Time intervals and distances travelled for prehospital ambulance stroke care: data from the randomised-controlled ambulance-based Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2)

Dixon, Mark; Appleton, Jason P.; Scutt, Polly; Woodhouse, Lisa J.; Haywood, Lee J.; Havard, Diane; Williams, Julia; Siriwardena, A. Niroshan; Bath, Philip M.

Abstract

Objectives
Ambulances offer the first opportunity to evaluate hyperacute stroke treatments. We investigated the conduct of a hyperacute stroke study in the ambulance-based setting with a particular focus on timings and logistics of trial delivery.

Design
Multicentre prospective, single-blind, parallel group randomised controlled trial.

Setting
Eight NHS ambulance services in England and Wales; 54 acute stroke centres.

Participants
Paramedics enrolled 1,149 patients with likely stroke, face, arm speech (2 or 3), within four hours of symptom onset and systolic BP>120mmHg.

Interventions
Paramedics administered randomly assigned active transdermal glyceryl trinitrate or sham.

Primary and Secondary Outcomes
Modified Rankin scale at day-90. This paper focuses on response time intervals, distances travelled and baseline characteristics of patients, compared between ambulance services.

Results
Paramedics enrolled 1,149 patients between September 2015 and May 2018. Final diagnosis: intracerebral haemorrhage 13%, ischaemic stroke 52%, TIA 9%, mimic 26%. Timings (minutes) were (median [25, 75 centile]): onset to emergency call 19 [5, 64]; onset to randomisation 71 [45, 116]; total time at scene 33 [26, 46]; depart scene to hospital 15 [10, 23]; randomisation to hospital 24 [16, 34] and onset to hospital 97 [71, 141]. Ambulances travelled (km) 10 [4, 19] from scene to hospital. Timings and distances differed between ambulance service, e.g. onset to randomisation (fastest 53, slowest 77 minutes; p<0.001), distance from scene to hospital (least 4, most 20 km; p<0.001).

Conclusion
We completed a large pre-hospital stroke trial involving a simple-to-administer intervention across multiple ambulance services. The time from onset to randomisation and modest distances travelled support the applicability of future large-scale paramedic-delivered ambulance-based stroke trials in urban and rural locations.

Citation

Dixon, M., Appleton, J. P., Scutt, P., Woodhouse, L. J., Haywood, L. J., Havard, D., …Bath, P. M. (2022). Time intervals and distances travelled for prehospital ambulance stroke care: data from the randomised-controlled ambulance-based Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2). BMJ Open, 12(11), Article e060211. https://doi.org/10.1136/bmjopen-2021-060211

• Journal Article Type: Article
• Acceptance Date: Sep 19, 2022
• Online Publication Date: Nov 21, 2022
• Publication Date: Nov 21, 2022
• Deposit Date: Sep 21, 2022
• Publicly Available Date: Sep 21, 2022
• Journal: BMJ Open
• Electronic ISSN: 2044-6055
• Publisher: BMJ Publishing Group
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 11
• Article Number: e060211
• DOI: https://doi.org/10.1136/bmjopen-2021-060211
• Public URL: https://nottingham-repository.worktribe.com/output/11466850
• Publisher URL: https://bmjopen.bmj.com/content/12/11/e060211