[Comparison of two models of a treatment area with respect to treatment times in critically ill patients : A pilot study]

Background: In the case of a mass casualty incident an advanced medical post (AMP) plays a central role in the medical care by ambulance service and civil protection units. Besides the traditional organization with one triage category per medical services tent, it can also be structured in a mixed form (i.e. a defined number of patients with different triage categories are assigned to each medical services tent). To date it remains unclear which organization format is better in order to rapidly evacuate those patients with the highest priority.

Methods: The Medical Task Force of Lower Franconia treated 50 identical and standardized training patients including 18 triage category red/emergency (36%), 12 triage category yellow/urgent (24%), 18 triage category green/non-urgent (36%) and 2 triage category black/dead (4%) in the course of a scheduled field exercise within two consecutive training sessions (first session: classical structure, second session: mixed structure). The training patients were represented by a dynamic patient simulation, whereby simulation cards showed injury patterns and the external appearance of the patients at a defined point which required certain interventions. The patients' conditions changed when these measures were accomplished or neglected. The length of stay of the patients with the triage category red/emergency at the AMP (start of triage to start evacuation) as well as the overall number of evacuated patients were collated and compared.

Results: Out of 18 patients with the triage category red/emergency, 13 patients in each session were evacuated in one pass. During the first session the mean evacuation time at the AMP was 25 min and during the second session the mean evacuation time was 18 min. After the end of the 90 min of exercise time in the first session 14 non-critical patients (triage categories yellow/urgent and green/non-urgent, n = 30) were still left at the AMP (16 evacuated) and in the second session 12 (18 evacuated).

Conclusion: Depending on the mission requirements the mixed form of AMP organization can provide several advantages. In addition to rapid operational readiness and high flexibility the patient distribution by triage category could be processed better and the evacuation time of critical patients could be shortened.