someone who knows what they’re doing. There’s a risk of bleeding and pain.
Autolytic debridement
Autolytic debridement is when you let your body’s own enzymes break down the slough. This method is picky about what it removes and doesn’t hurt, but it’s slower than other methods.
Enzymatic debridement
Enzymatic debridement uses special creams with enzymes to dissolve the slough. This can be faster than letting your body do it on its own, but these creams can be pricey.
Mechanical debridement
Mechanical debridement is when you use physical force to remove the slough. One way to do this is with wet-to-dry dressings, where you put a wet bandage on the wound and let it dry, then pull it off, taking the slough with it. Another way is to flush out the wound with a strong stream of water. This method can hurt and can also remove healthy tissue along with the slough.
Managing infection and promoting wound healing
When you’re dealing with a wound that has slough, the two main goals are to manage any infection and to help the wound heal.
Infection control
It’s important to control the level of bacteria in and around a wound. Slough can be a breeding ground for bacteria, which can lead to infection and other complications.
Infection control strategies include:
- Antimicrobial dressings
- Topical antiseptics
- Systemic antibiotics (when needed)
Because of the rise of antibiotic-resistant bacteria, doctors try to use antibiotics judiciously.
Moist wound environment
It’s important to keep the wound moist to promote cell migration and proliferation. That’s why healthcare providers often use hydrogels, hydrocolloids, foams, and other advanced wound dressings.
Wound-healing adjuvants
In some cases, healthcare providers may use wound-healing adjuvants, such as growth factors or hyperbaric oxygen therapy (HBOT). Removing slough in a controlled way can promote the formation of granulation tissue, reduce the risk of infection, and generally prepare the wound bed for healing.
Special considerations for specific wound types
The type of wound you have will affect how you manage the slough.
Diabetic foot ulcers
Diabetic foot ulcers present unique challenges when it comes to managing slough, largely because of the neuropathy, poor circulation, and higher risk of infection that are common in people with diabetes. It’s very important to relieve pressure on the wound and keep blood sugar levels in a healthy range.
Venous leg ulcers
Venous leg ulcers also present challenges in slough management, due to chronic venous insufficiency and edema. Compression therapy is essential for these types of ulcers.
Pressure injuries
Pressure injuries (also known as bedsores or pressure ulcers) come with their own set of slough-related challenges, often related to pressure, shear, and friction at the wound site. To treat these injuries effectively, it’s important to redistribute pressure and use support surfaces that minimize friction.
Will slough go away on its own?
Sometimes. Your body has processes that can remove dead tissue. These include:
- Autolytic debridement, where your body uses its own enzymes to dissolve dead tissue
- Granulation, where new connective tissue and blood vessels form
- Epithelialization, where new skin cells migrate to close the wound
But slough may persist if you have underlying health conditions, an infection, or if the wound hasn’t been cleaned well enough.
You should seek medical care if the slough doesn’t go away, if you see signs of infection, or if the wound isn’t healing.
In Conclusion
Slough is often present in wounds, and how it’s managed can make or break the healing process. Accurately assessing the wound, choosing the right debridement method, and providing comprehensive wound care are all essential. Complex wounds often require a team approach, bringing together different healthcare professionals to provide the best possible care.
To improve outcomes for patients and reduce the impact of chronic wounds on their lives, we need ongoing research and more education for healthcare providers. By staying up-to-date on the latest best practices, we can ensure that people with wounds receive the most effective and compassionate care possible, helping them heal and get back to living their lives to the fullest.