To the Editor—Early measures of infection prevention and control (IPC) when patients enter a healthcare facility during a pandemic are important in avoiding nosocomial spread as well as protecting healthcare workers. ^{Reference Berlin, Gulick and Martinez1} Severe acute respiratory coronavirus virus 2 (SARS-CoV-2), for example, is transmitted through close contact, droplets, or airborne particles formed by aerosol generation in the hospital setting. Patients with suspected or confirmed coronavirus disease 2019 (COVID-19) are frequently triaged and subsequently receive management, even resuscitation, in the emergency department (ED). Resuscitation of the critically ill patients may generate infectious aerosol during endotracheal intubation or chest compression. ^{Reference Wang, Hu and Hu2} Therefore, the critically ill patients with possibility of undergoing aerosol-generating procedures are recommended to receive treatment in negative pressure isolation rooms (NPIRs). ³

To prevent nosocomial infections, lessons learned from the 2003 severe acute respiratory syndrome (SARS) outbreak were early cataloguing of and then isolating suspected cases. ^{Reference Chen, Twu and Chang4,Reference Hsieh, Chen and Hsu5} The specific protocol adopted by our ED during the current COVID-19 pandemic for containing critically ill patients was the establishment of screening point at the corridor in front of the main ED entrance. We separated 3 distinct routes for patient diversion (Fig. 1). Based on the risk of COVID-19 and triage acuity levels, patients were categorized into 3 groups, each with a specific procedural route. We check the risks of COVID-19 according to symptoms and/or signs, as well as travel, occupation, contact, and cluster (TOCC) history at the screening point. After initial screening, patients not suspected of COVID-19 are guided to the main ED via route 1 for a regular triage process. Patients who suspected of COVID-19 with low acuity are moved to a well-ventilated tent via route 2. Critically ill patients suspected of COVID-19 are checked at the screening point and are then moved to the NPIR via route 3. A specific route for critically ill patients to be admitted to the NPIR without entering the main ED reduces the risk of nosocomial spread during management and resuscitation. A well-designed corridor in front of the main ED entrance plays an important role in infection prevention and control during pandemics.

Fig. 1. (A) Regular patient flow before the pandemics. (B) Patient flow during the pandemics. The left sides of panels A and B show the first-floor plan of the hospital, and the yellow area is the emergency department (ED). The blue dotted area of the ED was amplified and shown on the right side of panel A and B. The orange area within panel A and B is the negative pressure isolation area where 2 negative-pressure isolation rooms are located. Portable radiography, sonography, electrocardiography, airway and resuscitation management equipment is available in the isolation area. In panel A, patients enter the ED through the main entrance (black arrow), and patients suspected of COVID-19 disease are triaged to the isolation area. In panel B, patients are classified as not suspected of having COVID-19, suspected of having COVID-19 with low acuity, and suspected of having COVID-19 with high acuity before allocation to route 1, route 2, and route 3, respectively.