Local exhaust ventilation for infection control in hospitals

Health care workers (HCWs) treating infectious patients, such as Severe Acute Respiratory Syndrome (SARS) patients, are at high risk of nosocomial infection. The concern is particularly serious during the bioaerosol-induced procedures, in which droplets and bioaerosols emitted by an infectious patient may enter the respiratory system of the HCW in dose contact with the patient. These medical procedures include endotracheal intubation, bronchoscopy, ambu bagging, among others. Infection control professionals have identified local exhaust ventilation (LEV) as a promising solution to remove the contagious pollutants for protection against nosocomial transmission of diseases. In this study, computation fluid dynamics (CFD) models were developed to simulate the transport of droplets and bioaerosols for design optimisation of a LEV system, taking into account the important particle deposition and turbulence effects. A LEV prototype was built and tested. The details of the computational analysis and empirical results are presented in this paper.