Are pressure ulcer (decubitus ulcer) cultures of diagnostic value?

From the Guidelines

Decubitus wound cultures are generally of limited value in guiding treatment decisions, and routine culturing of pressure ulcers is not recommended unless there are clear signs of infection. When infection is suspected clinically, tissue biopsies or validated quantitative swab techniques are preferred over standard swabs, as they can better differentiate between colonization and true infection 1. The distinction between colonization and infection is crucial, as unnecessary antibiotic use based on positive cultures from uninfected wounds contributes to antibiotic resistance without benefiting the patient. Some key points to consider in the management of decubitus wounds include:

• Surface swab cultures are particularly problematic as they typically identify surface colonization rather than true infection 1.
• All chronic wounds are colonized with bacteria, and this colonization alone does not indicate infection or require antimicrobial therapy 1.
• Treatment should focus on proper wound care including debridement of necrotic tissue, pressure offloading, appropriate dressings, and nutritional support 1.
• If antibiotics are needed for a clinically infected wound, they should be targeted based on culture results from properly obtained specimens, with initial empiric therapy covering common pathogens like Staphylococcus aureus, streptococci, and gram-negative organisms 1. It is essential to prioritize proper wound care and use antibiotics judiciously to minimize the risk of antibiotic resistance and promote optimal patient outcomes.

From the Research

Value of Decubitus Wound Cultures

• Decubitus wound cultures can be valuable in certain situations, such as when there is a clinical suspicion of infection 2, 3, 4.
• The cultures can help identify the causative organisms and guide antibiotic therapy 2, 3, 4.
• However, indiscriminate and routine wound cultures are not recommended 2, 3, 4.
• Tissue biopsy is considered the gold standard for diagnosing infection, but it is rarely used in clinical settings 2, 3.
• Swab culture is the most frequently employed method of confirming wound infection, but a standardized procedure is lacking 2.

Techniques for Obtaining Wound Cultures

• There are various techniques used in clinical practice to obtain cultures for diagnosing wound infections 3.
• The deep tissue biopsy is regarded as the gold standard for identification of wound bioburden and clinical infection 3.
• However, controversy persists among practitioners as to the relevancy of doing cultures and the technique to use 3.

Decubitus Ulcers and Wound Cultures

• Decubitus ulcers are a worldwide health care concern affecting tens of thousands of patients and costing over a billion dollars a year 5.
• Susceptibility to pressure ulcers comes from a combination of external and internal factors 5.
• A team-focused approach integrating all aspects of care, including pressure relief, infection control, nutrition, and surgery, may improve healing rates 5.
• Accurate risk assessment and preventative care can help minimize complications and mortality owing to decubitus ulcers 5.

Antibiotic Therapy for MRSA-Infected Wounds

• MRSA colonisation or infection of non surgical wounds can result in MRSA bacteraemia, which is associated with high mortality rates 6.
• The optimal antibiotic regimen to use in these cases is not known 6.
• A review of randomised controlled trials found no evidence that any one antibiotic was better than the others for treating MRSA-infected non surgical wounds 6.
• Further well-designed RCTs are necessary to determine the best antibiotic treatment for MRSA-infected wounds 6.