Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) study protocol: a stepped wedge randomised trial of stroke screening using the National Institutes of Health Stroke Scale in the ambulance

Prehospital stroke diagnostics using three different simulation methods: A pragmatic pilot study

INTRODUCTION

The optimal pathway for ultra-early diagnostics and treatment in patients with acute stroke remains uncertain. The aim of this study was to investigate how three different methods of simulated, rural prehospital computed tomography (CT) affected the time to prehospital treatment decision in acute stroke.

MATERIALS AND METHODS

In this pragmatic, simulation, pilot study of prehospital CT we investigated a conventional ambulance with transport to a standard care rural stationary CT machine managed by paramedics, a Mobile Stroke Unit (MSU), and a helicopter with a simulated CT machine. Each modality completed 20 real-life dispatches combined with simulation of predetermined animated patient cases with acute stroke symptoms and CT images. The primary endpoint of the study was the time from alarm to treatment decision.

RESULTS

Median time from alarm to the treatment decision differed significantly between the three groups (p = 0.0005), with 38 min for rural CT, 33 min for the MSU, and 30 min for the helicopter. There was no difference in time when comparing rural CT with MSU, nor when comparing the MSU with the helicopter. There was a difference in time to treatment decision between the rural CT and the helicopter (p < 0.0001). The helicopter had significantly lower estimated time from treatment decision to hospital (p = 0.001).

DISSCUSSION/CONCLUSION

Prehospital CT can be organized in several ways depending on geography, resources and need. Further research on paramedic run rural CT, MSU in rural areas, and helicopter CT is needed to find the optimal strategy.

Remote neurological evaluation reliably identifies patients eligible to endovascular therapy while non-eligible to intravenous thrombolysis

INTRODUCTION/BACKGROUND

Early identification of suspected stroke patients who might be eligible for a reperfusion strategy is a daily challenge in the management of patient referrals. The aim of this study was to evaluate the performance of a remote medical assessment in identifying patients eligible for endovascular therapy (EVT) while not eligible for intravenous thrombolysis (IVT), compared with a decision based on bedside clinico-radiological data.

METHODS

Patients admitted to the emergency department for acute neurological symptoms lasting for less than 24h were prospectively included. Assessment of the clinical severity and medical history was performed simultaneously by two vascular neurologists (VNs), one remotely using a mobile telemedicine solution (NOMADEEC), the other at the bedside. RACE score was calculated from the NIHSS score. At the end of the evaluation, both VNs quoted their treatment convictions (IVT/EVT). Final therapeutic decision following brain and vascular imaging was recorded and compared to remote and bedside predictions. The performances of three different conditions were evaluated: complete medical evaluation (NIHSS+medical history), NIHSS score alone, and RACE score alone. Remote and bedside performances were also compared. Diagnostic accuracy parameters (sensitivity, specificity, positive and negative predictive values) of each condition were estimated, along with their two-sided 95% binomial confidence intervals.

RESULTS

Out of 215 enrolled patients, 186 had a complete evaluation, 91 (54.3%) were diagnosed with an ischemic stroke or transient ischemic attack and 46 (24.7%) had an intracranial occlusion. Considering the three conditions evaluated remotely, RACE score-based decision provided the best sensitivity 54.6% [95% CI 23.4; 83.2]/specificity 80.6% [73.9; 86.2] combination. However, the complete medical evaluation had the best specificity (88.6% [82.9; 92.9] compared to RACE scores alone (P=0.038). Remote and bedside performances did not differ (κ=0.68 [0.59; 0.77]).

DISCUSSION/CONCLUSION

This real-life study performed in the setting of emergency demonstrates that remote medical evaluations including recording of extensive medical information and NIHSS examination to address patient's eligibility to revascularization treatment is swiftly feasible and is as effective as bedside prediction to EVT and/or IVT. Remote standardized medical evaluation might improve the decision of patients' primary orientation and avoid overcrowding of comprehensive stroke centres.

Experiences from a cluster-randomized trial (ParaNASPP) exploring triage and diagnostic accuracy in paramedic-suspected stroke: a qualitative interview study

BACKGROUND AND PURPOSE

Timely prehospital stroke recognition was explored in the Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) by implementation of stroke education for paramedics and use of the National Institutes of Health Stroke Scale (NIHSS) through a mobile application. The study tested triage and facilitated communication between paramedics and stroke physicians. To complement the quantitative results of the clinical trial, a qualitative approach was used to identify factors that influence triage decisions and diagnostic accuracy in prehospital stroke recognition experienced by paramedics and stroke physicians.

METHOD

Semi-structured qualitative individual interviews were performed following an interview guide. Informants were recruited from the enrolled paramedics and stroke physicians who participated in the ParaNASPP trial from Oslo University Hospital. Interviews were audio recorded, transcribed verbatim and approached inductively using the principles of thematic analysis.

RESULTS

Fourteen interviews were conducted, with seven paramedics and seven stroke physicians. Across both groups two overarching themes were identified related to triage decisions and diagnostic accuracy in prehospital stroke recognition: prehospital NIHSS reliably improves clinical assessment and communication quality; overtriage is widely accepted whilst undertriage is not.

CONCLUSION

Paramedics and stroke physicians described how prehospital NIHSS improved communication quality and reliably improved prehospital clinical assessment. The qualitative results support a rationale of an application algorithm to decide which NIHSS items should prompt immediate prenotification rather than a complete NIHSS as default.

Prehospital identification of acute ischaemic stroke with large vessel occlusion: a retrospective study from western Norway

BACKGROUND

In 2019, the emergency medical services (EMS) covering the western Norway Regional Health Authority area implemented its version of the prehospital clinical criteria G-FAST (Gaze deviation, Facial palsy, Arm weakness, Visual loss, Speech disturbance) to detect acute ischaemic stroke (AIS) with large vessel occlusion (LVO). For patients with gaze deviation and at least one other G-FAST symptom, a primary stroke centre (PSC) may be bypassed and the patient taken directly to a comprehensive stroke centre (CSC) for rapid endovascular treatment (EVT) evaluation. The study aim was to investigate the efficacy of the G-FAST criteria for LVO patient selection and direct transfer to a CSC.

METHODS

This retrospective study included patients with code-red emergency medical communication centre (EMCC) stroke suspicion ambulance dispatch between August to December 2020. Stroke suspicion was defined as having at least one G-FAST symptom at EMS arrival. We obtained patient data from dispatches from EMCCs, EMS records and local EVT registries. Clinical features, CT images, and reperfusion treatment were recorded. The test characteristics for gaze deviation plus one other G-FAST symptom in detecting LVO were determined.

RESULTS

Among 643 patients, 59 were diagnosed with LVO at hospital arrival. In this group, seven fulfilled the G-FAST criteria for direct transport to a CSC at EMS arrival on scene, resulting in a sensitivity of 12% (95% CI 5% to 23%). The specificity was 99.66% (95% CI 98.77% to 99.96%), the positive predictive value 78%, and the negative predictive value 92%. EVT was performed in 64% (38/59) of LVO cases. Median time from PSC arrival to start of EVT at a CSC was 163 min.

CONCLUSION

The use of local G-FAST prehospital criteria by EMS personnel to identify patients with AIS with LVO is not suitable for selection of patients with LVO for direct transfer to a CSC.

Telephone triage and dispatch of ambulances to patients with suspected and verified acute stroke - a descriptive study

OBJECTIVES

In this study we aimed to explore EMCC triage of suspected and confirmed stroke patients to gain more knowledge about the initial phase of the acute stroke response chain. Accurate dispatch at the Emergency Medical Communication Center (EMCC) is crucial for optimal resource utilization in the prehospital service, and early identification of acute stroke is known to improve patient outcome.

MATERIALS AND METHODS

We conducted a descriptive retrospective study based on data from the Emergency Department and EMCC records at a comprehensive stroke center in Oslo, Norway, during a six-month period (2019-2020). Patients dispatched with EMCC stroke criteria and/or discharged with a stroke diagnosis were included. We identified EMCC true positive, false positive and false negative stroke patients and estimated EMCC stroke sensitivity and positive predictive value (PPV). Furthermore, we analyzed prehospital time intervals and identified patient destinations to gain knowledge on ambulance services assessments.

RESULTS

We included 1298 patients. EMCC stroke sensitivity was 77% (95% CI: 72 - 82%), and PPV was 16% (95% CI: 14 - 18%). EMCC false negative stroke patients experienced an increased median prehospital delay of 11 min (p < 0.001). Upon arrival at the scene, 68% of the EMCC false negative patients were identified as suspected stroke cases by the ambulance services. Similarly, 68% of the false positive stroke patients were either referred to a GP, out-of-hours GP acute clinic, local hospitals or left at the scene by the ambulance services, indicating that no obvious stroke symptoms were identified by ambulance personnel upon arrival at the scene.

CONCLUSIONS

This study reveals a high EMCC stroke sensitivity and an extensive number of false positive stroke dispatches. By comparing the assessments made by both the EMCC and the ambulance service, we have identified specific patient groups that should be the focus for future research efforts aimed at improving the sensitivity and specificity of stroke recognition in the EMCC.

Application of Telemedicine in the Ambulance for Stroke Patients: A Systematic Review

INTRODUCTION

The use of telemedicine for the prehospital management of emergency conditions, especially stroke, is increasing day by day. Few studies have investigated the applications of telemedicine in Emergency Medical Services (EMS). A comprehensive study of the applications of this technology in stroke patients in ambulances can help to build a better understanding. Therefore, this systematic review was conducted to investigate the use of telemedicine in ambulances for stroke patients in 2023.

METHODS

A systematic search was conducted in PubMed, Cochrane, Scopus, ProQuest, Science Direct, and Web of Science from 2013 through March 1, 2023. The authors selected the articles based on keywords and criteria and reviewed them in terms of title, abstract, and full text. Finally, the articles that were related to the study aim were evaluated.

RESULTS

The initial search resulted in the extraction of 2,795 articles. After review of the articles, and applying the inclusion and exclusion criteria, seven articles were selected for the final analysis. Three (42.85%) studies were on the feasibility and intervention types. Also, randomized trials, feasibility, feasibility and prospective-observational, and feasibility and retrospective-interventional studies were each one (14.28%). Six (85.71%) of the studies were conducted in the United States. The National Institutes of Health Stroke Scale (NIHSS) and RP-Xpress were the most commonly used tools for neurological evaluations and teleconsultations.

CONCLUSION

Remote prehospital consultations, triage, and sending patient data before they go to the emergency department can be provided through telemedicine in ambulances. Neurological evaluations via telemedicine are reliable and accurate, and they are almost equal to in-person evaluations by a neurologist.

Prehospital screening of acute stroke with the National Institutes of Health Stroke Scale (ParaNASPP): a stepped-wedge, cluster-randomised controlled trial

BACKGROUND

Timely treatment of acute stroke depends on early identification and triage. Improved methods for recognition of stroke in the prehospital setting are needed. We aimed to assess whether use of the National Institutes of Health Stroke Scale (NIHSS) by paramedics in the ambulance could improve communication with the hospital, augment triage, and enhance diagnostic accuracy of acute stroke.

METHODS

The Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) was a stepped-wedge, single-blind, cluster-randomised controlled trial. Patients with suspected acute stroke, who were evaluated by paramedics from five ambulance stations in Oslo, Norway, were eligible for inclusion. The five ambulance stations (defined as clusters) all initially managed patients according to a standard stroke protocol (control group), with randomised sequential crossover of each station to the intervention group. The intervention consisted of supervised training on NIHSS scoring, a mobile application to aid scoring, and standardised communication with stroke physicians. Random allocation was done via a simple lottery draw by administrators at Oslo University Hospital, who were independent of the research team. Allocation concealment was not possible due to the nature of the intervention. The primary outcome was the positive predictive value (PPV) for prehospital identification of patients with a final discharge diagnosis of acute stroke, analysed by intention to treat. Prespecified secondary safety outcomes were median prehospital on-scene time and median door-to-needle time. This trial is registered with ClinicalTrials.gov, NCT04137874, and is completed.

FINDINGS

Between June 3, 2019, and July 1, 2021, 935 patients were evaluated by paramedics for suspected acute stroke. 134 patients met exclusion criteria or did not consent to participate. The primary analysis included 447 patients in the intervention group and 354 in the control group. There was no difference in PPV for prehospital identification of patients with a final discharge diagnosis of acute stroke between the intervention group (48·1%, 95% CI 43·4-52·8) and control group (45·8%, 40·5-51·1), with an estimated percentage points difference between groups of 2·3 (95% CI -4·6 to 9·3; p=0·51). Median prehospital on-scene time increased by 5 min in the intervention group (29 min [IQR 23-36] vs 24 min [19-31]; p<0·0001), whereas median door-to-needle time was similar between groups (26 min [21-36] vs 27 min [20-36]; p=0·90). No prehospital deaths were reported in either group.

INTERPRETATION

The intervention did not improve diagnostic accuracy in patients with suspected stroke. A general increase in prehospital time during the pandemic and the identification of smaller strokes that require more deliberation are possible explanations for the increased on-scene time. The ParaNASPP model is to be implemented in Norway from 2023, and will provide real-life data for further research.

FUNDING

Norwegian Air Ambulance Foundation and Oslo University Hospital.

Gamification of the National Institutes of Health Stroke Scale (NIHSS) for simulation training-a feasibility study

BACKGROUND

Training prehospital personnel in identifying patients with acute stroke is key to providing rapid treatment. This study aimed to investigate whether game-based digital simulation training is a feasible alternative to standard in-person simulation training.

METHODS

Second-year paramedic bachelor students at Oslo Metropolitan University in Norway were invited to participate in a study to compare game-based digital simulation (intervention) to standard in-person training (control). For 2 months, students were encouraged to practice the NIHSS, and both groups logged their simulations. Then, they performed a clinical proficiency test, and their results were assessed using a Bland-Altman plot with corresponding 95% limits of agreement (LoA).

RESULTS

Fifty students participated in the study. Individuals in the game group (n = 23) spent an average (SD) of 42:36 min (36) on gaming and performed 14.4 (13) simulations on average, whereas the control group (n = 27) spent 9:28 min (8) simulating and performed 2.5 (1) simulations. Comparing time variables collected during the intervention period, the mean time for each simulated assessment was significantly shorter in the game group (2:57 min vs. 3:50 min, p = 0.004). In the final clinical proficiency test, the mean difference from the true NIHSS score was 0.64 (LoA: - 1.38 to 2.67) in the game group and 0.69 (LoA: - 1.65 to 3.02) in the control group.

CONCLUSION

Game-based digital simulation training is a feasible alternative to standard in-person simulation training to acquire competence in NIHSS assessment. Gamification seemed to give an incentive to simulate considerably more and to perform the assessment faster, with equal accuracy.

TRIAL REGISTRATION

The study was approved by the Norwegian Centre for Research Data (reference no. 543238).