Reliability of Field Assessment Stroke Triage for Emergency Destination Scale Use by Paramedics: Mobile Stroke Unit First-Year Experience

Mobile stroke units: Beyond thrombolysis

In the last decade, mobile stroke units (MSUs) have shown the potential to transform prehospital stroke care, marking a paradigm shift in delivering ultra-rapid thrombolysis and streamlining triage processes. These units bring acute stroke care directly to patients, significantly shortening treatment times. This review outlines the rationale for MSU care and discusses the potential applications beyond the original purpose of delivering thrombolysis, including large vessel occlusion detection, intracerebral hemorrhage management, and innovative forms of prehospital research.

Diagnostic Accuracy of Posterior Circulation Stroke by Paramedics: A Systematic Review

OBJECTIVE

This systematic review aims to identify the diagnostic accuracy of posterior circulation stroke (PCS) by paramedics and the causes and duration of delay in its recognition.

METHODS

A systematic search using CINAHL Plus, MEDLINE, Scopus, and PubMed was performed. All databases were searched up to May 25, 2022. Studies were included where patients were adults, assessed by paramedics, and PCS was the primary diagnosis. Bias was assessed using the Newcastle-Ottawa Scale and the Effective Practice and Organization of Care tool. Results have been described by proportions, and both sensitivity calculations and subgroup analysis were performed utilizing MedCalc.

RESULTS

A total of 797 titles/abstracts and a subsequent 87 full texts were screened, of which 15 were included. There were 5395 patients who were assessed by paramedics and had a confirmed diagnosis of PCS. Among five studies containing both true positive and false negative data, there were 98 (45.8%) true positives. PCS patients lost an average of 27 min (p < 0.001) compared to anterior stroke patients in the prehospital setting. One study revealed that educational intervention, including implementing the finger-to-nose test, increased the sensitivity for diagnosis from 45.8 to 74.1% (p = 0.039) and decreased the time from door to computed tomography from 62 to 41 min (p = 0.037).

CONCLUSION

There is a substantial lack of evidence regarding the diagnosis of PCS by paramedics. Despite the low quality of evidence available, overall, the sensitivity for paramedic PCS diagnosis appears to be poor. Further investigation is required into paramedics' diagnosis of PCS and the use of educational interventions.Prospective Register of Systematic Reviews Registration Number: CRD42022324675.

Comparison of Prehospital Assessment by Paramedics and In-Hospital Assessment by Physicians in Suspected Stroke Patients: Results From 2 Prospective Cohort Studies

BACKGROUND

It is unknown if ambulance paramedics adequately assess neurological deficits used for prehospital stroke scales to detect anterior large-vessel occlusions. We aimed to compare prehospital assessment of these stroke-related deficits by paramedics with in-hospital assessment by physicians.

METHODS

We used data from 2 prospective cohort studies: the LPSS (Leiden Prehospital Stroke Study) and PRESTO study (Prehospital Triage of Patients With Suspected Stroke). In both studies, paramedics scored 9 neurological deficits in stroke code patients in the field. Trained physicians scored the National Institutes of Health Stroke Scale (NIHSS) at hospital presentation. Patients with transient ischemic attack were excluded because of the transient nature of symptoms. Spearman rank correlation coefficient (rs) was used to assess correlation between the total prehospital assessment score, defined as the sum of all prehospital items, and the total NIHSS score. Correlation, sensitivity and specificity were calculated for each prehospital item with the corresponding NIHSS item as reference.

RESULTS

We included 2850 stroke code patients. Of these, 1528 had ischemic stroke, 243 intracranial hemorrhage, and 1079 stroke mimics. Correlation between the total prehospital assessment score and NIHSS score was strong (rs=0.70 [95% CI, 0.68-0.72]). Concerning individual items, prehospital assessment of arm (rs=0.68) and leg (rs=0.64) motor function correlated strongest with corresponding NIHSS items, and had highest sensitivity (arm 95%, leg 93%) and moderate specificity (arm 71%, leg 70%). Neglect (rs=0.31), abnormal speech (rs=0.50), and gaze deviation (rs=0.51) had weakest correlations. Neglect and gaze deviation had lowest sensitivity (52% and 66%) but high specificity (84% and 89%), while abnormal speech had high sensitivity (85%) but lowest specificity (65%).

CONCLUSIONS

The overall prehospital assessment of stroke code patients correlates strongly with in-hospital assessment. Prehospital assessment of neglect, abnormal speech, and gaze deviation differed most from in-hospital assessment. Focused training on these deficits may improve prehospital triage.

Prehospital stroke management and mobile stroke units

PURPOSE OF REVIEW

Delayed presentation at the hospital contributes to poorer patient outcomes and undertreatment of acute stroke patients. This review will discuss recent developments in prehospital stroke management and mobile stroke units aimed to improve timely access to treatment within the past 2 years and will point towards future directions.

RECENT FINDINGS

Recent progress in research into prehospital stroke management and mobile stroke units ranges from interventions aimed at improving patients' help-seeking behaviour, to the education of emergency medical services team members, to the use of innovative referral methods, such as diagnostic scales, and finally to evidence of improved outcomes by the use of mobile stroke units.

SUMMARY

Understanding is increasing about the need for optimizing stroke management over the entire stroke rescue chain with the goal of improving access to highly effective time-sensitive treatment. In the future, we can expect that novel digital technologies and artificial intelligence will become relevant in effective interaction between prehospital and in-hospital stroke-treating teams, with beneficial effects on patients' outcomes.

Assessment of Clinical Scales for Detection of Large Vessel Occlusion in Ischemic Stroke Patients from the Dijon Stroke Registry

(1) Background: The limited availability of thrombectomy-capable stroke centres raises questions about pre-hospital triage of patients with suspected stroke (IS) due to large vessel occlusion (LVO). Aims: This study aimed to evaluate the diagnostic accuracy of clinical stroke severity scales available for LVO detection. (2) Methods: Patients with IS were prospectively identified among residents of Dijon, France, using a population-based registry (2013–2017). Clinical signs and arterial imaging data were collected. LVO was defined as an occlusion site affecting the terminal intracranial internal carotid artery, the M1 segment of the middle cerebral artery (MCA), or the basilar artery (restricted definition). A wide definition of LVO also included the M2 segment of the MCA. For each of the 16 evaluated scales, a receiver operator characteristic (ROC) analysis was performed, and the c-statistic representing the area under the ROC curve was evaluated to assess discrimination for predicting LVO. (3) Results: 971 patients were registered, including 123 patients (12.7%) with an LVO according to the restricted definition. The c-statistic for LVO detection ranged between 0.66 and 0.80 according to the different scales, with a sensibility varying from 70% to 98% and a specificity from 33% to 86%. According to the wide definition of LVO (174 patients, 17.9%), the c-statistic was slightly lower, ranging between 0.64 and 0.79. The sensitivity was 59% to 93%, and the specificity was 34% to 89%. (4) Conclusion: The clinical scales failed to combine a high sensitivity and a high specificity to detect LVO. Further studies are needed to determine the best strategy for pre-hospital triage of IS patients.

Telemedicine-enabled ambulances and mobile stroke units for prehospital stroke management

The recognition and management of stroke in the prehospital setting has become increasingly important to improve patient outcomes. Several strategies to advance prehospital stroke care have been developed, including the mobile stroke unit and the telemedicine-enabled ambulance-or "mini-MSU." These strategies both incorporate ambulance-based audio-visual telemedicine evaluation with a vascular neurologist to facilitate faster treatment but differ in several areas including upfront and recurring costs, scalability or growth potential, ability to integrate into existing emergency medical services systems, and interoperability across multiple specialties or conditions. While both the mobile stroke unit and mini-mobile stroke unit model are valid approaches to improve stroke care, the authors aim to compare these models based on costs, scalability, integration, and interoperability in order to guide our prehospital leaders to find the best solutions for their communities.

[Border areas of thrombectomy]

Mechanical thrombectomy (MT) has become the standard procedure in the treatment of patients with acute ischemic stroke (AIS) due to occlusion of a large proximal cerebral artery of the anterior circulation. Nevertheless, according to the current guidelines large patient collectives are still excluded from this highly effective treatment method. Therefore, this article gives an overview of possible extensions of the indications for treatment with MT. For example, patients in the extended time window with distal occlusions, with large infarct cores and also for very old (90+ years) or young (0-17 years) patients. Furthermore, we discuss recent developments in the interventional treatment of stroke, such as new triage concepts or the question whether an additional intravenous thrombolysis is necessary in patients with MT. We conclude with our own estimations for the discussed indications for treatment based on our clinical experience and the current literature.