A sterile dressing protects the wound and promotes tissue healing. Wounds heal from the deepest exposed tissues first, then builds layer upon layer of new tissue within the wound. A sterile dressing should almost eliminate the chances of introducing infection while these new layers of tissue are laid in and while each layer knits itself to existing tissue.
What are individually wrapped sterile unmediated wound dressing used for...
A sterile dressing.
a sterile dressing
a dressing is moist at wound site and a dry dressing in covering it
To prevent infection.
A "sterile" dressing is free of germs prior to use.
dry sterile dressing
Dressing and Bandage
You want sterile dressing for open wounds. If you put a dirty dressing on an open wound, you are increasing the likelihood for infections and diseases. But if all that you have is a ripped t-shirt to put on a wound, that is definitely better than nothing at all.
The purpose of a pressure dressing is to stop the blood flow from a wound.