Non-surgical Debridement of Burn Injuries

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

Top Contributors - Stacy Schiurring, Jess Bell and Matt Huey

Introduction

Burn wound injuries are a common injury worldwide. Burn wound therapy continues to be a challenging and dynamic field of medicine and rehabilitation. The first and most critical step in burn wound care and wound bed preparation is the removal of eschar and other non-vitalised tissue. This helps to reduce the bioburden and potential for biofilm formation in the wound, minimises the risk for infection and compartment syndromes, and promotes healthy granulation and wound healing.

Since the 1970s, early surgical excision and debridement of burn wounds have been the standard of care. Surgical debridement can quickly and fully remove non-viable and necrotic tissue from a burn wound. However, it has the disadvantages of causing huge trauma, excessive bleeding, and being very non-selective in the removal of unwanted tissue in the burned area. Alternative non-surgical methods of debridement have been explored and researched. These methods provide less invasive and more selective options for the removal of non-vitalised tissue from a burn wound.

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

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 an 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 affects 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, including the following:

1. Medically unstable patients who would not tolerate sedation and/or surgical interventions
2. When surgical resources are 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. The 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

Clinical Pearls: a deeper look at eschar

Burn wound injuries lead to the formation of a non-viable tissue called eschar. Similar to burn classification, the depth of eschar in a wound bed may be superficial or deep. The presence of any non-viable tissue, including eschar, in a burn wound bed, serves as a base for bacterial growth and may result in an inflammatory response, which can contribute to the extension of the burn wound injury. It also creates the potential for local and systemic infection. Therefore, the removal of eschar is a primary focus of burn wound therapy.

According to a study by Gurfinkel et al., the initial diagnosis of the extent of the eschar within the wound bed is the first step in any debridement strategy. Unfortunately, assessing burn wound depth through the opaque eschar is "difficult, if not impossible." Furthermore, the depth of a burn injury can be inconsistent throughout the damaged area. The colour and texture of the eschar found within a burn wound can be misleading even to wound care experts. Very often, the extent and depth of tissue damage may only be determined days after injury when the secondary damage has already extended beyond the original burn wound.

Keep this information in mind as you continue to learn about the types of non-surgical debridement. Consider how a more selective form of debridement can spare tissue which has the potential to heal, and would limit the amount of ongoing tissue trauma which occurs following a burn wound injury. What psychological effect could this have on a patient following a burn wound injury?

Non-surgical Debridement

Non-surgical debridement is the removal of materials which limit or impair healing from a wound bed 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, necrotic tissue, bioburden, biofilm, or foreign matter.

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 the wound bed
• inability to control pain
• patients with poor perfusion

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 responses 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 burn wound surface. As the gauze dries, anything on the wound surface, including loosened devitalised tissue or healthy granulation tissue, can adhere to the gauze. When the gauze is removed, both types of tissue are ripped off the wound surface. This method of debridement can be very painful and highly non-selective.
7. Soak and wipe. Involves applying towels or gauze saturated with saline or an antimicrobial solution to the surface of the burn wound and allowing 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.

Advantages

• Quick to perform with appropriate pain management
• Can be used with active infection
• Efficient for larger wounds
• Effective at the bedside or in the outpatient setting with adequate pain management

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, it can be used with other debridement techniques, such as mechanical debridement, if wounds are infected.

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 wounds with large surface areas

Local Sharp Debridement

"Devitalized tissue (slough, necrotic, or eschar) in the presence of underlying infection is removed using sharp instruments."

Tools that can be used for local sharp debridement include a scalpel, scissors, and/or curettes. Local sharp debridement is performed by a skilled clinician with wound specialist training. In order to safely perform local sharp debridement, wound care professionals must be able to distinguish between tissue types and have a good understanding of functional anatomy as this procedure carries the risk of damage to blood vessels, nerves, and tendons.

Indications

• Recommended for infected wounds
• Can be combined with all the other debridement methods

Contraindications

• Patients on anticoagulation therapy due to bleeding risk
• Intact eschar and no clinical evidence of an underlying infection

Advantages

• Can be fairly quick
• Very specific form of debridement
• Good method for bedside or outpatient procedures

Disadvantages

• Can be painful
• Can be an invasive procedure, depending on the depth of debridement
• This technique requires specialised training, certification, and/or licensure. Please review your local practice act and complete appropriate and required training before performing local sharp debridement as part of a wound care treatment plan.

Biological Debridement

Biological debridement (larval therapy, maggot therapy, biosurgery) uses sterile larvae of the green bottle fly to debride devitalised tissue. This is done via the release of proteolytic enzymes from larvae secretions and excretions, which dissolve necrotic tissue from the wound bed.

The larvae are applied directly to the wound bed and can be either enclosed and contained in a "biological bag" or "free-range." Research has shown that biological debridement performed by free-range larvae is twice as fast as those enclosed in the biological bag.

Other benefits of biological debridement include:

1. Bactericidal because the larvae ingest and digest bacteria
2. Inhibiting bacterial growth by releasing ammonia into the wound bed, which increases the pH of the wound
3. Breaking down existing biofilm at the wound bed and inhibiting new biofilm growth
4. Direct ingestion of necrotic tissue

Advantages

• Essentially painless
• Very selective form of debridement
• Fairly rapid and can debride areas that are difficult to access by other debridement methods
• Appropriate for use on large wound areas

Disadvantages

• Containment of the larvae, limits application in the outpatient setting
• Patient or caregiver acceptance of the treatment intervention

This optional video overviews the evidence supporting the use of maggot therapy in wound care.

Enzymatic Debridement

Enzymatic debridement "uses naturally occurring proteolytic enzymes or proteinases, which can aid in the wound repair process. These enzymes remove devitalized tissue by digesting and dissolving the non-viable tissue and thus chemically liquefying non-viable tissues within the wound bed."

This is a highly studied form of non-surgical debridement, and there is an extensive evidence base to support its use. At the time of writing, there are two products approved for medical use in the United States, Collagenase and NexoBrid, which will be discussed below.

Contraindications

• A relative contraindication is use in heavily infected wounds
• Collagenase should not be used in conjunction with silver-based products or with Dakin solution.
• NexoBrid safety and effectiveness have not been established on:
  • chemical or electrical burns
  • burns on the face
  • burns on the perineum or genitalia
  • burns on the feet of patients with diabetes mellitus
  • burns on the feet of patients with occlusive vascular disease
  • circumferential burns
  • burns in patients with significant cardiopulmonary disease (including burn inhalation injuries)
  • established compartment syndromes

• NexoBrid should NOT be used in patients with uncontrolled disorders of coagulation
• NexoBrid can be used WITH CAUTION in patients on anticoagulant therapy or other medications which affect coagulation, and in patients with low platelet counts and "increased risk of bleeding from other causes."

	Enzyme	Basic Application Procedure	Special Considerations
Collagenase	Derived from the fermentation by Clostridium histolyticum. Possesses the unique ability to digest collagen in necrotic tissue.	According to the Santyl website: Prior to Collagenase application, the wound should be cleansed of debris and digested material by gently rubbing with a gauze pad saturated with normal saline solution, then rinsed with normal saline solution. If infection is present, an appropriate antibiotic powder should be applied to the wound to the wound before applying Collagenase. However, if the infection is not responding, enzymatic debridement treatments should be discontinued until the infection clears. Collagenase may be applied directly to the wound or to a sterile gauze pad, which is then applied to the wound and properly secured. A vaseline-coated gauze, such as Xeroform or Vaseline gauze, can also be used in multiple layers to maintain the necessary moisture in the dressing. Use of Collagenase should be discontinued when debridement of devitalised tissue is complete and granulation tissue is well established.	Requires daily dressing changes. It is not recommended to leave it on for more than 24 hours at a time. When clinically appropriate, crosshatch thick eschar with a #10 scalpel blade to increase the surface area contact of the ointment with necrotic debris.
NexoBrid	A mixture of bromelain-based proteolytic enzymes extracted from the stems of pineapple plants.	According to the NexoBrid website: Thoroughly clean the wound and apply a dressing soaked with an antibacterial solution to the treatment area for at least 2 hours. Afterwards, ensure the wound bed is clear of any topical agent remnants (e.g. silver sulfadiazine or povidone iodine). Apply an ointment skin protectant (e.g., petrolatum) 2-3 cm outside of the treatment area to create a skin barrier. Protect any open wounds (e.g., laceration, abraded skin and escharotomy incision) with skin protectant ointments or ointment gauze. Moisten the burn wound treatment area with 0.9% Sodium Chloride. Using a sterile tongue depressor, completely cover the moistened treatment area with a 3-mm thick layer. Only cover the burn wound area (avoid the periwound area). Cover the treated wound with a sterile occlusive film dressing. Cover the dressed wound with a sterile loose, thick, fluffy dressing and secure with a sterile bandage. Leave in place for 4 hours. After 4-hours: Remove the occlusive film dressing using an aseptic technique and remove the ointment barrier using a sterile, blunt-edged instrument. Remove the dissolved eschar from the burn wound by scraping it away with a sterile, blunt-edged instrument. To remove remnants of dissolved eschar, apply a dressing soaked with an antibacterial solution for at least 2 hours. Wipe the wound thoroughly with a large sterile dry gauze, then repeat with a sterile gauze soaked with sterile 0.9% Sodium Chloride. Rub the treated area until the wound bed has the appearance of "clean dermis or subcutaneous tissues with pinpoint bleeding".	NexoBrid should be applied in hospital settings by a medical doctor, physician's assistant or nurse practitioner. Begin pain control measures at least 15 minutes prior to NexoBrid application and maintain proper pain management throughout the treatment. If the burn wound area is greater than 15% total body surface area, apply in two separate sessions. Apply the second application 24 hours after the first application to the same or new burn wound area. The total treatment area must not exceed 20% total body surface area across two treatment sessions.

The above procedure lists are based on instructions found on the drug manufacturer's websites. Please study and review the manufacturer's information and attend hands-on training prior to using as indicated. Please review your discipline's practice act before performing any type of debridement.

Advantages

• Less aggressive form of debridement compared to surgical options
• Faster results than autolytic debridement
  • NexoBrid has faster results than Collagenase. When applied correctly, it can remove 100% eschar with a single application
• Very selective form of debridement
• Reported to be the most cost-effective debridement method, with a shorter duration of treatment and fewer clinical visits compared to other types of debridement
• Can be beneficial and an effective adjunct to surgical excision
• Good alternative to surgery in areas that are difficult to debride (deep skin folds, fingers, hands), and areas where cosmesis and function are important (e.g. face, neck, hands)
• Collagenase use produces minimal pain
• Collagenase has a simple application, can easily be utilised at the patient bedside, outpatient or home setting

Disadvantages

• Not effective or adequate for severe deep burns or critical patients
• Can cause maceration to periwound tissue
• NexoBrid use requires hospitalisation - it is only appropriate for use on inpatients
  • treatments are painful, and analgesia and/or anaesthesia are required during use
  • requires medical doctor/physician's assistant/nurse practitioner to apply and monitor the patient during use, preferably in a Burn Unit or at a Burn Centre
  • risk of bleeding during use
  • can only apply to a total body surface area of 15% or less at a time

Conclusion

Several evidence-supported non-surgical debridement methods are available for treating burn wound injuries. While, in general, these debridement methods require more time to fully remove devitalised tissue from a burn wound, they do so with less trauma and bleeding risk to the surviving tissue. These techniques can be used alone or in combination with the ultimate goal of creating a clean wound bed ready for healing and closure.

One of the greatest benefits of non-surgical debridement is the elimination of the need for a skin graft or a decrease in the size of a skin graft for wound closure. This means there is also a smaller or no donor site. Related benefits include uninterrupted and/or unmodified occupational and physiotherapy to continue throughout the healing process. The functional gains and continued independence for the patient healing from a burn wound are key to their mental health and motivation for future interventions.

Resources

Optional Additional Reading

• Heitzmann W, Fuchs PC, Schiefer JL. Historical perspectives on the development of current standards of care for enzymatic debridement. Medicina. 2020 Dec 17;56(12):706.
• Thomas DC, Tsu CL, Nain RA, Arsat N, Fun SS, Lah NA. The role of debridement in wound bed preparation in chronic wound: A narrative review. Annals of medicine and surgery. 2021 Nov 1;71:102876.

Optional Additional Video

Expand your knowledge of this related topic, compartment syndrome, by viewing this 5-minute video.