Infection Management

The incorporation of silver into wound dressings has been a breakthrough to combat the effects of antibiotic resistance, despite silver safety concerns. Regardless of its recent popularity, silver is not a new tool in health care.

As a cost-effective alternative to topical antibiotics, silver is now widely available in wound dressings. However, what does silver really do within the wound bed? Silver uses a multifaceted approach to combating infection that attacks bacteria internally.

Silver has become one of the most commonly used alternatives to topical antibiotics in recent years because of the growing concern over antibiotic resistance. Silver offers a multifaceted antimicrobial approach that makes it less likely for resistance to develop. With its limited and uncommon cytotoxicity, silver can be used to treat infected wounds over time and prevent further complications.

Before the discovery of penicillin in 1928, silver was the primary antimicrobial agent available. Now, as antibiotic resistance plagues the health care field, silver has new value for wound care. Additionally, silver has demonstrated limited cytotoxicity when used topically, thus making it a suitable alternative to antibiotics.

Wounds typically heal in four sequential but overlapping phases — hemostasis, inflammatory, proliferative and remodeling — ultimately leading to tissue regeneration. Healing sometimes stalls for various reasons, a key one being extensive inflammation, which disrupts the normal cascade of healing and leads to chronic and hard-to-heal wounds. A vicious cycle of ongoing inflammation, pain and poor quality of life often follows. Understanding how to break this cycle is essential for wound care clinicians who want to optimize healing outcomes and patient quality of life.

Wound healing can stall for a number of reasons. Wounds that have not healed or significantly reduced in size after four to six weeks are considered chronic. They are characterized by a multitude of impeding factors including biofilm, excess matrix metalloproteinases (MMPs) and extracellular matrix degradation, inflammation, fibrosis, unresponsive keratinocytes and fibroblasts, and atypical growth factor signaling.

Biofilm: Colonies of multiphenotype, free-floating bacteria that secrete a polysaccharide matrix that protects the bacteria from immune response and antibiotics.

Chronic wounds: Wounds that stall in the inflammation phase and fail to progress toward healing within 3 months are considered chronic or hard to heal.

Continuous inflammation: When wound healing becomes stalled in the inflammatory phase because of the presence of bacteria and their endotoxins, the wound is unable to move out of the inflammatory phase and into the repair phase.

As scientists and researchers have delved deeper into the causes of wounds and wound chronicity, matrix metalloproteinases, or MMPs, have come into sharper focus. MMPs are not just present in chronic wounds — they also play an essential role in acute wounds.

An injury to the human body initiates a wound healing chain reaction that occurs in four sequential but overlapping phases: hemostasis, inflammatory, proliferative and maturation. This post focuses on the second (inflammatory) phase, which begins after blood flow stops (i.e., hemostasis) and defender white blood cells, or leukocytes, migrate to the site of the injury — a process known as chemotaxis.

Anoxia: A condition marked by the absence of oxygen reaching the tissues. It differs from hypoxia, in which there is a decrease in the oxygen levels to tissue.

Biocide tolerance: Demonstrating a tolerance to substances that destroy living things, such as bacteria. The initial stage in the life of biofilm can become biocide tolerant within 12 hours.

Calcium alginate: A water-insoluble, gelatinous substance that is highly absorbent. Dressings with calcium alginate can help to maintain a moist healing environment.