Module 1 - Wound care & Healing

Physiological Stages

Physiological Stages of Wound Repair

1.) Inflammatory Phase

  • Initial response to injury
  • Day 1-4 post injury
  • Characterized by rubor, tumor, dolor, calor
  • Platelet aggregation and activation
  • Leukocyte (PMNs, macrophages) migration, phagocytosis and mediator release
  • Venule dilation
  • Lymphatic blockade
  • Exudative
  • In wounds closed by primary intention, lasts 4 days
  • In wounds closed by secondary or tertiary intention, continues until epithelialization is complete

2.) Proliferative Phase

  • Day 4-42
  • Fibroblast proliferation stimulated by macrophage-released growth factors
  • Increased rate of collagen synthesis by fibroblasts
  • Granulation tissue and neovascularization
  • Gain in tensile strength

3.) Remodeling Phase

  • 6wks-1 year
  • Intermolecular cross-linking of collagen via vitamin C-dependent hydroxylation
  • Characterized by increase in tensile strength
  • Type III collagen replaced with type I
  • Scar flattens

 Author: SP Zinn