Lights and Siren Transport and the Need for Hospital Intervention in Trauma Patients

Abstract

Emergent ambulance transportation is associated with increased risk of collision, injury, and death for EMS professionals, patients, and the general public. Time saved using lights and siren (L&S) is typically small, and often provides minimal clinical benefit. Our objective was to investigate the frequency of L&S transports, describe the precision of the decision to employ L&S to predict the need for a time critical hospital intervention (TCHI) within 15 minutes of hospital arrival, identify clinical predictors of a TCHI, and compare clinical outcomes in patients transported by Emergency Medical Services (EMS) with and without L&S in a trauma-specific population. EMS patient care reports and trauma registry data were retrospectively reviewed for trauma patients consecutively transported from the field by three EMS agencies to three trauma centers within urban and suburban settings over a two-year period. TCHIs were collaboratively developed by the study team. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were utilized to report the precision of the decision to employ L&S to predict the need of a TCHI. Univariate and multivariate analyses determined predictors of a TCHI and compared clinical outcomes. 2,091 patients were included in the study. Of the 19.8% of patients transported with L&S, 22.9% received a TCHI. The most common TCHI was airway or respiratory procedures (87.2% of all TCHI's). The sensitivity and specificity of L&S to predict the need for a TCHI was 87.2% (95% CI 79.4-92.8) and 84.0% (95% CI 82.2-85.5), respectively. PPV was 23.0% (95% CI 23.53-38.01); NPV was 99.2% (95% CI 98.6-99.6). L&S was predictive for the need for a TCHI (p < 0.001), as was abnormal Glasgow Coma Score (p < 0.001), abnormal systolic blood pressure and age (p < 0.05 for all). Among patients that received a TCHI, over a third that were transported with L&S (36.8%) expired, compared with two of 14 patients (14.3%) not transported L&S. EMS professionals in this study demonstrated a high ability to discern which trauma patients did not require L&S. Nevertheless, L&S transport resulted in a TCHI less than one quarter of the time, suggesting an opportunity for further reduction of L&S transports in trauma patients.

The Use of Emergency Lights and Sirens by Ambulances and Their Effect on Patient Outcomes and Public Safety: A Comprehensive Review of the Literature

“…4,5,[11][12][13][14][15] Where controversy remains is whether the timed saved is clinically significant, with many of these studies concluding that it generally was not. Most published studies demonstrate a variable, but statistically significant, reduction in response/transport.…”

Dispatch and prehospital transport for acute septic patients: an observational study

“…Although, the Danish healthcare system is free, some patients bypass the dispatch system or public prehospital transport, and arrive on their own accord. In contrast to other diseases as trauma [25], cardiac arrest [26, 27], acute myocardial infarction [28] and stroke [29, 30], septic patients, to a lesser extent, arrived by public prehospital transport. In our study, part of the explanation for patients arriving without public pre-hospital transport could be the short distances with low traffic load.…”

Lights and Siren Transport and the Need for Hospital Intervention in Non-Trauma Patients: A Prospective Study

“…Furthermore, the time saved -a couple of minutes -is considered moderate, with no clinical benefit demonstrated to date [8][9][10][11].…”

“…Some studies have applied a more comprehensive approach, using the application of time-critical hospital intervention (TCHI) as an endpoint to indicate the appropriateness of LST [2,9,10,15]. TCHI is defined as those procedures or treatments that are urgently needed, requiring skills or devices that are either not available or cannot be properly performed in the prehospital setting [2,8,10]. Recent studies have demonstrated that up to a quarter of life-threatening situations, such as airway obstruction, severe dyspnoea, hemodynamic instability and abnormal Glasgow Coma Scale, require TCHI [8][9][10].…”

“…TCHI is defined as those procedures or treatments that are urgently needed, requiring skills or devices that are either not available or cannot be properly performed in the prehospital setting [2,8,10]. Recent studies have demonstrated that up to a quarter of life-threatening situations, such as airway obstruction, severe dyspnoea, hemodynamic instability and abnormal Glasgow Coma Scale, require TCHI [8][9][10]. As proposed by the American Heart Association and the American Stroke Association since 2013, acute ST-elevation myocardial infarction (STEMI), suspicion of acute stroke and out-of-hospital cardiac arrest (OHCA) require rapid transportation from the field (fast-track) to benefit from an urgent procedure and therefore also may be considered as TCHI [16][17][18].…”