ITAP, Department of Energy and Fluid Mechanics, University of Valladolid, Valladolid, Spain.
Department of Physical Chemistry and Applied Thermodynamics, University of Cordoba, Córdoba, Spain.
PLoS One. 2019 Jan 30;14(1):e0211390. doi: 10.1371/journal.pone.0211390. eCollection 2019.
Efficient ventilation in hospital airborne isolation rooms is important vis-à-vis decreasing the risk of cross infection and reducing energy consumption. This paper analyses the suitability of using a displacement ventilation strategy in airborne infection isolation rooms, focusing on health care worker exposure to pathogens exhaled by infected patients. The analysis is mainly based on numerical simulation results obtained with the support of a 3-D transient numerical model validated using experimental data. A thermal breathing manikin lying on a bed represents the source patient and another thermal breathing manikin represents the exposed individual standing beside the bed and facing the patient. A radiant wall represents an external wall exposed to solar radiation. The air change efficiency index and contaminant removal effectiveness indices and inhalation by the health care worker of contaminants exhaled by the patient are considered in a typical airborne infection isolation room set up with three air renewal rates (6 h-1, 9 h-1 and 12 h-1), two exhaust opening positions and two health care worker positions. Results show that the radiant wall significantly affects the air flow pattern and contaminant dispersion. The lockup phenomenon occurs at the inhalation height of the standing manikin. Displacement ventilation renews the air of the airborne isolation room and eliminates the exhaled pollutants efficiently, but is at a disadvantage compared to other ventilation strategies when the risk of exposure is taken into account.
医院空气隔离病房的通风效率对于降低交叉感染风险和降低能耗非常重要。本文分析了在空气传播感染隔离病房中使用置换通风策略的适宜性，重点关注感染患者呼出的病原体对医护人员的暴露。该分析主要基于数值模拟结果，这些结果得到了 3D 瞬态数值模型的支持，该模型使用实验数据进行了验证。一个躺在病床上的热呼吸人体模型代表着源患者，另一个热呼吸人体模型代表着站在床边面对患者的暴露个体。一个辐射墙代表暴露在太阳辐射下的外墙。在设置了三种空气更新率（6 h-1、9 h-1 和 12 h-1）、两种排气口位置和两种医护人员位置的典型空气传播感染隔离病房中，考虑了空气交换效率指数和污染物去除效率指数以及医护人员吸入患者呼出污染物的情况。结果表明，辐射墙显著影响空气流动模式和污染物扩散。在站立人体模型的吸入高度处发生锁定现象。置换通风可以更新空气隔离病房的空气并有效地消除呼出的污染物，但在考虑暴露风险时，与其他通风策略相比处于劣势。
