Non-surgical Debridement of Burn Injuries

This article or area is currently under construction and may only be partially complete. Please come back soon to see the finished work! (28/07/2023)

Original Editor - Stacy Schiurring based on the course by Diane Merwarth

Top Contributors - Stacy Schiurring, Jess Bell and Matt Huey

Introduction

Please see this article for a list of useful wound care terminology.

Indications for Debridement

Indications for debridement:

• Remove devitalised tissue, this is the primary function of debridement. The presence of non-living tissue in a wound bed impedes wound healing by:
  • acting as a nutrient source and ideal living environment for unwanted microbes which can cause infection
  • creating a physical barrier for re-epithelialisation
  • creating a barrier against topical antimicrobial agents which limits their ability to manage infection in the wound
• Stimulate the wound bed in chronic wounds to reinvigorate the wound healing cascade. The presence of non-living tissue in a wound bed effects the wound healing cascade by inhibiting:
  • angiogenesis (the formation of new blood vessels from existing vasculature)
  • granulation tissue formation
  • re-epithelialisation

Surgical excision of non-viable tissue is the standard of care, however there are times when less aggressive debridement methods are required. This can include:

1. Medically unstable patients who could not tolerated sedation and/or surgical interventions
2. Surgical resources not available
3. Non-surgical management is preferred
4. Areas of deep partial and full thickness injury are small and can be properly managed with less invasive methods
5. Area of the burn wound injuries is not serious enough to warrant surgery
6. The risk of surgery damaging vital structures is greater than non-surgical care such as on the fingers or hands

Images for this section: eschar, necrotic tissue, slough, bioburden, biofilm, and those apoptotic or senescent cells that accumulate on the surface of the burn.

Non-surgical Debridement

Non-surgical debridement is the removal of materials which limit or impair healing from a wound bed without by means other than sharp excisional methods into viable tissue in a sterile surgical setting. Examples of unwanted materials in a wound can include: eschar, necrosic tissue, bioburden, biofilm, or foreign matter.

This article will explore five types of non-surgical debridement: (1) mechanical, (2) autolytic, (3) local sharp, (4) biosurgical, and (5) enzymatic.

Mechanical Debridement

"Mechanical debridement is a nonselective type of debridement, meaning that it will remove both devitalized tissue and debris and viable tissue. It is usually carried out using mechanical force."

The amount of force applied during mechanical debridement is subjective and is based on the wound care professional's clinical skill and comfort level. Currently, there is little evidence in the literature to support the use of mechanical debridement in the treatment of burn wound injuries.

Indications for mechanical debridement:

• acute and chronic wounds with moderate to large amounts of non-viable tissue
• can be used regardless of the presence of active infection

Contraindications for mechanical debridement:

• greater percentage of granulation tissue than devitalised tissue in wound bed
• inability to control pain
• patients with poor perfusion
• intact eschar with no clinical evidence of an underlying infection.

Clinical Pearls: a deeper look at eschar

explain stable versus unstable eschar

Examples of mechanical debridement:

1. Pulsatile lavage. Involves moderate-to-high pressure irrigation which is well controlled and known to be safe for the surface of wounds, including burn wounds.
2. Wound Irrigation. Can be achieved using a syringe with a known gauge needle to provide a known amount of pressure. Not commonly effective for use in burn wound injuries.
3. Shower. Please see this article for more information.
4. Whirlpool. Please see this article for more information, especially regarding the physiological responces and risks of whirlpool use with burn injuries.
5. Scraping. Achieved using the edge of a scalpel, a curette, or some other flat instrument, such as a tongue blade, to scrape the surface of the burn wound and remove any loosened debris.
6. Wet-to-dry dressings. Involves applying gauze which has been moistened with either saline or an antimicrobial agent on to the surface of the burn wound, allowing the gauze to dry, then removing it from the bur wound surface. As the gauze dries, anything on the wound surface, which can be loosened devitalised tissue or healthy granulation tissue, can adhere to the gauze. When the gauze is removed, both types of tissue is ripped off the wound surface. This method of debridement can be very painful and highly nonselective.
7. Soak and wipe. Involves applying towels or gauze saturated with saline or an antimicrobial solution to the surface of the burn wound and allow them to "soak" for 5-10 minutes. Next, using a saturated gauze, wipe the wound surface with an applied force in circular motions to remove debris. The wiping is performed to the patient's tolerance. Caution should be taken to only use clean gauze when wiping, and discard gauze as it collects devitalised tissue. When treating a large burn wound, only expose a small area at a time to prevent hypothermia. Please see this article for more information.

Special Topic: Wet-to-Dry Dressings

Once well known and widely used, now no longer considered standard of care. Evidence based practice ...

Advantages

• Quick to perform with appropriate pain management
• Can be used with active infection
• Efficient for larger wounds
• Effective at bedside or in the outpatient setting with adequate pain management. And there was one study that showed the effectiveness of pulse lavage. This was a study that was done after surgical excision of the burn wound, then using pulse lavage to clean the surface of the burn wound, and then a skin graft is applied to that cleaned wound bed. And this study showed that using pulsatile lavage after surgical excision increased the success rate of skin graft take and decreased the amount of infection that occurred after that skin graft surgery.

Disadvantages

• Very non-selective form of debridement
• Very painful

Autolytic Debridement

"[Autolytic] debridement is a natural process by which endogenous phagocytic cells and proteolytic enzymes break down necrotic tissue. It is a  highly selective process whereby only necrotic tissue will be affected in the debridement."

This is the most conservative type of debridement. Autolytic debridement involves dissolving or separating eschar from the underlying dermis to allow it to be removed or debrided away. A moist dressing environment optimises autolytic debridement. The effectiveness of autolytic debridement depends upon the amount of devitalised tissue present in the wound and the true wound size.

Indications

• recommended for non-infected wounds, however can be used with other debridement techniques, such as mechanical debridement, in the case of infected wounds.

Contraindications

• Immuno-compromised patients

Examples of dressings that facilitate autolytic debridement:

1. Hydrocolloids (most effective)
2. Hydrogels
3. Transparent films
4. Medical grade honey

Advantages

• Very selective because it only targets the necrotic tissue
• Essentially painless
• Fairly simple process to utilise

Disadvantages

• Slow debridement process when compared to other methods
• Not indicated in the presence of an active infection
• Not effective or efficient for use in burn wound with large surface areas

Local Sharp Debridement

Local sharp debridement is another method of non-surgical debridement. It essentially uses a scalpel or a pair of scissors along with forceps or other devices to specifically and sharply remove non-viable tissue. The advantages of local sharp debridement is it can be fairly quick, if it's a small area that needs to be debrided. It's very specific, again, depending on the skill and the technique used. And it's good for bedside or outpatient procedures, if it's a small area that needs to be debrided as well. The person who performs the sharp debridement must be certified to do so. Depending on where you live and what your specialty is, some require additional certification. I know in the United States, physical therapists under their license are able to perform local sharp debridement. It varies state to state how deep they can go into the tissue when they're performing that debridement. But all of us are allowed to perform sharp debridement using these instruments. Most nurses in the United States, unless they go through the wound, ostomy, and continence courses and become wound certified, require additional certification through a course before they can perform bedside debridement on a patient. And it varies, again, like I said, from discipline to discipline and from country to country based on regulatory requirements.

Disadvantages to local sharp debridement is it can be painful because you are interacting with the viable wound bed, depending on how deep you're going with your debridement, and it is slightly invasive. So there is a risk of of bleeding, and if they're anticoagulated, that risk, you know, can be pretty severe. And so those things need to be assessed prior to performing the local sharp debridement.

Biosurgical Debridement

Biosurgery or larval therapy, otherwise known as maggot therapy, and

Another method of non-surgical debridement is biosurgery, or larval therapy, using maggots to debride the burn wound. Maggots come from the sterile larvae of the green bottle fly. They can be ordered either free range, meaning they're just loose, or in a mesh bag to be placed on the wound surface. I found one study that showed the use of maggots very effectively debriding a subcutaneous electrical burn wound. The basic mechanisms for larval therapy debridement is the secretions produced by the maggots have proteolytic enzymes that help to dissolve that nonviable tissue, and then the maggots ingest and digest that non-viable tissue to get rid of it. They also release ammonia, which increases the pH in the area of the maggots, and that is antimicrobial because bacteria don't like the higher pH and so they don't tend to grow in those areas. Maggots can be very effective in reaching areas that you can't access manually, deep crevices. Particularly with non-burn wounds, they can be very effective in getting in nooks and crannies and debriding burn wounds, but they can also be effective on burn wounds.

The advantages of maggot therapy include it's essentially painless, although there have been some reports of minimal pain. It's very selective because they're going after that necrotic tissue. It's fairly rapid and it can debride, as I said, areas that are difficult to access. The disadvantages of maggot therapy include the containment of the larvae. It has been found that the free-range or free-roaming maggots are much more effective and efficient than the ones that are contained in the mesh bags. There's also the patient or caregiver acceptance of having maggots on them, or otherwise known as the ick factor. And it's really not conducive to outpatient care because the difficulty in managing the larvae really needs to be under constant supervision, which is better done in the hospital setting.

Enzymatic Debridement

The final method of non-surgical debridement that I'm going to talk about in this module is enzymatic debridement. Essentially, enzymes are chemical agents that are composed of exogenous proteolytic enzymes to debride the necrotic tissue in a burn wound or any wound in general. Enzymes have probably been the most extensively studied of the forms of mechanical debridement that I've talked about today. And currently there are only two enzymes available on the market. There have been several over the years that have been available commercially for a while. And for various reasons, they have all been removed from the market except for these two remaining that are specifically approved as debriding agents, in their formulation.

So Collagenase made by Santyl is the one that's been around the longest. It is derived from a bacterium, the clostridium histolyticum, and it was the first enzyme approved by the FDA in the United States, and it's been around for several decades. The second one is a bromelain-based enzyme derived from the stems of pineapples, and it provides multiple proteolytic enzymes in its formulation. It was approved for use as a debriding agent in Europe since 2012, under the name NexoBrid. It was just approved in the United States as of April 2023 for debridement of burn wounds, also under the name NexoBrid. There's been only one study and it was a recent study comparing directly the bromelain-based debriding agent with a collagenase debriding agent. Other studies have been conducted looking at each of these enzymes individually, they've been small studies, animal-based studies, and they typically compare the use of enzyme and monitoring wound healing, compared to the use of non-debriding agents such as silver sulfadiazine, or moist gauze dressings, or some other form of dressing that's not indicated for debridement.

There have been multiple case reports, case series reports, expert opinion reports about the use of enzyme in managing burn wounds, and I'm going to discuss some of the findings of these in a little bit. There's also been consensus reached by large expert panel looking specifically at the use of NexoBrid as an enzymatic debriding agent, and providing guidelines of when it's appropriate and the best ways to use that particular agent. Everyone seems to agree that enzymatic debridement is not effective or adequate for severe deep burns or critical patients, where surgical excision is still the standard of care and necessary to provide the most optimal outcome and hopefully survival of that particular patient. However, the enzymatic debridement techniques can be an a very beneficial and effective adjunct to surgical excision as well.

It's also been found that enzymatic debridement can be effective when surgery isn't feasible, such as in areas that are difficult to debride. The deep skin folds, those areas of thin dermal tissue that I talked about, like the fingers and the hands, as well as areas that are more important for cosmesis, where surgical excision can result in scars that are more deforming or less appealing to the patient once they've healed, where the enzymes are less aggressive and can provide a better outcome, such as the neck, the face, and the hands.

The advantages of using enzymatic debridement as a form of non-surgical debridement for burn care include both of the products that I've talked about, the collagenase and the bromelain-based enzyme are faster than autolytic debridement. They're very selective, although autolytic debridement is also selective, these particular devices are very selective to just the non-viable tissue on the burn wound, and they're good alternatives when surgical intervention isn't feasible either at that moment or for the length of the recovery of that particular burn patient. For collagenase, the advantages also include minimal pain associated with the use of collagenase. It's a simple application and it can be applied at bedside or in the outpatient setting.

The advantages specific to NexoBrid include it is a good alternative to surgery in those areas of function, such as the hands, which I mentioned earlier, where cosmesis is important such as the hands, the face, the neck, and those areas that are difficult to access, like deep skin folds, where getting in there manually can be challenging. NexoBrid is also much faster in accomplishing debridement than is collagenase.

The disadvantages of enzymatic debridement, and these are really specific to the debriding agent. So the disadvantages of collagenase is it's a very slow process compared to the bromelain-based enzymatic therapy. It can cause maceration because you need a moist dressing to keep the enzyme activated and to facilitate the separation of that eschar from the underlying wound bed. You risk the maceration of the peri-wound skin as that drainage accumulates under that dressing. And collagenase can be deactivated by other agents that we may be using to provide care for that burn wound, specifically, silver-based dressings and Dakin's solution.

The disadvantages that are specific to bromelain or NexoBrid include pain. The patients require ongoing pain management while the NexoBrid is in contact with the patient's burn wound, and that may be anaesthesia or a significant amount of sedation. According to the guidelines, the application is limited to a total body surface area of 15% or less, although there is some studies that indicate that it's safe for up to 30% total body surface area. It's only appropriate as an inpatient because of the pain medication that's necessary during the process, although there have been a couple reports where it was performed on an outpatient in a very small surface area. It requires a skilled provider to apply the NexoBrid and monitor the patient during the process. And bleeding can be a risk, particularly if the patient either prior to their burn injury or as a result of the changes related to their burn injury, has a coagulopathy where bleeding is difficult to control.

It has been found through various studies that the timing of applying the enzyme for debridement will affect the outcome of the success of that particular debridement. So most studies show that application of the enzyme within 12 hours of injury or up to 72 hours post-injury is the most optimal for getting the best success rate in using enzymes. If there is a delay of greater than 72 hours after burn injury before an enzyme is applied, then they recommend that a biopsy be done to rule out the presence of infection and if infection is found, to begin treating that infection while the enzymatic therapy is undertaken. And that the burn wound be pre-soaked, and this is really specific to the NexoBrid application process that the burn wound be pre-soaked to soften that eschar for at least two hours prior to the application of the enzyme.

Compare/contrast collagenase and the bromelain-based enzyme in table:

Now I'm going to review various studies that have been done with both collagenase and NexoBrid, starting with collagenase or Santyl collagenase. As I said, most of the studies compare using collagenase with non-enzymatic type interventions, such as the use of silver sulfadiazine, or even surgical excision. The mechanism of action for collagenase is specific degradation of denatured collagen, which is why it is considered so specific, because that's what eschar and non-viable tissue is, is denatured collagen. One of the studies was a summary through a systematic review that showed that collagenase was very effective in managing debridement of non-complicated burns of 10 to 20% total body surface area. They found no difference between surgery and using this enzyme to achieve debridement in paediatric burns. It resulted in shorter length of stay, less bleeding, and less surgery for partial thickness burn wounds, and in comparison to silver sulfadiazine, collagenase achieved a faster end result of a clean wound bed and more rapid healing.

Another study like the one that I mentioned previously compared collagenase to the bromelain-based enzyme, and it found that even after 14 days of daily application of collagenase, it was not successful in 100% removal of eschar, where the bromelain-based enzyme was successful in removing 100% of the eschar in one four-hour application. However, this was a very small animal study and more studies are obviously indicated.

Another study was a small study that was sponsored by the industry that manufactures the collagenase, and it showed that in vitro, after surgical excision, the collagenase increased proliferation of the vascular endothelial cells and keratin; and in vivo, it enhanced re-epithelialisation and resulted in speedier wound closure. Another study reviewed multiple randomised controlled trials, and it found that the timing of enzyme application was best at about 48 hours after injury, but was essential in less than seven days after injury. And the same study also showed that collagenase was effective in removing fibrin and small areas of necrotic tissue.

The procedure for application of collagenase. One, it does require daily dressing changes. As I said before, it is a bacterial-based enzyme and it's not recommended to leave it on for more than 24 hours at a time. It's most effective when applied directly to the eschar or necrotic tissue in a thick, and by thick, they describe it as nickel thickness or a two-millimetre thickness of enzyme to the necrotic tissue. There is no risk to the surrounding viable tissue if you get collagenase on the viable tissue. It's more just effective use and monitoring the cost and being more cost-effective. And there's minimal risk to the peri-wound of maceration, but there is that risk because of the increased drainage produced while that enzyme is working, so you can protect the peri-wound skin with a skin protectant of some kind, or even just Vaseline so that the maceration does not become excessive.

After the enzyme is applied, you cover it with a moist, non-adherent dressing. As I said before, you shouldn't use a silver-based dressing or anything with Dakin's on the dressing. Probably one of the easiest dressings to use over the collagenase is a Vaseline-coated gauze, such as Xeroform or Vaseline gauze, used in multiple layers to provide the moisture that the enzyme needs. It's also important to know that if there is not enough drainage or moisture from the wound itself to keep the enzyme activated, that the dressing put over the top of the enzyme needs to add moisture to the wound to provide that moist environment. The dressing, as I said, is changed daily at each dressing change. Other methods of mechanical debridement can be performed, just the soak and wipe or scraping, if there's loosened necrotic tissue to be removed, and then the process is repeated.

Most studies and anecdotal reports that I've seen say that they discontinue the use of collagenase once the eschar has been eradicated. However, the manufacturer itself says that it is safe and effective in use throughout the wound healing process. And part of that is because of the effectiveness that it has on reducing fibrin and promoting that endothelial activity that was mentioned in the one study.

So this picture is just an example of how I have applied collagenase in the past. Because collagenase is an ointment and the wound bed is typically moist, it's very difficult to apply the ointment directly to the wound bed because it just kind of slides around. So we have found it to be much more effective to apply the collagenase to the dressing, such as the multiple layers of Xeroform or Vaseline gauze, or a foam dressing if you're using that. Applying it in the area of the eschar and then placing that onto the burn wound. Again, since there's not a risk to the viable tissue, you don't have to be extremely precise in where you are applying the collagenase, you just want to be fairly efficient so that you're not wasting the product. And then you dress the entire wound.

In the wound pictured here, it can be done in a couple of ways. You can apply the collagenase on the Vaseline-based dressing to the eschar, and then apply Vaseline dressing to the entire wound bed without the debriding agent and change that entire wound daily. Or you can apply a dressing that can be used for an extended period of time, a silver foam, a regular foam that can be left on for several days at a time and place that dressing around the eschar. Place the collagenase and whatever dressing you're using to hold that collagenase in place on the eschar, and then bandage the entire hand. And then in 24 hours you can remove the outer gauze wrap, change the collagenase, but leave the dressing intact on the viable parts of that burned hand and then redress, reapply the collagenase and redress that hand wound. That decreases the dressing change and trauma to the areas that are continuing to heal, but still provides effective and safe management of the eschar using collagenase as the primary debriding mechanism.

The bromelain-based enzyme has also undergone extensive studies. A compilation of the study results have found that after pre-soaking and applying the enzyme for four hours, followed by mechanical debridement and soaking overnight, a skin graft has an 86% rate of effectiveness once that wound, that skin graft has been applied after that overnight soaking. It also found that burns treated with the bromelain-based product usually only require one four-hour application to be successful in removing all of the eschar. It has contributed to fewer surgeries and smaller skin graft areas, which results in decreased blood loss and decreased time to complete eschar removal on the surface of that burn wound, and it found that there was no difference in the quality of the scar following debridement using the bromelain-based agent versus conventional surgical excision. It also found that early application, in these studies early application was within 12 to 72 hours of the injury is the gold standard. Delays greater than 72 hours should be managed, as I said before, first assuring that there's no infection, and then pre-soaking to soften that eschar before application of the enzyme.

It was also found to be effective in reducing the need for an escharotomy if applied early enough. If the compartment syndrome had already become established and there were already high pressures in those compartments, then a surgical escharotomy was indicated. But if the compartments were still somewhat soft, but the patient was noted to be at significant risk of developing one, then application of the bromelain-based enzyme could eliminate the need for that escharotomy. Other studies show that one treatment of four hours, followed by a two-hour soaking, resulted in complete eschar removal of deep partial and full thickness burn wounds. This was a small animal study. Another one showed that after eschar removal, a skin graft should be delayed for two days. That is a recommendation of the consensus panel that presented several of these guidelines.

There are also precautions that should be considered when using the bromelain-based enzyme. For one thing, it has not been studied in large surface area burn wounds as far as applying the product all at once. As I said, most of the recommendations are 15% TBSA or less. So if you have a larger burn, then you need to apply it in sequential parts of 15% to achieve that complete debridement. It has also not been studied on chemical burns, so there's no known effect for that. They have found poor results in using the bromelain-based enzyme on early application for scald burns and in applying it to burn wounds on the surface of diabetic feet. And that needs further study because they're not really sure why those results are so poor. It's also not recommended for high-voltage electrical injuries or the established compartment syndromes, as I'd said before.

As for the procedure for applying the NexoBrid to eschar in a burn wound, most of what I'm going to list has come from various studies, the consensus recommendations, and case reports. The insert that's included with NexoBrid from the manufacturer has very little detail as far as the application instructions. The main thing it does say is that the patient needs to be an inpatient when using NexoBrid for burn wound debridement, and it should be either in a burn unit or a burn centre, if at all possible.

So the procedure is a combination of the insert as well as the insert of the manufacturer's recommendations as well as the consensus and some of the studies that I found. The current recommendations are that it should be only applied to an area of 15% total body surface area or less per application. It should be applied by a skilled practitioner such as an MD (medical doctor) or a nurse practitioner or a physician's assistant, usually in the operating room. The patient needs to have adequate pain medication during the application process and for the entire four hours that the enzyme is in contact with their burn wound. It's important to protect the peri-wound skin with a thick layer of petroleum or some other skin protectant to prevent maceration and to prevent burning of the NexoBrid on the skin, although it doesn't destroy or damage the skin, it can cause some burning and maceration. It should be applied in a thick layer and then covered with an occlusive dressing. It should not be used in combination with Silvadine or Betadine. And it should stay in place for four hours. At four hours the dressing is removed. There are some studies that showed performing mechanical cleaning or wet-to-dry dressings for a short period after removal of the NexoBrid dressing will help remove the residual non-viable tissue and the residual product that stays on the wound after that dressing has been removed.

Then the wound bed needs to be assessed. If there is punctate bleeding, just little spots of bleeding throughout that burn eschar, then the burn is expected to re-epithelialise without the need of a skin graft. If there is more large-calibre vessel bleeding when that dressing is removed, then there is indication that a skin graft is needed to help complete the wound healing process. If a skin graft is not determined to be necessary at that particular time, then dressings are used to provide the moist wound environment for healing to continue. That can be allografts, if the resources are available, or some other form of skin substitute or dressings that your facility uses for ongoing burn care, preferably ones that can be left in place for several days at a time, so you're not disturbing that burn wound and the healing process can continue. If a skin graft is indicated, some studies or the consensus panel recommend a delay of two days to allow that burn wound to stabilise for the vascular granulation tissue surface to become more stable, so it will be ready to accept the skin graft.

There has been some off-label use of NexoBrid reported in the literature, including applying it up to 30% total body surface area in one application without adverse effects. And a study that showed it could be used in the outpatient setting, although it's only approved for inpatient use, in a very small burn wound with adequate pain medication. The recommendations for when it's appropriate to apply a skin graft vary from immediately after that NexoBrid dressing is removed to the delay of up to two days to allow that wound bed to become a little bit more stable.

I do want to point out that there is another bromelain-based debriding agent on the market under the name of EscharEX. It's produced by the same manufacturer that produces NexoBrid, but it is indicated for non-burn wounds, those chronic hard-to-heal wounds like diabetic foot ulcers, venous leg ulcers where NexoBrid is indicated specifically for burn injuries. I just wanted you to be aware of that in case you hear the other name and are wondering what the differences are.

So for large surface area burns, patients in critical condition, established compartment syndromes, surgery remains the standard of care. But as we've seen, there are many situations when surgery may not be indicated or feasible at a particular time or even throughout the course of healing. And so non-surgical interventions are very appropriate in these situations. Those patients who are unstable, burns that are very small and can be managed locally very effectively, or those burns of mixed depth where a wide surgical excision can cause more damage to salvageable tissue, and thereby waiting for those less severe burns to heal using non-surgical interventions can be beneficial, so that surgery can focus on just those deep areas when they become more well defined. Surgical excision may also not be the best intervention for certain areas of burn. Those areas that are difficult to access, deep skin folds, deep in the perineum, or those areas that can be damaged further by aggressive surgical intervention or with cosmetic concerns such as the hands and the face.

So non-surgical debridement with a combination of those non-surgical methods can be very effective. It's very common to use a dressing that promotes autolysis and at each dressing change, perform mechanical debridement, and even local sharp debridement to further debride the non-viable tissue and eschar from that burn wound. It's a slower process, but it can be very effective in removing areas of eschar under those smaller dressings. Collagenase can also be combined with an autolytic-type dressing. It's important to remember that that is a daily dressing change, so the dressing you choose should be appropriate for a daily change as far as cost goes and time management, so those Vaseline-coated gauzes in multiple layers that can provide a somewhat occlusive covering will facilitate the work of collagenase much more effectively.

Santyl is, as I said, the only collagenase-based debriding agent currently on the market. It is slower compared to the other methods of debridement that we've discussed, particularly surgical excision or the bromelain-based enzyme. However, it's very appropriate to be used at bedside or in the outpatient setting, so it does not require that excessive pain medication, and it can be applied by a family member or a caregiver after instructions so that these dressing changes can continue at home in between visits to the outpatient setting.

NexoBrid remains the only bromelain-based debriding agent on the market. The main disadvantages of NexoBrid are that the patient needs to be hospitalised. They need to have significant pain medication administered during the application process of NexoBrid, and the application is generally limited to a surface area of less than 15% total body surface area. So for larger burns, it requires multiple applications in different sections on consecutive days to achieve complete debridement of that burn wound. There is an off-label report that shows safe use of bromelain on a surface area up to 30%, but that remains off-label, and the consensus guidelines still limit the use of bromelain to the 15% total body surface area.

The advantages are that it only requires a single application in most cases to achieve complete removal of the eschar. There have been some times when the eschar is not completely eradicated and repeat application to the same area is not recommended, except in very certain circumstances, and currently it does require a skilled clinician, a physician, or a mid-level to apply this in the inpatient setting.

The greatest benefits of the bromelain-based product is that it does achieve 100% removal of the eschar in most cases, and it allows for immediate, or very shortly thereafter, skin grafting to that area if a skin graft is indicated. There are some reports that say a delay of two days is preferable to allow that wound bed to become stable before a skin graft is applied. And there are documented procedures that show the benefits of mechanical debridement, a scrubbing, or a wet-to-dry dressing immediately after the removal of the NexoBrid dressing to allow that wound to be cleaned up to remove any residual necrotic tissue that remains on the surface of the wound to remove the remaining product that remains on the surface of the wound before that skin graft is applied. And in those situations where a skin graft isn't indicated, then it prepares that wound bed for another temporary coverage. An allograft or another type of skin substitute or even ongoing dressing changes until that burn wound goes on to heal or the area that needs skin graft is small enough and a smaller skin graft can be applied.

So the biggest benefits for non-surgical debridement include the elimination for the need of a skin graft or a decrease in the size of the skin graft that is needed, which also decreases the size of the donor site. It also allows for ongoing therapy to limit the negative effects of having to immobilise a body part after a skin graft. You can continue with occupational therapy and physical therapy throughout the healing course, which decreases the long-term comorbidities and recovery. The rapid removal of eschar decreases the risk of infection and also decreases the length of hospitalisation. Now, surgery is obviously the most rapid way to remove that eschar, but as I've said with these smaller situations where surgery may not be indicated, the combination of non-surgical debridement interventions can also remove that eschar fairly rapidly and can be done on an outpatient basis if it's a smaller burn and the patient is stable.

So non-surgical debridement has been found to be very safe and effective on smaller burns, management of patients when surgery isn't indicated or not appropriate. Those large burns where they will epithelialise within a three-week time don't necessarily need to go to surgery for any reason, they can be managed locally. Severe hand burns, where the damage from surgery can cause long-term functional problems when they're managed locally with non-surgical interventions, some of those problems can be avoided. And a combination of methods has been found to provide a significant improvement in the efficiency of the non-surgical debridement and the gradual removal of that eschar.

So this particular picture shows the initial burn wound and after seven days of application with collagenase, the improvement in that burn wound with significant re-epithelialisation and a remaining burn in the centre that can continue to granulate and allow further epithelialisation. However, in all cases, if the burn has not fully re-epithelialised within 21 days, then most experts agree that a skin graft is essential to limit the comorbidities of allowing that wound to go on and heal secondarily, such as dysfunctional scarring, contractures, and that ongoing risk of infection with that open wound. So in both cases, with these photos, allowing the outer areas to re-epithelialise definitely decreases the area that will need surgical intervention if they don't continue to re-epithelialise completely within that 21-day timeframe.

Other Agents to Facilitate Debridement

There are other reports out there of using agents that are not specifically intended for debridement to facilitate debridement. One of those is medical grade honey. Because medical grade honey puts the wound in an increased pH where bacteria don't like to thrive and it adds that moist environment to the wound bed, then a lot of people use medical grade honey to facilitate the local sharp debridement and mechanical debridement that they do at each dressing change. So you may hear about medical grade honey in the realm of debriding, the burn wound, but it is not specifically a debriding agent.

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