Preventing surgical-site infections: the importance of timing and glucose control.

Our understanding of the physiology of wound healing and wound infection and the most effective strategies to reduce the risk of wound infection have progressed over a very long time. Perhaps the earliest significant advance in this field was the recognition of the role of bacteria in wound infection and the subsequent development first of antisepsis and then of asepsis. Important milestones in this progression included the development of the steam sterilizer, the introduction of rubber gloves for the surgical team, and effective techniques for skin preparation at the operative site. These developments occurred so long ago that no one currently practicing either surgery or infection control was present for their introduction. Nevertheless, occasional failures in their application, with resulting clusters of surgical-site infections (SSIs), serve to remind us of their continued importance. The introduction of antibiotics in the 1950s did not bring the promise of reduced SSIs, as many had hoped, until laboratory studies by John Burke in the 1960s1 and subsequent prospective clinical trials2,3 demonstrated the elements required to achieve reduced infection rates through the use of prophylactic antibiotics. Hundreds of clinical trials since that time have refined our understanding of the most effective and appropriate methods of employing these useful drugs to prevent SSIs.4,5 Although appropriate use of prophylactic antibiotics can reduce infection rates by 40% to 80%,3-7 there is abundant evidence that unacceptable infection rates can result despite antibiotic administration in settings where wound management and antisepsis break down.3,8 In the 1970s and before, extensive hair removal with a razor at and around the operative site was common, in the belief that it improved local antisepsis, and the shaving often occurred the night before the operation. Several publications in the 1980s clearly demonstrated that this practice increased the risk of infection by promoting the growth of bacteria in microscopic (or macroscopic) cuts induced by the razor and populated by bacteria from hair follicles.9-11 Current practice encourages no hair removal or limited hair removal occurring immediately prior to the operative procedure using clippers or depilatories rather than a razor. The effect of hair removal is most obvious in clean operative procedures, where exposure to endogenous bacterial is limited to skin flora. Despite this, one still can find razors stocked routinely in operating room supply carts in many modern hospitals and medical centers. A number of investigators have demonstrated a strong association between the colonization of the nares with Staphylococcus aureus and subsequent staphylococcal SSIs following clean operative procedures.12,13 Despite the promise suggested by the strategy of eliminating or suppressing carriage prior to scheduled clean operative procedures and several papers with historical controls that show a reduction in SSIs, we do not have any definitive, prospective publication demonstrating efficacy in a clinical setting to date. Finding and targeting the high-risk population in an efficient and costeffective manner may be part of the problems. In addition, it may be that strategies aimed primarily at the nares fail to deal with simultaneous colonization of the axillae, groin, or rectum. Temperature control in the operating room did not receive much attention in the past, but a recent study has demonstrated the value of preventing hypothermia during major operative procedures. When patients undergoing colectomy were randomized to have their temperature actively managed to maintain it as close as possible to 37oC, the SSI rate was approximately one third that of patients whose temperature was allowed to fall during the opera-