##common.pageHeaderLogo.altText##
DOI:
https://doi.org/10.57187/5264

Original article

Vol. 156 No. 10 (2026)

Performance of the Lausanne Ischemic Stroke Pathway prehospital triage system in identifying acute reperfusion candidates: a quality-control study

Cite this as:
Swiss Med Wkly. 2026;156:5264
Published
29.10.2026

Summary

BACKGROUND AND OBJECTIVE: Accurate identification is one of the cornerstones of prehospital care for patients with suspected acute ischaemic stroke (AIS). In the Lausanne Ischemic Stroke Pathway triage system, emergency medical service (EMS) providers use dedicated criteria to identify acute reperfusion candidates and call a coordinated medical team (CMT, including a neurologist and an emergency physician), which can activate the stroke code pathway. The objective of this study was to evaluate the performance of the system in identifying acute reperfusion candidates.

METHODS: This was a retrospective single-centre quality-control study conducted in a Swiss university-based stroke centre, from 1 January 2019 to 31 May 2022. Inclusion criteria were patients aged ≥18 years, for whom the EMS called the CMT or patients with AIS eligible for acute reperfusion managed by the EMS. The main outcomes were the performance of both the EMS and the CMT in detecting AIS patients eligible for acute reperfusion, as assessed through their respective under- and overtriage rates. A secondary outcome was the identification of alternative diagnoses in overtriaged patients.

RESULTS: Of 1071 patients included, the EMS phone-contacted the CMT for 937 (87.5%) of them. Among the 1071 patients, 440 (41%) had an AIS eligible for reperfusion. The system’s undertriage rate was 30% (133 patients without stroke pathway activation among the 440 patients with an AIS eligible for acute reperfusion). The undertriage rates were 21% for the EMS and 11% for the CMT. The overtriage rates were 63% for the EMS and 57% for the CMT. The main alternative diagnoses in overtriaged patients were seizures (14%), intracranial haemorrhages (9.9%) and functional disorders (6.5%).

CONCLUSION: Undertriage and overtriage rates were relatively high, but both were reduced by the CMT call, highlighting the added value of a second expert assessment step, with a higher level of expertise. Concerning overtriage, a better prehospital identification of alternative diagnoses, such as seizures or functional disorders, could help to better classify our patients.

References

  1. 1. Feigin VL, Brainin M, Norrving B, Martins S, Sacco RL, Hacke W, et al. World Stroke Organization (WSO): Global Stroke Fact Sheet 2022. International Journal of Stroke. 2022 Jan;17(1):18-29. doi:10.1177/17474930211065917
  2. 2. Emberson J, Lees KR, Lyden P, Blackwell L, Albers G, Bluhmki E, et al. Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials. The Lancet. 2014 Nov;384(9958):1929-1935. doi:10.1016/s0140-6736(14)60584-5
  3. 3. Saver JL, Goyal M, van der Lugt A, Menon BK, Majoie CBLM, Dippel DW. Time to Treatment With Endovascular Thrombectomy and Outcomes From Ischemic Stroke: A Meta-analysis. JAMA. 2016 Sep;316(12):1279–88.
  4. 4. Campbell BCV, Mitchell PJ, Churilov L, Yassi N, Kleinig TJ, Dowling RJ. Effect of Intravenous Tenecteplase Dose on Cerebral Reperfusion Before Thrombectomy in Patients With Large Vessel Occlusion Ischemic Stroke: The EXTEND-IA TNK Part 2 Randomized Clinical Trial. JAMA. 2020 Apr;323(13):1257–65.
  5. 5. Palaiodimou L, Sarraj A, Safouris A, Magoufis G, Lemmens R, Sandset EC, et al. Endovascular treatment for large-core ischaemic stroke: a meta-analysis of randomised controlled clinical trials. Journal of Neurology, Neurosurgery & Psychiatry. 2023 Oct;94(10):781-785. doi:10.1136/jnnp-2023-331513
  6. 6. Nogueira RG, Jovin TG, Liu X, Hu W, Langezaal LCM, Li C, et al. Endovascular therapy for acute vertebrobasilar occlusion (VERITAS): a systematic review and individual patient data meta-analysis. The Lancet. 2025 Jan;405(10472):61-69. doi:10.1016/s0140-6736(24)01820-8
  7. 7. Kleinig TJ, McMullan P, Cloud GC, Bladin PC, Ranta A. Hyper-Acute Stroke Systems of Care and Workflow. Current Neurology and Neuroscience Reports. 2024 Aug 16;24(10):495–505. doi:10.1007/s11910-024-01367-6
  8. 8. Powers WJ, Rabinstein AA, Ackerson T, Adeoye OM, Bambakidis NC, Becker K, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2019 Dec;50(12):e344–418. doi:10.1161/str.0000000000000211
  9. 9. Kobayashi A, Czlonkowska A, Ford GA, Fonseca AC, Luijckx GJ, Korv J, et al. European Academy of Neurology and European Stroke Organization consensus statement and practical guidance for pre‐hospital management of stroke. European Journal of Neurology. 2018 Mar;25(3):425-433. doi:10.1111/ene.13539
  10. 10. Acker JE, Pancioli AM, Crocco TJ, Eckstein MK, Jauch EC, Larrabee H, et al. Implementation Strategies for Emergency Medical Services Within Stroke Systems of Care. Stroke. 2007 Nov;38(11):3097-3115. doi:10.1161/strokeaha.107.186094
  11. 11. Michel P. Prehospital Scales for Large Vessel Occlusion. Stroke. 2017 Feb;48(2):247-249. doi:10.1161/strokeaha.116.015511
  12. 12. Pérez de la Ossa N, Abilleira S, Jovin TG, García-Tornel Á, Jimenez X, Urra X. Effect of Direct Transportation to Thrombectomy-Capable Center vs Local Stroke Center on Neurological Outcomes in Patients With Suspected Large-Vessel Occlusion Stroke in Nonurban Areas: The RACECAT Randomized Clinical Trial. JAMA. 2022 May;327(18):1782–94.
  13. 13. Dami F, Emery A, Pasquier M, Carron P, Fuchs V, Yersin B, et al. Proposition and operational characteristics of a new dispatch scale to specifically identify acute strokes. European Journal of Emergency Medicine. 2017 Jun;24(3):202-207. doi:10.1097/mej.0000000000000356
  14. 14. van Swieten JC, Koudstaal PJ, Visser MC, Schouten HJ, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients.. Stroke. 1988 May;19(5):604-607. doi:10.1161/01.str.19.5.604
  15. 15. Bonita R, Beaglehole R. Recovery of motor function after stroke.. Stroke. 1988 Dec;19(12):1497-1500. doi:10.1161/01.str.19.12.1497
  16. 16. Scheitz JF, Abdul-Rahim AH, MacIsaac RL, Cooray C, Sucharew H, Kleindorfer D, et al. Clinical Selection Strategies to Identify Ischemic Stroke Patients With Large Anterior Vessel Occlusion. Stroke. 2017 Feb;48(2):290-297. doi:10.1161/strokeaha.116.014431
  17. 17. Michel P, Diepers M, Mordasini P, Schubert T, Bervini D, Rouv J, et al. Revascularisation aiguë en cas d’accident vasculaire cérébral ischémique. Forum Médical Suisse ‒ Swiss Medical Forum. 2021 May 25;21:362–8. doi:10.4414/fms.2021.08584
  18. 18. Michel P, Odier C, Rutgers M, Reichhart M, Maeder P, Meuli R, et al. The Acute STroke Registry and Analysis of Lausanne (ASTRAL). Stroke. 2010 Nov;41(11):2491-2498. doi:10.1161/strokeaha.110.596189
  19. 19. Adams HP, Bendixen BH, Kappelle LJ, Biller J, Love BB, Gordon DL, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Trial of Org 10172 in Acute Stroke Treatment.. Stroke. 1993 Jan;24(1):35-41. doi:10.1161/01.str.24.1.35
  20. 20. Hatano S. Experience from a multicentre stroke register: a preliminary report. Bull World Health Organ. 1976;54(5):541–53.
  21. 21. Peng J, Xiang H. Trauma undertriage and overtriage rates: are we using the wrong formulas?. The American Journal of Emergency Medicine. 2016 Nov;34(11):2191-2192. doi:10.1016/j.ajem.2016.08.061
  22. 22. Duvekot MHC, Venema E, Rozeman AD, Moudrous W, Vermeij FH, Biekart M, et al. Comparison of eight prehospital stroke scales to detect intracranial large-vessel occlusion in suspected stroke (PRESTO): a prospective observational study. The Lancet Neurology. 2021 Mar;20(3):213-221. doi:10.1016/s1474-4422(20)30439-7
  23. 23. American College of Surgeons. ACS TQP Best Practices Guidelines [Internet]. Chicago (IL): American College of Surgeons. Available from: https://www.facs.org/quality-programs/trauma/quality/best-practices-guidelines/
  24. 24. Morris RS, Karam BS, Murphy PB, Jenkins P, Milia DJ, Hemmila MR, et al. Field-Triage, Hospital-Triage and Triage-Assessment: A Literature Review of the Current Phases of Adult Trauma Triage. Journal of Trauma and Acute Care Surgery. 2021 Jun;90(6):e138-e145. doi:10.1097/ta.0000000000003125
  25. 25. Glober NK, Fulks T, Supples M, Panagos P, Kim D. Factors Predicting Misidentification of Acute Ischemic Stroke and Large Vessel Occlusion by Paramedics. Critical Pathways in Cardiology: A Journal of Evidence-Based Medicine. 2022 Dec;21(4):172-175. doi:10.1097/hpc.0000000000000307
  26. 26. Medoro I, Cone DC. An Analysis of EMS and ED Detection of Stroke. Prehospital Emergency Care. 2017 Jul 4;21(4):476-480. doi:10.1080/10903127.2017.1294222
  27. 27. Abboud ME, Band R, Jia J, Pajerowski W, David G, Guo M, et al. Recognition of Stroke by EMS is Associated with Improvement in Emergency Department Quality Measures. Prehospital Emergency Care. 2016 Nov 1;20(6):729-736. doi:10.1080/10903127.2016.1182602
  28. 28. Hsieh M, Tang S, Chiang W, Tsai L, Jeng J, Ma MH. Effect of prehospital notification on acute stroke care: a multicenter study. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2016 Dec;24(1):57. doi:10.1186/s13049-016-0251-2
  29. 29. Mould-Millman N, Meese H, Alattas I, Ido M, Yi I, Oyewumi T, et al. Accuracy of Prehospital Identification of Stroke in a Large Stroke Belt Municipality. Prehospital Emergency Care. 2018 Nov 2;22(6):734-742. doi:10.1080/10903127.2018.1447620
  30. 30. Sartini M, Carbone A, Demartini A, Giribone L, Oliva M, Spagnolo AM, et al. Overcrowding in Emergency Department: Causes, Consequences, and Solutions—A Narrative Review. Healthcare. 2022 Aug 25;10(9):1625. doi:10.3390/healthcare10091625
  31. 31. Pearce S, Marchand T, Marr E, Shannon T, Lang E. Emergency department crowding: an overview of reviews describing measures causes, and harms. Canadian Journal of Emergency Nursing. 2023 May 11;46(1):4-5. doi:10.29173/cjen214
  32. 32. Rudd AG, Bladin C, Carli P, De Silva DA, Field TS, Jauch EC, et al. Utstein recommendation for emergency stroke care. International Journal of Stroke. 2020 Jul;15(5):555-564. doi:10.1177/1747493020915135
  33. 33. Duvekot MHC, Garcia BL, Dekker L, Nguyen TM, van den Wijngaard IR, de Laat KF, et al. Prehospital Stroke Triage: A Modeling Study on the Impact of Triage Tools in Different Regions. Prehospital Emergency Care. 2023 Jul 4;27(5):630-638. doi:10.1080/10903127.2023.2215859
  34. 34. Lupton JR, Davis-O'Reilly C, Jungbauer RM, Newgard CD, Fallat ME, Brown JB, et al. Under-Triage and Over-Triage Using the Field Triage Guidelines for Injured Patients: A Systematic Review. Prehospital Emergency Care. 2023 Jan 2;27(1):38-45. doi:10.1080/10903127.2022.2043963
  35. 35. Poncet C, Carron P, Darioli V, Zingg T, Ageron F. Prehospital undertriage of older injured patients in western Switzerland: an observational cross-sectional study. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 2024 Oct 8;32(1):100. doi:10.1186/s13049-024-01271-5
  36. 36. Bhatt NR, Frankel MR, Nogueira RG, Fleming C, Bianchi NA, Morgan O, et al. Reliability of Field Assessment Stroke Triage for Emergency Destination Scale Use by Paramedics: Mobile Stroke Unit First-Year Experience. Stroke. 2021 Aug;52(8):2530-2536. doi:10.1161/strokeaha.120.033775
  37. 37. Ali M, Dekker L, Daems JD, Ali M, van Zwet EW, Steyerberg EW. Sex Differences in Prehospital Identification of Large Vessel Occlusion in Patients With Suspected Stroke. Stroke. 2024 Mar;55(3):548–54.
  38. 38. Richoz B, Hugli O, Dami F, Carron P, Faouzi M, Michel P. Acute stroke chameleons in a university hospital. Neurology. 2015 Aug 11;85(6):505-511. doi:10.1212/wnl.0000000000001830
  39. 39. Moulin S, Leys D. Stroke mimics and chameleons. Current Opinion in Neurology. 2019 Feb;32(1):54-59. doi:10.1097/wco.0000000000000620
  40. 40. Bogle BM, Asimos AW, Rosamond WD. Regional Evaluation of the Severity-Based Stroke Triage Algorithm for Emergency Medical Services Using Discrete Event Simulation. Stroke. 2017 Oct;48(10):2827-2835. doi:10.1161/strokeaha.117.017905
  41. 41. Keselman B, Berglund A, Ahmed N, Grannas D, von Euler M, Holmin S, et al. Analysis and modelling of mistriage in the Stockholm stroke triage system. European Stroke Journal. 2022 Jun 1;7(2):126-133. doi:10.1177/23969873221077845
  42. 42. Keselman B, Berglund A, Ahmed N, Bottai M, von Euler M, Holmin S, et al. The Stockholm Stroke Triage Project: Outcomes of Endovascular Thrombectomy Before and After Triage Implementation. Stroke. 2022 Feb;53(2):473-481. doi:10.1161/strokeaha.121.034195

Most read articles by the same author(s)

1 2 > >>