Lights and Siren Transport and the Need for Hospital Intervention in Nontrauma Patients: A Prospective Study

BACKGROUND: The use of lights and siren transport (LST) has been a matter of debate because of the short time savings and well-established increased risks for Emergency Medical Services (EMS) and bystanders. Time-critical hospital intervention (TCHI) denotes urgently needed procedures that cannot be performed properly in an out-of-hospital setting. Since 2013, rapid transportation from the field, fast-track, is currently used for patients with acute ST-elevation myocardial infarction, suspicion of acute stroke and out-of-hospital cardiac arrest. The aim of this study was to determine whether the use of LST was associated with the realization of TCHI for nontrauma cases within 15 minutes of hospital arrival, to quantify overtriage (LST without TCHI) and to identify the predictors of TCHI. METHODS: This is a monocentric prospective observational study of nontrauma patients transported by ambulance. Based on Ross et al.'s work in 2016 on trauma patients, TCHI procedures were developed by the study team. Descriptive statistics were used to determine whether the use of LST was associated with the realization of TCHI. Multivariable analyses determined the predictors of TCHI and compared clinical outcomes. RESULTS: On the 324 patients included, 67 (20.7%) benefitted from LST, with 40 (59.7%) receiving TCHI (p < 0.001). The overtriage rate was 40.3%. The most common medical TCHI was the fast-track (65.2% of all TCHI). LST was predictive of the need for TCHI (p < 0.001), as was the clinical condition of the patient and also when EMS providers expected TCHI. CONCLUSIONS: A majority of the LST benefitted from TCHI with an overtriage rate of 40%. To reduce the rate of overtriage (LST without TCHI), LST should mainly be used for fast-track and when TCHI is expected by the EMS providers.