Triage and Trauma Workload in Mass Casualty: A Computer Model

Background The aim of this study was to quantitatively analyze the impact of hospital triage on the workload of trauma teams in the Emergency Department during a mass casualty incident, using a computer model. Methods The inflow and triage of casualties into an Emergency Department with 5 trauma teams was modeled using the Monte Carlo method. Triage was represented as a binary classification task performed in one or two sequential steps. The input variables were triage accuracy (specificity and sensitivity) and casualty load, and the key output variable was the time to saturation (TTS) of the trauma teams, which was computed from the available and needed team minutes. Results The relationship between an increasing casualty load and the TTS describes a sigmoid-shaped curve. Improving triage accuracy extends the TTS and shifts the curve to the right. Switching to sequential competent triage (80% accuracy) results in TTS that is similar to perfect single-step triage (100% accuracy) but at the cost of investing less team time in urgent casualties. The optimal ratio of trauma teams to urgent casualties in sequential mode is 1:8, indicating that the treatment of urgent casualties must be delegated to reinforcement staff. Conclusions This study introduces innovative tools for quantitative analysis of hospital triage in mass casualty incidents and shows how triage accuracy and mode affect the ability of trauma teams to cope with heavy casualty loads. These tools can be used to optimize the hospital response to future threats.