Debridement Methods

Debridement 

The most appropriate method of debridement is largely dependent on the level of nonviable tissue in the wound; however, the decision to debride and the method used must align with the goals and preferences of the patient. Many factors should be considered when ordering or performing debridement, including context, cost, and system factors.

The optimum debridement modality

Debridement is intended to replicate and facilitate a natural bodily function. In most cases, when someone inadvertently cuts themselves, the normal phases of wound healing occur and wound closure is achieved in a timely fashion. A scab forms while proteolytic enzymes in wound fluid break down the connective tissue until the scab falls off, and clean slightly pink epithelium remains and continues to heal by forming scar tissue to close the wound increasing tissue strength and eventually softening and may disappearing over time.

Debridement is thought to restore natural processes in stalled wounds, so normal wound healing can occur. The medical approach to debridement is not new. We have known for centuries that honey appeared to be helpful even if its autolytic and enzymatic debriding action was not understood at the time. To date there is a lack of persuasive evidence for use of honey to debride wounds however in some unique cases where all factors are considered there may be an appropriate use.

In the case of Mr. Jones’s foot, the health care professional must first follow wound bed preparation concepts. This is described in detail in Chapter 1. First, aim to treat the underlying cause of the wound, address patient-centred concerns, and establish healability. Patient assessment, including vascular supply using ankle-brachial pressure index (ABPI), audible handheld Doppler or imaging for lower limbs, is a foundational prerequisite for debriding wounds on the lower extremities. If determined to be healable, clinicians may now begin to consider the best approach for managing his wound.

Black eschar presents a particular obstacle as it impedes visualization of the wound bed. The first likely task is to determine that the wound is healable, obtain patient consent and then utilize a suitable method of debridement to allow visualization of the wound bed, wound edges, and any exposed underlying structures. Table 1 provides guidance regarding factor(s) that require consideration for each debridement method.  Autolytic debridement is considered the slowest and least expensive while active surgical debridement, recommended to be performed by a surgeon in an operating room, is rapid; although, it is likely the most expensive intervention.

Table 1 Comparative desirability of factors across the six modalities of debridement for a healable wound

Note. This table compares factors across six debridement methods where 1 is most desirable and 6 is least desirable. CSWD = conservative sharp wound debridement.

Alone, Table 1 does not provide sufficient information to proceed with debridement. Table 2 provides the definition, indications, contraindications, precautions, advantages, and disadvantages for six methods of debridement included in this chapter. All forms of wound debridement pose potential risk for the patient; therefore, access to an interprofessional wound care team is crucial for consultation to avoid making potentially dangerous decisions. Although not well defined, debridement (and care below the dermis) is a controlled act in many countries and each health care professional is accountable should unintentional negative outcomes occur. Important factors that require consideration regarding an appropriate debridement method also includes safety of the setting, availability of appropriate supplies and equipment, and the availability of emergency medical intervention should there be potential unintended outcomes for the method. Some wounds should not be debrided until the interprofessional team has been consulted and agreed upon the wound etiology and plan of care. Prior to initiating any form of debridement, it is imperative to obtain and document informed patient consent.

Table 2 Summary of the six different debridement modalities

Autolytic

• Definition: the body’s natural process for debridement; further facilitated by moisture-donating or moisture-retentive dressings that activate the body’s enzymes present in wound exudate to promote the destruction of nonviable tissue.
• Indications: healable, uncomplicated wounds with minimal amounts of nonviable tissue.
• Contraindications: sensitivity to products, patients with peripheral arterial disease, ischemic wounds, and diabetic foot ulcers; patients who are palliative or end-of-life where healing is not the goal; and where acute infection or sepsis is suspected.
• Advantages: is selective; activates the body’s natural process; readily available and inexpensive; simple application; minimal training and skill required; suitable for all care settings; not usually painful
• Disadvantages: slowest form of debridement; risk of infection due to anaerobic bacteria; risk of maceration; increased product utilization and nursing time.
• Other considerations: amount of exudate determines dressing; periwound protection required.

Mechanical

• Definition: removal of nonviable tissue through the application of external force.
• Indications: healable wounds containing large amounts of slough or infected chronic wounds.
• Contraindications: painful wounds or in patients with bleeding disorders, peripheral arterial disease, ischemic wounds, persons with diabetes; patients who are palliative or end-of-life.
• Advantages: rapid process for the removal of large amount of slough; may disrupt biofilm; some methods are readily available; suitable for most settings.
• Disadvantages: nonselective; can damage healthy tissue; can be painful and cause bleeding; ineffective with dry eschar; time consuming; cost related to frequent dressing replacement.
• Other considerations: many methods including dressings and monofilament pad.

Enzymatic

• Definition: introduction of proteolytic enzymes to the wound to dissolve nonviable tissue.
• Indications: healable wounds containing moist nonviable tissue and partial thickness wounds.
• Contraindications: rare sensitivity to collagenase; dry necrotic eschar; wounds where acute infection or sepsis are suspected.
• Advantages: selective, nontraumatic debridement; suitable for all care settings; minimal training required; fast application; usually not painful.
• Disadvantages: requires a prescription in most countries; daily application; if no coverage, can be costly; is slower than CSWD; risk of maceration so requires periwound protection.
• Other considerations: inactivate by metal ions.

Biological

• Definition: application of sterile, medical-grade larvae into the wound to digest soft nonviable tissue and bacteria to promote wound healing by softening and liquefying nonviable tissue.
• Indications: healable wounds containing moist, nonviable tissue. Suitable when surgical debridement is not an option or when wounds are infected.
• Contraindications: patients with allergies to egg, soybean, or fly larvae; not to be used on facial wounds, upper gastrointestinal wounds, open vessels or near major vessels, deep wounds, cavities, or sinus tracts; patients on anticoagulant therapy and where the position/location of the wound would affect survival of larvae.
• Advantages: selective, rapid form of debridement; assists in the removal of biofilm; inexpensive due to short length of time required; can remain in place for 4 to 5 days.
• Disadvantages: increased cost compared to autolytic; requires an order from a prescriber; medical grade required and not always available; time consuming application.
• Other considerations: pain may present in ischemic wounds; bleeding can occur; do not use occlusive dressings over larvae to ensure viability.

CSWD

• Definition: removal of clearly identifiable, nonviable tissue including senescent cells and bacteria using sharp instruments including sterile scalpels, curettes, or scissors and forceps (does not extend to bleeding tissue).
• Indications: healable wounds containing nonviable tissue including callous.
• Contraindications: where there is inadequate pain control, impaired perfusion, exposed bone, tendons, or ligament; patients who are immunocompromised, on anticoagulant therapy, or have bleeding disorders; wounds in temporal areas, on the neck, axilla, groin, or other areas close to major blood vessels, nerves, and tendons; in patients with advanced age, multiple comorbidities, or in those who are palliative or near end-of-life; should not be performed by anyone without advanced education, training, knowledge, skills, and judgment or where there is no access to sterile equipment.
• Advantages: selective and rapid form of debridement; best used in combination with other methods; can be performed at the bedside (see section on infection control and practice setting); cost effective.
• Disadvantages: requires performance by only those with advanced training; higher risk of complication; setting may not be suitable; increased risk of bleeding, infection, and pain; sterile equipment required.
• Other considerations: requires a sterile field and should only be done by a health care professional with advanced education and training; requires access to safe disposal of sharps.

Surgical

• Definition: may include viable and nonviable tissue and most commonly performed by a surgeon under sterile conditions with sedation or anesthesia.
• Indications: healable wounds with extensive nonviable tissue, where there is need to extend into viable tissue, or where urgent debridement is needed for life or limb threatening infection good vascular flow exists.
• Contraindications: patients with advanced age, multiple comorbidities, poor general health, palliative, or near end-of-life, those on anticoagulant therapy, with bleeding disorders, or inadequate tissue perfusion; lack of an experienced surgeon.
• Advantages: selective; very rapid; stimulates the healing process; removes biofilm and infected tissue.
• Disadvantages: risk of surgical complications may warrant admission to hospital; requires anesthesia; requires health care professional able to perform surgery.
• Other considerations: risk of postoperative bleeding and pain.

Interprofessional Team Collaboration in Debridement

Prior to initiating debridement, a comprehensive assessment of the patient and the wound should be conducted. Assessment includes consultation with various interprofessional team members to ensure debridement is appropriate and to verify the most appropriate method of debridement to minimize potential risks of harm associated with the debridement.

Consultation with the interprofessional team ensures the patient will receive the optimal method of debridement at the appropriate time. In some situations, it is advisable to avoid debridement and leave nonviable tissue intact to dry.

Decisions about debridement should not be determined in isolation of other health care professionals. A collaborative team approach includes dialogue with other professionals with advanced knowledge, skills, and experience in debridement to provide valuable insight to ensure patient safety, optimal wound outcomes, and efficient use of resources.

Prior to initiating and performing debridement, it is important to:

• determine when a referral is recommended
• solicit the help of others on your team who have expertise in performing debridement
• connect with your team members
• ensure appropriate follow up and monitoring is in place post procedure
• assess potential risks associated with the procedure.

Other professionals that may have advanced education, knowledge, training, and experience in debridement described by their scope of practice may include specialized nurses, nurse specialized in wound, ostomy, and continence (NSWOC), physiotherapists, chiropodists, podiatrists, and physicians, including vascular surgeons.

 Special Considerations for Lower Extremity Wounds

Patients with multiple comorbidities present complex challenges increasing the risks associated with debridement. Wound healing is anticipated when there is adequate perfusion to the affected area and when underlying causative factors are addressed. Patient risk factors such as nutritional status, some medications, smoking, and chronic disease processes should be considered during the patient assessment and optimized to support wound healing.

Debridement is recommended for healable wounds. Chronic diseases such as diabetes mellitus (DM) and peripheral arterial disease reduce the level of perfusion to the lower extremities thereby minimizing the delivery of oxygen and nutrients required for wound healing. Any method of debridement (including use of a semi-occlusive dressing) on a lower limb without adequate perfusion can have devastating effects including sepsis, amputation, and death.

Close monitoring is required for patients with DM and peripheral vascular disease due to risks for slow wound healing, infection, and rapid wound deterioration.

Factors that influence wound healing in a patient who has prolonged elevated glucose levels related to diabetes include:

• Stiffening of the arteries (calcification) rendering them noncompressible resulting in inaccurate elevated Ankle Brachial Pressure Index (ABPI) readings (consider audible handheld Doppler test);
• atherosclerosis (narrowing of arteries), reducing perfusion of oxygen and nutrients especially in the small capillaries of the lower extremities which slows wound healing;
• decreased perfusion as glucose replaces the oxygen and nutrients delivered by red blood cells;
• decreased white blood cell function, decreasing the efficacy of the immune system resulting in increased the risk of infection; and
• progressive neuropathy from damaged nerves causing numbness. Loss of sensation decreases the ability to feel pain, increasing the risk for traumatic injury; delays wound detection; and prolongs implementation of required interventions, especially on the foot.

Peripheral artery disease (PAD), defined as atherosclerotic occlusive disease (narrowing of arteries) of the lower extremities, results in reduced blood flow and impaired oxygen and nutrient delivery to the tissues resulting in impaired wound healing. Peripheral arterial disease increases the risk of thrombosis causing vessel occlusion and increasing the potential for lower extremity amputation.

Peripheral arterial disease is more severe and diffuse in persons with DM as increased blood viscosity and fibrinogen production increases plaque development. Smoking also increases the risk for PAD.

The most common symptom of PAD is claudication characterized by cramping or aching pain in the calves, thighs, or buttocks when ambulating but relieved with rest. Lower limb assessment, including an ABPI, may be unreliable and computed tomography angiography (CTA) may be required to confirm PAD.

• Lower limb assessment (LLA) is mandatory for all wounds located on the lower limb or foot regardless of etiology
• Pain history and structure of the limbs should be included in the assessment
• Assess for neuropathy and loss of protective sensation (LOPS) using a 10g monofilament
• The LLA should include a visual inspection to differentiate signs of ischemia; assessment of pulse strength, regularity, and waveform, capillary refill (or toe brachial pressure index, audible handheld Doppler and photoplethysmography (PPG), if available)
• Presence of pulses in the foot alone is not a reliable indicator of perfusion status
• Consider the potential benefit of a referral to a vascular surgeon for bilateral lower extremity CTA and to review options for revascularization (NSWOCC, 2021)

Limbs without adequate perfusion should NOT be debrided until the patient has seen a vascular surgeon. This includes avoiding the use of moist wound healing using autolytic debridement method.

Debridement of any kind is contraindicated for adherent dry eschar on heels, ischemic limbs, toes, and digits. These wounds should be kept dry, free from moisture, and debridement avoided unless the eschar becomes unstable or there is evidence of infection. In these cases, the black eschar caps on heels for example, can serve as a protective barrier from bacteria entering. In some cases, if there is borderline vascular supply, the wound may still heal underneath the black cap over time and eventually the cap will fall off. Wounds of this type should be referred to the interprofessional team for further assessment. An urgent referral for surgical debridement in a controlled setting is recommended for unstable eschar when acute infection or sepsis is suspected and if aligned with the goals of care (NSWOCC, 2021).