Simulating emergency patient flow during the COVID-19 pandemic

The work presented in this paper is based on two projects that were conducted at St. Olavs Hospital (Norway) when preparing for the COVID-19 pandemic. Three discrete event simulation models are provided to evaluate the resource requirements during the peak of the pandemic. First, we estimate the number of beds needed in the emergency department (ED). In the second model, we estimate the number of ambulances required to maintain prepandemic response times for emergency patients. The third model is a coupling of the two former models, and it is used to study the effects of ED boarding time for COVID-19 patients. The resource needs are analysed under different COVID-19 testing policies. A strict testing policy increases the bed requirements in the ED, while it has the opposite effect for ambulances. Two distinct mechanisms causing boarding time are found. The effects from boarding time are most prominent during night and weekends.