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%