Learning Objectives
By the end of this section, you will be able to:
- Define debridement
- Distinguish the various types of debridement
- Identify clinical implications and contraindications for debridement therapy
A wound cannot heal in the presence of necrotic or nonviable tissue. The first documented reference to the debridement of a wound for treatment dates to 25 CE, when a Roman author described the surgical removal of burned tissue to treat a wound (Heitzmann, Fuchs, & Schiefer, 2020). Debridement has become the cornerstone of the comprehensive management of patients with nonhealing wounds.
Necrotic tissue creates a physical barrier that prevents the cell migration that facilitates wound healing and acts as a medium for bacterial growth and infection. As tissue dies, it changes color, consistency, and adherence to the wound bed. It is critical for the nurse to both recognize and differentiate necrotic tissues from healing tissue. This module will focus on the importance of debridement in treating wounds by breaking down the various debridement methods and identifying the clinically appropriate debridement method for the wound.
Types of Debridement
Debridement is essential in treating acute and chronic wounds. Although nonviable tissue is devitalized, it may be burdened with senescent cells. A senescent cell is a nonfunctioning cell that has stopped dividing but has not died. The debridement process removes foreign debris, necrotic tissue, and bacteria from the wound’s surface. Debridement stimulates a chronic wound’s healing response by creating an acute wound and restarting the healing cascade.
Slough and eschar are two terms used to describe necrotic tissue in full-thickness wounds. The two are differentiated by appearance. The yellow or tan fibrin that typically lies on top of the wound bed is called slough. The texture of slough can be stringy, loose, or adherent. Slough should not be used interchangeably with purulence, which is a sign of infection.
Necrotic tissue that is brown, black, or tan in appearance is known as eschar. Its texture can be soft or hard, depending on the location of the wound. It is essential to note stable intact eschar, like that found on the heels, should not be removed. Intact eschar is dry and adherent, with no signs of cracking or redness. In this instance, the eschar is a natural barrier to infection. If the eschar texture or appearance becomes unstable, then it should be debrided. Unstable eschar appears wet, boggy, loose, or draining, and it can be erythematous. Eschar is not the same as the word scab, and the two should not be used interchangeably. A scab is the formation of a crust by exudate or blood coagulation; in contrast, eschar is nonviable tissue.
Selecting a debridement method is based on the appearance of the wound bed, wound type, amount of necrotic tissue, patient condition, and care setting.
Autolytic Debridement
The most conservative type of debridement, called autolytic debridement, is the process of using the body’s intrinsic debriding mechanism to remove nonviable tissue. This type of debridement involves a highly selective process that affects only necrotic tissue.
Autolytic debridement requires a moist environment, as this technique induces the softening—and, eventually, separation—of the necrotic tissues. Selecting the correct dressing will facilitate autolytic debridement. For example, if the necrotic tissue is dry, the clinician must “donate” moisture to facilitate debridement. Hydrogels or medicinal honey are common moisture-donating agents. If the tissue is already moist, hydrocolloid or foam dressings will work best. Dressing and product selection is discussed later in the section.
Autolytic debridement relies on a functioning immune system and is indicated for noninfected wounds through a process called autolysis: the destruction of cells by one’s own enzymes. Compared with other forms of debridement, autolysis is a slow process and should be evaluated on a case-by-case basis (Heitzmann, Fuchs, & Schiefer, 2020). It is an adjunctive therapy for treatment of infected wounds in that it can be used with other debridement techniques. The overall effectiveness of autolytic debridement relies on the amount of devitalized tissue needed to be removed and the size of the wound. For example, if a wound measures 3 by 3 cm with thick, black eschar, autolytic debridement would take longer than taking a scalpel and removing the necrosis. In contrast, a 3 by 3 cm wound with yellow slough in the wound bed would likely benefit from autolytic debridement to further degrade and soften the necrotic tissue for removal.
Biological Debridement
The process of biological debridement, also known as maggot larval therapy (MT), uses sterile larvae of the Lucilia sericata species of the green bottle fly. The maggots are sterilely prepared and applied to the wound bed, either in a bio bag or free range, for one to four days. The success of maggot therapy is due to the secretion by the maggots of proteolytic enzymes, which break down the necrotic tissue. The maggots then ingest the liquified tissue. It is an effective mode of debridement, particularly appropriate in large, chronic wounds for which a painless method for removal of necrotic tissue is needed.
Enzymatic Debridement
The process of enzymatic debridement, also known as chemical debridement, is a selective method that uses an exogenous enzyme known as collagenase. Collagenase ointment, commercially known as SANTYL (from Smith+Nephew), actively debrides the necrotic tissue along the denatured collagen strand of the enzyme. Currently in the United States, SANTYL ointment is the only FDA-approved enzymatic debriding agent; it requires a prescription for use. Clinicians who are applying the ointment must follow the manufacturer’s guidelines to ensure optimal therapeutic outcomes.
Link to Learning
Visit this site to learn more about the application of SANTYL Ointment to help with wound healing.
The application of SANTYL is critical to achieving therapeutic success for those cases in which it is used. Although the application process itself is simple, if the wound is not prepared to receive the medication, the debridement will not be optimally efficacious, thus prolonging the wound-healing process.
Surgical Debridement
The process of surgical debridement, also known as sharp debridement, involves the use of a scalpel, forceps, curette, scissors, or other instruments to remove necrotic tissue from the wound base. The terms are used interchangeably and often reflect the site of care in which the therapy is used: the process can be done at the bedside, in an office setting or wound care center, or within an operating room. The location of service depends on the severity of the wound and the ability to control potential perioperative complications such as bleeding or pain. Surgical debridement should be performed by a skilled, trained, qualified provider who is licensed to provide surgical treatments. The main advantage of this type of debridement is the speed of wound cleaning and visualization. Disadvantages of this technique include adverse events from the procedure itself, such as blood loss or infection.
Surgical debridement is indicated for removing thick, adherent, or large amounts of nonviable tissue. This method can be used as a form of adjunctive therapy, in conjunction with other debridement modalities. Often the provider will add an antibiotic solution to be used as irrigation to avoid infection during wound care.
Mechanical Debridement
The process of mechanical debridement is a nonselective type of debridement in which physical force is applied to remove necrotic tissue. The procedure is nonselective in that it removes both devitalized tissue debris and viable tissue. Examples of mechanical debridement include wet-to-dry gauze dressings and wound irrigation. Mechanical debridement is indicated for acute and chronic wounds with moderate to large amounts of necrotic tissue, regardless of the presence of an active infection.
Wet-to-dry gauze dressings are well known. However, in recent years they have fallen out of favor as a clinical practice due to the frequency of dressing changes, associated pain, and nonselectivity. Wet-to-dry gauze dressings can be challenging and costly to apply and may cause maceration to the surrounding tissues. Moreover, wet-to-dry gauze dressings may release airborne organisms and cause cross-contamination.
Wound irrigation removes necrotic debris using pressurized fluids. Hydrotherapy is a form of wound irrigation, using specialized tubs with jets. Another example includes pulse lavage or high-pressure irrigation, which involves delivering between 8 to 12 pounds per square inch (psi) of fluid to the wound bed. The process may involve using a 35-ml syringe with 19-gauge angiocatheter to deliver fluid, such as saline, to the wound. The allotted pressure permits enough force to separate the necrotic tissue from the wound bed but not so much as to push bacteria into the wound bed. Clinicians performing this bedside procedure should wear personal protective equipment (PPE) to protect against potential bacterial contamination and the potential aerosolization of bacteria.
Clinical Implications
The debridement method selected for a wound is based on the wound’s presentation, the provider’s evaluation of the current treatment plan, and the patient’s comprehensive history and physical. It is critical to remember the whole patient, not just “the hole in the patient.”
For a bedside nurse, the most important role will be to support the patient by explaining the procedure, and anticipated outcomes. Understanding how to apply the prescribed therapy—whether collagenase ointment, hydrogel, or biobag—is critical for the nurse. Always refer to the institution’s guidelines as well as policy and procedure for debridement therapy. The nurse’s role can also include monitoring and evaluating the wound post-treatment, assessing and treating pain, providing emotional support, and facilitating dressing changes. For surgical debridement, the bedside nurse will support the provider performing the debridement by dressing the wound, assessing and evaluating the patient’s tolerance for the therapy, and providing education to the patient.
Contraindications
Therapy contraindications must be considered, even in wound care and in the debridement processes. As a critical rule, it cannot be overstated that debridement is inappropriate if there is dry, stable eschar present, such as in unstageable pressure injuries with no overt signs of infection. In these instances, the dry eschar acts as a natural covering. Precautions should be taken for patients with poor perfusions, such as patients with arterial disease. Beyond ensuring blood flow and stable eschar presentation, contraindications are specific to the specific debridement technique.
Contraindications for surgical debridement include accounting for the patient’s overall condition and risk stratification. Examples of contraindications for surgical debridement include patients who are hemodynamically unstable, those with bleeding disorders, and those currently undergoing anticoagulation therapy. Surgical debridement is also contraindicated in patients with an intact eschar and no clinical evidence of an underlying infection. Depending on choice of modality of the mechanical debridement, contraindications include analyzing the presence of granulation tissue and the ratio of granulation tissue to devitalized tissue; providers must also consider the patient’s level of perfusion and their own ability to control the patient’s pain.
When using autolytic debridement, the clinician must consider the overall goal and presentation of the patient. Autolytic debridement takes several days to work. If the wound requires an immediate and significant decrease in necrotic tissue, a different modality should be considered. If autolytic debridement is selected and improvement is not observed within one or two days, a different debridement method should be considered for the patient. Contraindications to using biological debridement include pyoderma gangrenosum wounds in patients with immunosuppression therapy and abdominal wounds adjacent to the intraperitoneal cavity. Enzymatic debridement contraindications include use on wounds with a known infection and concurrent use with silver products. The therapy is also contraindicated if a patient is allergic to any of the ingredients within the enzymatic debriding agent.