Stroke and the emergency medical services : enhancing performance within the chain of survival

Tuukka Puolakka

Research output: ThesisDoctoral ThesisCollection of Articles


Ischaemic stroke is an important cause of death and disability worldwide. The occluded cerebral artery can be opened using recanalization therapy, but only within the first few hours after symptom onset. Early hospital admission is therefore essential. The aim of this thesis was to describe the current performance of the Finnish emergency medical service (EMS) system in prehospital stroke care and explore new innovations to improve it. The thesis was based on the analysis of emergency phone call tapes, prehospital patient reports and in-hospital data. The emergency medical dispatchers used the stroke code in more than 60% of the calls and dispatched more than 80% of the ambulances with high priority. The paramedics suspected less than 90% of the patients to have stroke symptoms and transported the patients using the high priority designation at nearly the same frequency. The prehospital time intervals of patients who received recanalization treatment were analysed sequentially. Both the door-to-needle time (DTT) and onset-to-treatment time (OTT) were significantly reduced during the study period, which was reciprocated by the increasing number of treated patients, but none of the prehospital time intervals [onset-to-door time (ODT), onset-to-dispatch time, transportation time] changed appreciably. Ambulance transport using high priority and onset-to-call time duration were the most significant predictors of early hospital arrival (ODT 2h) was the onset-to-call time (41 minutes), the single most dominant operational variable in the mean additional delays was OST, with >2 minutes of added delay. Using fire engines to support ambulances in prehospital stroke care more than doubled the number of EMS personnel on the scene but no change in on-scene time (OST) or other prehospital time intervals was observed. Only the use of stroke code in ambulance dispatch was associated with a short OST (
Original languageEnglish
Place of PublicationHelsinki
Print ISBNs978-951-51-2913-0
Electronic ISBNs978-951-51-2914-7
Publication statusPublished - 2017
MoE publication typeG5 Doctoral dissertation (article)

Fields of Science

  • 3112 Neurosciences
  • 3124 Neurology and psychiatry
  • 3126 Surgery, anesthesiology, intensive care, radiology

Cite this