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Ambulance waiting and associated work flow improvement strategies: a pilot study to improve door-in-door-out time for thrombectomy patients in a primary stroke center
  1. Eva Gaynor1,
  2. Emma Griffin2,3,
  3. John Thornton2,
  4. Jack Alderson2,
  5. Mary Martin4,
  6. Anne O'Driscoll4,
  7. Patricia Daly4,
  8. Cathal O'Donnell5,
  9. Ronan Conroy6,
  10. Paul O'Brien4
  1. 1 Department of Medicine, Naas General Hospital, Naas, Ireland
  2. 2 Department of Neuroradiology, Beaumont Hospital, Dublin, Ireland
  3. 3 Royal College of Surgeons, Dublin, Ireland
  4. 4 Department of Geriatric and Stroke Medicine, Naas General Hospital, Naas, Kildare, Ireland
  5. 5 National Ambulance Service, HSE National Ambulance Service, Dublin, Ireland
  6. 6 Department of Health Research Methods, Royal College of Surgeons in Ireland, Dublin, Ireland
  1. Correspondence to Dr Emma Griffin, Department of Neuroradiology, Beaumont Hospital, Dublin 9, Ireland; emma.griffin.2{at}


Background Rapid access to thrombectomy for patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) is critical for improving outcome. A major challenge for the ‘drip and ship’ model is reducing the door-in-door-out time (DIDO). We propose a new protocol with the aim of reducing DIDO, without adversely affecting emergency service usage time.

Methods Consecutive patients with suspected LVO AIS admitted to a Primary Stroke Center (PSC) from October 2018 to January 2021 were included. On arrival, the ambulance crew remained with the patient. Following immediate clinical and radiological evaluation, patients were transferred to the Comprehensive Stroke Center (CSC) by the same waiting crew. Key time metrics were collected and compared with historical data prior to the new protocol.

Results 27 patients had an LVO amenable for mechanical thrombectomy during the time period. There was a significant reduction in the DIDO times compared with the historical group (median 45 min vs 96 min; p<0.0001). There was no significant difference in ambulance usage time between the two time periods (median 53 min vs 45 min; p=0.530). There was an increase in ambulance usage time in FAST-positive patients not for transfer in the pilot group compared with FAST-positive patients not for transfer in the historical group (27 min vs 58 min; p<0.001). In addition, door-to-needle times (24 min vs 40 min; p=0.018) and door-to-CT times (11 min vs 25 min; p<0.0001) improved between the two groups.

Conclusion Our data show a significant reduction in the DIDO for patients transferred for thrombectomy, with no adverse effects on ambulance usage time.

  • stroke
  • thrombectomy
  • CT angiography

Data availability statement

Data are available upon reasonable request. Data are available upon reasonable request.

Statistics from

Data availability statement

Data are available upon reasonable request. Data are available upon reasonable request.

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  • EGa and EGr are joint first authors.

  • EGa and EGr contributed equally.

  • Contributors All authors made the following contributions: (1) Substantial contributions to the conception and design of the work. (2) Drafting and revision of the work. (3) Final approval of the version to be published. (4) Agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests EG and JA received funding from Medtronic during the course of this trial.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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