The addition of a mobile ultra-clean exponential laminar airflow screen to conventional operating room ventilation reduces bacterial contamination to operating box levels

Further bacteriological evaluation of the TOUL mobile system delivering ultra-clean air over surgical patients and instruments

“…However, as the screen could never be positioned closer than 2.0e 2.3 m to the groin area of the patient, RFs of only 0.4e4.4 (mean 2.7) were achieved, and thus there was no significant reduction in airborne bacteria. These ACHs had to be performed under conditions suboptimal for the TOUL-400 unit, illustrating its limited reach, as did the study of hernia operations by Friberg et al 5 When the present study was extended to an OR with 16 ACH, ultra-clean air was obtained at distances of 1.3e1.8 m in only three of six actual operations. In the other three operations, the screen had to be moved aside, again illustrating the difficulty of positioning the TOUL-400 unit properly during surgery.…”

“…In a followup study of actual inguinal hernia operations, the air and surface counts of bacteria measured downstream of the wound and the operating team were reduced by only 50% (1.4 m from the screen). 5 This indicated that optimal positioning of the TOUL-400 screen relative to the wound is crucial for its bacteriological performance. In addition, the width of its effect area was not studied.…”

The ventilation needed to control thermal plume and particle dispersion from manikins in a unidirectional ventilated protective isolation room

“…Instead, PIR uses positive-pressure ventilation and the purpose of ventilation is to protect patients from being infected by others. Also researchers have studied the ventilation, airborne or droplets transmission characteristics in operating theatres (OT) where surgical-site infections are a major problem (Friberg et al 2003;Chow and Yang 2005;Chow et al 2006;Liu et al 2009;Zoon et al 2011;Balocco et al 2012;Chow and Wang 2012). The ventilation in both PIR and OT intends to create a unidirectional airflow environment to protect the patients.…”

Effect of a portable ultra-clean exponential airflow unit on the particle distribution in an operating room

“…It was proven experimentally that MLAF constitutes a valuable complement to the OR ventilation in reducing the OR bacterial load (Friberg, Lindgren, Karlsson, Bergström, & Friberg, 2002;Friberg, Ardnor, Lundholm, & Friberg, 2003;Nilsson, Lundholm, & Friberg, 2010;Pasquarella et al, 2007;Thore & Burman, 2006;Whyte, Hambraeus, Laurell, & Hoborn, 1992). Friberg et al (2002) examined the MLAF as an addition to conventional turbulent mixing OR ventilation during a sham operation and they concluded that the additional MLAF screen reduced the number of viable airborne bacteria and sedimenting bacteria-carrying particles (BCPs) to the same level as for ultra-clean LAF OR ventilation units.…”

“…Friberg et al (2002) examined the MLAF as an addition to conventional turbulent mixing OR ventilation during a sham operation and they concluded that the additional MLAF screen reduced the number of viable airborne bacteria and sedimenting bacteria-carrying particles (BCPs) to the same level as for ultra-clean LAF OR ventilation units. In another study, Friberg et al (2003) investigated MLAF screen units used in 60 standardized operations for groin hernia and they found no correlation between surface and air contamination of BCPs when MLAF was used. Thore and Burman (2006) experimentally used MLAF over instrument and operation table areas, and concluded that MLAF reduced the counts of BCPs by about 14-fold.…”