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.

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.

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.

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).

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.

BACKGROUND: Less than 50% of stroke patients in Norway reach hospital within 4 h of symptom onset. Early prehospital identification of stroke and triage to the right level of care may result in more patients receiving acute treatment. Quality of communication between paramedics and the stroke centre directly affects prehospital on-scene time, emphasising this as a key factor to reduce prehospital delay. Prehospital stroke scales are developed for quick and easy identification of stroke, but have poor sensitivity and specificity compared to an in-hospital assessment with the National Institutes of Health Stroke Scale (NIHSS). The aim of the Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) is to assess whether a structured learning program, prehospital NIHSS and a mobile application facilitating communication with the stroke physician may improve triage of acute stroke patients. METHODS: A stepped wedge cluster randomised controlled intervention design will be used in this trial in Oslo, Norway. Paramedics at five ambulance stations will enrol adult patients with suspected stroke within 24 h of symptom onset. All paramedics will begin in a control phase with standard procedures. Through an e-learning program and practical training, a random and sequential switch to the intervention phase takes place. A mobile application for NIHSS scoring, including vital patient information for treatment decisions, transferring data from paramedics to the on-call stroke physician at the Stroke Unit at Oslo University Hospital, will be provided for the intervention. The primary outcome measure is positive predictive value (PPV) for prehospital identification of patients with acute stroke defined as the proportion of patients accepted for stroke evaluation and discharged with a final stroke diagnosis. One thousand three hundred patients provide a 50% surplus to the 808 patients needed for 80% power to detect a 10% increase in PPV. DISCUSSION: Structured and digital communication using a common scale like NIHSS may result in increased probability for better identification of stroke patients and less stroke mimics delivered to a stroke team for acute diagnostics and treatment in our population. TRIAL REGISTRATION: ClinicalTrials.gov NCT04137874 . Registered on October 24, 2019.

Prehospital Advanced Diagnostics and Treatment of Acute Stroke: Protocol for a Controlled Intervention Study.

BACKGROUND: Acute ischemic stroke (AIS) is a medical emergency. The outcome is closely linked to the time elapsing from symptom onset to treatment, and seemingly small delays can mean the difference between full recovery and physical and cognitive dysfunction. Recanalization to allow blood to reenter the affected area is most efficient immediately after symptoms occur, and intravenous thrombolysis must be initiated no later than 4.5 hours after the symptom onset. A liable diagnosis is mandatory to administer the appropriate treatment. Prehospital diagnosis and, in cases where contraindications are ruled out, prehospital initiation of intravenous thrombolysis have been shown to significantly decrease the time from alarm to the treatment. OBJECTIVE: The objective of this paper is to investigate the effectiveness of prehospital thrombolysis as measured by (1) time spent from symptom onset to treatment and (2) the number of patients treated within 4.5 hours. In addition, we want to conduct explorative studies. These will include (1) the use of biomarkers for diagnostic and prognostic use where we will collect blood samples from various time points, including the hyperacute phase and (2) the study of magnetic resonance imaging (MRI) images at day 1 to determine the infarct volume and if the time to thrombolysis has an influence on this. METHODS: This is a prospective controlled intervention study. The intervention will involve a computed tomography (CT) and thrombolysis in a physician-manned ambulance called a mobile stroke unit (MSU). The control will be the conventional pathway where the patient is transported to the hospital for CT, and thrombolysis as per current procedure. RESULTS: Patient inclusion has started and a total of 37 patients are enrolled (control and intervention combined). The estimated time to completed inclusion is 36 months, starting from May 2017. The results of this study will be analyzed and published at the end of the trial. CONCLUSIONS: This trial aims to document the feasibility of saving time for all stroke patients by providing prehospital diagnostics and treatment, as well as transport to appropriate level of care, in a safe environment provided by anesthesiologists trained in prehospital critical care. TRIAL REGISTRATION: ClinicalTrials.gov NCT03158259; https://clinicaltrials.gov/show/NCT03158259 (Archived by WebCite at http://www.webcitation.org/6wxNEUMUD).

Interpretation of Brain CT Scans in the Field by Critical Care Physicians in a Mobile Stroke Unit.

BACKGROUND AND PURPOSE: In acute stroke, thromboembolism or spontaneous hemorrhage abruptly reduces blood flow to a part of the brain. To limit necrosis, rapid radiological identification of the pathological mechanism must be conducted to allow the initiation of targeted treatment. The aim of the Norwegian Acute Stroke Prehospital Project is to determine if anesthesiologists, trained in prehospital critical care, may accurately assess cerebral computed tomography (CT) scans in a mobile stroke unit (MSU). METHODS: In this pilot study, 13 anesthesiologists assessed unselected acute stroke patients with a cerebral CT scan in an MSU. The scans were simultaneously available by teleradiology at the receiving hospital and the on-call radiologist. CT scan interpretation was focused on the radiological diagnosis of acute stroke and contraindications for thrombolysis. The aim of this study was to find inter-rater agreement between the pre- and in-hospital radiological assessments. A neuroradiologist evaluated all CT scans retrospectively. Statistical analysis of inter-rater agreement was analyzed with Cohen's kappa. RESULTS: Fifty-one cerebral CT scans from the MSU were included. Inter-rater agreement between prehospital anesthesiologists and the in-hospital on-call radiologists was excellent in finding radiological selection for thrombolysis (kappa .87). Prehospital CT scans were conducted in median 10 minutes (7 and 14 minutes) in the MSU, and median 39 minutes (31 and 48 minutes) before arrival at the receiving hospital. CONCLUSION: This pilot study shows that anesthesiologists trained in prehospital critical care may effectively assess cerebral CT scans in an MSU, and determine if there are radiological contraindications for thrombolysis.

Pre-hospital ct diagnosis of subarachnoid hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) is associated with higher mortality in the acute phase than other stroke types. There is a particular risk of early and devastating re-bleeding. Patients therefore need urgent assessment in a neurosurgical department, and the shorter the time from symptom onset to diagnosis the better. CASE PRESENTATION: The Norwegian Acute Stroke Pre-hospital Project (NASPP) has developed a Mobile Stroke Unit (MSU) model, which is staffed with anesthesiologists also trained in pre-hospital clinical assessment of acute stroke patients and interpretation of computerized tomography (CT). The MSU was operated on-call from the local dispatch center in a rural area 45-160 km away from a neurosurgical department. Two patients presented with clinical symptoms and signs compatible with SAH. In both cases, the CT examination confirmed the diagnosis of SAH. Both were transported directly from patient location to the regional neurosurgical department, saving at least 2-2.5 h of pre-neurosurgical time. CONCLUSION: The Norwegian MSU model staffed with anesthesiologists can rapidly establish an exact diagnosis of SAH, which in a rural area significantly reduces time to neurosurgical care. TRIAL REGISTRATION: Study data are retrospectively registered in ClinicalTrail.gov. NCT03036020 Unique Protocol ID: NASPP-2 Brief Title: The Norwegian Acute Stroke Prehospital Project Overall Status: Completed Primary Completion Date: January 2016 [Actual] Verification Date: January 2017.