Infected Pressure Ulcers
Many factors are thought to predispose patients to the formation of pressure ulcers: paralysis, paresis, immobilization, malnutrition, anemia, infection, and advanced age. Four factors thought to be most critical to their formation are pressure, shearing forces, friction, and moisture; however, there is still debate as to the exact pathophysiology of pressure sore formation. The areas of highest pressure are generated over the bony prominences.
Pressure sores are routinely colonized by a wide variety of microorganisms; gram-negative aerobes and anaerobes are most often associated with the infections.
Most pressure sores are colonized by bacteria; however, bacteria frequently infect healthy tissue. A large variety of aerobic gram-positive and gram-negative bacteria, as well as anaerobes, are frequently isolated.
More than 95% of all pressure sores are located on the lower part of the body.
Pressure sores can be classified in stages.
Pressure sores vary greatly in their severity, ranging from an abrasion to large lesions that can penetrate into the deep fascia involving both bone and muscle.
Without treatment, an initial small localized area of ulceration can rapidly progress to 5 to 6 cm within days.
PREVENTION AND TREATMENT
Prevention is the single most important aspect in the management of pressure sores. Friction and shearing forces can be minimized by proper positioning. Skin care and prevention of soilage are important, with the intent being to keep the surface relatively free from moisture. Relief of pressure (even for 5 minutes once every 2 hours) is probably the single most important factor in preventing pressure sore formation.
Medical management is generally indicated for lesions that are of moderate size and of relatively shallow depth (stage 1 or 2 lesions) and are not located over a bony prominence.
The main factors to be considered for successful topical therapy (local care) are the relief of pressure, debridement of necrotic tissue, wound cleansing, dressing selection, and prevention and treatment of infection.
Debridement can be accomplished by surgical or mechanical means (wet-to-dry dressing changes). Other effective therapies are hydrotherapy, wound irrigation, and dextranomers. Pressure sores should be cleaned with normal saline.
A number of agents have been used to disinfect pressure sores (e.g., acetic acid, sodium hypochlorite, hydrogen peroxide, mupirocin, bacitracin) as well as other types of open wounds; however, these agents should be avoided as they impair healing.
A short, 2-week trial of topical antibiotic (silver sulfadiazine or triple antibiotic) is recommended for a clean ulcer that is not healing or is producing a moderate amount of exudate despite appropriate care.