교차감염 예방을 위한 전실 유무에 따른 음압병실에서의 입자 유출 해석 = A Numerical Study on Particle Migration for Prevention of Cross-Infection in Negative Pressure Isolation Room According to the Presence of Anteroom

국문 초록 (Abstract)

본 연구는 전실이 없는 외부가 비음압 복도인 음압병실과 전실을 갖춘 음압격리병실에서의 의료진 이동과출입문 개폐에 따른 오염 공기와 입자의 이동에 대해 알아보고자 하였다. 그 결과 다음과 같은 결론을 도출할 수 있었다. (1) 의료진의 이동에 의해 입자가 영향을 받는 것으로 나타났다. 입자는 의료진의 이동에 따른 의료진 뒤쪽에발생하는 후류를 따라 이동하며, 이를 통해 병실 밖으로의 입자 유출 가능성이 있는 것으로 보인다.
(2) 외부가 비음압 복도인 음압병실과 전실을 갖춘 음압격리병실 모두 의료진 이동과 출입문 개폐에 따라병실의 오염공기와 입자가 유출되는 것으로 나타났다. Smoke 유출률은 Case A의 경우 2.69%, Case B의경우 2.53%이고, 유출된 입자는 Case A의 경우 11개, Case B의 경우 1개로 전실이 있는 경우 Smoke와입자의 유출이 상대적으로 감소됨을 알 수 있다.
외부가 비음압 복도인 음압병실과 전실을 갖춘 음압격리병실 모두 의료진이 병실 밖으로 나갈 때 병실내부의 감염입자가 유출될 수 있는 것으로 나타났다. 특히 외부가 비음압 복도인 음압병실의 경우, 복도는감염관리 대상이 아닌 일반환자들과 의료진이 공동으로 사용하는 공간이므로 교차감염의 위험이 상당히 커질수 있다. 따라서 전실이 없는 음압병실에 감염환자가 입원한 경우 의료진의 각별한 주의가 필요하다. 또한감염환자는 전실을 갖춘 음압격리병실에 입원하여 병실의 감염입자가 직접적으로 외부로 유출되는 것을방지하는 것이 교차감염 예방 차원에서 권장된다.

다국어 초록 (Multilingual Abstract)

Negative pressure isolation rooms are used to contain infected aerosols within the room for patients with airborne infections. When the door is opened, the pressure difference in the two rooms cannot be maintained and this leads to the risk of cross-infection. Anterooms plays an crucial role in minimizing the escape of infectious particles into a corridor when the door is opened. However, most of the hospitals use isolation room with no anteroom when hospitalizing patients with infectious diseases like tuberculosis. Two cases were evaluated through the performance of CFD simulations to examine the effects of a healthcare worker walking in and out of isolation rooms, and door opening/closing on the transport characteristics of cough particles from the infected patient in the isolation room. The first case was a negative pressure isolation room with an open space corridor and no negative pressure. The second case was a negative pressure isolation room with anteroom both of which were negatively pressurized by mechanical ventilation. The simulation results showed that the movement of healthcare worker has a significant influence on airflow patterns by producing distinct wave flow regions which affect suspended particles. In both cases, air and cough particles from isolation rooms moved to the corridor and anteroom when the door opened and a healthcare worker walked out from the isolation room.

참고문헌 (Reference)

1 김준영, "음압격리병상에서의 힌지 문의 개폐속도 및 의료진의 이동방향에 따른 실간 압력변동 및 공기교환량에 대한 해석적 연구" 대한설비공학회 30 (30): 310-320, 2018

2 이두루나, "국가지정 음압격리 입원치료병상의 슬라이딩 도어의 개폐속도 및 의료진의 이동속도에 따른 오염공기 유출에 관한 해석적 연구" 대한설비공학회 30 (30): 211-221, 2018

3 Byers, R. J, "Transfer and reaerosolization of biological contamination following field technician servicing of an aerosol sampler" 2013

4 Nicas, M., "Toward understanding the risk of secondary airborne infection : emission of respirable pathogens" 2 (2): 143-154, 2005

5 Duguid, J. P., "The size and the duration of air-carriage of respiratory droplets and droplet-nuclei" 44 (44): 471-479, 1946

6 Yang, S., "The size and concentration of droplets generated by coughing in human subjects" 20 (20): 484-494, 2007

7 Gralton, J., "The role of particle size in aerosolised pathogen transmission : A review" 62 (62): 1-13, 2010

8 Guan, Y., "The effects of patient movement on particles dispersed by coughing in an indoor environment" 19 (19): 172-183, 2014

9 Zhu, S., "Study on transport characteristics of saliva droplets produced by coughing in a calm indoor environment" 41 (41): 1691-1702, 2006

10 Kwon, S. -B., "Study on the initial velocity distribution of exhaled air from coughing and speaking" 87 (87): 1260-1264, 2012

11 Chen, C., "Some questions on dispersion of human exhaled droplets in ventilation room : answers from numerical investigation" 20 (20): 95-111, 2010

12 Hang, J., "Potential airborne transmission between two isolation cubiclesthrough a shared anteroom" 89 : 264-278, 2015

13 Xu, C., "Measuring the exhaled breath of a manikin and human subjects" 25 (25): 188-197, 2015

14 Fitzgerald, D., "Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases" Elsevier Churchill Livingstone 2005

15 Siegel, J. D., "Healthcare Infection Control Practices Advisory Committee, Guideline for Isolation Precautions : Preventing Transmission of Infectious Agents in Healthcare Settings"

16 Gupta, J. K., "Flow dynamics and characterization of a cough" 19 (19): 517-525, 2009

17 Tao, Y., "Dynamic meshing modelling for particle resuspension caused by swinging manikin motion" 123 : 529-542, 2017

18 McCluskey, R., "Detection of airborne cytomegalovirus in hospital rooms of immunocompromised patients" 56 (56): 115-118, 1996

19 Cole, E. C., "Characterization of infectious aerosols in health care facilities : An aid to effective engineering controls and preventive strategies" 26 (26): 453-464, 1998

20 Chao, C. Y. H., "Characterization of expiration air jets and droplet size distributions immediately at the mouth opening" 40 (40): 122-133, 2009

21 Chao, C. Y. H., "Characterization of expiration air jets and droplet size distributions immediately at the mouth opening" 40 (40): 122-133, 2009

22 Kalliomäki, P., "Airflow patterns through single hinged and sliding doors in hospital isolation rooms e Effect of ventilation, flow differential and passage" 107 (107): 154-168, 2016

23 Owen, M. K., "Airborne particle sizes and sources found in indoor air" 26 (26): 2149-2162, 1992