Class | Definition | Inf. Risk |
Clean | An uninfected operative wound in which no inflammation is encountered and the respiratory, alimentary, genital, or infected urinary tract is not entered; clean wounds are closed primarily and, if necessary, drained with closed drainage. | <2% |
Clean contaminated |
Operative wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination. | <10% |
Contaminated | Open, fresh, accidental wounds; operations with major breaks in sterile technique or gross spillage from the gastrointestinal tract, and incisions in which acute, nonpurulent inflammation is encountered. | 20% |
Dirty | Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera. | 40% |