The crowd-out effect of a mass casualty incident: Experience from a dust explosion with multiple burn injuries

A mass casualty incident (MCI) can have an enormous impact on an already crowded emergency department (ED), affecting the quality of health care provided to non-MCI ED patients. On June 26, 2015, a burn MCI (BMCI) occurred due to a cornstarch explosion at a party at a water park. The competing needs of the BMCI patients might have crowded out the needs of the non-BMCI patients. Although crowd-out effects have been previously documented in a variety of health care situations, they have not been extensively evaluated during MCIs. We aimed to determine whether the outcomes of the non-MCI patients were compromised during this incident. We conducted a retrospective observational study comparing several health care parameters and outcomes between non-BMCI patients and historical controls during the designated period using institutional electronic records and the National Health Insurance Research Database. On the night of the incident, 53 patients were sent to our ED; most of them arrived within 3 hours after the BMCI. There was a significant increase in the wait time for ICU beds among non-BMCI patients compared to the wait times during the corresponding week of the previous year (8.09 ± 4.21 hours vs 3.77 ± 2.15 hours, P = .008). At the hospital level, there was a significantly increased length of hospital stay (LOS) in the ICU after the MCI compared with the LOS in the ICU in the same week of the preceding year (median days: 15 vs 8, P ≤ .001). At the regional level, there were no significant differences between the 2 periods in the LOS in acute care, LOS in the ICU or mortality rates at the involved medical centers. Crowd-out effects from the MCI occurred in the ED and at the institutional level. Although there was an increased wait time for admission to the ICU and a longer LOS in the ICU, the LOS in acute care beds, treatment of time-sensitive diseases, and mortality rates were not compromised by the current MCI protocol at either the institutional or regional levels.