Preoperative hair removal with a razor blade became awidely established practice based on the assumption that it would prevent postoperative surgical site infections. This has remained routine practice until relatively recent times. One randomized study of approximately 400 patients compared wet shaving with no hair removal. The authors found no statistically significant decrease in the incidence of surgical site infection in the unshaved study group. Other studies comparing shaving with no hair removal used different preoperative skin preparation solutions.
Therefore the study results are not a reliable representation of the effects of hair removal. Studies using large samples, (60,000 wounds and 10 year follow up) with less rigorous designs favored no hair removal and demonstrated statistical significance. These findings are weakened by the lack of controls, and by the use of different treatments between study groups. The results suggest an association between shaving and infection, but do not demonstrate a reliable effect.
In summary, shaving has been found to increase the incidence of surgical site infection in low quality studies, while higher quality studies suggest, but have not conclusively demonstrated, a benefit associated with no hair removal.
Clean: An uninfected operative wound in which no inflammation is encountered and the respiratory, alimentary, genital, or uninfected urinary tract is not entered. In addition, clean wounds are primarily closed and, if necessary, drained with closed drainage. Operative incisional wounds that follow non-penetrating (blunt) trauma should be included in this category if they meet the criteria.
Clean-Contaminated: An operative wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination. Specifically, operations involving the biliary tract, appendix, vagina, and oropharynx are included in this category, provided no evidence of infection or major break in technique is encountered.
Contaminated: Open, fresh, accidental wounds. In addition, operations with major breaks in sterile technique (e.g. open cardiac massage) or gross spillage from the gastrointestinal tract, and incisions in which acute, non-purulent inflammation is encountered are included in this category.