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Predicting the need for extrication in traffic accidents reported to 911: Is anyone pinned/trapped?


Extrication activities at the scene of motor vehicle accidents (MVA) result in extended scene times and increase morbidity and mortality. Identifying the need for extrication-capable resources during the 911 call-taking process, and dispatching them without delay, is crucial to delivering the required response and patient care. Determining the need for extrication using the Traffic/Transport Incidents Protocol in the Medical Priority Dispatch System (MPDS®) currently relies on the 911 caller’s answer to a single key question in the protocol: “Is anyone pinned (trapped)?”

The aim of this study was to evaluate how accurate current 911 practices are in recognizing pins and entrapments resulting from MVAs. Additionally, the study sought to identify whether a Head-On (HO) MVA or an MVA with Semi-Tractor Trailer (Semi) involvement should warrant the immediate assignment of specialized extrication resources.

This was a retrospective descriptive study of all MVA cases in three Kansas counties (Butler, Sedgwick, and Johnson), encountered from January 1, 2016, through June 30, 2017. 911 calltakers in the study population utilize the MPDS Protocols to triage MVA calls. Traffic accident data was extracted from ProQA and matched with CAD records.

A total of 985 calls were analyzed, of which 218 (22.1%) required extrication and 267 (27.1%) involved Semi/HO—as documented by responders. Of the 218 cases that required extrication, 123 (56.4%) were reported pinned at dispatch and 21 (9.6%) involved Semi/head-on—15 of which were already captured by the pinned Key Question. Of the 267 cases that involved a Semi/HO, 21 (7.9%) required extrication. Of the cases that were initially reported pinned at dispatch, 123 (32.3%) required extrication by responders; and of the cases initially reported not pinned at dispatch, 59 (11.4%) required extrication by responders.

A “yes” answer to the protocol key question “Is anyone pinned (trapped)?” is a better predictor of extrication by responders for MVAs than is the presence of Semi/head-on involvement. Further research should examine whether High Mechanism and Major Incident determinant suffixes will capture additional extrication incidents.


Davis, C., Dodson, P., Pore, C., Sangaraju, S., Broadbent, M., Scott, G., Gardett, I., & Olola, C. (2018). Predicting the need for extrication in traffic accidents reported to 911: Is anyone pinned/trapped? Annals of Emergency Dispatch and Response, 6(3), 5-9.

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Last Updated: 12/12/23