Olmsted Russell N
Infection Control Services, Saint Joseph Mercy Health System, Ann Arbor, MI, USA.
Am J Infect Control. 2008 May;36(4):260-7. doi: 10.1016/j.ajic.2007.10.028.
Containment of airborne microorganisms to prevent transmission in a positively pressured operating room (OR) is challenging. Occupational transmission of Mycobacterium tuberculosis (M tuberculosis) to perioperative personnel has occurred, but protection of the surgical site is of equal importance. High-efficiency particulate air (HEPA) filters can mitigate occupational exposure and improve air quality. Smoke plumes and submicron particulates were released to simulate aerobiology of M tuberculosis and assess impact and efficacy of particle removal in an OR suite using different HEPA filtration units and configurations.
My objectives were to compare the impact of freestanding HEPA filter units, which are currently more commonly deployed inside the OR, with a novel portable anteroom system (PAS)-HEPA combination unit (PAS-HEPA) placed outside the OR and assess the efficiency of removal of particulates from an OR.
Smoke plume and submicron particles were generated inside an OR. Plume behavior was observed during deployment of 3 different configurations of HEPA units. Two of these involved different models of freestanding HEPA filtration units inside the OR, and the third was the PAS-HEPA unit located outside the OR. The concentration of submicron airborne particles was quantified for each configuration of freestanding HEPA and PAS-HEPA units. In addition to measurement of submicron airborne particulates, a high concentration of these was generated in the OR, and time for removal was quantified.
Observations of released plumes, using the PAS-HEPA unit revealed a downward evacuation, away and toward the main entry door from the sterile field. By contrast, when portable freestanding HEPA units were placed inside the OR, plumes moved vertically upward and directly into the breathing zone of where the surgical team would be stationed during a procedure. The PAS-HEPA unit, working in tandem with the OR heating, ventilation, and air conditioning system, was confirmed to have removed over 94% of an initial release of at least 500,000 submicron particles/ft(3) within 20 minutes after release.
This pilot study clearly indicates that avoiding the use of freestanding HEPA filters inside an OR during a surgical procedure is prudent and consistent with Centers for Disease Control and Prevention guidelines. A PAS-HEPA unit is effective in removing submicron particles and will enhance safety of care of a patient with an airborne infection requiring surgery.
在正压手术室（OR）中控制空气传播微生物以防止传播具有挑战性。结核分枝杆菌（M tuberculosis）已发生职业性传播给围手术期人员，但保护手术部位同样重要。高效空气过滤器（HEPA）可减轻职业暴露并改善空气质量。释放烟雾羽流和亚微米颗粒以模拟M tuberculosis的空气生物学特性，并评估使用不同HEPA过滤单元和配置的手术室中颗粒去除的影响和效果。
我的目的是比较目前更常用于手术室内部的独立式HEPA过滤单元与放置在手术室外部的新型便携式前室系统（PAS）-HEPA组合单元（PAS-HEPA）的影响，并评估从手术室中去除颗粒的效率。
在手术室内部产生烟雾羽流和亚微米颗粒。在部署3种不同配置的HEPA单元期间观察羽流行为。其中两种涉及手术室内部不同型号的独立式HEPA过滤单元，第三种是位于手术室外部的PAS-HEPA单元。对每种独立式HEPA和PAS-HEPA单元配置的空气中亚微米颗粒浓度进行定量。除了测量空气中的亚微米颗粒外，在手术室中产生高浓度的这些颗粒，并对去除时间进行定量。
使用PAS-HEPA单元观察释放的羽流，发现其向下排空，远离无菌区域并朝向主入口门。相比之下，当便携式独立式HEPA单元放置在手术室内部时，羽流垂直向上移动并直接进入手术过程中手术团队所在的呼吸区域。经证实，PAS-HEPA单元与手术室的加热、通风和空调系统协同工作，在释放后20分钟内可去除初始释放的至少500,000个亚微米颗粒/立方英尺中的94%以上。
这项初步研究清楚地表明，在手术过程中避免在手术室内部使用独立式HEPA过滤器是谨慎的，并且符合疾病控制和预防中心的指南。PAS-HEPA单元在去除亚微米颗粒方面有效，并将提高对需要手术的空气传播感染患者的护理安全性。
