Course Overview

Course Overview

Wounds are classified in several ways according to incidence, cause, status, and others. Several factors are associated with impaired wound healing, including ongoing disease and malnutrition. This course will present a background on wounds, the healing process, treatment options, and guidelines.

 

Learning Objectives

Upon completion of this Journal Club the participant will be able to:
1. List four barriers to wound healing
2. Describe two ways chronic wounds are categorized
3. Describe two advanced treatment treatment options for chronic wounds

 

The Learning Objectives for this course are fairly straightforward.

1. There are four main barriers to wound healing which we will explore in this course. They can prevent wounds from healing, cause them to heal more slowly, and cause more discomfort to the patient. All, if present, will cause more health care dollars to be spent.

 

2. There are several classifications of wounds, including pressure injuries, venous stasis ulcers, and diabetic ulcers. Each of these types of wounds is further sub-classified according to severity and phase. In the case of diabetic foot ulcers, multiple sub-classifications are used to assist in determining an appropriate course for assessment and treatment. Patient assessment factors include the wound and patient background information to remove or reduce the causal or aggravating factors. The wound is then classified and documented.

 

3. Wound care plans are tailored to the patient according to their systemic barriers to wound healing and local wound factors. If healing does not occur as expected, additional assessment is conducted and additional therapeutic options can be considered.  This course will outline definitions and descriptions of chronic wound characteristics, systemic and local factors that contribute to non-healing, and selected therapeutic options to promote healing. A summary algorithm for chronic wound care will be presented as well.

So let’s get started…

Background Information

Stage/Time	Characteristics	Description
Hemostasis 0-3 hours	Bleeding is minimized, clots are formed	Platelet cells release epinephrine to constrict peripheral vessels and reduce bleeding into soft tissues, platelet cells assist blood clotting and release cytokines that orchestrate the inflammatory stage and platelet-derived growth factor for later stages
Inflammatory 0-3 days	Swelling and heat, prevention of infection	Immediately after hemostasis stage, leukocytes and macrophages are attracted to destroy bacteria and clear cellular debris from devitalized tissues; cytokines, chemo-attractants, and enzymes are released to initiate healing process and contract the wound
Proliferative 3-21 days	Granulation, angiogenesis, and epithelialization	Macrophages, neutrophils, fibroblasts, immature collagen (deposited by fibroblasts), blood vessels, and extracellular ground substance form red, shiny, “beefy” granulation tissues to fill the cavity; epithelial cells migrate from wound margins and divide/cover wound; contraction is signaled; the proliferative stage requires adequate vascularization and epithelialization cannot occur over necrotic tissues
Maturation 21 days - 1.5 years	Contraction and improved tensile strength of tissues	Fibroblasts, matrix metalloproteinases (MMPs), growth factors are involved in collagen fibers reorganization over time to improve tensile strength to 80% of uninjured tissues

Wounds can be categorized as acute or chronic. Acute wounds have a predictable pathway to healing characterized by four phases, including hemostasis, inflammatory reaction, proliferation, and maturation. Chronic wounds differ from acute wounds primarily because they stall in the inflammatory phase of the healing process. Let’s look at the Normal Healing Process. The acute wound follows a predictable and timely process of healing within a short period of time and with limited care. In this case the function of tissues is generally well-sustained after the healing process. This slide shows the four stages to wound healing. The first stage, hemostasis, prevents continued bleeding and allows the subsequent processes to start. Platelets are key cells in this stage which mediate clotting. The next stage involves inflammatory processes. Leukocytes and macrophages are featured during this stage to destroy bacteria and clean the wound of cellular debris. The third stage, proliferation, is characterized by growth factor stimulation of epithelialization angiogenesis granulation tissue formation, and collagen deposition. The wound environment, including the newly formed extracellular matrix and fluids, stimulates healing in acute wounds, the wound is responsive to healing signals. The fourth and final stage is maturation. During this stage the wound and healed tissue contract to result in smaller amounts of scarred tissue. The tensile strength of the healed tissues is up to 80% of the tensile strength of uninjured tissue. However, this tissue is never fully restored to its full tensile strength.