1755 The differential determinants of delivering prehospital emergency anaesthesia within 45-minutes of the 999-call – a multi-centre, retrospective observational study

Aims, Objectives and Background Prehospital emergency anaesthesia (PHEA) is a necessary intervention for significant proportion of severely injured trauma patients. The National Institute Health Care Excellence (NICE) quality standards include delivery prehospital (PHEA), where indicated, ≤45-minutes the 999-call. aim this study was to report differential determinants meeting standard in large regional cohort Method Design A consecutive sample adult patients undergoing PHEA (2015–2020) at three Helicopter Emergency Medical Services (HEMS) East England. primary outcome 999-call; defined as duration between call ‘pick-up’ administration anaesthetic drugs. Data were extracted from all HEMS electronic medical records (HEMSbase, MedicOne Systems), combined. Variables included: dispatch type (immediate, interrogate, crew-request), demographics, time day (day/night), indication, pre-PHEA physiology. purposeful selection logistic regression model used R (a language environment statistical computing). Each variable first tested turn explore unadjusted association with outcome. Significant variables then included multivariable analysis. successively eliminated until only statistically remained. This service evaluation (EAAA 2021/025). Results Conclusion 1,155 outcome, ≤45-minute 999-call, achieved n=196 (17.0%) cases. data under construction. However, there signal that non-immediate type, older age, night-time operations are associated reduced likelihood delivering Less than one five receive 999-call project may positively influence systems order increase timely indicated (pending complete model).