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Primary postoperative wound infection due to Staphylococcus pyogenes
Abstract:
Using S. pyogenes as a tracer organism, an examination of the importance of air-borne infection of clean wounds in the modern, plenum-ventilated operating room has been made. It appears that, for most surgical procedures, additional ultra-clean air installations are not necessary. It has been shown that even if the air is sterile, the skin remains a possible source of infection. This is especially so as far as the patient's skin is concerned. It will remain so, since the skin cannot be sterilized. Indeed, until the ecology of the skin is better understood, rigorous efforts directed toward its disinfection may compromise its inherent defense mechanisms and its protective bacterial flora. It will be argued by some that operating rooms with ultraclean air should be afforded for certain specialized procedures in sugery; for example, those in which prosthetic materials are being implanted or in which the patient's immune mechanisms are depressed. Although not disagreeing with this, I wish to note that the only controlled trial on this aspect of surgery that exists to date shows no advantage for patients randomly apportioned to have hip arthroplasty, either in an isolator or in the same modern operating room but without the isolator. From this experience, I believe that any further trial of this nature, if it is to be controlled to a similar high level, will require very large numbers of patients to show even a marginal advantage for ultraclean air or isolator installations over the modern, plenum-ventilated and meticulously managed operating suite. The verdict on the need to install ultraclean air plant for operating rooms must, therefore, be couched in the third alternative that exists under Scots Law-- "not proved." I suggest the money could be better spent on devising methods to keep skin pathogens out of surgical wounds. Perhaps more urgently, there is a need to discover how to increase the defense mechanisms of the wound milieu to implanted harmful bacteria. There is also a pressing need to improve the ward environment with the aim of diminishing secondary infections of surgical wounds.
Insights
For most surgeries, ultra-clean air installations in operating rooms are unnecessary. Patient skin remains a primary infection source, and funds may be better allocated to wound infection prevention strategies.
Area of Science:
- Infection control in surgical environments
- Microbiology of skin flora
- Wound healing and infection prevention
Background:
- Modern operating rooms utilize plenum ventilation systems.
- Airborne infection is a concern in surgical settings, particularly with organisms like *S. pyogenes*.
- The patient's skin is an unavoidable source of potential surgical site infections.
Purpose of the Study:
- To evaluate the necessity of ultra-clean air installations in modern operating rooms.
- To assess the contribution of airborne bacteria versus skin flora to surgical wound infections.
- To identify more effective strategies for preventing surgical site infections.
Main Methods:
- Utilized *Streptococcus pyogenes* as a tracer organism to study airborne infection.
- Reviewed existing controlled trials, including hip arthroplasty studies comparing isolators to standard operating rooms.
- Analyzed the limitations of current sterilization techniques for skin.
Main Results:
- Ultra-clean air installations are likely unnecessary for most surgical procedures.
- Patient skin, which cannot be fully sterilized, remains a significant source of infection.
- Existing evidence does not demonstrate a clear advantage of isolators over meticulously managed, modern operating rooms for procedures like hip arthroplasty.
Conclusions:
- The requirement for ultra-clean air systems in operating rooms is currently 'not proved'.
- Resources may be better invested in methods to prevent skin pathogens from entering wounds.
- Further research is needed to enhance wound defense mechanisms and improve the ward environment to reduce secondary infections.