The four overlapping and organized phases of wound healing are hemostasis, inflammation, proliferation, and maturation. These phases and their related biophysiological processes must occur in the correct order, at the right time, and at the right level for a set period of time. A variety of factors can influence wound healing, interfering with one or more stages of the process and resulting in inadequate or impaired tissue restoration.
Hemostasis – (injury to 15 minutes) This phase begins within the first 15 minutes after an injury and extends into the dermis through the epidermis. Capillaries deliver blood to the dermis layer of the skin. When vessels are injured, coagulation is activated. Aggregation and activation of platelets result in the formation of clots. The release of growth factors is therefore referred to as fibrinolysis. Vasoconstriction will then complete this phase.
Inflammatory (1-5 days) – During the inflammatory phase, “normal” physiological changes such as erythema, warmth, pain, and localized edema may occur. This is the location of cell proliferation and activation, as well as re-epithelialization.
Proliferative (5 to 25 days) – This phase can take place only in a full-thickness wound. This would include a stage III and IV pressure injury/ulcer. During this phase, granulation occurs.
Maturation (21—24 months) – This is the concluding phase of the healing cascade for full-thickness wounds. Additionally, you may hear it referred to as the “remodeling” phase. In comparison to the original tissue, the tensile strength of scar tissue will be only about 80%.
Hemostasis, inflammation, proliferation, and remodeling all contribute to the healing of wounds. Numerous cell types are involved in this process, including neutrophils, macrophages, lymphocytes, keratinocytes, fibroblasts, and endothelial cells. Numerous local and systemic factors may hinder wound healing by altering one or more process steps. These influences do not exclude one another. In any one or more of the specific phases, a single or multiple factors may influence the overall outcome of the healing process.
Important Notice: The views and opinions stated in this blog are exclusively those of the author and do not reflect iWound Global, iWound Care USA, Inc., its affiliates, or partner companies. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment.