title: Effect of mobile unidirectional air flow unit on microbial contamination of air in standard urologic procedures.
abstract: BACKGROUND
  Infection is one of the most feared complications of surgery. New instrumentation is being developed to reduce deposition of bacteria.
  
  
  METHODS
  We investigated 45 major surgical procedures (21 radical nephrectomies [RN] and 24 radical retropubic prostatectomies [RRP]) in our urology department during 2007. In about one-half of the interventions, an ultraclean air flow mobile (UAF) unit was used. Bacterial sedimentation was evaluated by nitrocellulose membranes placed on the instrument tray and by settle plates positioned at four points in the operating room. In 27 operations, an additional membrane was located near the incision.
  
  
  RESULTS
  Bacterial counts on the nitrocellulose membranes during RN were 230 colony-forming units (cfu)/m(2)/h with the UAF unit and 2,254 cfu/m(2)/h without the unit (p = 0.001). During RRP, the values were 288 cfu/m(2)/h and 3,126 cfu/m(2)/h respectively (p = 0.001). The membrane placed near the incision during RN showed a microbial count of 1,235 cfu/m(2)/h with the UAF unit and 5,093 cfu/m(2)/h without the unit (p = 0.002); during RRP, the values were 1,845 cfu/m(2)/h and 3,790 cfu/m(2)/h, respectively (difference not significant). Bacterial contamination detected by settle plates during RN showed a mean value of 2,273 cfu/m(2)/h when the UAF unit was used and 2,054 cfu/m(2)/h without the unit; during RRP, the values were 2,332 cfu/m(2)/h and 2,629 cfu/m(2)/h with and without the UAF unit, respectively (NS). No statistically significant differences were detected in the clinical data registered in patients operated on under standard conditions and while the UAF unit was functioning.
  
  
  CONCLUSIONS
  The UAF appears able to reduce microbial contamination at the operating table, reaching a bacterial number obtained in ultraclean operating theatres.
authors.affiliation: Urology Unit, University Hospital of Parma, Parma, Italy. sferretti@ao.pr.it
authors.forename: Stefania
authors.initials: S
authors.lastname: Ferretti
authors.forename: Cesira
authors.initials: C
authors.lastname: Pasquarella
authors.forename: Samanta
authors.initials: S
authors.lastname: Fornia
authors.forename: Elisa
authors.initials: E
authors.lastname: Saccani
authors.forename: Carlo
authors.initials: C
authors.lastname: Signorelli
authors.forename: Pietro
authors.initials: P
authors.lastname: Vitali
authors.forename: Giuliano Ezio
authors.initials: GE
authors.lastname: Sansebastiano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000391:Air Microbiology; D000392:Air Movements; D000397:Air Pollution / Q000517:prevention & control*; D001419:Bacteria / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D005374:Filtration; D006801:Humans; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D009873:Operating Rooms; D011468:Prostatectomy; D014570:Urologic Diseases / Q000601:surgery*