Continuing Education Activity

The skin is the body's largest organ and is pivotal in maintaining physiological balance and protection against the external environment. When the skin is compromised due to wounds, a complex healing process is triggered by various cell types and microenvironments. Choosing the proper wound dressing is crucial to accelerate healing, reduce treatment costs, and improve the patient's overall well-being. However, the array of available wound dressings can pose a challenge, especially when healthcare professionals have different educational backgrounds. Proper wound care is essential to prevent adverse consequences.

This educational activity explores the fundamental aspects of wound care assessment and provides an in-depth exploration of wound dressing materials. This activity also defines wounds, their potential to heal, and the various factors impeding the healing process, particularly in patients with comorbidities. This course explores the 3 critical phases of wound healing, from the initial inflammatory response to the maturation of the extracellular matrix. Participants learn to perform comprehensive wound assessments and consider crucial factors when selecting wound dressings, such as exudate management, maintaining a moist environment, ease of application, cost-effectiveness, and treatment duration. By the end of this course, healthcare professionals will be better equipped to make informed decisions, ultimately enhancing wound care outcomes and patients' quality of life.

Objectives:

• Identify various types of wounds and recognize the importance of wound assessment in determining appropriate dressing options.

• Develop an understanding of the differences among wound dressings commonly used. 

• Determine the appropriate wound dressing in various clinical scenarios. 

• Implement effective collaboration among interprofessional team members to improve outcomes and treatment efficacy for patients with chronic wounds. 

Introduction

A wound is defined as a discontinuity of the epithelial lining of the skin or mucosa due to physical or thermal damage, which may lead to temporary or permanent dysfunction.[1] All wounds have the potential to heal well. However, various factors can impede the process, especially in patients with multiple comorbidities. Understanding the healing process can build the foundation to assist in selecting an appropriate wound dressing.

There are 3 phases critical in wound healing. The process begins with the inflammatory phase, involving the coagulation cascade leading to clot formation, serving as the scaffold for the new extracellular matrix. Growth factors and additional signaling components are subsequently released. This action prompts the migration of fibroblasts, neutrophils, and macrophages and then transitions to the proliferative phase. During this phase, type III collagen is synthesized but later is replaced by type I collagen during maturation.[2][3][2] After a comprehensive assessment of the patient and their wound, the clinician needs to consider many different factors before choosing a wound dressing, which is not limited to its ability to absorb exudate effectively, provide a moist environment, ease of application, duration of treatment, and cost, among other factors.[4][5][6][7] 

Issues of Concern

Before applying any wound dressing, it is important to assess for the following factors that may influence the type of dressing chosen. All of these should be addressed, if present:

• Mechanism of injury
• Risk of contamination
• Potential injury to deeper structures
• Underlying nerve or tissue damage
• Presence of perfusion deficits
• Presence of tissue edema  
• Tetanus status
• Amount of tissue loss
• Presence of infection 

After the initial wound evaluation, the wound should be copiously irrigated using a neutral solution such as normal saline or sterile water to remove any debris during the initial evaluation. Using toxic or irritating solutions, such as hydrogen peroxide, is not encouraged as they can be painful and detrimental to wound healing.[8][9][10][11][12][13] Current evidence suggests using at least 50 to 100 mL of irrigant per centimeter of the wound to optimize bacterial clearance.[13] However, adjustments should be made based on the wound. Devitalized tissue can be sharply excised as re-epithelization does not occur in necrotic tissue.[3][12] While low bacterial loads contribute to wound healing with proteolytic enzyme production, persistent bacteria will produce biofilm. They should be removed as their presence can lead to persistent inflammation, ultimately delaying healing.[2][3]

Historically, dry wounds were believed to facilitate better healing. However, recent research has revealed that a moist wound environment is more effective in promoting wound healing. An optimal moist wound bed can enhance recovery in many forms. Cell communication is facilitated by the secretion of pertinent growth factors and signaling molecules, an avenue for epithelial cell migration is provided to allow for efficient re-epithelization, and collagen synthesis is enabled while simultaneously nurturing an environment for the autolysis of necrotic tissue.[14] Nonetheless, a wound bed rich in exudate can hinder wound healing. Thus, selecting a dressing that will control the exudate is critical to avoid maceration of surrounding tissue. 

A few common themes visited when choosing among dressings are the depth of the wound, amount of exudate, chronicity, and the presence of infection. The ideal wound dressing possesses many crucial characteristics. The dressing would protect the wound from the environment, not adhere to the wound, and minimize pain. Moreover, the dressing should provide a moist wound bed to promote autolytic debridement while controlling exudate and protecting the surrounding skin from potential maceration. Finally, the dressing should be chosen to improve the patient's quality of life by optimizing patient compliance, minimizing cost, and allowing for maximal function.[2][3][15]

Below are the various categories of modern wound dressings, their advantages and disadvantages, clinical applications, and general recommendations for the frequency of dressing changes. Further information about specific dressings' indications may be accessible on the manufacturer's website or from a sales representative.

Gauze: Moistened gauze provides mechanical debridement when removed.

• Advantages: Gauze is cost-effective and widely available. 
• Disadvantages: Gauze is not moisture-retentive. This dressing performs non-selective debridement, which can lead to removing new granulation tissue with dressing changes. This dressing is susceptible to bacterial contamination and requires a secondary dressing. 
• Clinical Application: This includes the early stages of deeper wounds that require packing. 
• Frequency of Dressing Changes: Change dressing multiple times a day if used for packing.[16]

Films: Films are thin and transparent dressings.

• Advantages: Films are flexible and retain moisture. They provide the ability to monitor wounds visually. Films are semi-permeable, thus allowing for gas exchange while not allowing for external bacteria to enter the wound. These are self-adhesive. 
• Disadvantages: Films are non-absorbent and impermeable to fluid; thus, they can cause maceration. 
• Clinical Applications: Use films for shallow wounds, split-thickness skin graft donor sites, minor wounds, intravenous access sites, and secondary dressings. 
• Contraindications: These include moderate to heavy exudative or infected wounds. 
• Frequency of dressing changes: This ranges from every few days a week to routine dressing changes every 7 days.[2][3][16][17]

Foams

• Bilayer dressing: In this dressing, the inner layer is polyurethane or silicone, while the outer layer is a hydrophobic, permeable layer.   
• Advantages: Foams absorb exudate. They are semi-occlusive and semi-permeable. Their thickness allows for extra protection from external trauma. 
• Disadvantages: These include the inability to visualize wounds and drying out a wound.
• Clinical Application: Use foam for moderate to heavy exudative and chronic wounds and pressure injuries. 
• Frequency of dressing changes: Change daily or a few times a week.[2][3][17]

Hydrogels: Hydrogels are hydrophilic starch polymers (predominately composed of water). These are available in sheets, amorphous gels, or gauze. 

• Advantages: These include absorbing water and providing a cooling effect, which can reduce pain. Hydrogels are generally transparent or clear. They provide a moist environment, which encourages autolytic debridement. 
• Disadvantages: Hydrogels have a low absorptive capacity and require a secondary dressing. 
• Clinical Applications: These are used for venous or arterial ulcers and surgical wounds; hydrogels also prevent tissue desiccation. 
• Contraindications: These are not for heavy exudative wounds. 
• Frequency of dressing changes: Every 1 to 3 days.[2][3][17][18]

Hydrocolloids: There are cross-linked hydrophilic polymers with cellulose, gelatin, or pectin. Hydrocolloids can be in sheets, paste, or powder form; hydrofiber dressings are an available dressing variant. 

• Advantages: They are initially impermeable to water but progressively absorb water, becoming more permeable and forming a gel. Hydrocolloids lower wound pH, inhibiting bacterial growth. These can be placed across joints or fill wound cavities. 
• Disadvantages: It is not possible to visualize wounds. 
• Clinical Applications: Use these for pressure wounds and minimal to moderate exudative wounds.  
• Contraindications: These are not for necrotic or infected wounds. 
• Frequency of Dressing Changes: Change dressings every 2 to 4 days.[2][3][16][17]

Alginate: This seaweed polysaccharide dressing has calcium ions exchanged for sodium ions to transform into a gel.

• Advantages: Alginate is highly porous, and the calcium ions have hemostatic properties. 
• Disadvantages: This dressing may adhere to the wound bed when dried—and can change into a yellow or brown color, which can be mistaken for purulence. Alginate has an unpleasant odor and requires a secondary dressing to avoid drying. 
• Clinical Applications: This dressing is for moderate to heavy exudative wounds. 
• Contraindications: These are not for minimally exudative wounds. 
• Frequency of Dressing Changes: Change dressing every 1 to 3 days.[2][3][16][17]

Antimicrobial: Silver ions disrupt bacterial cell walls and DNA synthesis in addition to inactivating bacterial enzymes. Iodine-impregnated dressings are available as well. 

• Advantages: These have broad-spectrum antimicrobial properties. 
• Disadvantages: Oxidized silver can stain skin. Silver ions cannot penetrate deep wounds; there is concern for systemic adverse effects with prolonged use of iodine-based products. 
• Clinical Applications: These can be used on superficially infected wounds or those with a high risk of infection. 
• Contraindications: These are not for deep wounds. 
• Frequency of Dressing Changes: Change daily or every few days, depending on dressing saturation.[2][3][16]

Honey is an alternative wound dressing option. Honey is hypertonic and limits bacterial proliferation by dehydrating the wound and creating an acidic environment.[13] 

Not all wounds will heal adequately with the classic dressings mentioned above. Certain wounds may require more specialized wound dressings, such as skin substitutes, biological skin products, and other complex wound dressing products, which is beyond the scope of this activity.[19][20][21] 

An Alternative Perspective of Wound Types and Their Appropriate Treatment:

1. Infection: Topical antimicrobials and antimicrobial dressings can be used for local infections. However, antibiotics should be considered if there are signs of systemic infection. 
2. Dryness: Hydrogel can provide hydration to the wound. Dry eschars can also benefit from enzymatic debridement, such as collagenase. 
3. Exudate: High exudate can be managed with foam, hydrocolloid, or alginate dressings. Low exudate can be managed with hydrogel, hydrocolloid, or film dressings. 
4. Odor: Excessive odor can be controlled with topical metronidazole or activated charcoal dressings. 
5. Deep wounds: Use negative pressure therapy or wound packing for deep wounds.[12][22][23][24]

Clinical Significance

Effective wound assessment is crucial for providing quality care to patients. Unfortunately, healthcare professionals use various terminologies when describing wounds, which indicates a lack of consensus on wound assessment. This discrepancy highlights the need for a universal wound assessment system to ensure that all healthcare professionals receive adequate education and training on wound assessment.[25] Selecting the appropriate dressing for treatment is crucial. Establishing a correct assessment as the foundation for any effective treatment is imperative.

Chronic wounds affect millions of individuals in the United States, which continues to grow due to increasing older and diabetic populations. Moreover, chronic wounds also serve as a significant cause of morbidity, and their treatment contributes to more than $25 billion annually.[2] Cost plays a significant role in wound care, especially in outpatient treatment. Nevertheless, the cost is a more extensive concept and is not restricted to the cost of the individual dressing itself. Instead, the cost should be considered as a measure of the comprehensive cost of care and the patient's outcome in addition to the cost of the dressing.[26] 

Enhancing Healthcare Team Outcomes

Many wound dressings are available, but not all are universally applicable. Therefore, every interprofessional team member needs to comprehend the differences among dressings. Despite many treatment options, a successful wound-healing process requires a team effort from various disciplines.[25] The team can optimize patient outcomes through collaboration among many specialties. Any trained team member can perform wound care. Research has demonstrated that adopting a multidisciplinary approach can significantly enhance the healing process of wounds while simultaneously decreasing their severity.[27] 

Wounds should be re-evaluated during every dressing change to ensure that the wound bed is vascularized, has viable tissue, and is infection-free. Nurses should adhere to the dressing change schedule if performing the dressing changes and communicate any concerns to the providers. A nutritionist should also be involved to ensure adequate calorie intake and provide recommendations for nutritional supplements. The wound care team should be consulted for complex or non-healing wounds. Consult a surgical team if there is potential for excisional debridement; further, they can assist with any recommendations.[28][29] Ultimately, the primary team should formulate treatment plans to improve patient factors that may impede proper wound healing while ensuring that these changes enhance the patient's quality of life.[30]