CLASSIFICATIONS OF SURGICAL WOUNDS RELATIVE TO RISK OF INFECTION

The higher the class, the higher the risk: a class IV wound carries much more risk than a class I.

1. Class I (clean wound)
1. No break in sterile technique
2. No inflammation encountered
3. GI, Respiratory or GU tract not entered
2. Class II (clean-contaminated wound)
1. GI, GU or respiratory tract entered with no spillage of contents
2. Minor breaks in technique
3. Operations involving the biliary tract, appendix, vagina, and oropharynx
3. Class III (contaminated wound)
1. Acute inflammation without pus
2. Spillage from a hollow viscus occurs
3. Trauma from a clean source
4. Class IV (dirty)
1. Pus or a perforated viscus
2. Trauma from a dirty source
3. Organism causing infection present before surgery
4. Surgical variables that increase risk of infection
5. Prolonged preoperative hospital stay
6. Body location of surgery
7. Surgical technique: delayed wound closure, excess blood loss, presence of drain, improper suture tension
8. Presence of bacteria at closure