maple
Canadian Medical Alliance for the Preservation of the Lower Extremity
Debridement
"To destroy is always the first step in any creation."
-- e e cummings
“There are some wounds that one can heal only by deepening them and making them worse.”
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Debridement is one of the basic concepts of wound healing.
The term refers to the removal of dead and damaged tissue
that tends to accumulate on a wound.
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The word "debridement" is derived from French word for
unbridling, (dé- ('un') + bride ('bridle') = "débridement.")
The origin of the term refers to the idea that dead tissue
present at the wound site tends to inhibit wound healing,
just as a bridle (the leather straps attached to the head of
a horse, as seen to the right) can rein in the movements of
a horse.
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So removal of the dead, non-viable tissue unharnesses the
healing potential of the wound, just as unbridling a horse
allows free movement of the horse.
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What tissue needs to be debrided? And why?
Many wounds tend to develop dead (necrotic) tissue. In
particular, diabetic feet, and in those with other forms of
neuropathy, dead tissue known as a callus tends to develop
around and over the ulcer site.
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To the right we see a callus overlying an ulcer in a Charcot
neuropathic foot (where the bones that make up the arch
of the foot have collapsed, and a bone that normally doesn't
bear weight begins to have pressure bear down on it.)
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When a callus covers a pressure spot like this, it is difficult to
assess whether a wound is present, and if it is, its depth, width,
and infection status.
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Some examples
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Look at the six calluses below. Can you tell which two of these
is just routine a callus--that is to say a region of thickened skin?
Which one covers an ulcer extending to the soft tissue (not bone)?
Which one covers an uninfected ulcer that extends down to bone?
Which one covers a soft tissue infection? And one which covers a
bone infection?
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Take a look. Can you tell?
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You can click here to find out the answers to the quiz on another page. If you are like us, however, you'll find it difficult to answer these questions. This is because it's difficult to assess what you can't see. You must debride to fully assess the extent and severity of a wound.
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The classic neuropathic ulceration tends to develop a ring of callus
surrounding an ulcer (right).
Even here, when the presence of an ulcer is not in doubt, it's
difficult to know the width of the ulceration. Does it undermine
the skin? If so, how far do the margins of the ulcer extend under
the callus ring?
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Further, the callus is dead tissue--a food source for bacteria, tissue
unable to mount a response.
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And its thickness puts more pressure on a wound, which is primarily
what caused the ulcer in the first place.
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Besides calluses forming around a wound, many types of wounds
develop necrotic tissue within the wound, as seen to the right.
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This dead tissue within the wound is known as slough (pronounced
"sluff").
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Slough is usually creamy white to yellow. It can be tough,
stringy, sticky, or slimy. It can be loose and easily removed
or very firmly attached to deeper structures.
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Slough is composed of dead tissue, proteins, and fibrin. Because
bacteria like dead tissue, there are always bacteria present,
at least living on top of the wound (colonizing it), even if
there is no actual infection breaching the patient's defenses.
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Even if there is no actual infection present, the bacteria living
on the slough can place a burden on the body's ability to heal.
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What about infected wounds?
Should these be debrided, too?
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Yes, most wounds should be debrided in the presence of an
infection, too.
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To the right is a diabetic patient with a history of foot ulcers
and amputations who didn't feel well. His wife looked at his
feet and legs and saw he had a red streak heading up the leg.
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When she looked at the foot and attempted to examine the
wound, but the wound burst open, covering her and their bed
with pus.
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The patient presented to the hospital. The wound was inspected,
but no debridement was done.
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An infection was correctly diagnosed, and the patient was placed
on a very strong (and very appropriate) antibiotic delivered
through IV (via a needle in the arm).
But after several days of antibiotics, the wound was still draining
pus and looked like you see to the right.
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The issue is that no debridement had been done. (Nor was the
patient offloaded--but this is a topic for another page.)
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And because no debridement had been done, no proper assessment
of the depth or extent of the infection could have been performed.
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How deep does the wound extend? Does the infection extend
to bone? How far does it undermine healthy tissue to the sides?
Unless you remove the dead tissue, how can you make this
determination?
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The wound needs debridement. The dead tissue cannot heal. And
it puts more pressure on the wound. Further, it inhibits healing by
holding the dead and infected tissue within the foot.
And because liquids cannot be compressed, leaving the fluid (pus,
serous fluid) inside the foot only causes adjacent normal tissues to
tear, allowing bacteria to spread.
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To the right you can see how the necrotic tissue was removed.
Approximately 5ccs of pus drained from the wound.
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With the necrotic tissues removed, we can see a how far the
infection undermined surrounding tissue. We can see a good,
healthy, red, granular base. We can determine that healing is
very likely.
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And to that end, by debriding, we're also expediting healing
by removing tissue that only causes harm.
And we can probably avoid expensive invasive imaging that
would typically have been ordered in lieu of debridement.
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The wound was dressed with an absorbent dressing
and offloaded. It healed without further issue.
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In the photo to the left we see another patient with a history of an infected foot ulcer.
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In this case, the patient has been on 8 weeks of IV antibiotics followed by three weeks of oral antibiotics.
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The wound on the bottom of the foot is mostly closed. Yet when we inserted a needle and pulled, we were able to pull 6ccs of pus from the wound. (This technique is called aspiration.)
This example gives you an idea how much fluid can exist inside
a foot, even when the wound doesn't look that large.
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Other Reasons to Debride a Wound
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Other reasons to debride a wound are at the cellular level--removing older, less productive cells, removing chemicals that inhibit wound healing, stimulating the growth of newer, younger cells, and increasing growth factors.
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Schultz, Gregory & A Mast, Bruce. (1999). Molecular Analysis of the Environments of Healing and Chronic Wounds: Cytokines, Proteases and Growth Factors. Wounds. 10.
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How do we know debriding an ulcer works?
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We have a page devoted to research supporting the use of debridement here.
How is debridement performed?
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There are numerous ways that debridement may be performed.
For example, there are high-powered jet sprays that can be used to wash
away necrotic tissue (slough).
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Enzymes that can be applied to dissolve the slough.
And even maggots may be applied to assist in the removal of non-viable
tissue, particularly in painful wounds.
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But by far and away, the most common way, and the most efficient way,
to debride most wounds of the dead and unwanted material is with a scalpel.
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For more on this patient, visit our page on the evidence for debridement here.
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Clinical Examples
Our goal is convert
this ugly wound filled with necrotic slough... to a nice, clean bleeding base... that has the chance to heal.
For more on this patient, visit our page on the evidence for debridement here.
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We want to convert a chronic,
non-responsive wound covered
with slough... to a bright beefy-red wound bed... that can close.
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We used sharp (scalpel) and enzymatic
debridement to go from this... to this... to resolution.
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This wound had very poor prospects
to heal and was nearly a year old. With regular sharp debridement... the wound was able to close.
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Without debridement, we'd not We were able to close the wound
have known that below this crust... was open bone with a sinus tract. before infection took the leg
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For more on the above patient and the importance of glucose control in wound healing, click here.
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The slough over this wound does the
patient no good and exposes her to harm. Debridement to a nice, bleeding base... allowed for healing.
It's an axiom of the wound care world that"It's not what you put on a wound that counts. It's what you take off."
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In other words it's not so much about the medications we put on the wound or the dressing we apply. What's important is what we remove, like dead tissue and body weight.
In other words, while wound care in Canada focuses on bandage changes, (things provincial health care covers) what's really important is to debride and offload (things provincial health care does not cover). This is something for which Canadian MAPLE is advocating.
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A major shoe company once had an advertising slogan, "Just Do It".
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JUST DO IT.
We like to think the D means Debride, and the O means offload. Then, we'd agree. Debride and Offload. Just DO it.
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JUST DO IT.
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We need to do it because statistics show that 90% of ulcers will heal within 6-8 weeks if they are debrided and offloaded.
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If you do not debride or offload, only a third will ever heal.
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Debridement is simply a basic tenet of wound healing.
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Occasionally we hear someone say a callus is the body's way of trying to heal. Leave it alone.
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But if it is your body's way of trying to heal, it's failing. Dead tissue will never heal. It's dead. You need, healthy, living tissue.
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If your treating physician is not offering debridement and offloading, and if your wound is being managed by someone who is not a wound care specialist and you're not making progress, you will likely need to ask for a referral to someone who is a wound care specialist. Someone who will debride and offload.
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In truth, there are relatively few in the medical field will do this. Many times this will be a podiatric wound specialist, as surgical debridement and understanding the biomechanics of wound healing is our specialty. And unfortunately, because most podiatric services are probably not insured by your provincial pan, you may need to have your extended medical plan cover these costs. Or you may need to pay some out-of-pocket costs to get this done.
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Caveat:
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With this all said, it's important to point out that while
debridement is extremely important as a basic concept
of wound healing, sometimes it is better to leave a
hardened crust of dead tissue, called an eschar, than to
remove it and create an open wound, particularly if blood
flow is insufficient to heal from the debridement procedure,
and if the crust is stable and the wound is not inflamed.
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So this is an exception to the rule. You need to have a
conversation with your treating wound care specialist to
discuss the specifics of your individual case.
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To visit our other pages on treating wounds, visit our page on offloading, on treating infections, on dressings, and on specialized treatments.
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To return to the top of the page, click on the maple leaf below.
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Why Must We Debride a Wound?
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1. To allow the clinician to assess the size and depth of the wound.
2. To allow for the clinician to assess the wound for possible infection.
3. To remove the dead tissue that applies pressure and creates the wound.
4. To remove bacteria / biofilm that build up to inhibit healing and cause
infection.
5. To allow for drainage of fluids that build up in a wound, such as pus
(bacteria and our cells that fight bacteria) and exudate (proteins and
cellular debris produced by the wound).
6. To remove the dead tissue bacteria use as a food source.
7. To remove old, less-active cells (senescent cells).
8. To provide new, younger cells a less competitive environment for
reproduction (mitosis).
9. To increase the number of growth factors that promote healing.
10. To remove the chemicals (MMPs or matrix metalloproteases) that may, in
chronic wounds and in patients with high blood sugar, break down newly-
formed tissue.
11. To remove the pro-inflammatory chemicals (inflammatory cytokines) that
may, in chronic wounds and in patients with high blood sugar, inhibit wound
healing.
“Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.”
-- Antoine de Saint-Exupéry
Airman's Odyssey
This page written by Dr. S A Schumacher
Podiatric Surgeon
Surrey, British Columbia Canada
All clinical photographs are owned and provided by Dr. S A Schumacher. They may be reproduced for educational purposes with attribution to:
Dr. S A Schumacher, Surrey, BC Canada