Prehospital triage for mass casualty incidents using the META method for early surgical assessment: retrospective validation of a hospital trauma registry.

BACKGROUND: In mass casualty incidents (MCI), death usually occurs within the first few hours and thus early transfer to a trauma centre can be crucial in selected cases. However, most triage systems designed to prioritize the transfer to hospital of these patients do not assess the need for surgery, in part due to inconclusive evidence regarding the value of such an assessment. Therefore, the aim of the present study was to evaluate the capacity of a new triage system-the Prehospital Advanced Triage Method (META)-to identify victims who could benefit from urgent surgical assessment in case of MCI.

METHODS: Retrospective, descriptive, observational study of a multipurpose cohort of patients included in the severe trauma registry of the Gregorio Marañón University General Hospital (Spain) between June 1993 and December 2011. All data were prospectively evaluated. All patients were evaluated with the META system to determine whether they met the criteria for urgent transfer. The META defines patients in need of urgent surgical assessment: (a) All penetrating injuries to head, neck, torso and extremities proximal to elbow or knee, (b) Open pelvic fracture, (c) Closed pelvic fracture with mechanical or haemodynamic instability and (d) Blunt torso trauma with haemodynamic instability. Patients who fulfilled these criteria were designated as "Urgent Evacuation for Surgical Assessment" (UESA) cases; all other cases were designated as non-UESA. The following variables were assessed: patient status at the scene; severity scales [RTS, Shock index, MGAP (Mechanism, Glasgow coma scale, Age, pressure), GCS]; need for surgery and/or interventional procedure to control bleeding (UESA); and mortality. The two groups (UESA vs. non-UESA) were then compared.

RESULTS: A total of 1882 cases from the database were included in the study. Mean age was 39.2 years and most (77%) patients were male. UESA patients presented significantly worse on-scene hemodynamic parameters (systolic blood pressure and heart rate) and greater injury severity (RTS, shock index, and MGAP scales). No differences were observed for respiratory rate, need for orotracheal intubation, or GCS scores. The anatomical injuries of patients in the UESA group were less severe but these patients had a greater need for urgent surgery and higher mortality rates.

CONCLUSION: These findings suggest that the META triage classification system could be beneficial to help identify patients with severe trauma and/or in need of urgent surgical assessment at the scene of injury in case of MCI. These findings demonstrate that, in this cohort, the META fulfils the purpose for which it was designed.