All About Wound Drainage

When the body is injured, it initiates the inflammatory process.  White blood cells migrate to the site of injury and attack foreign invaders such as bacteria that have infiltrated the wound.  Like any battle field, many white blood cells and bacteria die.  These bodies pile up around the site in the watery fluid our bodies have between cells.  This debris is called exudate.

Exudate

The amount of exudate really depends on the size of the wound and how badly infected the tissue became.  Three main kinds of exudate are serous, purulent and sanguineous. 

To find out if a wound is infected, doctor's order a wound culture.  Nurses carefully role a long q-tip over the surface of the wound and send the culture away for testing. Lab results will identify the type of bacteria, which will help the physician know how to treat it.  Although bacterial infections are treated with antibiotics, not every antibiotic works for every bacteria.  It's important to identify the bacterial specie.

Serous Exudate

The body has two main fluid compartments.  One is called the extracellular fluid compartment or ECF.  This compartment contains all body water that is outside of cells.  Human bodies contain a lot of water.  Babies are about 80% water; adults are about 60% water and geriatrics are only 40% water.  The tissues of the body contain a lot of this water around each cell.  When the tissue is damaged, this clear liquid oozes out. 

Purulent Exudate

When a wound becomes infected, white blood cells and bacteria fight it out and die.  In this process, a white, thick discharge develops.  It's commonly called pus.  Pus can be different colors including white, green, blue or yellow, depending on what organism infected the region.

Sanguineous Exudate

Sanguineous is just a fancy word that means "blood red."  There's no trickery here.  This type of exudate is a mixture of serous fluid and red blood cells.  A small amount is common to see on a wound dressing right after surgery, but a large amount can be an indication of a problem and require attention from the physician.  

Purosanguineous Exudate

When a wound becomes infected, the drainage isn't always just one type.  Purosanguineous exudate is a mixture of blood and pus seen in infected wounds.  Along with this drainage, the wound may contain debris or dead tissue.