Debridement

SlOugh

eSchar

---

FibrinOuS tiSSue 

lack OF blOOd FlOw Or lack OF tiSSue PerFuSiOn

5

Lack of blood flow or lack of tissue perfusion can be caused by 

occlusion, vasoconstriction, venous hypertension, hypotension, 

dehydration, medications, radiation, smoking, and inability to 

transport O

2

.  O

2

 fuels the cellular functions essential to the 

repair process, making it critical to wound healing.  Lack of 

blood flow causes a decrease in oxygen, slowing or stalling the 

healing process. 

elevated PrOteaSe activity

Elevated protease activity may occur in chronic wounds and 

may inhibit healing by degrading extra-cellular matrix proteins, 

growth factors, their receptors and protease inhibitors.

8

  

Protease activity can potentially be reduced by lowering  

the pH of a wound.  This also may result in increased oxygen 

release, enhanced destruction of abnormal wound collagen, 

and increased macrophage and fibroblast activity.

9

Free radicalS

Non-healing wounds typically display increased reactive 

oxygen species (ROS). ROS are deleterious in excess amounts 

due to their high reactivity, which causes oxidative stress.  

This is associated with reperfusion injury, one of the primary 

factors in chronic wound development.  In the chronic wound 

environment, ROS attack DNA, causing an accumulation of 

lipofuscine (which the cell cannot degrade) and DNA damage-

induced cell cycle arrest.

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  Tight regulation of ROS production 

and detoxification is crucial for the repair process in wounds.