Understanding Wound Management
- Volume 11 - Issue 3 - March 2003
- Posted: 9/4/2008 - 4:34pm
- 2438 reads
I n a utopia, diabetics would get their feet checked regularly, vascular studies would be performed before any major malformations developed, the elderly would be repositioned in their beds or wheelchairs in a timely manner, and skin cancers would be immediately removed upon detection.
Now, back to reality. We all know that wound prevention and management is an important part of medical practice and an increasingly challenging aspect of care, especially when you consider the following statistics:
• Up to 10% of hospitalized patients and 20% of nursing home patients suffer from pressure ulcers.
• Chronic wounds account for at least $1 billion per year in the United States and $7 billion per year worldwide in health care costs.1
We also know that as our patient populations continue to age and cases of diabetes mellitus keep skyrocketing, we’ll need to manage more patients with wounds. This article will provide information on how to assess and evaluate wounds, it will review the phases of wound healing and provide a look at how to effectively treat wounds with different methods of debridement as well as how to select the appropriate dressing based on the wound type.
Assessing and Evaluating Wounds
The first step in mastering wound management is assessing and evaluating the wound; in other words, performing an accurate history and physical. Unfortunately, many clinicians first attribute the cause of delayed healing to untreated hypertension, which is one of the most common causes of chronic leg wounds. However, a thorough wound examination combined with relevant historical information is necessary for determining the most appropriate treatment, as well as ensuring the best possible clinical outcome for the patient.2 Here are some clues to determining the type of wound your patient has.
• Arterial ulcers. Patients with arterial ulcers are generally over the age of 45 years old. Their past medical history may be significant of intermittent claudication, severe ulcer pain, and limb pain at rest. The patient may say that the pain is intensified when the limb is elevated. Physical examination may reveal absent or weak peripheral pulses, perpetuated capillary refill time, pallor on limb elevation, rubor, loss of hair, shiny atrophic dry skin, and thickened nails.
• Neuropathic ulcers. With this type of wound, it’s common for the patient to have a history of numbness, burning, paresthesias and pain. Upon physical examination, you’d find a deep ulcer over a site where pressure is commonly applied — such as the heels. A condensed callus usually surrounds the ulcer.
• Venous ulcers. A patient presenting with a venous ulcer customarily has throbbing pain and swelling in the legs. These symptoms are often worse at night and or when the patient is mobile, standing or sitting without the leg elevated. More often than not, the patient will have some alleviation of symptoms when the leg is elevated. Most venous ulcers are located in the gaiter area, from 2.5 cm below the malleoli to the point at which calf muscles become prominent posteriorly.3 Other symptoms that may be found upon physical examination include, varicose veins, lower leg edema, pigmentation, eczema and fibrosis.
In assessing and evaluating wounds, it’s also important to distinguish whether you’re dealing with an acute or a chronic wound. When a patient presents with an acute wound, it’s important to realize that the human body has already begun to heal itself. Within minutes to hours, changes have begun to occur on the cellular level. Many textbooks delineate the physiology of what is transpiring into three different phases such as, inflammation, fibroplasia and maturation. Although the depiction of the three individual phases may allow one to more easily comprehend the process it doesn’t give the overall view that these phases are overlapping. One analogy would be that wound healing, at least for acute wounds, is like a symphony of several movements. While each movement has its own theme, there are overlaps and indeed a return to previous themes throughout the musical composition.4 In other words, they’re not occurring individually but rather rapidly all at once.
The Phases of Wound Healing
Follow this timetable to understand what is occurring at the level where our eyes can and can not penetrate:
Within the first 6 hours — neutrophils have arrived at the site of the wound although they are not overly significant in wound healing. In other words, a deficiency of neutrophils (neutropenia) will not intervene with wound healing.
After 24 hours — neutrophils reach a peak in population. Meanwhile, the initiation of epidermal healing is relying on the epidermal cell migration that is occurring within the first 24 hours.
After 48 hours — rectified from low oxygen and high lactate levels fibroblasts begin to occupy the wound. A fibroblast is, “any cell or corpuscle from which connective tissue is developed; it produces collagen, elastin, and reticular protein fibers.”5 All in all, the fibroblasts are responsible for wound contraction. Simultaneous to the arrival of fibroblasts, epidermal healing is now depending on epidermal cell migration, which has now peaked. The rate of the re-epithelialization is going to depend on how moist the wound is kept. The more moistness the quicker the epidermal healing.
After 72 hours — the neutrophils start to disappear.
After one week — wound contraction begins.
If the wound is properly cared for, the amount of healing time will depend on the size of the wound. The larger and the deeper the wound, the longer it will take to heal. If created by destructive nature, such as cryosurgery or chemical cautery, the wound will heal slower than a distinct wound contrived from a scalpel. Healing time will also depend on the whether the wound is a full thickness or partial thickness wound. With full-thickness wounds, the epidermis and dermis are missing and the wound itself lies beneath the hair follicles and sweat ducts. Full-thickness wounds heal by contraction, granulation tissue formation, and re-epithelization. Partial-thickness wounds involve destruction of the epidermis and part of the dermis. Shave excisions, curettage, and chemical peels are examples of things that may cause a partial thickness wound. These types of wounds heal rapidly through re-epithelialization with possibly some minor contraction.6
Confirming the Diagnosis
After a comprehensive history and physical there are certain tests that may be administered to confirm the diagnosis, such as an ultrasound. The Trendelenburg test may help to diagnose a venous ulcer. This test is achieved by lifting the patient’s leg above the level of the heart until the veins are drained. Then the leg is slowly released and if there is any venous distention that suggests incompetent valves and that the cause of the ulcer is venous. Another test to diagnose venous ulcers is the Perthes’ test. Incompetent deep circulation is suggested if there’s a change in superficial circulation after tying a tourniquet above the knee of the patient and asking them to ambulate. Color duplex, air plethysmography, and photoplethysmography are tests that may be used to distinguish if an ulcer is venous. Ankle Brachial Index or ABI is useful in diagnosing arterial ulcers. Arteriography may also be used to demarcate arterial cause.
Treating the Wound — Debridement: The First Step
One technique that wound care practitioners should master is debridement. Proper debridement is crucial in all chronic wounds. Different types of wound debridement are available. These include autolytic, chemical, mechanical, surgical and biologic.
• Autolytic. This is the most effortless and customary type of debridement. Autolytic debridement is the use of a synthetic dressing over an ulcer that allows the eschar to self-digest through the action of enzymes normally present in the wound fluid. It’s not indicated for infected ulcers.
In autolytic debridement, it is important to compare a moist vs. a dry environment. Sustaining a moist environment for the wound has been shown to expedite wound healing by as much as 50% as compared with the dry environment caused by air exposure.8 Wounds that are not covered and permitted to dry out make it more difficult for re-epithelialization to occur because a crust forms over the wound. When wounds are not occluded and kept moist, autolytic debridement takes a considerable amount of time and energy.9 A moist wound encourages autolytic debridement for acute and chronic wounds. A wound kept moist by occlusion yields painless debridement, advocates formation of granulation tissue, and decreases and persistent pain and tenderness.10 When allowing a wound to heal through the method of autolytic debridement, practitioners should make sure that their patient’s wounds remains moist and occluded.
• Chemical. Also known as enzymatic debridement, this method is achieved through the use of proteolytic enzymes. There are a few types of proteolytic enzymes available for the use of chemical debridement. Enzymatic debridement, utilizing topical debriding agents to devitalized tissues, should be considered when the patient cannot tolerate surgery or when a patient has a non-infected ulcer.
Proteolytic enzymes are added to the wound to remove cellular debris. It’s been said that proteolytic enzymes have been used for centuries and that 500 years ago Christopher Columbus used the proteolytic enzymes from pineapple to treat the wounds of his warriors.11 Currently, a combination of fibrinolysin and DNAse (Elase) is used as a therapeutic combination for chemical debridement. Collagenase is another available proteolytic enzyme. It’s obtained from Clostridium histolyticum. Several clinical trials of collagenase have reported rapid cleansing and enhanced removal of necrotic debris.12
Finally, there’s a combination of papain and urea that’s available for use of chemical debridement. Papain, which is derived from papaya, is extremely useful because it’s capable of staying active at a pH of 3 to 12. Papain must be combined with urea because the urea discloses the activators of papain.
Pitfalls of chemical debridement include the pH sensitive agents used — when the wound environment changes the agents may become inactivated. The agents are also deactivated by heavy metals, which are present in a numerous amount of the topical agents used for wounds.
• Mechanical. This method may be painful and does not differentiate between viable and non-viable tissue; however, it may be very useful. Mechanical debridement physically removes debris from the wound in an expeditious manner.
The three main forms of mechanical debridement are wet-to-dry dressings, hydrotherapy and irrigation, and dextranomer therapy.
• The wet-to-dry dressing method of mechanical debridement, which is not often used anymore, involves placing dampened gauze on the wound and allowing it to dry completely. Afterward, the dried dressing, to which necrotic debris has become embedded in, is removed. The removal of the dressing can be agonizing. Don’t use wet-to-dry dressings on clean granulating wounds because these dressings can cause disturbance to the granulation tissue and new epithelium.13
• Hydrotherapy and irrigation shouldn’t be used on clean wounds either. They’re best for wounds with heavy exudate. Hydrotherapy is performed by using a whirlpool and irrigation can be accomplished by using syringes or angiocatheters.
• Dextranomer is manufactured as dry spherical beads, and is placed in the wound bed to absorb exudate, bacteria and other debris.
• Surgical. It involves the actual expulsion of necrotic areas using surgical instruments. It requires a skilled practitioner and anesthesia. Use caution in patients with bleeding disorders.
• Biological. Also known as maggot therapy, this has been shown to be effective in several studies. One study showed that maggot therapy was able to heal wounds infected with Staphylococcus aureus and methicillin-resistant S.aureus.14 Five patients who were referred for leg amputation had their extremities salvaged with maggot therapy.15 By applying a chiffon dressing the young sterile maggot larvae encounter the precise area to be debrided.16
Choosing the Best Dressing
Knowledge of wound dressing is imperative. Dressings are what protect a wound. They act as a barricade not allowing anything from the outside world to encounter the wound. There are many types of dressings and it’s useful to know what type of dressing to use and the reason you should use it. Different types of dressings include alginates, collagen dressing, films, foams, hydrocolloids, hydrogels, hydrofibers, hydropolymers and superabsorbents.17 All of these are various types of moisture-retentive dressings.
• Alginates. Derived from seaweed, these dressings are composed of calcium alginate. Alginates can be packed into deep wounds and are good for wounds with thick exudate.
• Collagen dressings. Good for wounds with moderate exudate, the material for these dressings is obtained from cowhide.
• Films. These gaunt, adhesive sheets are penetrable to oxygen and water and impenetrable to bacteria and other fluids. Films are frequently made of polyurethane, and they make for a good secondary dressing or they may be used for minor lacerations, on top of sutures, superficial surgical wounds or minor burns. For an acute wound that has been sutured, films are very useful.
• Foams. Useful for infected wounds and for wounds with moderate to thick exudate, foam dressings are fabricated from microporous polyurethane.
• Hydrocolloids. These dressings have many uses. They may be put to use in ulcers, abrasions, and postoperative wounds.
• Hydrogels. These dressings are beneficial in blisters and wounds caused from chemical peels.
• Hydrofibers. This type of dressing may be packed into wounds or wounds that are prone to bleeding.
For more information, see the table titled “Comparing Dressing Characteristics.”
There are different degrees of chronic wounds. According to several authors, certain types of dressing-wound combinations should also be considered depending on the degree of the wound.17-23 (See “The Best Options.” )
Care Tips to Consider
You may find that certain therapies or combinations work best for your patients. Whatever you choose to do, consider the following:
Saline irrigation provides a safe and appropriate cleansing method for most pressure ulcers. Avoid agents toxic to wound tissue such as povidone iodine, iodophor, sodium hypochlorite solution, hydrogen peroxide or acetic acid.
Debride any necrotic tissue observed during wound assessment if appropriate. Debride wounds only if the removal of the necrotic tissue speeds up the healing process. Curetting of the borders of the lesions often stimulates increased granulation and wound healing.
All infected ulcers should be debrided more rapidly. Consider pain control and adequately prep the patient. The most rapid method of removing areas of thick, adherent eschar and devitalized tissue is with sharp debridement generally utilizing sterile surgical scissors.25
All stage II, III and IV ulcers are bacteria-colonized, which can be minimized through effective wound cleansing and debridement. Swab cultures only detect surface colonization and should not be used. Needle aspiration or biopsy can be used when a culture is needed. Biopsy to rule out malignancy with any chronic ulcer that is not healing by conventional measures. Consider a 2-week trial of topical antibiotics (triple antibiotic, silver sulfadiazene) if a clean ulcer isn’t healing or continues to have exudate despite optimal care for two to four weeks. Systemic antibiotics are appropriate for patients with bacteremia, sepsis, advancing cellulitis or osteomyelitis, but not for local pressure ulcers.
Aggressive care should be given to those patients with pronounced edema, signs of vascular compromise, gangrene, and diabetic and other troublesome ulcers. Consider a consult with a vascular surgeon. Conservative measures such as support stockings, elevation of legs, and so-called “bunny boots” or other devices should be used for protection whenever indicated.
Beware of “soggy sox syndrome,” brought on by keeping the sox on for too long, resulting in maceration and skin breakdown. It can contribute to fungal infections as well as foul-smelling feet, and lead to further infection and ulcers. Change the sox (and other clothing) frequently and make sure the sox and shoes fit comfortably.
Consider physical therapy consults for patients with contractures. Podiatrists should be utilized for routine care and maintenance of the feet, especially with diabetic patients.
Assure adequate nutrition. Assess nutrition in an ongoing manner including regular monitoring of intake, weights, and appropriate laboratory parameters. Assess problems with anorexia including possible etiologies such as undiagnosed medical illness, medications, depression or other psychological problems, sensory losses, or swallowing difficulties.
Prevent deterioration in nutritional status. Nutritional status can deteriorate rapidly in those who are marginally nourished to begin with. Minimize days of NPO status and if prolonged consider alternative forms of nutritional support. Utilize supplements as needed. Assure an adequate mealtime environment.
Provide adequate assistance with meals including the use of adaptive devices. Do not overly restrict diets.
Avoid prolonged bed rest and its adverse effects as much as possible. Avoid the use of restraints as much as possible. They fail to “protect” patients but may lead to multiple problems including all the complications of immobility. Involve rehabilitation specialists such as physical or occupational therapists early to prevent contractures. Protect against the adverse affects of external forces such as pressure, friction, and shear. Utilize proper positioning techniques and repositioning schedules. Elevating the head of the bed produces shearing forces. Prevent shear injuries by utilizing lifting devices to move patients. Friction injuries may be reduced by the use of lubricants, protective dressings or films, and protective padding.
Assess and intervene regarding bowel and/or bladder incontinence. Don’t accept incontinence without a thorough evaluation as to the etiology of the problem and a trial of treatment strategies.
Making Wound Care Uncomplicated
Wound care is an ever-changing process. More technology and medication are created on almost a daily basis. Despite the constant developments, managing wounds does not have to be a complicated procedure if the practitioner is up to date and aware of the choices available for managing a wound.
Next month, we’ll have more on wound care where in part two of this two-part series we’ll focus on bacterial infections in the elderly.