[Reassessment of the emergency medical service deployment indication catalogue after traffic accidents]. / Reevaluation des Notarzteinsatzindikationskataloges nach Verkehrsunfällen.

BACKGROUND: The emergency physician indication catalogue is based on outdated studies and provides limited guidance for alarm criteria following traffic accidents. Advances in vehicle safety technology and changes in available resources necessitate a re-evaluation of the indications. The aim of this retrospective registry study is to identify preclinically assessable variables for severe injuries sustained in traffic accidents. METHODS: A total of 47,145 individuals involved in accidents between 1 January 2000 and 31 December 2021 from the GIDAS database were included. Separate datasets for severe (AIS 3+) and minor injuries were evaluated. RESULTS: Ejection (PPV 80.6%), entrapment (PPV 75.6%), burning vehicles (PPV 57.1%), challenging rescue situations (PPV 56.3%), vehicle disintegration (PPV 51.6%), and amnesia (PPV 50.3%) indicated severe injuries among vehicle occupants. For vulnerable road users (motorcyclists, cyclists, pedestrians), helmet loss (PPV 61.1%), being run over/dragging (PPV 41.9%), opponent vehicle window breakage (PPV 35.8%), and subsequent collision with objects (PPV 31.1%) were also identified. The χ2-test revealed significant associations between the variables and severe injuries. Combined variables achieved PPV values above 82%. DISCUSSION: The current emergency physician indication catalogue provides limited preclinically detectable criteria and should be revised based on the objective registry data. Query models for emergency dispatchers should be tested.

Passenger and heavy vehicle collisions with pedestrians: Assessment of injury mechanisms and risk.

OBJECTIVE: Automated Driving System (ADS) fleets are currently being deployed in several dense-urban operational design domains within the United States. In these dense-urban areas, pedestrians have historically comprised a significant portion, and sometimes the majority, of injury and fatal collisions. An expanded understanding of the injury risk in collision events involving pedestrians and human-driven vehicles can inform continued ADS development and safety benefits evaluation. There is no current systematic investigation of United States pedestrian collisions, so this study used reconstruction data from the German In-Depth Accident Study (GIDAS) to develop mechanistic injury risk models for pedestrians involved in collisions with vehicles. DATA SOURCE: The study queried the GIDAS database for cases from 1999 to 2021 involving passenger vehicle or heavy vehicle collisions with pedestrians. METHODS: We describe the injury patterns and frequencies for passenger vehicle-to-pedestrian and heavy vehicle-to-pedestrian collisions, where heavy vehicles included heavy trucks and buses. Injury risk functions were developed at the AIS2+, 3+, 4+ and 5+ levels for pedestrians involved in frontal collisions with passenger vehicles and separately for frontal collisions with heavy vehicles. Model predictors included mechanistic factors of collision speed, pedestrian age, sex, pedestrian height relative to vehicle bumper height, and vehicle acceleration before impact. Children (≤17 y.o.) and elderly (≥65 y.o.) pedestrians were included. We further conducted weighted and imputed analyses to understand the effects of missing data elements and of weighting towards the overall population of German pedestrian crashes. RESULTS: We identified 3,112 pedestrians involved in collisions with passenger vehicles, where 2,524 of those collisions were frontal vehicle strikes. Furthermore, we determined 154 pedestrians involved in collisions with heavy vehicles, where 87 of those identified collisions were frontal vehicle strikes. Children were found to be at higher risk of injury compared to young adults, and the highest risk of serious injuries (AIS 3+) existed for the oldest pedestrians in the dataset. Collisions with heavy vehicles were more likely to produce serious (AIS 3+) injuries at low speeds than collisions with passenger vehicles. Injury mechanisms differed between collisions with passenger vehicles and with heavy vehicles. The initial engagement caused 36% of pedestrians' most-severe injuries in passenger vehicle collisions, compared with 23% in heavy vehicles collisions. Conversely, the vehicle underside caused 6% of the most-severe injuries in passenger vehicle collisions and 20% in heavy vehicles collisions. SIGNIFICANCE: U.S. pedestrian fatalities have risen 59% since their recent recorded low in 2009. It is imperative that we understand and describe injury risk so that we can target effective strategies for injury and fatality reduction. This study builds on previous analyses by including the most modern vehicles, including children and elderly pedestrians, incorporating additional mechanistic predictors, broadening the scope of included crashes, and using multiple imputation and weighting to better estimate these effects relative to the entire population of German pedestrian collisions. This study is the first to investigate the risk of injury to pedestrians in collisions with heavy vehicles based on field data.