Ventilation in operating theatres

Segadal L, Andersen B M, Haugsbo A, Hotvedt R, Jacobsen T, Kristiansen I S, Nordsletten L, Sondenaa V G, Kjonniksen I
Record ID 32002000085
Authors' objectives:

This report aims to assess the available evidence on ventilation in operating theatres. It forms part of the project 'Measures for preventing infections in operating theatres'.

Authors' recommendations: - The rationale for keeping the bioburden (the number of microorganisms) in the air of operating theatres as low as possible is that microorganisms are a necessary, but not sufficient, condition for the development of surgical site infections. In general, ventilation with ultraclean air will provide lower concentration of microorganisms in the air ("bacterial air counts") than conventional positive-pressure ventilation. However, the increased and directed air flow may in some instances lead to increased bacterial wound contamination. - The association between the number of microorganisms in the air during surgery and the frequency of surgical site infections is not well documented. - There is no documentation for the claim that ventilation with ultraclean air (less than 10 colony forming units/m3) gives lower frequency of surgical site infections than conventional positive-pressure ventilation. - The recommended maximum limits for bacterial air contamination proposed by The Norwegian National Board of Health are not supported by scientific documentation. - Whether ventilation with ultraclean air is cost-effective depends on several uncertain factors. If the risk of surgical site infections is high with traditional ventilation, and if ultraclean air is effective in reducing this risk, the net cost ultraclean air may be negative (i.e. cost savings). - The majority of the Norwegian county and regional hospitals have operating theatres with conventional positive-pressure ventilation, and about 50% of the hospitals have at least one theatre with ultraclean air. - There is a need for large and well-designed studies to establish the effectiveness of various ventilation measures in reducing the incidence of surgical site infections.
Authors' methods: Systematic review
Project Status: Completed
URL for project:
Year Published: 2001
English language abstract: An English language summary is available
Publication Type: Not Assigned
Country: Norway
MeSH Terms
  • Operating Rooms
  • Postoperative Complications
  • Surgical Wound Infection
  • Ventilation
Organisation Name: Norwegian Institute of Public Health
Contact Address: Universitetsgata 2, Postbox 7004 St. Olavs plass, NO-0310 Oslo NORWAY. Tel: +47 23 25 50 00; Fax: +47 23 25 50 10;
Contact Name:,
Contact Email:,
Copyright: The Norwegian Knowledge Centre for the Health Services
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