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Wound Series Part 2: Approaches to treating chronic wounds

Author: Linda Cowan

 

Wound Series Part 2: Approaches to treating chronic wounds | Copyright © 2013 CEUFast.com


Course Contents

   Purpose
   The Objectives
   The problem of wounds
   Expected pathways to healing: Acute wounds
     vs. chronic wounds

       Partial thickness versus full thickness
         wounds

       Wound healing intentions
       The process of full thickness wound
          healing

   Wound Care
   Hand Washing
   Specific Wound Needs
   Wound Cleansing
       Cleansers or killers
       A word about Dakins solution
       Water or saline
   Removing Necrotic or Non-viable Tissue
     from the Wound Bed

       Debridement
       Natural debridement therapy
   Infection
   Wound Assessment and Monitoring
   Moisture Control
   Common Wound Dressings Overview
       Why are we still using wet-to-dry?
       When, Where, What, Why and How?
       Dressing Types
       Gauze (and nonstick Telfa)
       Wound Gels
       Impregnated Gauze
       Hydrocolloids
       Alginates and fiber gelling dressings
       Hydrofibers
       Foams
       Silver products
       Iodine products
       Compression and layered dressings
       Composite dressings
   Pain Management for Chronic Wounds
   References

   Click any section in the index above to browse to the corresponding course section 

 

Purpose

The purpose of this educational module is to present an overview of wound care for most chronic wounds. This is not meant to be an extensive or all inclusive course which details advanced wound therapies for the wound care specialist. Rather, it is to help the typical nurse or clinician (in any setting) to become more familiar with principles of good wound healing and provide a guide to wound dressings, thereby answering the age old question, what should I put on the wound? This module will also include pain management for wounds - an under-addressed clinical problem.

 

The Objectives
   
1. Describe expected healing pathways in acute versus chronic wounds.
   
2. Discuss important considerations for cleansing wounds
   
3. Select wound dressing supplies relevant to any healthcare setting.
   
4. Select 5 essential items which should be assessed, addressed and included in wound care documentation.
   
5. Apply pain management options for pain in chronic wounds.

 

The problem of wounds

A Health Technology Assessment (HTA) related to wound care management (Bradley, Cullum, & Sheldon, 1999) estimated the worldwide prevalence of wounds includes 40 to 50 million non-healing surgical wound, 8 to 10 million leg ulcers, 7 to 8 million pressure ulcers, and 7-10 million burn wounds. These numbers reflect that more people throughout the world have chronic, complex or non-healing wounds than the total US population with cardiovascular disease (approximately 15 million), asthma (18 million), or diabetes (10 million) (CDC - 2011 National Estimates - 2011 National Diabetes Fact Sheet - Publications - Diabetes DDT, n.d.). Chronic, complex or non-healing wounds represent a major health problem and a growing economic concern. To improve wound healing outcomes and decrease the number of chronic or non-healing wounds worldwide, evidence-based wound prevention and treatment strategies are necessary.

 

Expected pathways to healing: Acute wounds vs. chronic wounds

Partial thickness versus full thickness wounds

When an alteration in skin integrity occurs, such as when a teenager falls from a skateboard and scrapes his/her knee, it results in a wound. If the wound extends only through the epidermis and perhaps involves part of the dermis (but does not involve subcutaneous tissue or underlying structures), it is considered a partial thickness wound. We expect this type of wound will heal by re-epithelialization, and likely will not scar. If the wound extends through the epidermis and the dermis, and includes subcutaneous tissue or underlying structures, it is considered a full thickness wound. We expect this type of wound to heal by a complex process resulting in scar tissue formation. The location of the wound determines the depth of tissue loss required to establish if a wound is a partial or full thickness wound. Some parts of the body (over the anterior shin, the knuckles of the hands, bridge of the nose, etc.) have very thin skin and do not have a significant amount of subcutaneous fat/tissue. A shallow wound over these areas would be a full-thickness wound though they may only extend 2mm deep (or less). Alternatively, wounds over the buttocks or fleshy parts of the body may be the same 2mm depth and yet remain partial thickness wounds, because they do not extend into subcutaneous tissue. Areas of the body such as the ears and bridge of the nose have cartilage directly covered by dermis and epidermis. Any wound that involves cartilage is a full thickness wound, even if it appears very superficial.

Wound healing intentions

Wounds are said to be healing by primary intention if a linear wound (such as a surgical incision) is re-approximated (edges pulled together) and sutured, stapled, glued or taped together (without gaps). These wounds will typically form a healing ridge by post-operative day 5 in healthy individuals (Sussman & Bates-Jensen, 2007). This healing ridge is evidence of collagen deposition knitting the two separate wounded edges together resulting in a healed surgical site. In such a case, the skin at the wounded site should have the same tensile strength as surrounding tissue after healing has fully occurred. This point is important to remember as we move on to discuss wounds that heal by secondary intention.

Wounds are described as healing by secondary intention if they are left open to heal or fill in with new granulation tissue and finally close by re-epithelialization. Scar tissue in full thickness wounds that heal by secondary intention (or scar tissue formation) will continue to mature 12-18 months after complete closure of the wound opening. The tensile strength of the resulting scar tissue in the area of a wound healed by secondary intention will never reach more than 80% of the tensile strength of the surrounding tissue. Therefore, this will always be a weak spot, prone to breakdown before the surrounding tissue. Therefore, a full thickness pressure ulcer in a location likely exposed to repeated pressure such as the ischia or coccyx, which healed by secondary intention instead of flap closure, will be at greater risk of recurrence. This is one reason that surgeons prefer to create surgical skin flaps to close certain wounds such as clean, uncomplicated full thickness pressure ulcers in relatively healthy individuals (with the best chance of surgical healing), instead of leaving these wounds open to heal by secondary intention (Bryant & Nix, 2007).

On the other hand, full thickness wounds which are initially sutured closed, then re-opened (or left open at the start) for awhile and finally sutured, stapled, glued or taped closed again, are said to be closed by tertiary closure. These wounds heal by a combination of scar tissue formation and surgical wound healing. Therefore, their suture lines may or may not reach the tensile strength of the surrounding tissue, depending on the amount of scar tissue formation (Bryant & Nix, 2007; Sussman & Bates-Jensen, 2007).

The process of full thickness wound healing

As discussed above, full thickness wounds healing by secondary intention actually heal by scar tissue formation. The wounded human body sets into motion a cascade of processes that results in the production of new collagen to fill the open defect of a full thickness wound in the skin/tissue. If the skateboarder is young and healthy, his/her knee will bleed for a few seconds and clotting factors and fibrin will start clotting the blood. Chemical signals (cytokines) will be initiated which will result in localized edema, redness at the area, slight warmth and pain. The localized pain, edema, warmth and redness will typically resolve in 3-7 days (inflammatory phase of wound healing). If the wound bed is not kept moist, the wound will dry out and a scab will form. Next, the body will produce enzymes (matrix metalloproteinases or MMPs) under the scab to help lift it, especially at the edges. The wound bed under the scab will be moist to promote cellular communication, proliferation and movement (Bryant & Nix, 2007). The skateboarder will likely pick the scab off of the wound, especially if it feels tight or itchy. However, the scab will form again, smaller this time, as the wound contracts. If all goes as expected, the wound will completely close (re-epithelialize) in a few weeks. As described, this is an acute wound. Interestingly, George Winter (Winter, 1962) demonstrated that open wounds (not sutured surgical wounds), which are kept continuously moist actually heal almost 50% faster than those allowed to dry out and scab over. The skateboarders scenario demonstrates uncomplicated acute wound healing. The typical needs of acute wounds versus chronic wounds are described below.

The typical needs of the uncomplicated ACUTE wound are:

1. Moisture balance: Keeping the wound bed moist will allow optimal cellular communication, fibroblast proliferation, keratinocyte differentiation and migration. Preventing too much moisture will prevent maceration and avoid excess enzyme levels (such as MMPs) in the wound fluid.
   
2. Protection: Keeping the wound covered with an appropriate dressing will provide protection from external contamination (bacteria, parasites, foreign bodies, etc.) as well as friction and repeated trauma. It will also provide thermal protection, and of course, prevent the wound bed from drying out, if a moisture retentive dressing is used (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Schultz et al., 2003; Sussman & Bates-Jensen, 2007).
   

In contrast to acute wounds, any wound that does not follow the expected pathway to healing is a chronic wound. Chronic wounds most often get stuck in the inflammatory phase of healing, resulting in delayed wound healing, and often, persistent edema, redness and pain (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Schultz et al., 2003; Sussman & Bates-Jensen, 2007).

Inflammation in chronic wounds typically starts as it does in acute wounds: wounding  bleeding
clotting cascade release of cytokines edema, warmth, redness, pain. However, unlike acute wounds, in a chronic, complex or recalcitrant wound, the expected pathway to healing stops here and never progresses out of a chronic inflammatory state. The presence of biofilm, or overwhelming infection; malnutrition; immune suppression; certain medications and a variety of other factors can contribute to a wound remaining in a chronic inflammatory state. Chronic wounds get stuck in the inflammatory phase of wound healing

The typical needs of the CHRONIC wound are similar to the acute wound with one exception:

1. Moisture balance: Keeping the wound bed moist will allow optimal cellular communication, fibroblast proliferation, keratinocyte differentiation and migration. Preventing too much moisture will prevent maceration and avoid excess enzyme levels (such as MMPs) in the wound fluid (Bryant & Nix, 2007).
   
2. Protection: Keeping the wound covered with an appropriate dressing will provide protection from external contamination (bacteria, parasites, foreign bodies, etc.) as well as friction and repeated trauma. It will also provide thermal protection, and of course, prevent the wound bed from drying out, if a moisture retentive dressing is used (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Sussman & Bates-Jensen, 2007).
   
3. Address the chronic wound environment with the goal of reverting it back to an acute environment to get the wound back on a healing track (Bradley et al., 1999; Schultz et al., 2003; Schultz, Barillo, Mozingo, & Chin, 2004a)

More advanced chronic wound treatments and adjunctive therapies will be discussed in a future course.

 

Wound Care

This section seeks to provide specific information to help you approach the wound from a nursing or caregiver perspective, which focuses on the cleansing and dressing of wounds.

Ideally, care of a wound should begin with a game plan. There is no strict recipe that will fit all wounds, but the following are general measures and recommendations (Baranoski & Ayello, 2004; Hess, 2005; Sussman & Bates-Jensen, 2007) that should be considered with all wound care. Typically, the process of wound dressing changes will look something like this:

  Begin with gathering supplies (consider the appropriate supplies and verify current orders). If it appears inappropriate wound dressings/topic therapy has been ordered, it is your responsibility to question this and make more appropriate recommendations!
   

Common wound care supplies: gloves (sterile or non-sterile/clean), 4x4 gauze, saline or wound cleanser, paper measuring tape, skin prep wipes, disinfected scissors, primary dressing, secondary or cover dressing (if needed), tape or securing device, biological waste disposal bag, drape(s).

  Set up your workspace: there should be a clean drape for all supplies to sit on, appropriate disposal containers handy, gloves, etc.
   
  Make the patient comfortable they will likely remain in the same position for 15-30 minutes, so the patient should not be standing or holding themselves in an uncomfortable or unnatural position for wound care also consider pre-medicating the patient for pain (30 min prior to wound care for oral analgesics)
   
  Make sure that the person performing the wound care is comfortable (example: raising the bed if necessary, so they are not bent over to do the wound care)
   
  WASH YOUR HANDS
   
  Don your gloves and remove the old dressing (discarding the old dressing and your gloves in a biohazard or appropriate container), noting the characteristics of the wound, wound exudates (drainage) and specific needs of the wound bed (see TIME anagram below) (Carville, 2006)
   
  Wash your hands again (alcohol based hand cleanser is ok for non-soiled hands in most cases)
   
  Don new gloves
   
  Cleanse the wound with a non-toxic wound cleanser
   
  Measure and photograph the wound if necessary
   
  Apply a new dressing and secure the dressing appropriately (be mindful of the best way to secure the dressing to avoid trauma to the surrounding skin perhaps consider using a skin barrier wipe to the skin surrounding the wound where any adhesives will be applied)
   
  Discard gloves and used supplies
   
  Wash hands after wound care
   
  Document the wound care and educate patient & family

Now we will attempt to break this down into individual considerations. Gathering supplies, selecting the appropriate materials, setting up your workspace, and making the patient and caregiver comfortable are self-explanatory.

 

Hand Washing

Do not take hand washing for granted! You have heard it said that the most important infection control practice is hand washing. This is true. Proper hand washing prevents infection: Wash with soap under running water for at least 15 seconds. No short cuts. Wearing gloves when you perform wound care is necessary in most cases, unless it is a close family member or the patient is doing wound care for themselves. However, wearing gloves is no substitute for hand washing (CDC, 2012)! http://www.cdc.gov/healthywater/emergency/hygiene/.

 

Specific Wound Needs

Wound care has advanced tremendously with modern technology. This is good news for patients, but complicates things for health care providers. Forty years ago, there was only a small list of wound care products to choose from and today there are thousands. However, clinicians need not fret about approaching wound care in modern healthcare. Clinicians need only to remember a few basic principles similar to the ABCs of CPR. Think of this as the TIME for wound care. Schultz et al. (Carville, 2006; Schultz et al., 2003, 2004a) wrote a pivotal article on wound bed preparation which describes a systematic approach to addressing specific needs of the wound bed in full thickness open wounds. In their article they describe the anagram T-I-M-E to assist clinicians in performing evidence-based wound care.

 

T is for Tissue - the amount of non-viable or necrotic tissue in the wound bed should be noted and attended to (typically by debridement or removal of the necrotic tissue).
   
  I is for Infection - infection should be identified and determined if it may require systemic treatment (critical infection) versus non-critical chronic bacterial colonization that may require only local management (by debridement and topical therapies).
   
  M is for Moisture moisture in the wound bed should be managed. A balance of moisture is important for wound healing. Topical wound care (especially dressings) should prevent the wound bed from drying out - at the same time as eliminating excessive moisture in the wound bed. When there is excessive moisture in the wound, and it exceeds the capabilities of the dressing, it often causes moisture damage to the skin surrounding the open wound (maceration). Dressing selection is most important for addressing this specific need of the wound bed.
   
  E is for Edge of the wound - attention should be given to the wound edges. Rounded, rolled wound edges prevent epidermal cell migration, which may impair wound closure. Tracking or tunneling in the wound bed, as well as undermining (a lip or ledge under the wound edge) may also impair wound healing. Undermining is often caused by shearing forces upon the wound area, frequently seen in pressure ulcers around the sacral area typically due to the patient repeatedly sliding down in the bed. A later article by Carville (2005) suggested also addressing the tissue and skin surrounding the wound opening. The surrounding skin and tissue should be examined for the presence of or worsening of: erythema (redness), edema (swelling), warmth, and skin lesions (blistering, rash, irritation, callus, or maceration, etc.).

 

Wound Cleansing

Many experts agree it is necessary to cleanse wounds at each dressing change to remove wound exudates, cellular waste, debris, bacteria, etc. However, caution is warranted regarding antimicrobial wound cleansers. Several studies report on the cytotoxicity of various common wound cleansers. Cytotoxicity relates to the substance being toxic to human tissue cells. Cytotoxic wound cleansers will not only kill germs but also kill healthy cells such as the fibroblasts (white cells that manufacture collagen/new tissue) or epidermal keratinocytes (important skin cells). (Baranoski & Ayello, 2004; Krasner, Rodeheaver, Sibbald, & Woo, 2012; Rabenberg, Ingersoll, Sandrey, & Johnson, 2002; Wilson, Mills, Prather, & Dimitrijevich, 2005).

In addition, many of these cleansers are antimitotic (prevent cellular mitosis and regeneration), which is how some chemotherapy agents function to prevent cancer cell growth. While that may be a desirable trait for cancer treatment, it may not be as desirable for a wound cleanser!

Cleansers or killers

Wilson et al. (2005) reported on the cellular toxicity of common skin and wound cleansers such as dilute Acetic acid (0.25% vinegar), Cara-Klens, Dermal Wound Cleanser, Dial Liquid Antimicrobial Soap, Hibiclens, Hydrogen peroxide (3%), diluted Dakins solution (0.025% sodium hypochlorite/bleach), Povidone Iodine (10%), Puriclens, Restore Wound Cleanser, SAF-Clens, Saline (0.9% sodium chloride), Shur-Clens, Biolox, Techni-Care, etc. Their study revealed that only Shur-Clens, SAF-Clens and Saline were non-cytotoxic to fibroblasts (Toxicity index 0) without being diluted. Only Biolox, Shur-Clens and Techni-Care were non-cytotoxic to epidermal keratinocytes (Toxicity index 0) without being diluted. Some cleansers had higher toxicity indices such as 10 (need to dilute 10 times to reach a non-cytotoxic strength), 100, 1000, 10,000 or 100,000 (need to dilute 100,000 times to reach a non-cytotoxic strength). The higher the index, the more cytotoxic the cleanser. The cleansers which had the highest toxicity index against fibroblasts included Hibiclens (10,000), Dial Antibacterial Soap (100,000) and Ivory Liqui-Gel (100,000). The cleansers which had the highest toxicity index (100,000) against epidermal keratinocytes included Hydrogen peroxide, Povidone Iodine, and Dakins Solution.

A word about Dakins solution

Many clinicians are badly informed concerning Dakins solution, when to use and not to use, storage, documentations and strengths. Here are some things every clinician should know about Dakins:

1. Full strength Dakins solution is a 0.5% sodium chlorite (hypochlorous acid) solution. Most are buffered with sodium bicarbonate to bring the PH up to one more easily tolerated by human tissues. Why is 0.50% Dakins solution called "Full Strength"? The term "Full Strength" refers to the highest concentration tolerable to the skin, which is Sodium Hypochlorite 0.50%. "Full strength" has been the standard industry term since its inception (Century Pharmaceuticals, Inc., 2011, pg. 1).
   
2. At Full Strength, half strength, quarter strength (0.125% sodium hypochlorite), and even one-eighth strength (0.0625% sodium hypochlorite), Dakins solution is cytotoxic to fibroblasts and keratinocytes. Full strength Dakins solution would need to be diluted 50 times (one-fiftieth dilution) in order to reach a 0.01% sodium hypochlorite solution (non-cytotoxic).
   
3. Clinicians should be extremely careful to know: A) What strength was ordered? B) Is this strength appropriate? C)Short term use may be appropriate to address a high localized bioburden
   
4. Documentation of the use of any sodium hypochlorite solution should always be done by recording the exact strength that was used. Many times all strengths are just recorded as Dakins solution but this is in effect the same as documenting that insulin was given without recording the exact strength. Dakins solution is a 0.5% sodium hypochlorite solution and is often diluted because of its high cytotoxic properties. RECORD the correct strength!!!

The following is a chart which describes the different dilutions of sodium hypochlorite solution

Sodium Hypochlorite Strengths
(Century Pharmaceuticals, Inc., 2011, pg. 1)
(A Reference Guide)

Industry Term Percent of Sodium Hypochlorite  Active: Total NaOCl Parts per Million Dilution of Bleach
Bleach 5.00% 1:20 50,000 ppm None
Dakin's Full Strength * 0.500% 1:200 5,000 ppm 1/10th
Dakin's Half Strength * 0.250% 1:400 2,500 ppm 1/20th
Dakin's Quarter Strength * 0.125% 1:800 1,250 ppm 1/40th
Diluted Sodium Hypochlorite 0.0250% 1:4000 250 ppm 1/200th
Di-Dak-Sol * 0.0125% 1:8000 125 ppm 1/400th

Ohio State University Medical Center (OSUMC) Department of Inpatient Nursing (2002) published a nice patient education pamphlet, How to Make Dakins Solution (available at: http://www.itstactical.com/wp-content/uploads/2012/01/Dakins_Solution.pdf). This pamphlet describes diluting 3 ounces of common (unscented) household bleach (5.25% sodium hypochlorite solution) with 32 ounces of clean, boiled water (buffered with teaspoon baking soda/sodium bicarbonate) to make a full strength Dakins solution (0.5% sodium Hypochlorite solution).

To make strength Dakins solution (0.25% sodium hypochlorite), use only 3 tablespoons (48ml) bleach mixed with the same amount of water (32 ounces) and baking soda (1/2 tsp.). OSUMC reports tightly sealed jars of these solutions may be stored at room temperature up to one month (in a dark jar), but once opened, any unused solution should be discarded within 48 hours. University of Virginia Health System also created a similar document accessible at: http://www.virginia.edu/uvaprint/HSC/pdf/09024.pdf

Water or saline

In most cases, wound experts recommend using water or saline to cleanse the wound (Fernandez, Griffiths, & Ussia, 2007). Some articles suggest tap water may be appropriate to cleanse a chronic wound. However, a Cochrane systematic review of research exploring this tap water question concluded, The decision to use tap water to cleanse wounds should take into account the quality of water, nature of wounds and the patients general condition, including the presence of co-morbid conditions (Fernandez et al., 2007). They also point out that for tap water to be considered for wound cleansing, it must be potable. Caution may be warranted for several reasons when considering tap water. Most of the studies in the systematic review were small and did not have adequate sample sizes to determine significant differences between groups. It is not known if the water used for wound cleansing vs. normal saline was tested for bacterial, cysts, fungi or presence of any other contaminants. Tap water if obtained from a well may contain contaminants such as bacteria or other contaminants, undetectable to the human eye. Alternatively, city water is typically chlorinated at around 3 parts per million or 0.3mg/L and also typically contains fluoride (0.5mg/L to 1.0mg/L) - it is unknown what effect this may have on cellular activity in the wound bed, and this was not reported on by the studies included in the Cochrane systematic review. Therefore, the author recommends using primarily saline or a proven non-cytotoxic wound cleanser.

An exception to using cytotoxic wound cleansers is when the benefits outweigh the risks. For instance, in the case of localized bacterial invasion in which the host is unable to overcome the bioburden of the infecting organism(s) with its own immune defenses (such as pseudomona aeruginosa infection resulting in further wound deterioration), the fibroblasts and epidermal keratinocytes are not likely to survive this hostile wound environment anyway. Therefore, it may justify using a short-term application of cytotoxic wound cleanser such as a dilute Dakins solution (sodium hypochlorite) just long enough to eradicate the infecting organisms. Yes, this is likely to impair cellular function temporarily but the infecting organisms would do far worse if you did not address/control them. Once you have cleaned up the wound (perhaps a few weeks), you should return to non-cytotoxic moist wound healing principles for wound care.

Cleansing the wound should not only address washing or rinsing a wound but also includes debridement or addressing removal of non-viable (necrotic) tissue from the wound bed. Necrotic tissue is a breeding ground for bacteria and impairs wound healing (Schultz et al., 2003). Removing this unhealthy tissue (debridement) may be achieved by a variety of means: Sharp debridement, either selective or non-selective (with scalpel, scissors, curette); enzymatic (collagenase ointment or similar); autolytic (promoting the bodys own enzymatic activities); mechanical (rough friction or wet-to-dry) and larval debridement (maggots) (Schultz & Dowsett, 2012; Schultz et al., 2003)

 

Removing Necrotic or Non-viable Tissue from the Wound Bed

Necrotic tissue in the wound bed provides a breeding ground for bacteria, impairs optimal cellular communication and proliferation, and acts as a physiological barrier to new tissue deposition and wound contraction (Schultz & Dowsett, 2012; Schultz et al., 2003; Sussman & Bates-Jensen, 2007). In almost all cases, necrotic tissue should be removed when safely possible. This includes slough (white, yellow, grey chicken fat appearing tissue), fibrin (adherent, white yellow or grey fibrous non-viable tissue), and eschar (typically thick, brown to black, leathery dead tissue). There are a few exceptions to this rule. One very important exception is in the case of intact, hard, black eschar on the heel of the foot. There is no way to determine the depth of tissue damage underneath this eschar, so removing it may expose bone and predispose the patient to infection and osteomyelitis. Intact is the key word here. If this eschar is dry, and NOT soft or boggy or fluctuant, and does not have any lifting at any of the wound edges or drainage, then it may actually be beneficial to leave this eschar alone. Of course, pressure should be off-loaded from the area, and the eschar should be kept clean and dry. Cover the eschar with dry gauze for protection and paint it daily with a small amount of Betadine solution (letting it air dry thoroughly before applying dry gauze for protection and padding). With this tissue in place, it may act as a protective body bandage keeping bacteria and contaminants out of the wound. The wound healing process under this eschar may continue if other wound healing impediments are addressed (offloading pressure, adequate nutrition & blood flow, adequate immune function and tissue perfusion). If the wound under the eschar follows a healing trajectory, the eschar may lift itself after several weeks and display newly epithelialized skin underneath. In some cases, it may lift prematurely at an edge or starts feeling boggy or fluctuant underneath the eschar and may start draining. In this case, it may be best to remove the eschar (Bryant & Nix, 2007).

Debridement

Typical methods of debridement include sharp debridement, mechanical, autolytic, enzymatic and larval debridement. Sharp debridement is usually performed with a scalpel, curette, and/or scissors. This may occur in a surgical suite by a surgeon or at the bedside by a physician, PA, ARNP, or certified wound specialist if allowed by state board scope of practice limitations. Enzymatic debridement is typically achieved by applying ointment (collagenase) to the wound bed. Mechanical debridement may be accomplished by wet-to-dry dressings, by rubbing/friction while cleansing the wound, or by pulsed water jets & hydrotherapy (pulsed lavage, whirlpool). Autolytic debridement occurs by promoting natural enzymes in wound fluid to degrade non-viable tissues usually by placing an occlusive or semi-occlusive dressing over the non-viable tissue. In addition, autolytic debridement may be accomplished by osmotic wound products such as medical grade honey or gauze saturated with a hypertonic sodium chloride since these products draw fluid from wound bed tissues into the wound product and loosen necrotic tissue. Larval debridement is performed by allowing sterile maggots to remove non-viable tissue (Baranoski & Ayello, 2004; Bradley et al., 1999; Bryant & Nix, 2007; Schultz & Dowsett, 2012; Schultz et al., 2003; Sussman & Bates-Jensen, 2007).

Natural debridement therapy

Maggots are the unsung heroes of wound healing. Maggot(s) or larval debridement therapy (MDT or LDT) has been utilized for medical purposes for hundreds or thousands of years. Mayan Native Americans and other ancient cultures have documented reports of maggots being used in certain medical treatments, especially for wound care. Larvae of certain fly species, such as Phaenicia sericata (blow fly); remove only dead tissue while promoting healthy tissue in the wound bed, helping wounds heal faster.

An American Civil War surgeon, Dr. John Zacharias (1837-1901), is one of the first healthcare providers in the US who intentionally utilized maggots in the debridement of wounds. He noted that maggots cleansed opened wounds of necrotic tissue better and more rapidly than any other method at his disposal. In WWI, an orthopedic surgeon named Dr. William Baer recognized the efficacy of maggots to clean up compound fractures and large open flesh wounds when he discovered them in several untended war wounds from the battlefield. Dr. Baer and Dr Zacharias both credited the blow fly larvae with preventing sepsis and saving many soldiers lives in these battlefield cases. Dr Baer was very impressed with the usefulness of fly larvae/maggots as a medical treatment. After the war, Dr. Baer worked as a medical practitioner and researcher at Johns Hopkins Hospital, where he started to conduct research using blow fly larvae in 1929. Initially he used live larvae/maggots he found in the neighborhood or those he grew on a windowsill. One patient died after contracting tetanus from contaminated maggots, so Dr. Baer developed sterile maggot growing procedures. He is well known for his research using sterile maggots in 21 individuals with wounds infected with chronic osteomyelitis not responsive to other treatment. All of these wounds completely healed within six weeks and confirmed that maggots were effective at rapid wound debridement of necrotic tissue as well as reducing the presence of bacteria in wounds. In addition, wounds treated with larval therapy demonstrate reduced wound odor and a wound bed which tends to become more normalized to an alkaline ph environment (Baer, 2011; Schultz & Dowsett, 2012; Sherman, 2009).

Regrettably, with the development of antibiotics in the 1940's and various skin and wound antiseptics, the use of LDT declined. Systemic and topical antibiotics became more a standard of care and more antiseptics were utilized in skin and wound care. Maggot therapy was essentially abandoned in favor of more modern or easier methods, not because they were no longer effective, but largely because of negative reactions of patients, their caregivers and clinicians, who found it distasteful to apply small squirming worms that could crawl out of a wound.

The Food and Drug Administration (FDA) cleared medicinal maggots (Phaenicia or Lucilia sericata) for debriding non-healing necrotic skin and soft tissue wounds in the 1980s, after a renewed interest in larval debridement therapy due to increasing drug sensitivities and the exponential growth of antibiotic resistant organisms. Medical maggots were approved by the FDA as a medical device in the US, and are processed under controlled laboratory conditions. They are germ-free and disease-free as well as unable to reproduce (sterile in both cases). Interestingly, in Europe, Canada and Japan maggots are classified as medicinal drugs. The reason for this is because maggots debride non-viable tissue partly by secreting proteolytic digestive enzymes, which liquefy the necrotic tissue that the larvae then suck up and remove (along with bacteria and biofilm) from the wound bed. In addition, research suggests maggots are very effective at eliminating drug resistant organisms such as MRSA (methicillin resistant staphylococcus aureus), they do not excrete bacteria into the wound, and they are a most efficient way to debride a wound without the typical pain or bleeding associated with other forms of debridement such as sharp debridement. (Sherman, 2009)

 

Infection

In many cases, wound inflammation is often mistaken for wound infection, since the signs of inflammation are warmth, edema, pain, and localized redness. Patients with these symptoms are often placed on antimicrobial treatment regimes without the benefit of microbiological studies to guide them (no quantitative tissue cultures from the wound). This may be one contributing factor in the development of drug resistant organisms. There has been much written about wound infection and other authors can address this better than this brief wound care review (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Schultz, Davidson, Kirsner, Bornstein, & Herman, 2011; Schultz & Dowsett, 2012; Sussman & Bates-Jensen, 2007; Wolcott et al., 2010) Nevertheless, it is one of the most requested topics of wound care courses (to know when to treat and when not to treat infection). Therefore, we will quickly summarize some important facts and helpful tips regarding wound infection:

1. There is a difference between chronic bacterial colonization, critical colonization, and critical infection in a wound. Chronic bacterial colonization does occur in most chronic wounds. If the bioburden (high levels and certain types of bacteria) in the wound is not high enough to impair wound healing and does not invade surrounding tissue, the wound may close when other co-morbid conditions are addressed (such as nutrition); even if the bacteria are not removed or eliminated by the clinician. These cases of chronic colonization do not typically require antimicrobial intervention. In most of these cases, there may be persistent wound exudates but typically these wounds do NOT exhibit worsening pain, worsening edema, or spreading erythema (redness) beyond 1cm from wound edges. Alternatively, any open wound which is not improving AND has worsening symptoms of pain, worsening edema, or spreading warmth and/or erythema, should be evaluated for critical colonization (bacterial load is starting to penetrate surrounding tissue and/or impair wound healing). Critical colonization or infection is characterized by a high bioburden which requires intervention (Bryant & Nix, 2007).
   
2. Critical colonization or infection may be determined by a quantitative tissue culture (gold standard) typically obtained by a collecting small piece of tissue from the wound bed (usually a 3mm punch biopsy, a thorough curette scraping, a needle biopsy, or a small 2-4mm size tissue wedge removed by scalpel and pick-ups). In addition, wound fluid may be aspirated and placed in culture medium tube for wound culture as well. Any organism identified in greater than 105 or 100,000 (10x10x10x10x10) colony forming units (CFUs) per gram of tissue or milliliter of wound fluid within the wound could be considered a critical infection requiring intervention. Certain organisms are highly virulent (such as beta hemolytic streptococcus) and will require intervention even if found in small amounts within the wound bed. If your facility does not perform quantitative culture analysis but reports bacterial growth in a semi-quantitative (1+, 2+, 3+ or 4+) scale, this may be equated to quantitative measures by considering 3+ may be close to 105 CFU but 4+ is more than 105 CFU and considered a critical infection requiring intervention (Baranoski & Ayello, 2004). Some experts have pointed out that host immunity + virulence of organism + environmental factors + bacterial load are factors to consider when evaluating critical colonization and infection versus chronic colonization which would not require intervention. Bates-Jensen (Sussman & Bates-Jensen, 2007) (p 218) suggests infection represents an imbalance in these factors which results in impaired wound healing or invasion of bacterial organisms into surrounding tissue. Any wound which fails to progress for 2 weeks or more should be evaluated for high bioburden, keeping in mind that immune compromised individuals may not display any classic signs or symptoms of infection (warmth, redness, pain, or edema).
   
3. Most nurses only collect wound surface swab cultures and do not typically collect tissue samples from the wound bed. However, there is much variation among swab culture techniques and this may alter results significantly. Swab cultures of the wound bed surface immediately after removing a dressing may contain dressing contaminants and mostly loose free-floating bacteria and may not represent what is actually in the wound bed. How the swab is collected is extremely important to accurate diagnosis. Is the swab just lightly rubbed along the surface of the one with one stroke in one direction? Or, is it collected with a back and forth motion across all surface areas of the wound with moderate downward pressure? Is it rinsed with sterile saline first? These questions should be resolved with standard evidence-based wound culture collection protocols which all clinicians can agree upon. The author recommends using a curette scraping of the wound bed if available and a wound certified nurse or health care provider may do this within their scope of practice. Otherwise, a modified Levine technique may be utilized if swab cultures are the only option for culturing a wound.
   

Levine technique for obtaining swab culture (when a quantitative tissue sample is not an option):
Rinse the wound bed once with sterile saline (non-bacteriostatic and preservative- free). Moisten the sterile culture swab with sterile non-bacteriostatic and preservative-free saline and rotate the swab completely over a 1cm2 area in the wound bed where it is free of necrotic tissue. Press down slightly to illicit fresh wound fluid. Take your time to allow adequate time for fluid collection. Place in appropriate culture media transport tube and take care that the sample does not sit at room temperature longer than the lab recommends (Bryant & Nix, 2007). Note: A wound culture left on the desk overnight will likely need to be repeated. Check your labs policy on this!

 

Wound Assessment and Monitoring

As a general rule of thumb, the wound care provider who is ordering the wound care should re-evaluate the wound for progress at least 2 weeks after the initial wound orders are placed. If the wound is stable, the topical wound treatment is performing as anticipated, and the wound is progressing as expected, the wound treatment may be continued and the follow up could be extended to once every 2 to 4 weeks. If the wound has not improved after the initial 2 weeks, but the wound has not worsened, the clinician should make a decision if a change of wound treatment is in order or if there are other factors which need to be addressed which may be impairing wound healing (nutrition, medications, glycemic control, infection, etc.). After addressing these factors, have the patient return to the clinic in another week or two to re-evaluate progress with the current treatment. If no progress is noted, or the wound worsens at all, a change in treatment may be warranted (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Sussman & Bates-Jensen, 2007).

Measuring the wound is an essential component of wound monitoring and documentation. Wounds may be measured using a variety of techniques but the two most common techniques are the clock method and the longest axis method. The measurement method used should be performed consistently by all care providers. Only one method should be used for all wound measurement documentation for the entire facility to minimize confusion and inconsistency in the patients charts. The clock method consists of imagining the top of the patients head to be at the 12 oclock position of a clock and the soles of the feet to be at the 6 oclock position of an imaginary clock. All wounds are measured with length being the measure of the wound along the 6 to 12 oclock axis and the width being the measure of the wound opening along the 3 to 9 oclock axis. This works well to get the same measures no matter what position the patient is lying or sitting in. The longest axis method consist of taking the wound opening measurements along the longest axis of the wound as the length and the width measurement as the measurement of the wound opening along the perpendicular axis. Wound depth is measured the same way for both of these methods. Using the blunt end of a cotton tipped applicator, hold the stick lightly resting upon the deepest portion of the wound and using a gloved hand, grasp the stick at the wound edge and measure the straight depth of the wound at the deepest portion of the wound and record this as straight depth. Tunnels or tracking in the wound or undermining (lip under the inner aspect of the wound edge) should be measured at most shallow and deepest points. It should also be noted if tunneling or tracking connects two wounds or connects with any joint space or underlying structures (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Sussman & Bates-Jensen, 2007).

Photographing the wound (if desired) as an additional component of wound monitoring includes establishing a routine frequency of photographic documentation, a consistent camera and distance from the wound for all photographs, and a measuring ruler in the frame next to the wound for size reference. It is imperative that you consider who is taking the photos. If another person is taking the pictures, make sure they follow infection control practices and do not touch the patient with the camera or anything in the patients room, especially if they will be taking the camera back to a central work area or other patients room. If it is the same clinician performing the dressing change, care should be taken to follow strict infection control protocols concerning handling the camera and where it is stored during wound care. For example, it should not be laid on the patients bed or bedside table without a clean barrier under it. It should not be handled after touching the patient, the wound dressing or wound care supplies without first washing your hands. Hands should be washed again after handling the camera. The camera should not be in close proximity to the wound during dressing changes if at all possible. During dressing changes, bacteria may be aerosolized and could contaminate the camera. The camera should not be taken from one patients room to another for other photos without first using some kind of disinfecting wipe or changing camera covers if disposable covers are used.

If photographs are to be used in the electronic health record, the author recommends that a photo of the patients ID bracelet be taken, followed by a photo of the wound, then the ID bracelet again, so that this sequence of photos may be uploaded into the appropriate electronic health record, and minimize the chance of the picture being uploaded to the wrong patients chart. In most cases, identifiers such as patient name, initials, date, etc. should not be included in any photo that may be used for educational purposes. However, follow your facilitys protocols for taking and uploading wound photographs.

 

Moisture Control

One of the main functions of a wound dressing or wound therapy is moisture management. Specifically, to maintain a moist wound bed while also eliminating excessive wound drainage. Since George Winters seminal work in 1962, demonstrating open wounds treated with dressings which maintained a moist environment healed almost 50% faster than wounds allowed to dry out, no published studies have been able to refute the effectiveness of moist wound healing. In fact, current scientific investigations not only support what has been known about moist wound healing, but serve to further explain the role of a moist wound bed in relation to the local cellular activity associated with wound healing (cytokine signaling, fibroblast cell proliferation, collagen and matrix synthesis, epithelial cell migration, etc).

 

Common Wound Dressings Overview

Why are we still using wet-to-dry?
There are hundreds of commercially available wound care products in the United States. Numerous dressings or topical wound care applications have reported successful wound healing results in clinical trials, yet wet-to-dry dressings are still one of the most frequently ordered wound care modalities in nearly all healthcare settings (Cowan & Stechmiller, 2009; Fleck, 2009). Wet-to-dry dressings are no longer evidenced-based practice for wound care. As the name implies, a wet-to-dry dressing ultimately results in a dry wound bed (even if for limited amounts of time). Research demonstrates these dressings disrupt granulating tissue, impair epithelial cell migration, leaves behind foreign bodies in the wound bed, increase the risk of infection, aerosolize bacteria, and cause severe pain upon removal (Cowan & Stechmiller, 2009; Fleck, 2009). Nevertheless, wet-to-dry dressings have been a standard, traditional or default dressing for decades (Bryant & Nix, 2007; Cowan & Stechmiller, 2009; Mulder, 1995). Modern wet-to-dry dressings are accomplished by moistening sterile cotton gauze with a solution (usually 0.9% normal saline) and placing it in the wound, allowing it to dry, then removing it dry from the wound bed (along with tissue that adheres to it), thus performing mechanical debridement. There are several reasons why this form of debridement may be detrimental to the wound bed, and unnecessary with so many other forms of wound debridement available today. Cost, compliance, pain, increased risk of infection and re-injury to healthy granulating tissue are several of these reasons (Bryant & Nix, 2007; Cowan & Stechmiller, 2009; Mulder, 1995).

It is the authors belief that most health care providers have continued with wet-to-dry dressings more out of misunderstood tradition rather than evidence-based wound care practices. Furthermore, the use of wet-to-dry dressings as a wound care modality may be outdated and used with inappropriate frequency in todays health care arena (Cowan & Stechmiller, 2009).

When, Where, What, Why and How?

If not wet-to dry, then what how do you select a moist wound dressing? There are so many to choose from. What dressing has the most evidence supporting it? How often should you change the dressing? Unfortunately, several systematic reviews have failed to produce strong evidence in favor of one specific dressing type for all wounds. Most clinicians who are not very familiar with modern wound products just want to know, if not wet-to-dry, then what one product can safely be used in its place? The answer to this question should be, it depends.

Wound experts now realize the one size fits all approach is not ideal for wound care or dressing product selection. Multiple EBP wound treatment algorithms exist to assist the clinician in selecting wound treatment approaches. Krasner, Sibbald & Woo (2012) developed a Conceptual Framework for Wound Dressing Product Selection. This model reminds health care providers that wound care should be delivered using a Holistic, Interprofessional, and Patient-Centered Approach. This approach should also be in agreement with the principles of evidence based practice (EBP). The principles of EBP affirm that health care should be delivered based on the strongest and most current research evidence + the clinicians experience & expertise + the patients (and familys) preferences and values (Sackett, 1999; Sackett et al., 2000; Titler, 2008).

Before you can determine anything about the wound, you must assess the wound. However, the wound is only one small part of a person. In assessing the wound, dont forget to assess and talk to the person attached to the wound. Assess the person (physically as well as psychosocially). What are the preferences, personal needs, likes, dislikes of the patient (as well as their caregiver)? What are their feelings about the wound/wound care? For a caregiver who gets sick and faints at the sight of blood, asking them to empty bloody drainage from a drainage tube may not be a good choice. As you assess the wound itself, identify the etiology of the wound and co-morbid conditions which may affect wound healing. In Krasner, Sibbald & Woos model (2012), they suggest approaching wound care with one of 3 options or goals in mind.

1. Is the purpose of wound care curative or to heal the wound?
   
2. Is the goal of wound care temporary maintenance or to prevent further deterioration until the patient is able to tolerate more aggressive treatment? This scenario may be applicable if a patient has a gangrenous toe, or non-healing/necrotic arterial foot ulcer but the patient is also in the ICU following a massive stroke and is unable to tolerate any surgery until he/she is hemodynamically stable. In other words, the patients condition needs to stabilize before aggressive approaches to wound healing can be safely deployed.
   
3. Is the goal of wound care palliative? Knowing the wound is not likely to heal (as at the end of life with multiple organ failure). Different products and approaches may be employed for wound care if the purpose of wound care is not to heal or close the wound but to provide pain relief, moisture management, and/or odor control and prevent or reduce the risk of spreading infection. This may frequently occur with malignant lesions in hospice patients and these patients may present challenging situations but nonetheless rewarding outcomes may be possible to ease a persons suffering or improve quality at end of life.

Dressing Types

Probably the most effective and economical substitute for saline moistened gauze (wet-to-dry) dressings are wound gel moistened or impregnated gauze dressings. However, there are now a myriad of evidence-supported wound dressings to address specific needs of various types of wounds. This section is an introduction to some common dressings which have at least moderately strong evidence supporting their use. Please see Table 1 for list of common wound dressings and suggestions for frequency of dressing changes. Resources for all of this information were obtained from 5 main sources: (Baranoski & Ayello, 2004; Bryant & Nix, 2007; Hess, 2005; Krasner et al., 2012; Sussman & Bates-Jensen, 2007). In addition, the Agency for Healthcare Research & Quality (AHRQ) has several evidence synthesis summaries and technical assessments published or currently in progress (such as a review of skin substitutes for chronic wounds) which may be pertinent to wound care.

The ideal dressing should promote the best environment in the wound bed to promote wound healing. In other words, it should maintain a moist wound bed, be thermally insulating, protective to the wound, free of particles that could remain in the wound and become foreign bodies in the wound, be vapor permeable, hypoallergenic, non-toxic, comfortable, and cost effective (Carville, 2006; Hess, 2005; Jones, Grey, & Harding, 2006; Mulder, 1995). Health care providers should consider patient and/or caregiver cognitive and physical limitations/abilities when ordering a wound dressing, if the patient or caregiver will be expected to do the wound care. In addition, if at all possible, the wound dressing should also be aesthetically acceptable to the patient/caregiver (taking their preferences into account) and promote the patient continuing as many activities of daily living as possible (within the limits of his co-morbid conditions) (Krasner et al., 2012). The average health care provider or medical clinic should have at least a familiarity with the following products, and probably have at least one of each type of dressing on hand/in stock:

Gauze (and nonstick Telfa)

Gauze comes in a plethora of forms, sizes, shapes, and layered products. The most common gauze products are sterile or aseptic (packaged individually, in packages of 2 or in bulk packages of 50 or 200 cotton, woven, 8 or 12 layered, 4 x 4 or 2 x 2 sizes. Telfa is gauze which is coated with a plastic film to help render it non-adhesive. Gauze also comes in larger bulk dressings such as abdominal dressings. These dressings are commonly made today with bulky absorptive layers of cotton batting and woven gauze in larger sizes such as 5x 9 or 8 x 10. Gauze dressings are also manufactured in woven gauze of one rolled length (roll gauze) in a variety of widths (such as 2 of 4 or 6 widths). Gauze may be impregnated with other substances such as calamine, petrolatum, wound gels, silver, etc. In addition, combination products may have layers of gauze combined with layers of other wound products such as charcoal, alginates, adhesive backings or borders. Gauze pads are typically latex-free, however, not all gauze rolls are latex-free check packaging!

Wound Gels

Whereas, wet to dry dressings are moistened with saline and allowed to dry out, wound gels are a good alternative that effectively maintains a moist wound bed. The clinician may moisten gauze with a wound gel, or use a pre-packaged gel impregnated gauze. Typically, this only needs to be changed once a day instead of 2-3 times per day. Wound gel dressing changes would be less painful than wet-to-dry. Wound gels come in amorphous gels (in tubes) or in sheets of flexible semisolid gel. Wound gels are commonly made of organic polymers that maintain moisture in the wound bed but also swell with water or wound drainage. In addition, wound gel may contain silicone, water, glycerine, polyethylene oxide, alginate or collagen. Common brand names of these wound gels include (this is not meant to be all-inclusive): Saf-Gel, Vigilon, Elastogel, Curasol, Solugel, Intrasite Gel, Purulon Gel, DuoDERM gel, Nu-gel, Stimulen collagen gel, etc. Some gel sheets such as Vigilon come with polyethylene film covers on each side that should be removed before placing gel sheet on wound (this will allow more vapor permeability). Gel products may absorb up to 5 or more times their body weight in wound drainage yet will not dry out or dissolve. Typically the gel product is placed in the wound bed and covered with a secondary dressing to secure in place (such as gauze or foam). These products are normally changed daily, though gel sheets on certain wounds such as superficial wounds and skin tears may be left on for 1 week if the skin tear is clean (non-infected) with a well approximated flap and is not heavily exudating. Wound gel sheets that come with adhesive borders may be changed 3 times per week. Wound gels are appropriate for full thickness, shallow or deep wounds with scant to small amounts of drainage or varying amounts of drainage where the wound bed may dry out at times. Silicone gel sheets may also be useful in preventing or treating wound scarring (keyloids) for up to one year after wound closure.

Care should be taken to manage moisture so that excessive moisture is not allowed to seep out over the surrounding wound edges causing maceration. Skin Barrier wipes, powders or creams may be useful to protect periwound skin from adhesives (barrier wipes) or excessive moisture (barrier creams such as zinc oxide, or dimethicone). These are applied at each dressing change.

Impregnated Gauze

Another simple dressing to use is impregnated gauze. Pre-packaged impregnated gauze products are typically impregnated with petrolatum, hydrogel, Bismuth Tribromophenate, hypertonic sodium chloride, zinc, or crystalline iodine compound (iodoform). Common brand names of these dressings include (this is not meant to be all-inclusive): Vaseline Gauze, Adaptic, Xeroform, Curasalt, Mesalt, etc. The most basic and inexpensive of the petrolatum impregnated gauze may average $40 or less per box of 50. These dressings are conforming and may be good choice when filling tunnels or tracking as long as one piece and not multiple pieces are packed loosely into the tunnel. These dressings provide non-drying and moisture retaining wound interface, they conform to the wound bed, and petrolatum impregnated products may help protect periwound skin if they are shallow abrasions, so may be placed on the wound overlapping the edges. Normally these dressings are changed daily, and covered with a secondary dressing such as gauze pads or roll gauze, foam, bandage / wraps.

Hydrocolloids

Hydrocolloid dressings are typically opaque, self adherent patch type dressings made of sodium carboxymethylcellulose, pectin and gelatin mixed with polymers and adhesives. They also have a semipermeable film or foam sheet covering which makes them generally waterproof. However, waterproof does not mean it can be submersed such as in a bathtub or pool. These dressings are flexible wafers of differing sizes, thicknesses and shapes (some may be cut to desired size and shape). They can conform to many areas of the body. Common brand names of these dressings include (this is not meant to be all-inclusive): Restore, DuoDERM, DuoDERM CGF, Tegasorb, Comfeel, Granuflex, and 3M Tegaderm hydrocolloid thin. When exposed to exudate (wound drainage), the polysaccharides & other polymers absorb water and swell but remain contained in the adhesive matrix. Some have marks to tell you when the wound drainage is exceeding the dressing's limit and it is time to change. Most hydrocolloid dressings are Latex-free. Most if cut to size, should be cut larger than wound. These dressings are typically changed every 2-5 days and it is best to use a skin barrier wipe applied to the periwound skin before application of the hydrocolloid.

Alginates and fiber gelling dressings

Alginates are super absorbent fibers typically composed of calcium alginate manufactured from brown seaweed that becomes gel-like when exposed to sodium-rich wound exudates. It resembles angle hair and is manufactured from brown seaweed. They may absorb up to 20 times their weight in wound exudates. This makes them a good choice for highly exudating wounds. However, they are not recommended for dry or only slightly moist wound beds, as they will not remain a gel without the presence of moisture from the wound bed. Thus, they may dehydrate the wound bed, or allow the wound bed to dry out. Alginates may be available as sheets or pads and ropes and also are known for some hemostatic properties, making them a good choice for a wound bed that may be oozing a small amount of blood after sharp debridement. In addition, some alginates may have silver incorporated into the fibers as an antimicrobial agent. Alginates typically require a secondary cover dressing such as gauze or ABD pad and are changed daily or as necessary to manage wound exudates.

Hydrofibers

Hydrofiber dressings are non-wicking, absorptive primary dressings made of sodium carboxymethyl-cellulose fibers that absorb wound drainage and turn into a gel sheet. They may also keep the wound bed moist if the wound is sometimes dry (you would moisten them with saline or water). Hydrofibers act somewhat like an alginate but will not promote hemostasis like alginates. Some hydrofiber dressings include 1.2% silver as an antimicrobial component (usually delineated by the silver element symbol AG in the hydrofiber name). They are appropriate for full thickness wounds with minimal to moderately amounts of drainage. They are typically changed once every 1 to 3 days and require a secondary cover dressing.

Foams

Foam dressings are typically a thick both absorptive and protective. They may be selected to provide conforming padding and may be used in combination with other products (such as alginates or hydrofibers) if needed; Foams may be used as a packing material in large wounds to fill dead space. Not all foam dressings are appropriate for infected wounds. Check manufacturer guidelines if infection is an issue. Some foam dressings are impregnated with silver or other antimicrobial material (such as Methylene Blue and Gentian Violet or polyhexamethylene biguanide/PHMB) or coated with a silicone interface. Some foam dressings may be self-adhesive or have an adhesive border. Most foam dressings are latex-free and made of polyurethane foam coated with a waterproof outer surface. Change frequency may vary from daily to up to every 7 days for some products, depending on wound drainage amounts. Check manufacturer recommendations.

Silver products

Silver ions may be incorporated in wound gels, woven fabric dressings, foam, rope, alginates or hydrofiber dressings. Most silver fabric dressings are not very absorbant; they are used primarily to deliver silver ions to wound bed for the silvers antimicrobial effects. However, silver alginates, hydrofibers, foams, or composite dressings are absorbent. Silver ions are activated by wound exudates or water; some silver products (Acticoat 3 day or 7 day) should not be moistened with sodium chloride (saline). Most silver products should not be mixed with hydrogen peroxide or sodium hypochlorite (Dakins or DiDaksol) solutions because the ions will inactivate each other. Silver products should not be combined with iodine products for the same reason. Silver dressings may need secondary dressings and may be changed daily up to every 7 days, depending on the product.

Iodine products

In general, povidone iodine should not be used in chronic wound care due to its cytotoxic properties. However, cadexomer iodine is available which is antimicrobial while remaining non-cytotoxic to the wound bed. Cadexomer iodine is available in a wound gel (thick paste) or a flexible pad which is typically applied to the wound bed with a secondary dressing on top and left in the wound bed for 3 days, or until the color changes from a orange-brown to a grey-brown. They are used for antimicrobial effects on infected room and are effective against most bacteria including pseudomonas, staphylococcus aureus and streptococcus as well as fungus.

Compression and layered dressings

Compression dressings or bandage wraps are primarily used for lower extremity venous insufficiency. Compression garments are also appropriate for extremities effected by lymphedema (such as after mastectomies with axillary lymph node removal) or burns. Short-stretch compression is typically used for lymphedema (these are NOT ace bandages). Long-stretch compression (multilayer wraps and ace-type bandage) is also the typical treatment venous leg wounds. It is important to verify arterial perfusion to affected limb before applying compression. Compression may be applied in 2 to 4 layers, with a therapeutic layer such as zinc-oxide or calamine impregnated strips applied first, an absorptive layer next, possibly a bandage layer and/or Coban layer on top. These dressings may be applied every few days to weekly, depending upon amount of wound exudates. Once edema is under control and wounds healed, lifelong compression stockings should be worn by the patient (apply daily first thing in the morning before ambulating and remove at night just before retiring to bed).

Composite dressings

Composite dressings are combination dressings of various sizes that are made up of two or more separate materials to address unique needs of certain wounds. These dressings tend to be layered with a contact layer (may be non-adhesive), an absorptive layer, and possibly an antimicrobial layer or odor absorbing layer (such as charcoal). They also may have an adhesive border to secure them to the wound site.

Tissue engineered skin substitutes, matrix dressings, collagen products and negative pressure wound therapy are some of the advanced wound therapies to be discussed in a future article.

Wound Product Table

Type of product

Examples *Brands/Names

Types of wounds

Action

Petrolatum or Hydrogel Impregnated gauze Vaseline Gauze, Adaptic, Xeroform; Skintegrity, Elta, Restore, Dermagauze, Curafil Shallow and dry wounds; abrasions, skin tears, etc. Provides non-drying and moisture retaining wound interface, conforms to the wound bed, petrolatum impregnated products may help protect periwound skin if shallow abrasions. Typically changed daily, though may be left in place over well-approximated, non-infected skin tears up to 1 week.
 
Wound Gels/Hydrogels Saf-Gel, Vigilon, Elastogel, Curasol, Solugel, Intrasite Gel, Purulon Gel, DuoDERM gel, Nu-gel, Stimulen collagen gel Dry to minimally draining wounds; partial and full thickness depth, 2nd degree burns, exposed tendons Organic polymers that maintain moisture in the wound bed but also swell with water/drainage (some can absorb up to 5x their own weight in exudate). These gels typically will not dry out or dissolve. May be changed daily, though some gel sheets such as on skin tears may be left on for 1 week if a well approximated flap. Some gel sheets may also be used over scars to reduce hyperkeratosis (keyloid formation).
Hydrocolloids Restore, DuoDERM, DuoDERM CGF, Tegasorb, Comfeel, Granuflex, 3M Tegaderm hydrocolloid thin Partial and full thickness wounds; minimal to moderate drainage Typically a flexible wafer of differing sizes, thicknesses and shapes (some may be cut to desired size and shape); forms an Impermeable barrier (most are waterproof); self-adhesive; may contain gelatin, pectin and carboxy-methylcellulose together with other polymers and adhesives. When exposed to exudate (wound drainage), the polysaccharides & other polymers absorb water and swell but remain contained in the adhesive matrix. May be changed every 3-5 days.
Transparent films Op-Site, 3M Tegaderm, PolySkin, Suresite, Blisterfilm, Argomed and Argomed plus TPU films, Mefilm, Uniflex, AcuDerm Partial thickness or shallow wounds with minimal to small drainage Most are polyurethane films; provide moisture retention and may provide skin protection. May also assist with autolytic debridement. Most are oxygen or vapor permeable (not 100% occlusive). Sometimes used to "waterproof" a wound
Hydrofiber Aquacel, Aquacel AG mostly shallow; partial to full thickness; minimal to moderate drainage Non-wicking, absorptive dressing made of sodium carboxymethyl-cellulose fibers that absorb wound drainage and turn into a gel sheet. They may also keep wound bed moist if wound is sometimes dry (moisten with saline or water). Act somewhat like an alginate but will not promote hemostasis like alginates. Typically changed 1-3 days.
Non-adherent polyurethane foam or Silicone interfaced foam; Optifoam, Mepilex, Mepilex Border, Mepilex Transfer, Allevyn, PolyMem, Lyofoam, Hydrasorb shallow wounds to those with some depth; partial to full tickness; minimal to heavy drainage Absorptive & protective - provides conforming padding and may be used in combination with other products (such as alginates or hydrofibers) if needed; Some have self-adhesive borders. Foams that have a silicone contact layer may be useful in reducing hypertrophic (keyloid) scarring. Some have multiple layers (such as polyurethane foam+ polyacrylate fibers + waterproof film in Mepilex). Typically changed 1-3 days.
Calcium Alginate CalciCare, AlgiSite M, Maxsorb Moderate to heavily draining wounds with no necrotic tissue Highly absorptive fiber (rope or pad) product made from brown seaweed. Turns to gel when moistened with wound drainage. Change daily.
Foams Optifoam, Mepilex, Hydrasorb Deeper, full tickness; moderate to heavy drainage Absorptive and protective - provides conforming padding and may be used in combination with other products (such as alginates or hydrofibers) if needed; Foams may be used as a packing material in large wounds to fill dead space.
Silicone Mepitel, Elastogel, etc. Dry to exudating wounds or delicate wound beds (exposed tendons, etc.); or over newly closed wounds with high risk of scarring Some are fenestrated (have holes in them such as Mepitel) and may be applied directly to wound bed under negative pressure wound therapy or other dressing as a non-stick primary dressing. Some are thicker and used over shallow wounds or newly closed wounds to prevent hypertrophic (keyloid) scarring. May be changed every 2-7 days.
Roll Gauze   Deeper, full tickness; moderate to heavy drainage Absorptive and may be used to fill dead space; may also be used in combination with other products (such as alginates or hydrofibers) if needed; Kerlix not recommended due to loose fibers
Antimicrobial silver impregnated woven fabric Acticoat Burn (3day), 7day, flex, surgical site dressings Not for very dry wounds Not very absorbant - used primarily to deliver silver ions to wound bed for antimicrobial effects. Silver ions are activated by wound exudates or water; some silver products should not be moistened with sodium chloride (saline) or sodium hypochlorite (Dakins or DiDaksol) solutions because the ions will inactivate each other. Silver products should not be combined with iodine products.
Other silver products silver wound gels; Silver gel sheets (Silvasorb), silver alginate; silver hydrofiber, silver foam Application varies by type of base product Use silver gels as you would other wound gels, use silver alginates you would other alginates, silver foams as you would other foam dressings, etc.
Compression Profore, Profore lite, Unna Boots (with zinc oxide or calamine impregnated contact layer) or multilayer (2-4 layer) wraps, ace wraps, for lower extremity venous wounds Long-stretch compression (multilayer wraps and ace bandage) is typical treatment of choice for venous insufficiency and venous leg wounds. Verify arterial perfusion to affected limb first!
Silver Nitrate sticks same see notes Applied directly to rolled wound edges, hypergranulating tissue in wound bed; chemically cauterizes acute bleeding
Collagenase ointment Santyl wounds with necrotic tissue in wound bed only FDA approved active enzymatic ointment to help remove necrotic tissue from wound bed
Antifungal skin products 2% miconazole nitrate in powder, spray, cream, lotion, or ointment. Aloe Vesta Antifungal; Monistat 1, Neosporin AF, Baza Antifungal; Carrington Antifungal; Fungoid; Lotrimin AF, etc. Skin with fungal rash Generally for fungal rash affecting skin around wound. Typically apply small amount, gently rubbing into skin so it is no longer visible. Powder may be applied with a light dusting, then gently rub onto affected skin (and may blot with skin barrier liquid to seal in, if excessive moisture is present or under ostomy appliance).

 

Pain Management for Chronic Wounds

Pain management includes an accurate assessment and documentation of wound pain. The gold standard for an accurate assessment of the patients pain is the patients self reported pain level. Whether a pain scale of 0 (no pain) to 10 (excruciating pain) is used, or smiling faces/grimacing faces, the level of pain should be documented exactly as the patient reports it (Hess, 2005). The quality of pain (stabbing, shooting, throbbing, sharp, dull, constant or intermittent) along with what factors relieve the pain or make the pain worse (walking, standing, elevating the leg, etc.) should be ascertained and documented. Worsening wound pain is one hallmark of a deteriorating wound and may be more indicative of infection than other observable signs such as edema, warmth and erythema surrounding chronic wounds (Baranoski & Ayello, 2004).

Pain with dressing changes may be managed by topical anesthetic products such as 2% or 4% topical Lidocaine Jelly, or EMLA cream, or systemic medications such as NSAIDS or opioids. Topical anesthetics (Lidocaine, Prilocaine, etc.) should be applied with enough time prior to dressing change or debridement for the medication to take effect (approximately 10 min). Similarly, systemic pain medication should also be administered with enough time for pain relief (at least 30 minutes) (Bryant & Nix, 2007; Sussman & Bates-Jensen, 2007).

Addressing the pain when infection is suspected would include addressing the infection. Certain wound products may assist with pain management in specific types of wounds. Matrix applications using small intestine submucosa (SIS) technology (typically porcine) have been successful in relieving some wound pain, particularly over donor sites from split thickness skin grafts. Glycerine or silicone based gel sheets as well as hydrogel sheets (cross-linked polyethylene oxide and water) such as Vigilon may be cool and soothing to partial thickness wounds such as second degree burns and silicone is helpful in reducing scarring after wound closure (Hess, 2005; Sussman & Bates-Jensen, 2007).

Be on the alert for new, different (especially worsening), or persistent pain associated with chronic wounds. Persistent pain in a neuropathic extremity with a chronic wound, as well as may be associated with osteomyelitis (Bryant & Nix, 2007; Krasner et al., 2012; Schultz & Dowsett, 2012).

 

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