The classification of surgical wounds, or incisions, is part of an array of information used by surgeons, hospitals, medical centers, researchers and the U.S. Centers for Disease Control and Prevention to predict infections associated with surgeries, called surgical site infections, or SSIs. The most common surgical wound classification is one the CDC adapted from the American College of Surgeons. A key point in this system is that the classification is directed at the surgical incision, not to areas around it, even if they have the characteristics included in one or another of the classifications. In other words, the holes made by stitches that close an incision are not included. Should an infection occur there, it would be considered a skin infection. The CDC's surgical wound system includes four classifications.
Clean
In a wound classified as "clean," the surgeon doesn't expect to cut open any part of the body that might have or lead to inflammation or an infection, such as the urinary tract or stomach. Also, this type of incision is always closed after surgery, and any tubing that is placed to drain fluids away from the surgical site would be attached to a closed container.
Clean-contaminated
In wounds classified as "clean-contaminated," the surgeon does expect to make an incision in a part of the body that could have an infection, though it is not anticipated to have one. In other words, a surgery on the urinary tract could potentially lead to or expand an infection, but the surgeon doesn't think that will occur. Some types of surgeries are automatically included in this classification, as long as infection isn't anticipated and doesn't occur. They are surgical procedures involving the biliary tract, appendix, vagina and oropharynx.
Contaminated
Wounds classified as "contaminated" are those that occur when sterile surgical techniques have to be given up in order to provide a life-saving treatment to a patient. A wound may also be put in this classification if a lot of material from the gastrointestinal tract spills out or the surgeon runs into acute inflammation around the incision.
Dirty-infected
A classification of "dirty-infected" covers wounds that are known to be infected before the surgery begins. The surgical team will be aware that the patient has an existing infection, an old injury or wound site with dead tissue or a perforation of one of the internal organs in the abdomen, and will take extra precautions to contain the infection.
Other
Not all surgical wounds fit neatly into the four standard classifications. The CDC particularly notes pediatrics, procedures done in out-patient clinic settings and some of the newer minimally invasive surgeries may challenge the usual classifications. Surgeons and their teams must use their own judgment to determine the classification as well as the degree of likelihood that an infection will occur as a result of the surgery being performed.
