Wound Care - Debridement

What is the primary goal of wound bed preparation?

Create an optimal wound environment that promotes healing by removing barriers while preserving viable tissue.

What are the major goals of wound bed preparation?

Reduce bioburden

What is wound cleansing?

The removal of debris

What is wound disinfection?

The use of antimicrobial agents to actively kill microorganisms within a wound.

Cleansing vs. disinfection: what is the key difference?

Cleansing removes contaminants while preserving tissue; disinfection kills microorganisms but may damage healthy tissue.

Why is routine wound disinfection discouraged?

Many disinfectants are cytotoxic and delay wound healing by damaging healthy cells.

Define bioburden.

The total population of free-floating microorganisms present within a wound.

Why can excessive bioburden delay healing?

It prolongs inflammation

Define biofilm.

A structured community of microorganisms enclosed within a protective extracellular matrix attached to the wound surface.

Why is biofilm difficult to eliminate?

The extracellular matrix protects bacteria from antibiotics

Why is biofilm a major cause of chronic wounds?

It maintains persistent inflammation and prevents progression into normal healing.

What is usually required to eliminate biofilm?

Mechanical disruption combined with an appropriate topical antimicrobial.

What wound characteristics should influence cleanser selection?

Bioburden

What is cytotoxicity?

The ability of a substance to damage or kill living cells.

Why is cytotoxicity important in wound management?

Protect viable tissue

Which cleanser is preferred for most healthy wounds?

Normal saline.

When are cytotoxic cleansers appropriate?

Short-term treatment of infected or heavily contaminated wounds and traumatic injuries, procedure prep

What is Dakin's solution?

A dilute sodium hypochlorite (bleach) solution used as an antimicrobial cleanser.

What are indications for Hypochlorites (Dakin's solution)?

Actively infected wounds

Advantages of Dakin's solution?

Broad-spectrum antimicrobial activity and effectiveness against biofilms, actively infected or contaminated wounds

Disadvantages of Hypochlorites (Dakin's solution)?

Higher concentrations are cytotoxic and the solution degrades quickly, more frequent dressing changes

What is povidone-iodine (Betadine)?

An iodine-containing antimicrobial solution that slowly releases free iodine.

When is Povidone-Iodine (Betadine) indicated?

Temporary treatment of biofilm and surgical skin preparation.

Why is Povidone-Iodine (Betadine) avoided in deep or extensive wounds?

Granulating tissue due to toxicity

What common household substance is acetic acid?

Vinegar.

When is acetic acid indicated?

Biofilm and wounds colonized with Pseudomonas aeuginosa and other common bacteria.

Disavantages to acetic acid?

High concentrations are cytotoxic and inhibit wound healing, not for clean or granulating wounds

When should acetic acid NOT be used?

Clean wounds and healthy granulating wounds.

What is chlorhexidine primarily used for?

Wound cleansing and surgical skin preparation.

What are limitations of chlorhexidine?

Reduced effectiveness against fungi, viruses, mycobacteria

Which antimicrobial is often preferred over chlorhexidine?

Polyhexamethylene biguanide (PHMB).

What is the major advantage of non-cytotoxic cleansers?

Reduce bacterial burden while preserving healthy tissue.

Describe normal saline.

A sterile 0.9% sodium chloride solution considered the standard wound cleanser, never contraindicated

Why is normal saline considered ideal?

It is isotonic

Why should saline be warmed before irrigation?

Cold saline causes vasoconstriction that may reduce tissue perfusion.

Limitations of normal saline?

Poor disruption of mature biofilms and limited shelf life after opening.

What is the shelf life of opened normal saline?

Approximately 24-48 hours.

What are surfactant cleansers?

Solutions containing emulsifiers that loosen bacteria

Advantages of surfactant cleansers?

Effective biofilm removal with minimal tissue damage.

What is hypochlorous acid (VASHE)?

A non-cytotoxic antimicrobial wound cleanser.

Advantages of hypochlorous acid?

Broad antimicrobial activity (MRSA, VRE), effective against biofilms, non-irritation

Why is hypochlorous acid considered wound-friendly?

It has antimicrobial effects without significant cytotoxicity.

Define necrotic tissue.

Devitalized tissue resulting from tissue death.

Why must necrotic tissue be removed?

It prevents contraction

Describe eschar.

Dry, black/brown, leathery, can be soft or hard, full thickness tissue death

Describe slough.

Moist, yellow/white/tan/gray, loosely adherent

Which tissue is more firmly attached: eschar or slough?

Eschar.

Why is debridement considered essential?

Healing cannot proceed until nonviable tissue is removed.

List factors influencing debridement selection.

Wound appearance, etiology, type and amount of necrotic tissue, patient condition and perfusion, skill, care setting and frequency of care

What is selective debridement?

Removal of nonviable tissue while preserving viable tissue.

What is non-selective debridement?

Removal of both viable and nonviable tissue.

Which type of debridement carries greater risk of damaging healthy tissue?

Non-selective debridement.

What is mechanical debridement?

Removal of tissue through physical forces.

General contraindications for mechanical debridement?

Granulating wounds or epitheliazing wounds, bleeding disorders, poor perfusion, high pain sensitivity, dry stable intact eschar (especially over the heel due to poor blood supply; may create worse wound without sufficient blood supply to heal)

Why is mechanical debridement often avoided in healthy wounds?

It removes healthy tissue along with necrotic tissue and can be painful

What is a wet-to-dry dressing?

Moistened gauze allowed to dry before removal

Why are wet-to-dry dressings considered non-selective?

Healthy tissue adheres to the gauze and is removed with necrotic tissue. Not recommended for granulating wounds.

Advantages of wet-to-dry dressings?

Simple and inexpensive.

Disadvantages of wet-to-dry dressings?

Painful, very non-selective, can dry out wound bed, frequency, gauze shredding

Why are wet-to-dry dressings generally discouraged today?

Modern evidence favors moisture-retentive dressings that preserve healthy tissue.

What is whirlpool therapy?

Mechanical loosening of debris using moving water.

Advantages of whirlpool?

Softens necrotic tissue and assists debris removal.

Disadvantages of whirlpool?

Cross-contamination, non-selective, risk of maceration, possible high pressure from water turbines

Contraindications for whirlpool?

Clean proliferating wounds, vascular ulcers, ischemic wounds

What pressure range defines high-pressure wound irrigation?

Approximately 4-15 PSI.

Purpose of high-pressure irrigation?

Remove debris and loosen necrotic tissue using pressurized fluid.

Advantages of high-pressure irrigation?

Controlled cleansing and removal of loose devitalized tissue.

Disadvantages of high-pressure irrigation?

Risk of tissue trauma, can drive bacteria deeper

Risks of high-pressure irrigation?

Driving bacteria deeper into tissue and causing tissue trauma.

How far should the irrigation tip be held from the wound?

Approximately 1-2 inches.

How should irrigation pressure differ between clean and necrotic wounds?

Use greater pressure for necrotic wounds and gentler pressure for clean wounds.

What is pulsatile lavage?

Pressurized pulsating irrigation of saline combined with simultaneous suction.

Advantages of pulsatile lavage?

More controlled than standard irrigation, more efficient than immersion therapy

Indications of Pulsatile Lavage

Wounds requiring removal of bacteria, debris, exudate, and non-viable tissue

Contraindications for pulsatile lavage?

Fragile granulation tissue and caution near major vessels, insensate areas, facial wounds, exposed deeper structures, near major vessels

Disadvantages of pulsatile lavage?

Requires specialized equipment, potentially aerosolizes bacteria

Why should pulsatile lavage be performed in a private treatment room?

To minimize aerosolization and contamination of the environment.

List the four selective debridement methods.

Autolytic, enzymatic, biosurgical, sharp debridement

What is autolytic debridement?

A selective debridement method that uses the body's own enzymes and macrophages under a moisture-retentive dressing to liquefy and remove necrotic tissue.

Why is autolytic debridement considered selective?

It removes necrotic tissue while preserving viable tissue.

What dressings are commonly used for autolytic debridement?

Hydrocolloids

What is the primary mechanism of autolytic debridement?

Endogenous enzymes and macrophages digest devitalized tissue.

Which wounds are appropriate for autolytic debridement?

Non-infected necrotic wounds, low pain tolerance, difficult to debride with other methods

When should autolytic debridement NOT be used?

Active infection, dry gangrene or dry ischemic wounds, need for rapid tissue removal

Why is autolytic debridement contraindicated in infected wounds?

Occlusive dressings can promote bacterial growth and worsen infection.

Advantages of autolytic debridement?

Highly selective, easy, painless, reduced frequency of dressing changes

Disadvantages of autolytic debridement?

Slow, requires close monitoring for infection, malodor

How often are dressings typically changed during autolytic debridement?

Every 3-5 days.

When should autolytic debridement be reconsidered?

If there is no improvement after 1-2 weeks.

What is enzymatic debridement?

Selective removal of necrotic tissue using topical enzymes.

Which enzyme is discussed in the lecture for enzymatic debridement?

Collagenase (Santyl).

How does collagenase work?

It digests denatured collagen within necrotic tissue while minimizing damage to healthy tissue.

Indications for collagenase?

Moist necrotic wounds requiring maintenance debridement.

Contraindications for collagenase?

Dry ischemic wounds or dry gangrene, concurrent use of dressings with metals/acids

Why should acidic cleansers not be used with collagenase?

They reduce enzyme activity.

Advantages of enzymatic debridement?

Selective, can be used with sharp or autolytic debridement, maintains moist environment, can be used with infected wounds

Disadvantages of enzymatic debridement?

Requires prescription, costly, requires Rx, peri-wound irritation, daily application, slower

How should collagenase be applied?

After cleansing with normal saline or pH-neutral cleanser

When may dry eschar be cross-hatched before collagenase application?

To improve penetration of the enzyme into dry necrotic tissue.

Which type of heel eschar should NOT be cross-hatched?

Stable dry heel eschar.