Chronic Wound Healing
Authors: Hasan Gökcer Tekin MD., Christian Kaare Paaskesen Med.Stud., Dorte Barrit, Diploma of Health, Specialist nurse in wound care, and Magnus Avnstorp, MD
In most chronic wound an imbalance of inflammatory cytokines and high protease activity keeps the wound in a prolonged inflammatory phase. The inflammatory stimuli in chronic wounds are kept in a steady state by repeated trauma (cell necrosis) by factors such as ischemia and bacterial colonization. Mitogenic factors such as PDGF are decreased in chronic wounds compared with acute wounds. Pro-inflammatory cytokines (TNF-α, interleukines, TGF–β) and proteases (MMP) are elevated in chronic wounds resulting in continuous degradation and breakdown of extracellular matrix. This breakdown of extracelluar matrix initiates a new cycle of inflammation and locks the wound in a chronic inflammatory state. By preparing the wound bed (active debridement of non-vital tissue and bacterial colonization) and treating causal ischemic factors, this inflammatory cycle can be broken.
Multiple important factors differ in chronic and acute wounds:
|Acute wounds||Chronic Wounds|
|High level of mitogenic factors||Low level of mitogenic factors|
|Decreased levels of inflammatory cytokines||High levels of inflammatory cytokines|
|Low protease activity||High protease activity|