title: Wound ventilation with ultraclean air for prevention of direct airborne contamination during surgery.
abstract: OBJECTIVE
  Despite the novelties in operating room ventilation, airborne bacteria remain an important source of surgical wound contamination. An ultraclean airflow from the ceiling downward may convey airborne particles from the surgical team into the wound, thus increasing the risk of infection. Therefore, similar ventilation from the wound upward should be considered. We investigated the effect of wound ventilation on the concentration of airborne particles in a wound model during simulated surgery.
  
  
  METHODS
  Randomized experimental study simulating surgery with a wound cavity model.
  
  
  METHODS
  An operating room of a university hospital ventilated with ultraclean air directed downward.
  
  
  METHODS
  Particles 5 microm and larger were counted with and without a 5-cm deep cavity and with and without the insufflation of ultraclean air.
  
  
  RESULTS
  With the surgeon standing upright, no airborne particles could be detected in the wound model. In contrast, during simulated operations, the median number of particles per 0.1 cu ft reached 18 (25th and 75th percentiles, 12 and 22.25) in the model with a cavity and 15.5 (25th and 75th percentiles, 14 and 21.5) without. With a cavity, wound ventilation markedly reduced the median number of particles to 1 (range, 0 to 1.25; P < .001).
  
  
  CONCLUSIONS
  To protect a surgical wound against direct airborne contamination, air should be directed away from the wound rather than toward it. This study provides supportive evidence to earlier studies that operating room ventilation with ultraclean air is imperfect during surgical activity and that wound ventilation may be a simple complement. Further clinical trials are needed.
authors.affiliation: Division of Medical Engineering, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Persson
authors.forename: Jan
authors.initials: J
authors.lastname: van der Linden
mesh_terms: D000391:Air Microbiology; D009873:Operating Rooms; D013530:Surgical Wound Infection / Q000209:etiology / Q000517:prevention & control*; D014691:Ventilation / Q000295:instrumentation*