Mass casualty incidents (MCI) overwhelm existing resources in the emergency department. The existing method to recall staff in an MCI is text notification through the hospital call center. This study aims to assess the effectiveness of a novel method to recall senior emergency physicians during an MCI.

For this method, upon notification of a MCI, the senior physician on duty will start call tree activation based on four different senior physician job grades. He/she will call the first physician for each grade, who takes over calling and activating the remaining physicians in the same grade with a maximum of two attempts. Each physician receiving the activation call then texts an acknowledgement and estimated time of arrival at the department in the group chat. An unannounced, simulated MCI event was conducted at 02:00 and 14:00 on a weekday. Effectiveness was determined by the proportion of senior physicians available within 60 minutes of activation.

For the 02:00 activation, three of the 25 senior physicians were on clinical duty in the hospital while nine were contactable within 15 minutes and thirteen after 30 minutes. Eleven were able to return to the hospital in 60 minutes or less and one beyond 60 minutes. Nine were local but unable to return and one was overseas.

For the 14:00 activation, four of the 25 senior physicians were on clinical duty in the hospital while 15 were contactable within 15 minutes and six after 30 minutes. Nine were able to return to the hospital in 60 minutes or less and four beyond 60 minutes. Three were local but unable to return and five were overseas.

This method can achieve rapid manpower augmentation with more than half the staff present in the hospital within 60 minutes. Drills involving physical recall should be performed to further test this workflow.