Pressure Ulcer Colonization and Infection

Minimize pressure ulcer colonization and enhance wound healing by effective wound cleansing and debridement. (Strength of Evidence = A.) If purulence or foul odor is present, more frequent cleansing and possibly debridement are required. (Strength of Evidence = C.)

Several quantitative bacteriological studies found a direct correlation between high levels of bacteria in pressure ulcers and failure to heal (Bendy, Nuccio, Wolfe, et al., 1964; Daltrey, Rhodes, and Chattwood, 1981; Lyman, Tenery, and Basson, 1970; Sapico, Ginunas, Thornhill-Joynes, et al., 1986). High levels of bacteria are found in wounds that contain necrotic tissue (Sapico, Ginunas, Thornhill-Joynes, et al., 1986). Foul odor in a pressure ulcer is usually associated with the presence of anaerobic organisms (Sapico, Ginunas, Thornhill-Joynes, et al., 1986). Effective wound cleansing and debridement remove the debris that supports bacterial growth and delays wound healing.

Do not use swab cultures to diagnose wound infection, because all pressure ulcers are colonized. (Strength of Evidence = C.)

All open pressure ulcers are colonized with bacteria. Routine swab cultures detect only the surface contaminants and may not truly reflect the organism(s) causing the tissue infection (Rousseau, 1989). The level of bacteria in the ulcer tissue must be determined in order to document the presence of wound infection (Krizek and Robson, 1975). As recommended by the CDC, this can be accomplished by culture of fluid obtained by needle aspiration or biopsy of ulcer tissue (Garner, Jarvis, Emori, et al., 1988).

Consider initiating a 2-week trial of topical antibiotics for clean pressure ulcers that are not healing or are continuing to produce exudate after 2 to 4 weeks of optimal patient care (as defined in this guideline). The antibiotic should be effective against gram-negative, gram-positive, and anaerobic organisms (e.g., silver sulfadiazine, triple antibiotic). (Strength of Evidence = A.)

Data from two clinical trials support the effectiveness of topical antibiotics in reducing the levels of bacteria in pressure ulcers to 105 organisms per gram of tissue or less (Bendy, Nuccio, Wolfe, et al., 1964; Kucan, Robson, Heggers, et al., 1981). This decrease in bacterial count was accompanied by decisive improvement in the clinical appearance of the wound, consistent with progression toward healing. Case study reports of allergic sensitization and other adverse reactions suggest the need for close monitoring during this treatment (Johnson, 1988; Schechter, Wilkinson, and Del Carpio, 1984).

Perform quantitative bacterial cultures of the soft tissue and evaluate the patient for osteomyelitis when the ulcer does not respond to topical antibiotic therapy. (Strength of Evidence = C.)

Several studies documented that when the bacterial content in an ulcer exceeds 10[sup]5 organisms per gram of tissue, healing is impaired (Bendy, Nuccio, Wolfe, et al., 1964; Daltrey, Rhodes, and Chattwood, 1981; Lyman, Tenery, and Basson, 1970; Sapico, Ginunas, Thornhill-Joynes, et al., 1986). The level of bacteria in the ulcer tissue can best be determined by tissue biopsy (Garner, Jarvis, Emori, et al., 1988; Robson, 1991). The CDC recommends culture by tissue biopsy or fluid obtained by needle aspiration (Garner, Jarvis, Emori, et al., 1988).

Other studies suggested that approximately 25 percent of nonhealing pressure ulcers have underlying osteomyelitis (Allman, 1989; Lewis, Bailey, Pulawski, et al., 1988; Sugarman, 1984). Although numerous methods have been used to evaluate the bone underlying a pressure ulcer, the "gold standard" for diagnosing osteomyelitis is pathological examination of a bone biopsy specimen (Lewis, Bailey, Pulawski, et al., 1988; Sugarman, 1987). However, most experts have been reluctant to perform an immediate bone biopsy unless an extensive operative debridement procedure is to be performed anyway. Numerous strategies for noninvasive diagnosis of osteomyelitis have been reported. Lewis, Bailey, Pulawski, et al. (1988) reported that bone scans are rarely useful in practice because of their high false-positive rate. They suggested using instead a combination of three tests (white blood cell count, erythrocyte sedimentation rate, and plain x-ray); if all three tests were positive, the positive predictive value for osteomyelitis was 69 percent. The positive and negative predictive values of CT scan or magnetic resonance imaging (MRI) in diagnosing osteomyelitis under pressure ulcers were not reported in the literature.

Do not use topical antiseptics (e.g., povidone iodine, iodophor, sodium hypochlorite [Dakin's® solution], hydrogen peroxide, acetic acid) to reduce bacteria in wound tissue. (Strength of Evidence = B.)

No controlled studies have documented that repeated topical application of antiseptics to the surface of chronic wounds significantly decreases the level of bacteria within the wound tissue. Numerous studies, however, have documented the toxic effects of exposing wound-healing cells to antiseptics (Fleming, 1919; Lineaweaver, Howard, Soucy, et al., 1985; Teepe, Koebrugge, Lowik, et al., 1993).

Institute appropriate systemic antibiotic therapy for patients with bacteremia, sepsis, advancing cellulitis, or osteomyelitis. (Strength of Evidence = A.) Systemic antibiotics are not required for pressure ulcers with only clinical signs of local infection. (Strength of Evidence = C.)

Bacteremia, sepsis, advancing cellulitis, and osteomyelitis are systemic infections that cannot be successfully treated with further cleansing or debridement and require systemic antibiotics. The details of treatment for these conditions are not discussed in this guideline; however, a brief overview is provided below.

Bacteremia and sepsis associated with pressure ulcers are commonly caused by Staphylococcus aureus, gram-negative rods, or Bacteroides fragilis. If patients with pressure ulcers develop clinical signs of sepsis (e.g., unexplained fever, tachycardia, hypotension, deterioration in mental status), urgent medical attention is required. It is appropriate to rule out other causes of the symptoms, obtain blood cultures, and treat with antibiotics that will cover these organisms (Bryan, Dew, and Reynolds, 1983; Chow, Galpin, and Guze, 1977; Galpin, Chow, Bayer, et al., 1976; Lewis, Bailey, Pulawski, et al., 1988). According to one study, mortality is higher if patients are not treated with appropriate antibiotics (Chow, Galpin, and Guze, 1977). As a consequence, patients with clinical signs of ulcer-related sepsis must be treated with antibiotics that will cover the organisms noted above. Obtaining blood cultures will allow the initial empirical treatment regimen to be focused and simplified if the causative organism(s) can be identified.

Advancing cellulitis is indicative of invasive tissue infection. It should be treated with appropriate antibiotics.

Osteomyelitis is an infectious complication of pressure ulcers that can result in delayed healing, more extensive tissue damage, a longer length of hospitalization, and higher mortality rates (Allman, 1989; Lewis, Bailey, Pulawski, et al., 1988; Sugarman, 1984). Early recognition and effective treatment of osteomyelitis are critical. Invasive and noninvasive diagnostic strategies have been discussed. Although cleansing and debridement are important aspects of treatment, long-term systemic antibiotic therapy is essential (Aust and Page, 1985; Longe, 1986; Pearlman, McShane, Jochimsen, et al., 1976).

Protect pressure ulcers from exogenous sources of contamination (e.g., feces). (Strength of Evidence = C.)

One study confirmed that fecal incontinence is associated with slower rates of pressure ulcer healing (Ferrell, Osterweil, and Christenson, 1993). Exposure to feces increases the level of bacterial colonization in a pressure ulcer.

Infection Control

Follow body substance isolation (BSI) precautions or an equivalent system appropriate for the health care setting and the patient's condition when treating pressure ulcers. (Strength of Evidence = C.)

BSI is a system of infection-control procedures routinely used with all patients to prevent cross-contamination of pathogens. The system emphasizes the use of barrier precautions to isolate potentially infectious body substances (Lynch, Cummings, Roberts, et al., 1990). According to Lynch, Jackson, Cummings, et al. (1987), BSI has six components:

1. Wear gloves for anticipated contact with blood, secretions, mucous membranes, nonintact skin, and moist body substances for all patients. Change gloves before treating another patient. Handwashing between patients is essential.
2. After other types of patient contact, wash the hands for 10 seconds with soap and friction to remove transient microbial flora, and then rinse with running water (Garner and Favero, 1986).
3. Wear additional barriers such as gowns, plastic aprons, masks, or goggles when moist body substances (secretions, blood, or body fluids) are likely to soil the clothing or the skin or splash in the face. The panel notes that protective eyewear, mask (or a faceshield that covers the eyes and face), gloves, and in some cases protective gowns should be used for pressure ulcer irrigation when there is reasonable expectation that wound secretions might be aerosolized.
4. Place soiled reusable articles and linen, as well as trash, in containers that are securely sealed to prevent leaking. Double bagging is not necessary unless the outside of the bag is visibly soiled.
5. Place needles (without recapping them) and sharp instruments in puncture-resistant, rigid containers. If such containers are not available, recapping using the one-hand technique is acceptable.
6. Assign to private rooms those patients with diseases that could be transmitted by the airborne route (e.g., pulmonary tuberculosis) and other diseases listed under precautions for strict isolation in the category-specific isolation (Center for Disease Control, 1970). The use of private rooms is also indicated for those patients likely to soil articles in their environment with body substances.

In addition, the panel recognizes the potential for transmitting infection through whirlpool equipment. Whirlpool equipment should be disinfected between patients. For guidance regarding effective disinfection techniques, clinicians may consult the Association for Practitioners in Infection Control (APIC) guideline regarding the selection and use of disinfectants (Rutala, 1990).

Use clean gloves for each patient. When treating multiple ulcers on the same patient, attend to the most contaminated ulcer last (e.g., in the perianal region). Remove gloves and wash hands between patients. (Strength of Evidence = C.)

One set of gloves can be used on the same patient with multiple pressure ulcers. Hands must be washed and gloves changed between patients. No research evidence at this time supports the need to change gloves when caring for multiple ulcers on the same patient.

Use sterile instruments to debride pressure ulcers. (Strength of Evidence = C.)

To avoid introducing additional bacteria into an open wound when tissue integrity is disrupted during debridement, sterile instruments, as opposed to clean ones, should be used in hospitals, long-term care facilities, and nursing homes. Followup after debridement should include monitoring the patient's temperature and being alert for signs of bacteremia or sepsis (e.g., unexplained fever, tachycardia, hypotension, deterioration in mental status).

Use clean dressings, rather than sterile ones, to treat pressure ulcers, as long as dressing procedures comply with institutional infection-control guidelines. (Strength of Evidence = C.)

The fear of cross-contamination of microorganisms within institutions is realistic. Therefore, each institution should establish and rigorously adhere to procedures to prevent cross-contamination. There is no evidence to indicate that the use of sterile dressings results in a better outcome.

Infection-control procedures should include strict adherence to BSI and good handwashing between patients. Multipatient treatment carts that are taken to the bedside should not be used to house dressing supplies. Individual patients should have their own dressing supplies that are protected from inadvertent environmental contamination by water damage, dust accumulation, or contact contaminants. "Clean," bundled dressings can be purchased less expensively than can individual dressings; however, measures should be taken to ensure that they remain clean. Such measures include keeping dressings in the original package or in other plastic packaging; storing them in a clean, dry place; and discarding the entire package if any of the dressings become wet, contaminated, or dirty. Dressings, instruments, and solutions should be obtained from suppliers who can ensure that shipment and handling will not expose the dressings and supplies to water damage, pest and rodent contamination, or gross soiling. Caregivers must wash their hands before contact with the supply of clean dressings or dressing supplies. Prior to the dressing or treatment, only the number of dressings necessary for each dressing change should be removed from containers. Once the hands of the caregiver are soiled with wound secretions, they should not come in contact with the remaining clean dressings and other supplies until the gloves are removed and hands are washed.

Clean dressings may also be used in the home setting. Disposal of contaminated dressings in the home should be done in a manner consistent with local regulations. (Strength of Evidence = C.)

Clean dressings, as opposed to sterile ones, are recommended for home use until research demonstrates otherwise. This recommendation is in keeping with principles regarding nosocomial infections and with past success of clean urinary catheterization in the home setting and takes into account the expense of sterile dressings and the dexterity required to apply them. The "no-touch" technique can be used for dressing changes. This technique is a method of changing surface dressings without touching the wound or the surface of any dressing that might be in contact with the wound. Adherent dressings should be grasped by the corner and removed slowly, whereas gauze dressings can be pinched in the center and lifted off.

The Environmental Protection Agency recommends that soiled dressings be placed in securely fastened plastic bags before being added to other household trash (Environmental Protection Agency, 1993; Simmons, Trusler, Roccaforte, et al., 1990). Local regulations vary, however, and home care agencies and patients are advised to follow procedures that are consistent with local laws.