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- Keselman, Boris, et al.
(author)
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Analysis and modelling of mistriage in the Stockholm stroke triage system
- 2022
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In: European Stroke Journal. - : Sage Publications. - 2396-9873 .- 2396-9881. ; 7:2, s. 126-133
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Journal article (peer-reviewed)abstract
- Introduction: The Stockholm Stroke Triage System (SSTS) is a prehospital triage system for detection of patients eligible for endovascular thrombectomy (EVT). Assessment of hemiparesis combined with ambulance-hospital teleconsultation is used to route patients directly to the thrombectomy centre. Some patients are not identified and require secondary transport for EVT (undertriage) while others taken to the thrombectomy centre do not undergo EVT (overtriage). The aims of this study were to characterize mistriaged patients, model for and evaluate alternative triage algorithms.Patients and methods: Patients with suspected stroke transported by priority 1 ground ambulance between October 2017 and October 2018 (n = 2905) were included. Three triage algorithms were modelled using prehospital data. Decision curve analysis was performed to calculate net benefit (correctly routing patients for EVT without increasing mistriage) of alternative models vs SSTS.Results: Undertriage for EVT occurred in n = 35/2582 (1.4%) and overtriage in n = 239/323 (74.0%). Compared to correct thrombectomy triages, undertriaged patients were younger and had lower median NIHSS (10 vs 18), despite 62.9% with an M1 occlusion. In overtriaged patients, 77.0% had a stroke diagnosis (29.7% haemorrhagic). Hemiparesis and FAST items face and speech were included in all models. Decision curve analysis showed highest net benefit for SSTS for EVT, but lower for large artery occlusion (LAO) stroke.Discussion: Undertriaged patients had lower NIHSS, likely due to better compensated proximal occlusions. SSTS was superior to other models for identifying EVT candidates, but lacked information allowing comparison to other prehospital scales.Conclusion: Using prehospital data, alternative models did not outperform the SSTS in finding EVT candidates.
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2. |
- Keselman, Boris, et al.
(author)
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The Stockholm Stroke Triage Project : Outcomes of Endovascular Thrombectomy Before and After Triage Implementation
- 2022
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In: Stroke. - : Lippincott Williams & Wilkins. - 0039-2499 .- 1524-4628. ; 53:2, s. 473-481
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: The Stockholm Stroke Triage System (SSTS) is a prehospital algorithm for detection of endovascular thrombectomy (EVT)-eligible patients, combining symptom severity assessment and ambulance-to-hospital teleconsultation, leading to a decision on primary stroke center bypass. In the Stockholm Region (6 primary stroke centers, 1 EVT center), SSTS implementation in October 2017 reduced onset-to-EVT time by 69 minutes. We compared clinical outcomes before and after implementation of SSTS in an observational study.METHODS: We prospectively recruited patients transported by Code Stroke ambulance within the Stockholm region under the SSTS, treated with EVT during October 2017 to October 2019, and compared to EVT patients from 2 previous years.OUTCOMES: shift in modified Rankin Scale (mRS) scores, mRS score 0 to 1, mRS score 0 to 2, and death (all 3 months), National Institutes of Health Stroke Scale (NIHSS) score change 24-hour post-EVT, recanalization (Thrombolysis in Cerebral Infarction 2b-3), and symptomatic intracranial hemorrhage. mRS outcomes were adjusted for age and baseline NIHSS.RESULTS: Patients with EVT in the SSTS group (n=244) were older and had higher baseline NIHSS versus historical controls (n=187): median age 74 (interquartile range, 63-81) versus 71 (61-78); NIHSS score 17 (11.5-21) versus 15 (10-20). During SSTS, median onset-to-puncture time was 136 versus 205 minutes (P<0.001). Adjusted common odds ratio for lower mRS in SSTS patients was 1.7 (95% CI, 1.2-2.3) versus controls. During SSTS, 83/240 (34.6%) versus 44/186 (23.7%) reached 3-month mRS score 0 to 1 (P=0.014), adjusted common odds ratio 2.3 (95% CI, 1.4-3.6). Median NIHSS change 24-hour post-EVT was 6 versus 4 (P=0.005). Differences in Thrombolysis in Cerebral Infarction, symptomatic intracranial hemorrhage, and death were nonsignificant.CONCLUSIONS: With an onset to arterial puncture time reduction by 69 minutes, outcomes in thrombectomy-treated patients improved significantly after region-wide large artery occlusion triage system implementation. These results warrant replication studies in other geographic and organizational circumstances.
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3. |
- Mathé, Jan M
(author)
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The phencyclidine model of schizophrenia : dysregulation of brain dopamine systems induced by NMDA receptor antagonists
- 1998
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Doctoral thesis (other academic/artistic)abstract
- Non-competitive NMDA receptor antagonists, such as phencyclidine (PCP) and dizocilpine (MK-801) can even acutely induce a drug induced psychotic state which closely resembles schizophrenia. The midbrain dopamine (DA) neurons, which originate in the ventral tegmental area (VTA), are involved in motivational, attentional and cognitive processes, and have also been profoundly implicated in schizophrenia. Therefore, the present work analyzed, in detail, the effects of these psychotomimetics on the mesocorticolimbic DA neurons in the rat and associated behavioral significance as well as potential reversal by different types of drugs; the objectives being to reveal potential pathophysiological mechanisms underlying psychotic states and to assist the development of improved pharmacotherapy in schizophrenia. DA neuronal activity was studied by means of single cell recordings in vivo and DA and neurotensin (NT) release in nerve terminal regions was assessed with microdialysis in freely moving animals coupled to HPLC and RIA methodology. Behavioral techniques included measurements of locomotor activity, conditioned avoidance response (CAR) and catalepsy. Systemic administration of PCP and MK-801 produced an increased firing rate and decreased variability of firing in DA neurons. Burst firing was differentially affected in different subpopulations of VTA DA cells. A high frequency, burst-like firing pattern was obtained in neurons projecting to subcortical sites, e.g. to the nucleus accumbens (NAC). In contrast, burst firing was attenuated in DA cells which largely project to the medial prefrontal cortex (MPFC). PCP increased release of DA and the colocalized peptide NT in both the ventral striatum and the MPFC. The MK-801 evoked DA output in the NAC was blocked by inhibition of DA nerve impulse generation or by local antagonism of AMPA and kainate receptors in the VTA, a procedure which also blocked the locomotor stimulation. The MK-801 evoked DA output in the MPFC was, in contrast, not affected by inhibition of nerve impulses in the VTA. Pretreatment with the [alpha]1-adrenoceptor antagonist prazosin also antagonized the MK-801 induced increase in DA output in the NAC, and associated locomotor stimulation. Finally, systemic administration of the AMPA receptor antagonist LY326325 was found to specifically suppress the CAR without affecting escape behavior, and did not cause catalepsy. PCP and MK-801 thus profoundly dysregulate mesocortical and mesolimbic DA neurons in a differential manner. The drugs cause a pronounced augmentation of mesocortical DA output, that is independent of nerve impulse activity, and is instead mediated at the nerve terminal level. In contrast, a nerve impulse dependent increase in mesolimbic DA output is obtained by systemic MK-801, that seems elicited in the VTA by AMPA and/or kainate receptor activation. Since both the [alpha]1-adrenoceptor antagonist and the AMPA receptor antagonist effectively reversed several of the behavioral and biochemical correlates to dysregulated mesocorticolimbic DA system induced by PCP-like drugs, an antipsychotic potential of both types of drugs is indicated, especially as shown by the suppression of CAR by LY326325.
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4. |
- Mazya, Michael V., et al.
(author)
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Implementation of a Prehospital Stroke Triage System Using Symptom Severity and Teleconsultation in the Stockholm Stroke Triage Study
- 2020
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In: JAMA Neurology. - : American Mathematical Society (AMS). - 2168-6149 .- 2168-6157. ; 77:6, s. 691-699
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Journal article (peer-reviewed)abstract
- Importance: To our knowledge, it is unknown whether a prehospital stroke triage system combining symptom severity and teleconsultation could accurately select patients for primary stroke center bypass and hasten delivery of endovascular thrombectomy (EVT) without delaying intravenous thrombolysis (IVT).Objective: To evaluate the predictive performance of the newly implemented Stockholm Stroke Triage System (SSTS) for large-artery occlusion (LAO) stroke and EVT initiation. Secondary objectives included evaluating whether the Stockholm Stroke Triage System shortened onset-to-puncture time for EVT and onset-to-needle time (ONT) for IVT.Design, Setting, and Participants: This population-based prospective cohort study conducted from October 2017 to October 2018 across the Stockholm region (Sweden) included patients transported by first-priority ("code stroke") ambulance to the hospital for acute stroke suspected by an ambulance nurse and historical controls (October 2016-October 2017). Exclusion criteria were in-hospital stroke and helicopter or private transport. Of 2909 eligible patients, 4 (0.14%) declined participation.Exposures: Patients were assessed by ambulance nurses with positive the face-arm-speech-time test or other stroke suspicion and were evaluated for moderate-to-severe hemiparesis (≥2 National Institutes of Health stroke scale points each on the ipsilateral arm and leg [A2L2 test]). If present, the comprehensive stroke center (CSC) stroke physician was teleconsulted by phone for confirmation of stroke suspicion, assessment of EVT eligibility, and direction to CSC or the nearest primary stroke center. If absent, the nearest hospital was prenotified.Main Outcomes and Measures: Primary outcome: LAO stroke. Secondary outcomes: EVT initiation, onset-to-puncture time, and ONT. Predictive performance measures included sensitivity, specificity, positive and negative predictive values, the overall accuracy for LAO stroke, and EVT initiation.Results: We recorded 2905 patients with code-stroke transports (1420 women [49%]), and of these, 323 (11%) had A2L2+ teleconsultation positive results and were triaged for direct transport to CSC (median age, 73 years [interquartile range (IQR), 64-82 years]; 55 women [48%]). Accuracy for LAO stroke was 87% (positive predictive value, 41%; negative predictive value, 93%) and 91% for EVT initiation (positive predictive value, 26%; negative predictive value, 99%). Endovascular thrombectomy was performed for 84 of 323 patients (26%) with triage-positive results and 35 of 2582 patients (1.4%) with triage-negative results. In EVT cases with a known onset time (77 [3%]), the median OPT was 137 minutes (IQR, 118-180; previous year, 206 minutes [IQR, 160-280]; n = 75) (P < .001). The regional median ONT (337 [12%]) was unchanged at 115 minutes (IQR, 83-164; previous year, 115 minutes [IQR, 85-161]; n = 360) (P = .79). The median CSC IVT door-to-needle time was 13 minutes (IQR, 10-18; 116 [4%]) (previous year, 31 minutes [IQR, 19-38]; n = 45) (P < .001).Conclusions and Relevance: The Stockholm Stroke Triage System, which combines symptom severity and teleconsultation, results in markedly faster EVT delivery without delaying IVT.
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