The Role of Moisture in Wound Healing

• The research confirmed that a dry wound creates an environment that is hostile to wound healing. 

• A dry wound allows the formation of wound scab and eschar, which inhibit migration of epithelial cells, provide food for pathogens, and affect blood flow to the wound bed. 

• A dry wound also allows cooling of the wound surface; without a protective barrier, the surface temperature of the wound is decreased and healing is slowed. 

• Bacteria enter a dry wound more readily because of the lack of a protective barrier. 

• Wound management experts agree that adequate wound hydration is the most important external factor responsible for optimal wound healing. 

• 15-18 Wounds are typically covered with an occlusive or semi-occlusive dressing. This type of dressing is also called a moisture-retentive dressing because the dressing retains fluids on the wound bed. There are many types and styles of dressings that will facilitate a moist environment.

• Maintaining a moist wound with an occlusive dressing should hold an appropriate amount of endogenous fluids on the wound, preserving the cells needed for healing and keeping them in contact with the wound bed. 

• Some chronic wound fluid may contain substances that can delay healing so a balance must be maintained between moisture and exudate removal. 

• Moisture softens wound scab and eschar because, under the right conditions, the body's own enzymes will dissolve the eschar in a process called autolytic debridement. 

• Occlusive dressings maintain appropriate wound surface temperature to prevent delays in healing and protect the wound surface from trauma and from bacteria and other contaminants. 

Basic principles of moist wound healing include:

• Covering the wound with a barrier (occlusive dressing) that serves adequate wound hydration

• Limiting fluid loss from the wound surface while the dressing is in place

• Allowing gaseous exchange

• Maintaining peri-wound integrity

• Controlling heavy exudate, and removing the dressing when exudate begins to leak out from edges of the dressing.

• It has long been believed that occlusive dressings should not be applied over infected wounds because trapped bacteria could fulminate.