Wound Bed Preparation:  The 5 Types of Debridement

As a Naval Officer, I thoroughly enjoy history.  I couldn’t help to do some data mining and review the literature on the history of wound care and debridement.  It is very fascinating how the methodologies of ancient cultures have an impact and are still considered today.  One of the earliest records comes from Sumerian Clay Tablets dating back to 2200 BCE.  What has become known as the “3 Healing Gestures” outlines the first wound care in washing, the use of plasters, and dressings.  Interestingly, the mixture of plasters were often times composed of mud, clay, and plants which provided a platform for absorption for exudate. The Egyptians were the first to use adhesive dressings containing honey, grease, and dry lint in a dry clay mixture.  The honey and grease not only served to help secure the dressing in place, but also served as medicinal antiseptics against bacteria.  The color green represented life for the Egyptians and they commonly painted the wound with a green pigment which also contained copper which is also toxic to bacteria (7).

Even though we may not use plasters today, we still use honey and the concepts are all too familiar. In fact, the concept of debridement is structured under 5 classes: (1) Biological, (2) Autolytic, (3) Enzymatic, (4) Mechanical, and (5) Sharp Debridement. 

1. Biological debridement is also known as medicinal maggot therapy.  The maggots from the green bottle fly are used to secrete proteolytic enzymes which liquify dead tissue, thus neutralizing bacteria.  This process increases granulation tissue growth, oxygenation, and growth factors through wound bed PH level changes.  Care needs to be taken in ensuring the wound does not have heavy exudates which can drown the maggots as well as high pressure areas which can also crush them.
2. Autolytic debridement allows for the rehydration of the wound and uses the body’s own enzymes and moisture.This is the most commonly used method in debridement and consists of Hydrogels, Hydrocolloids, Hydrofibers, and Calcium Alginates.  This method of debridement is very easy to perform, extremely versatile and causes little to no pain.  This is an excellent methodology for highly exudative wounds.  Interestingly, Alginate dressings can absorb up to 20 times their weight in wound fluid.  However, autolytic debridement is a very slow, cumbersome process and is a potential for infection and maceration of the peri-wound skin.  It is also contradicted in patients who are immunosuppressed or need elimination of necrotic tissue immediately.
3. Enzymatic debridement is also known as chemical debridement.  It is very effective in the removal of necrotic tissue and can either work from top down (Papain based) or from bottom up (Collagenases).  They are derived from animal, plant, and bacteria sources and come in the form of gels and ointments.  This method is ideal for any bleeding disorders and or issues encountered especially in anti-coagulant therapy.  However, pain can be a problem with use as well as drainage.
4. Mechanical debridement is also known as wet-to-dry dressing, whirlpool, forceful irrigations, pulse lavage, and ultrasound debridement.  It is basically the initial tissue cleansing preceding other debridement methodologies which provide a physical abrasiveness to remove non-viable tissue.  It may be considered especially if the patient has issues with access to wound care as a means of providing daily dressing changes at home.  However, it can also be very painful especially upon removing the dressing where the top layer of the wound is exfoliated followed by bleeding.  Therefore, caution is recommended with elevated INR levels greater than 2.5 with this method. It is also considered a non-selective debridement methodology since it will remove not only non-viable but also viable tissue.
5. Sharp debridement is also a non-selective debridement method and is highly effective in the removal of Biofilm. Depending on the instrumentation utilized, acumen and skillsets become paramount especially with the use of scapples and curettes.A component of sharp debridement known as Conservative Sharp Debridement is defined as sharp debridement to the very edge of the vascular bed with very minimal to no bleeding and is a common method used by clinicians. However, the scope of practice and licensure can provide barriers.  Pain is one of the most common features encountered with sharp debridement and topical analgesics are often employed prior to engagement.  Hemostasis is another problem that is often encountered especially with traditional sharp instrumentation and care must be taken especially in those patients who are on anti-coagulant medications.

As noted, Sharp debridement is vital in the removal of Bioburden or Biofilm, non-vital tissue, and the elimination of potential infection.  While the body of evidence continues to substantiate the benefits of sharp debridement, very little is known about the cost effectiveness of debridement methods.

In 2013, a Canadian Health Care System study was conducted to analyze the cost effectiveness of various wound debridement methods, the impact it an have on a health care system, and clinical outcomes. The analysis was based on expert opinions on a hypothetical patient with a chronic wound with only direct and indirect costs associated with wound debridement.  Further evidence-based data was collected from Federal and Provincial sources, and published literature (8).  The Key findings of the study are as noted below:

Key Findings:

1. Sharp Debridement (vascular layer of bleeding) was the most cost effective at $1039
2. Enzymatic $1119,  Autolytic $1504,  Mechanical $1840,  Biological $2150
3. Base case analysis of use of resources:  Sharp debridement was the lowest cost
4. Speeding up achieved wound debridement and fewer resources:  reduce costs
5. Conversely, the slower frequency to achieved wound debridement: higher costs
6. BLUF:  faster time to achieve a clean wound bed resulted in reduced costs
7. Sharp debridement is the most efficient way to achieve a clean wound bed

In my next installment of wound bed preparation, we will take a closer look at Biofilm and the negative impact it is causing in the wound care space.  Please check back often and until next time, fair winds and following seas.

Cheers,

Dr. F. Derk