I.Classification by Healing Progression

Acute Wounds

• Definition: Disruption of skin integrity caused suddenly by external factors, progressing through predictable healing stages (inflammatory, proliferative, and remodeling phases) without complications.

• Common Examples: Surgical incisions, traumatic abrasions or lacerations, first- and second-degree burns.

Chronic Wounds

• Definition: Wounds that fail to progress through the normal healing sequence and show no significant signs of healing for more than 30 days. Chronicity results from multiple interacting factors.

• Key Contributing Factors:

      o Persistent tissue pressure: e.g., pressure ulcers.

      o Inadequate blood perfusion: e.g., lower limb arterial ulcers, diabetic foot ulcers.

      o Impaired venous return: e.g., venous ulcers.

      o Dysfunctional wound microenvironment: Bacterial biofilm formation, elevated protease activity (degrading growth factors and extracellular matrix),cellular senescence/dysfunction.

     o Inappropriate treatment: Failure to address underlying causes.

• Common Examples: Diabetic foot ulcers, arterial ulcers, venous ulcers, pressure injuries (bedsores).

II. Classification by Depth of Tissue Damage

• Superficial wounds: Involve only the outermost epidermal layer. Typically heal quickly without scarring.

• Full-thickness wounds: Extend into the dermis and subcutaneous tissue. Healing requires granulation tissue formation, takes longer, and may result in scarring.

• Complex wounds: Damage involves deeper structures such as muscle, tendon, or bone. Often associated with high infection risk, requiring surgical debridement and complex reconstruction.

Wound healing typically progresses through four overlapping stages:

Hemostasis Phase

• Description: The initial phase begins immediately after injury, primarily aiming to control bleeding

• Key Processes:

    o Vasoconstriction to reduce blood flow

    o Platelet aggregation forming a provisional clot

    o Activation of coagulation cascade creating fibrin mesh

Inflammatory Phase

• Description: Lasting from hours to days, characterized by typical inflammatory responses

• Key Processes:

    o Vasodilation increasing local blood flow (manifesting as redness, swelling, heat)

    o Immune cell infiltration (neutrophils and macrophages) clearing pathogens and debris

    o Release of cytokines and growth factors initiating subsequent repair

Proliferative Phase

• Description: Extending over weeks to months, depending on wound severity

• Key Processes:

    o Granulation tissue formation (with new capillaries and fibroblasts)

    o Epithelial cell migration covering the wound bed

    o Collagen deposition and angiogenesis providing structural support

Maturation Phase

• Description: May continue for months to years, achieving tissue strengthening and maturation

• Key Processes:

    o Collagen remodeling and cross-linking enhancing tensile strength

    o Gradual normalization of vascular density

    o Scar tissue maturation with progressive stabilization of texture and appearance

The core theory of wound care has evolved from the classic TIME principle—focusing on "wound bed preparation"—to the more comprehensive, person-centered MOIST principle. This advanced framework ensures systematic and effective management strategies for complex wounds.

Part 1: Foundation – TIME Wound Bed Preparation Principle

TIME is a systematic tool for assessing and managing the wound bed to create optimal healing conditions.

• T (Tissue, Non-viable or deficient)

    o Focus: Identify and remove non-viable tissue

    o Issue: Necrotic tissue impedes healing and harbors infection

    o Action: Perform debridement (surgical, autolytic, enzymatic, or mechanical)

• I (Infection or Inflammation)

    o Focus: Control infection and excessive inflammation

    o Issue: Bacterial biofilms and persistent inflammation destroy growth factors

    o Action: Use antimicrobial dressings, systemic antibiotics when necessary

• M (Moisture Imbalance)

    o Focus: Manage exudate and maintain moisture balance

    o Issue: Excessive exudate causes maceration; dryness impedes epithelial migration

    o Action: Select absorbent or hydrating dressings based on exudate level

• E (Edge of wound, Non-advancing or undermined)

    o Focus: Assess wound edges and epithelial advancement

    o Issue: Stalled healing, rolled edges, undermining

    o Action: Use dressings that stimulate granulation, address undermining

Part 2: Advanced – MOIST Holistic Wound Management Framework

MOIST expands on TIME by extending care to encompass the whole patient.

• M (Moisture Balance)

    o Concept: Reinforces core importance of moisture management

    o Practice: Precise exudate assessment, dynamic dressing adjustment

• O (Oxygen Balance)

    o Concept: Focuses on tissue perfusion and oxygenation

    o Practice: Improve circulation, utilize topical oxygen therapy

• I (Infection Control)

    o Concept: Emphasizes ongoing infection management

    o Practice: Monitor for infection signs, manage bacterial load

• S (Support)

    o Concept: MOIST's unique contribution—addresses systemic support

    o Practice: Nutritional support, disease management, patient education

• T (Tissue Management)

    o Concept: Active cultivation of healthy tissue

    o Practice: Regular debridement combined with advanced dressings