To win or to lose: A strategy for overcoming wound infection.

IMPACT OF WOUND INFECTIONS

Wound infection significantly affects wound healing potential and patient outcomes. In clinical practice, the first step in managing an infected wound is to determine whether it is an acute or chronic wound infection. Acute wound infection can be destructive and is often a sufficiently underestimated clinical condition that has been reported to increase care costs by up to 70%. Chronic wound infections are associated with increased risk of delayed wound healing, complications such as tissue and structural infections, gangrene, amputation, sepsis, and even death. Chronic wounds differ microbiologically, immunologically, and clinically from acute wound infections and require a different treatment strategy. Understanding the differences between acute and chronic wound infections, including clinical manifestations, microbial involvement, and appropriate clinical assessment and management strategies to optimize outcomes, will ultimately improve healing outcomes and support antibiotic stewardship efforts in wound care.

Hemostasis (within 15 minutes after injury)

Hemostasis is the first stage of the disease the natural wound healing process that occurs with the formation of a clot, initiating the wound healing cascade. Hemostasis begins within the first 15 minutes of tissue injury in the epidermis dermis. Damage to blood vessels triggers the activation of coagulation processes the accumulation of platelets that seal the blood vessel wall. Fibrin strands bind together the coagulation process that strengthens the platelet seal. This process is called fibrinolysis or the breakdown of the clot, which releases growth factors and is followed by vasoconstriction

Inflammatory (1-5 days after injury)

Normal physiological changes may be seen during the inflammatory phase of wound healing including localized edema, warmth, erythema, and pain. Blood vessels leak transudate comprised of water, salt, and protein. As the fluid builds up, it allows healing and repair cells to move into the wound bed. Physiological changes such as increased pain, warmth, redness, and swelling are due to cellular activity from the presence of white blood cells, neutrophils, growth factors, and enzymes that support wound healing progression. A prolonged inflammatory stage of healing may result in a chronic wound

WOUND INFECTIONS IDENTIFIED

When the wound healing cascade is interrupted, wound infection can occur. Wound infection-related research defines wound infection as the host's inflammatory response to invading microorganisms that directly or indirectly damage living host tissue and prevent wound healing. This research clearly shows that there are two types of wound infections: acute and chronic. Both types of wound infection contain an inflammatory reaction that prevents improvement, but in acute infection, inflammation is a response to pathogen invasion. Host inflammatory processes can usually destroy pathogens with acute infection and resolve within a few days.

ASSESSMENT AND TREATMENT OF CHRONIC AND ACUTE WOUNDS

Determining whether a wound is chronically or acutely infected begins with wound assessment. Clinical suspicion of acute infection is based on the presence of clear, classic signs of inflammation.12 The obvious signs of an acutely infected wound include warmth (calor), pain (dolor), swelling (edema), redness (rubor), and loss of function.

INFECTION PERMANENCE

In 1998, Davis initially described the theoretical stages of increasing wound bacterial burden: contamination occurring immediately after injury, then colonization where bacteria begin to grow and multiply on the wound surface, and finally critical colonization.8 Gardner et al. subsequently found specific signs in infected chronic wounds of secondary wound infection, namely increased pain, friable granulation tissue, wound breakdown, and malodor, which are expressed earlier than the classic signs and symptoms of infection.9 Both researchers noted that these wounds were characterized not only by the absence of acute infection signs, but also by notable delays in healing, increased exudate, and unhealthy-appearing granulation tissue, all of which are related to the body's stalled efforts to destroy biofilm. The international wound community now agrees with Wolcott that this "critical colonization" stage should more accurately be called biofilm maturation. Understanding biofilm development as part of infection persistence is crucial when evaluating the microbiology of acute and chronic wounds. Acute wound infection involves the invasion of living wound tissue by metabolically active planktonic microorganisms that trigger the host's inflammatory reaction,12 for example, direct host response to virulence expression and tissue invasion by attracted pathogens.

BIOFILM LIFECYCLE AND CLINICAL CHALLENGES

Understanding acute treatment of chronic wound infections requires an understanding of biofilm. In the biofilm life cycle, planktonic or free-floating organisms adhere to a surface, then begin to produce adhesive, protective extracellular polymeric substance (EPS).14-18 They continue to develop into a three-dimensional structure that may be macroscopic but difficult to isolate from the wound containing other materials. The organisms then disperse from the EPS to colonize adjacent areas, thus biofilm multiplies. How planktonic microbes within the wound bed cause acute infection depends on how effective topical wound care is and how skilled the host immune system is at killing the microbes before they can establish and begin to multiply in host tissue.19,20 Treatment of biofilm and free-floating planktonic bacteria (within a biofilm) differs. Microorganisms within the protection of biofilm are not sensitive to antimicrobial agents and host inflammatory cells, while free-floating, planktonic microorganisms are sensitive to antimicrobial agents such as antibiotics and topical antiseptic dressings. This tolerance to antimicrobial effects highlights the clinical problem that biofilm presents in wound care.

THE ROLE OF ANTIBIOTICS IN THE MANAGEMENT OF WOUND INFECTIONS

Wound specialists agree that infection diagnosis can be one of the most difficult aspects of wound management. Incorrect diagnosis of wound infection can result in morbidity and even death. Over-diagnosis or failure to recognize signs of chronic infection due to the presence of biofilm can expose patients to unnecessary treatment and costs, as well as increased risk of antibiotic resistance. Antimicrobial resistance is one of the greatest public health problems of our time. Every year in the United States, at least 2.8 million people become infected with antibiotic-resistant infections, resulting in the death of more than 35,000 people. Antimicrobial resistance is associated with $20 billion in healthcare costs. Treatment of clinically diagnosed infection should be the primary reason providers prescribe antibiotics. Instead, the top three reasons they do so are fear of poor clinical outcomes, patient demands, and uncertainty about the presence of infection. Bacterial infections that fail treatment due to antimicrobial resistance cause at least 700,000 deaths worldwide annually and are projected to be associated with the deaths of 10 million people annually by 2050, with a $100 trillion loss to the global economy in productivity.22 Given the potential for antimicrobial resistance and associated dangers, it is important to determine the presence of infection before prescribing an acute antibiotic for infection. There are several methods to determine the presence of infection. Tissue biopsies are considered the gold standard for quantitative analysis, but many providers collect swabs for semi-quantitative analysis.

A COMPLETE ONE-STOP TREATMENT FOR WOUND INFECTION

Here is the translation of the text into English: In the treatment of acute infected wounds, all risk factors for infection should be reassessed to ensure optimal treatment potential. Systemic antibiotics will help the host immune system regain control over microbial invasion. Local wound care is equally important for managing acute wound infection as prescribing systemic antibiotics. Devitalized wound tissue should be removed. Optimization of the wound microenvironment, including moist wound environment and effective management of wound edges, should also be considered. In the treatment of chronic infected wounds, healing potential and current treatment strategies should be reviewed. Hardware or structural infection should be excluded, and infected hardware or osteomyelitis (bone infection) requires more than local treatment. Internal and external factors that may impede wound healing, such as poorly managed blood glucose levels or the patient's poor nutritional status, should also be considered. Management of chronic or hard-to-heal wounds also involves effective management of the wound environment. The demonstration of biofilm-based wound care using the Wound Hygiene protocol14 supports the wound healing process.

RESULT

Acute and chronic wound infections differ from immunological, microbiological, and clinical perspectives. Consequently, acute and chronic wound infections need to be approached differently to achieve wound healing. While an acute infection can be resolved by assessing risk factors, managing local wound concerns, and clinically applying antibiotics as noted, alternative strategies are required to address the various factors associated with a chronic wound infection. Chronic wound infections benefit from regular and repeated use of the Wound Hygiene protocol to support improved patient outcomes. The Wound Hygiene protocol consists of four steps: wound cleansing, performing debridement, wound edge renewal, and selecting appropriate wound dressing. In addition to promoting treatment of chronic wound infections, the Wound Hygiene protocol also achieves antibiotic management goals because it addresses the root cause of chronic wound infection at the local level affecting biofilm. AQUACEL® Ag Advantage dressings can be used within the Wound Hygiene protocol framework to support optimization of the wound healing environment by removing barriers associated with biofilm present in chronic infected wounds. In winning the battle against wound infections, consider these strategies to successfully address the unique clinical challenges for acute and chronic wounds and support antimicrobial management goals.