Paramedic diagnosis of stroke: examining long-term use of the Melbourne Ambulance Stroke Screen (MASS) in the field

Prehospital stroke detection scales: A head-to-head comparison of 7 scales in patients with suspected stroke

BACKGROUND

Several prehospital scales have been designed to aid paramedics in identifying stroke patients in the ambulance setting. However, external validation and comparison of these scales are largely lacking.

AIMS

To compare all published prehospital stroke detection scales in a large cohort of unselected stroke code patients.

METHODS

We conducted a systematic literature search to identify all stroke detection scales. Scales were reconstructed with prehospital acquired data from two observational cohort studies: the Leiden Prehospital Stroke Study (LPSS) and PREhospital triage of patients with suspected STrOke (PRESTO) study. These included stroke code patients from four ambulance regions in the Netherlands, including 15 hospitals and serving 4 million people. For each scale, we calculated the accuracy, sensitivity, and specificity for a diagnosis of stroke (ischemic, hemorrhagic, or transient ischemic attack (TIA)). Moreover, we assessed the proportion of stroke patients who received reperfusion treatment with intravenous thrombolysis or endovascular thrombectomy that would have been missed by each scale.

RESULTS

We identified 14 scales, of which 7 (CPSS, FAST, LAPSS, MASS, MedPACS, OPSS, and sNIHSS-EMS) could be reconstructed. Of 3317 included stroke code patients, 2240 (67.5%) had a stroke (1528 ischemic, 242 hemorrhagic, 470 TIA) and 1077 (32.5%) a stroke mimic. Of ischemic stroke patients, 715 (46.8%) received reperfusion treatment. Accuracies ranged from 0.60 (LAPSS) to 0.66 (MedPACS, OPSS, and sNIHSS-EMS), sensitivities from 66% (LAPSS) to 84% (MedPACS and sNIHSS-EMS), and specificities from 28% (sNIHSS-EMS) to 49% (LAPSS). MedPACS, OPSS, and sNIHSS-EMS missed the fewest reperfusion-treated patients (10.3-11.2%), whereas LAPSS missed the most (25.5%).

CONCLUSIONS

Prehospital stroke detection scales generally exhibited high sensitivity but low specificity. While LAPSS performed the poorest, MedPACS, sNIHSS-EMS, and OPSS demonstrated the highest accuracy and missed the fewest reperfusion-treated stroke patients. Use of the most accurate scale could reduce unnecessary stroke code activations for patients with a stroke mimic by almost a third, but at the cost of missing 16% of strokes and 10% of patients who received reperfusion treatment.

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.

An updated review and meta-analysis of screening tools for stroke in the emergency room and prehospital setting

BACKGROUND

Stroke screening tools should have good diagnostic performance for early diagnosis and a proper therapeutic plan. This paper describes and compares various diagnostic tools used to identify stroke in emergency departments and prehospital setting.

METHODS

The meta-analysis was conducted according to the Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies (PRISMA-DTA) guidelines. The PubMed and Scopus databases were searched until December 31, 2021, for studies published on stroke screening tools. These tools' diagnostic performance (sensitivity and specificity) was pooled using a bivariate random-effects model whenever appropriate.

RESULTS

Eleven screening tools for stroke were identified in 29 different studies. The various tools had a wide range of sensitivity and specificity in different studies. In the meta-analysis, the Cincinnati Pre-hospital Stroke Scale, Face Arm Speech Test, and Recognition of Stroke in the Emergency Room (ROSIER) had sensitivity (between 83 and 91%) but poor specificity (all below 64%). When comparing all the tools, ROSIER had the highest sensitivity 90.5%. Los Angeles Pre-hospital Stroke Screen performed best in terms of specificity 88.7% but had low sensitivity (73.9%). Melbourne Ambulance Stroke Screen had a balanced performance in terms of sensitivity (86%) and specificity (76%). Sensitivity analysis consisting of only prospective studies showed a similar range of sensitivity and specificity.

CONCLUSION

All the stroke screening tools included in the review were comparable, but no clear superior screening tool could be identified. Simple screening tools like Cincinnati prehospital stroke scale (CPSS) have similar performance compared to more complex tools.

The Prehospital Stroke Score and telephone conference: A prospective validation

OBJECTIVES

The main aim of the study is to investigate the performance of a two-part stroke scale for screening and subsequent severity assessment combined with a telephone conference (teleconference).

MATERIALS AND METHODS

During a 6-month period, we prospectively tested the Prehospital Stroke Score (PreSS). PreSS part 1 is designed to identify stroke or TIA in a prehospital setting. PreSS part 2 is a stroke severity scale designed to identify large-vessel occlusion (LVO). PreSS was performed by emergency medical service (EMS) providers prior to a teleconference with a stroke neurologist.

RESULTS

Combined teleconference and PreSS part 1 were performed on 79.3% of all patients diagnosed with stroke/TIA, and 99.1% of the patients with positive scores were subsequently PreSS part 2 scored. PreSS part 1 and teleconference had a sensitivity to identify stroke/TIA of 89.3% (95% CI 85.7-92.2), specificity of 64.5% (95% CI 59.3-69.5), and an area under the curve (AUC) of 0.80 (95% CI 0.77-0.83). Regarding LVO, PreSS part 1 with teleconference recognized 96.7% (95% CI 88.7-99.6) of all cases as stroke. PreSS part 2 had a sensitivity of 55.7% (95% CI 42.4-68.5), specificity of 91.5% (95% CI 89.0-93.6), and AUC of 0.86 (95% CI 0.82-0.90) for identification of LVO.

CONCLUSIONS

PreSS was feasible and the sensitivity for stroke/TIA and LVO was high to moderate providing an overall high precision. Almost all LVO cases were ensured acute stroke admission. The high specificity for LVO could be useful for determining transfers strategies.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence when evaluating PreSS combined with teleconference.

Pitfalls in the Diagnosis of Posterior Circulation Stroke in the Emergency Setting

Posterior circulation stroke (PCS), caused by infarction within the vertebrobasilar arterial system, is a potentially life-threatening condition and accounts for about 20–25% of all ischemic strokes. Diagnosing PCS can be challenging due to the vast area of brain tissue supplied by the posterior circulation and, as a consequence, the wide range of—frequently non-specific—symptoms. Commonly used prehospital stroke scales and triage systems do not adequately represent signs and symptoms of PCS, which may also escape detection by cerebral imaging. All these factors may contribute to causing delay in recognition and diagnosis of PCS in the emergency context. This narrative review approaches the issue of diagnostic error in PCS from different perspectives, including anatomical and demographic considerations as well as pitfalls and problems associated with various stages of prehospital and emergency department assessment. Strategies and approaches to improve speed and accuracy of recognition and early management of PCS are outlined.

Characteristics of patients who had a stroke not initially identified during emergency prehospital assessment: a systematic review

BACKGROUND

Around 25% of patients who had a stroke do not present with typical 'face, arm, speech' symptoms at onset, and are challenging for emergency medical services (EMS) to identify. The aim of this systematic review was to identify the characteristics of acute stroke presentations associated with inaccurate EMS identification (false negatives).

METHOD

We performed a systematic search of MEDLINE, EMBASE, CINAHL and PubMed from 1995 to August 2020 using key terms: stroke, EMS, paramedics, identification and assessment. Studies included: patients who had a stroke or patient records; ≥18 years; any stroke type; prehospital assessment undertaken by health professionals including paramedics or technicians; data reported on prehospital diagnostic accuracy and/or presenting symptoms. Data were extracted and study quality assessed by two researchers using the Quality Assessment of Diagnostic Accuracy Studies V.2 tool.

RESULTS

Of 845 studies initially identified, 21 observational studies met the inclusion criteria. Of the 6934 stroke and Transient Ischaemic Attack patients included, there were 1774 (26%) false negative patients (range from 4 (2%) to 247 (52%)). Commonly documented symptoms in false negative cases were speech problems (n=107; 13%-28%), nausea/vomiting (n=94; 8%-38%), dizziness (n=86; 23%-27%), changes in mental status (n=51; 8%-25%) and visual disturbance/impairment (n=43; 13%-28%).

CONCLUSION

Speech problems and posterior circulation symptoms were the most commonly documented symptoms among stroke presentations that were not correctly identified by EMS (false negatives). However, the addition of further symptoms to stroke screening tools requires valuation of subsequent sensitivity and specificity, training needs and possible overuse of high priority resources.

European Resuscitation Council Guidelines 2021: First aid

The European Resuscitation Council has produced these first aid guidelines, which are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. The topics include the first aid management of emergency medicine and trauma. For medical emergencies the following content is covered: recovery position, optimal positioning for shock, bronchodilator administration for asthma, recognition of stroke, early aspirin for chest pain, second dose of adrenaline for anaphylaxis, management of hypoglycaemia, oral rehydration solutions for treating exertion-related dehydration, management of heat stroke by cooling, supplemental oxygen in acute stroke, and presyncope. For trauma related emergencies the following topics are covered: control of life-threatening bleeding, management of open chest wounds, cervical spine motion restriction and stabilisation, recognition of concussion, cooling of thermal burns, dental avulsion, compression wrap for closed extremity joint injuries, straightening an angulated fracture, and eye injury from chemical exposure.

Stroke Recognition for First Aid Providers: A Systematic Review and Meta-Analysis

Aim To perform a systematic review of the literature on the effectiveness of existing stroke recognition scales used in a prehospital setting and suitable for use by first aid providers. The systematic review will be used to inform an update of international first aid guidelines. Methods We followed the Cochrane Handbook for Systematic Reviews of Interventions methodology and report results according to PRISMA guidelines. We searched Medline, Embase and CENTRAL on May 25, 2020 for studies of stroke recognition scales used by first aid providers, paramedics and nurses for adults with suspected acute stroke in a prehospital setting. Outcomes included change in time to treatment, initial recognition of stroke, survival and discharge with favorable neurologic status, and increased layperson recognition of the signs of stroke. Two investigators reviewed abstracts, extracted and assessed the data for risk of bias. The certainty of evidence was evaluated using GRADE methodology. Results We included 24 observational studies with 10,446 patients evaluating 10 stroke scales (SS). All evidence was of moderate to very low certainty. Use of the Kurashiki Prehospital SS (KPSS), Ontario Prehospital SS (OPSS) and Face Arm Speech Time SS (FAST) was associated with an increased number of suspected stroke patients arriving to a hospital within three hours and, for OPSS, a higher rate of thrombolytic therapy. The KPSS was associated with a decreased time from symptom onset to hospital arrival. Use of FAST Emergency Response (FASTER) was associated with decreased time from door to tomography and from symptom onset to treatment. The Los Angeles Prehospital Stroke Scale (LAPSS) was associated with an increased number of correct initial diagnoses. Meta-analysis found the summary estimate sensitivity of four scales ranged from 0.78 to 0.86. The FAST and Cincinnati Prehospital Stroke Scale (CPSS) were found to have a summary estimated sensitivity of 0.86, 95% CI [0.69-0.94] and 0.81, 95% CI [0.70-0.89], respectively. Conclusion Stroke recognition scales used in the prehospital first aid setting improves the recognition and diagnosis of stroke, thereby aiding the emergency services to triage stroke victims directly down an appropriate stroke care pathway. Of those prehospital scales evaluated by more than a single study, FAST and Melbourne Ambulance Stroke Screen (MASS) were found to be the most sensitive for stroke recognition, while the CPSS had higher specificity. When blood glucose cannot be measured, the simplicity of FAST and CPSS makes these particular stroke scales appropriate for non-medical first aid providers.

2020 International Consensus on First Aid Science With Treatment Recommendations

This is the summary publication of the International Liaison Committee on Resuscitation's 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administration for hypoglycemia; techniques for cooling of exertional hyperthermia and heatstroke; recognition of acute stroke; the use of supplementary oxygen in acute stroke; early or first aid use of aspirin for chest pain; control of life- threatening bleeding through the use of tourniquets, haemostatic dressings, direct pressure, or pressure devices; the use of a compression wrap for closed extremity joint injuries; and temporary storage of an avulsed tooth. Additional summaries of scoping reviews are presented for the use of a recovery position, recognition of a concussion, and 6 other first aid topics. The First Aid Task Force has assessed, discussed, and debated the certainty of evidence on the basis of Grading of Recommendations, Assessment, Development, and Evaluation criteria and present their consensus treatment recommendations with evidence-to-decision highlights and identified priority knowledge gaps for future research. The 2020 International Consensus on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) Science With Treatment Recommendations (CoSTR) is the fourth in a series of annual summary publications from the International Liaison Committee on Resuscitation (ILCOR). This 2020 CoSTR for first aid includes new topics addressed by systematic reviews performed within the past 12 months. It also includes updates of the first aid treatment recommendations published from 2010 through 2019 that are based on additional evidence evaluations and updates. As a result, this 2020 CoSTR for first aid represents the most comprehensive update since 2010.

2020 International Consensus on First Aid Science With Treatment Recommendations

This is the summary publication of the International Liaison Committee on Resuscitation's 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administration for hypoglycemia; techniques for cooling of exertional hyperthermia and heatstroke; recognition of acute stroke; the use of supplementary oxygen in acute stroke; early or first aid use of aspirin for chest pain; control of life-threatening bleeding through the use of tourniquets, hemostatic dressings, direct pressure, or pressure devices; the use of a compression wrap for closed extremity joint injuries; and temporary storage of an avulsed tooth. Additional summaries of scoping reviews are presented for the use of a recovery position, recognition of a concussion, and 6 other first aid topics. The First Aid Task Force has assessed, discussed, and debated the certainty of evidence on the basis of Grading of Recommendations, Assessment, Development, and Evaluation criteria and present their consensus treatment recommendations with evidence-to-decision highlights and identified priority knowledge gaps for future research.

The role of the Cincinnati Prehospital Stroke Scale in the emergency department: evidence from a systematic review and meta-analysis

INTRODUCTION

Stroke is one of the leading causes of morbidity, disability, and mortality in high-income countries. Early prehospital stroke recognition plays a fundamental role, because most clinical decisions should be made within the first hours after onset of symptoms. The Cincinnati Prehospital Stroke Scale (CPSS) is a validated screening tool whose utilization is suggested during triage. The aim of this study is to review the role of the CPSS by assessing its sensitivity and specificity in prehospital and hospital settings.

METHODS

A systematic review and a meta-analysis of the literature reporting the CPSS sensitivity and specificity among patients suspected of stroke were undertaken. Electronic databases were searched up to December 2018, and the quality assessment was carried out by using the Revised Quality Assessment of Diagnostic Accuracy Studies -2  (QUADAS-2).

RESULTS

Eleven studies were included in the meta-analysis. Results showed an overall sensitivity of 82.46% (95% confidence interval [CI] 74.83-88.09%) and specificity of 56.95% (95% CI 41.78-70.92). No significant differences were found in terms of sensitivity when CPSS was performed by physicians (80.11%, 95% CI 66.14-89.25%) or non-physicians (81.11%, 95% CI 69.78-88.87%). However, administration by physicians resulted in higher specificity (73.57%, 95% CI 65.78-80.12%) when compared to administration by non-physicians (50.07%, 95% CI 31.54-68.58%). Prospective studies showed higher specificity 71.61% (95% CI 61.12-80.18%) and sensitivity 86.82% (95% CI 74.72-93.63) when compared to retrospective studies which showed specificity of 33.37% (95% CI 22.79-45.94%) and sensitivity of 78.52% (95% CI 75.08-81.60).

CONCLUSIONS

The CPSS is a standardized and easy-to-use stroke screening tool whose implementation in emergency systems protocols, along with proper and consistent coordination with local, regional, and state agencies, medical authorities and local experts are suggested.

Prehospital stroke scales as screening tools for early identification of stroke and transient ischemic attack

BACKGROUND

Rapid and accurate detection of stroke by paramedics or other emergency clinicians at the time of first contact is crucial for timely initiation of appropriate treatment. Several stroke recognition scales have been developed to support the initial triage. However, their accuracy remains uncertain and there is no agreement which of the scales perform better.

OBJECTIVES

To systematically identify and review the evidence pertaining to the test accuracy of validated stroke recognition scales, as used in a prehospital or emergency room (ER) setting to screen people suspected of having stroke.

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), Embase (Ovid) and the Science Citation Index to 30 January 2018. We handsearched the reference lists of all included studies and other relevant publications and contacted experts in the field to identify additional studies or unpublished data.

SELECTION CRITERIA

We included studies evaluating the accuracy of stroke recognition scales used in a prehospital or ER setting to identify stroke and transient Ischemic attack (TIA) in people suspected of stroke. The scales had to be applied to actual people and the results compared to a final diagnosis of stroke or TIA. We excluded studies that applied scales to patient records; enrolled only screen-positive participants and without complete 2 × 2 data.

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted a two-stage screening of all publications identified by the searches, extracted data and assessed the methodologic quality of the included studies using a tailored version of QUADAS-2. A third review author acted as an arbiter. We recalculated study-level sensitivity and specificity with 95% confidence intervals (CI), and presented them in forest plots and in the receiver operating characteristics (ROC) space. When a sufficient number of studies reported the accuracy of the test in the same setting (prehospital or ER) and the level of heterogeneity was relatively low, we pooled the results using the bivariate random-effects model. We plotted the results in the summary ROC (SROC) space presenting an estimate point (mean sensitivity and specificity) with 95% CI and prediction regions. Because of the small number of studies, we did not conduct meta-regression to investigate between-study heterogeneity and the relative accuracy of the scales. Instead, we summarized the results in tables and diagrams, and presented our findings narratively.

MAIN RESULTS

We selected 23 studies for inclusion (22 journal articles and one conference abstract). We evaluated the following scales: Cincinnati Prehospital Stroke Scale (CPSS; 11 studies), Recognition of Stroke in the Emergency Room (ROSIER; eight studies), Face Arm Speech Time (FAST; five studies), Los Angeles Prehospital Stroke Scale (LAPSS; five studies), Melbourne Ambulance Stroke Scale (MASS; three studies), Ontario Prehospital Stroke Screening Tool (OPSST; one study), Medic Prehospital Assessment for Code Stroke (MedPACS; one study) and PreHospital Ambulance Stroke Test (PreHAST; one study). Nine studies compared the accuracy of two or more scales. We considered 12 studies at high risk of bias and one with applicability concerns in the patient selection domain; 14 at unclear risk of bias and one with applicability concerns in the reference standard domain; and the risk of bias in the flow and timing domain was high in one study and unclear in another 16.We pooled the results from five studies evaluating ROSIER in the ER and five studies evaluating LAPSS in a prehospital setting. The studies included in the meta-analysis of ROSIER were of relatively good methodologic quality and produced a summary sensitivity of 0.88 (95% CI 0.84 to 0.91), with the prediction interval ranging from approximately 0.75 to 0.95. This means that the test will miss on average 12% of people with stroke/TIA which, depending on the circumstances, could range from 5% to 25%. We could not obtain a reliable summary estimate of specificity due to extreme heterogeneity in study-level results. The summary sensitivity of LAPSS was 0.83 (95% CI 0.75 to 0.89) and summary specificity 0.93 (95% CI 0.88 to 0.96). However, we were uncertain in the validity of these results as four of the studies were at high and one at uncertain risk of bias. We did not report summary estimates for the rest of the scales, as the number of studies per test per setting was small, the risk of bias was high or uncertain, the results were highly heterogenous, or a combination of these.Studies comparing two or more scales in the same participants reported that ROSIER and FAST had similar accuracy when used in the ER. In the field, CPSS was more sensitive than MedPACS and LAPSS, but had similar sensitivity to that of MASS; and MASS was more sensitive than LAPSS. In contrast, MASS, ROSIER and MedPACS were more specific than CPSS; and the difference in the specificities of MASS and LAPSS was not statistically significant.

AUTHORS' CONCLUSIONS

In the field, CPSS had consistently the highest sensitivity and, therefore, should be preferred to other scales. Further evidence is needed to determine its absolute accuracy and whether alternatives scales, such as MASS and ROSIER, which might have comparable sensitivity but higher specificity, should be used instead, to achieve better overall accuracy. In the ER, ROSIER should be the test of choice, as it was evaluated in more studies than FAST and showed consistently high sensitivity. In a cohort of 100 people of whom 62 have stroke/TIA, the test will miss on average seven people with stroke/TIA (ranging from three to 16). We were unable to obtain an estimate of its summary specificity. Because of the small number of studies per test per setting, high risk of bias, substantial differences in study characteristics and large between-study heterogeneity, these findings should be treated as provisional hypotheses that need further verification in better-designed studies.

Approaches to the field recognition of potential thrombectomy candidates

Systems of care for acute ischemic stroke are being challenged to implement processes that ensure rapid access to endovascular thrombectomy. Optimizing existing regionalized stroke thrombolysis programs for endovascular thrombectomy will require accurate field recognition of treatment candidates. We begin with a review of the development of early clinical tests for ischemic stroke, illustrating challenges relevant to future field tests for large vessel occlusion. Second, we discuss aspects of diagnosis, eligibility, feasibility, and system organization that are potentially relevant to the development and implementation of field tests and diversion criteria. These considerations may influence the choice and parametrization of field tests in individual jurisdictions. Third, we review the literature evaluating eight clinical tests for the field identification of probable large vessel occlusion. All candidate tests include evaluations for focal weakness, and six evaluate for cortical signs such as aphasia or gaze deviation. Most appear roughly comparable to the NIH Stroke Scale, but direct comparison between studies is inappropriate because of major methodological differences. Finally, we discuss our jurisdiction’s approach to the field recognition of thrombectomy candidates. We contextualize diagnostic, eligibility, and system considerations within distinct metro and rural environments and propose a screen-and-consult model for the rural setting.

Selecting cases for feedback to pre-hospital clinicians - a pilot study

Background There are currently limited avenues for routine feedback from hospitals to pre-hospital clinicians aimed at improvements in clinical practice. Objective The aim of this study was to pilot a method for selectively identifying cases where there was a clinically significant difference between the pre-hospital and in-hospital diagnoses that could have led to a difference in pre-hospital patient care. Methods This was a single-centre retrospective study involving cases randomly selected through informatics extraction of final diagnoses at hospital discharge. Additional data on demographics, triage and diagnoses were extracted by explicit chart review. Blinded groups of pre-hospital and in-hospital clinicians assessed data to detect clinically significant differences between pre-hospital and in-hospital diagnoses. Results Most (96.9%) patients were of Australasian Triage Scale category 1-3 and in-hospital mortality rate was 32.9%. Of 353 cases, 32 (9.1%; 95% CI: 6.1-12.1) were determined by both groups of clinical assessors to have a clinically significant difference between the pre-hospital and final in-hospital diagnoses, with moderate inter-rater reliability (kappa score 0.6, 95% CI: 0.5-0.7). Conclusion A modest proportion of cases demonstrated discordance between the pre-hospital and in-hospital diagnoses. Selective case identification and feedback to pre-hospital services using a combination of informatics extraction and clinician consensus approach can be used to promote ongoing improvements to pre-hospital patient care. What is known about the topic? Highly trained pre-hospital clinicians perform patient assessments and early interventions while transporting patients to healthcare facilities for ongoing management. Feedback is necessary to allow for continual improvements; however, the provision of formal selective feedback regarding diagnostic accuracy from hospitals to pre-hospital clinicians is currently not routine. What does this paper add? For a significant proportion of patients, there is a clinically important difference in the diagnosis recorded by their pre-hospital clinician compared with their final in-hospital diagnosis. These clinically significant differences in diagnoses between pre-hospital and in-hospital clinicians were most notable among acute myocardial infarction and trauma subgroups of patients in this study. What are the implications for practitioners? Identification of patients who have a significant discrepancy between their pre-hospital and in-hospital diagnoses could lead to the development of feedback mechanisms to pre-hospital clinicians. Providing pre-hospital clinicians with this selective feedback would be intended to promote ongoing improvements in pre-hospital assessments and thereby to improve service delivery.

Predictive Ability of an Emergency Medical Dispatch Stroke Diagnostic Tool in Identifying Hospital-Confirmed Strokes

BACKGROUND

Early hospital notification of a possible stroke arriving via emergency medical services (EMS) can prepare stroke center personnel for timely treatment, especially timely administration of tissue plasminogen activator. Stroke center notification from the emergency dispatch center-before responders reach the scene-may promote even earlier and faster system activation, meaning that stroke center teams may be ready to receive patients as soon as the ambulance arrives. This study evaluates the use of a Medical Priority Dispatch System (MPDS; Priority Dispatch Corp., Salt Lake City, UT) Stroke Diagnostic Tool (SDxT) to identify possible strokes early by comparing the tools' results to on-scene and hospital findings.

METHODS

The retrospective descriptive study utilized stroke data from 3 sources: emergency medical dispatch, EMS, and emergency department/hospital.

RESULTS

A total of 830 cases were collected between June 2012 and December 2013, of which 603 (72.7%) had matching dispatch records. Of the 603 cases, 304 (50.4%) were handled using MPDS Stroke Protocol 28. The SDxT had an 86.4% ability (OR [95% CI]: 2.3 [1.5, 3.5]) to effectively identify strokes among all the hospital-confirmed stroke cases (sensitivity), and a 26.6% ability to effectively identify nonstrokes among all the hospital-confirmed nonstroke cases (specificity).

CONCLUSIONS

The SDxT demonstrated a very high sensitivity, compared to similar tools used in the field and at dispatch. The specificity was somewhat low, but this was expected-and is intended in the creation of protocols to be used over the phone in emergency situations. The tool is a valuable method for identifying strokes early and may allow early hospital notification.

Sensitivity and Specificity of an Adult Stroke Screening Tool in Childhood Ischemic Stroke

BACKGROUND

There are frequent delays in the diagnosis of acute pediatric ischemic stroke. A screening tool that could increase the suspicion of acute ischemic stroke could aid early recognition and might improve initial care. An earlier study reported that children with acute ischemic stroke have signs that can be recognized with two adult stroke scales. We tested the hypothesis that an adult stroke scale could distinguish children with acute ischemic stroke from children with acute focal neurological deficits not due to stroke.

METHODS

We retrospectively applied an adult stroke scale to the recorded examinations of 53 children with acute symptomatic acute ischemic stroke and 53 age-matched control subjects who presented with focal neurological deficits. We examined the sensitivity and specificity of the stroke scale and the occurrence of acute seizures as predictors of stroke status.

RESULTS

The total stroke scale did not differentiate children with acute ischemic stroke from those who had acute deficits from nonstroke causes; however, the presence of arm weakness was significantly associated with stroke cases. Acute seizures were significantly associated with stroke cases.

CONCLUSIONS

An adult stroke scale is not sensitive or specific to distinguish children with acute ischemic stroke from those with nonstroke focal neurological deficits. The development of a pediatric acute ischemic stroke screening tool should include arm weakness and perhaps acute seizures as core elements. Such a scale must account for the limitations of language in young or intellectually disabled children.

Effect of prehospital notification on acute stroke care: a multicenter study

Background

The sooner thrombolytic therapy is given to acute ischemic stroke patients, the better the outcome. Prehospital notification may shorten the time between hospital arrival and brain computed tomography (door-to-CT) and the door-to-needle (DTN) time. This study investigated the effect of prehospital notification on acute stroke care in an urban city in Taiwan.

Methods

This retrospective observational study utilized a prospectively collected dataset from patients treated at 9 hospitals and the emergency medical service (EMS) system in Taipei City from September 1, 2012 to December 31, 2014. During the study period, prehospital notification was performed by emergency medical technicians if the patient met the following criteria: (1) positive Cincinnati Prehospital Stroke Scale (CPSS), (2) symptom onset within 3 h, and (3) a sugar pinprick test result ≥ 60 mg/dL. The demographics, final diagnoses, and data associated with stroke for all patients in the prenotification group and for patients diagnosed with acute stroke within 3 h of symptoms onset were prospectively recorded in the stroke registry. The primary outcome was door-to-CT time and the secondary outcome was DTN time. The sensitivity and positive predictive value (PPV) of prehospital notifications and the association between the volume of patients receiving thrombolytic therapy at individual hospitals and DTN time were also evaluated.

Results

There were 928 patients who presented ≤ 3 h from stroke onset. Among them, 727 (78.3 %) patients were in the prenotification group; of these, more were male, smokers, and presented with severe symptoms, and fewer had a history of prior stroke or cardiac diseases compared to patients in the non-prenotification group. The median door-to-CT time was significantly shorter in the prenotification group than among the non-prenotification group (13 versus 19 min, p < 0.001). Prenotification was associated with shorter DTN time (63 versus 68 min, p = 0.138). The sensitivity and PPV of prenotification of stroke were 78.3 % and 78.2 %, respectively. The DTN time demonstrated a significant and highly negative association with the volume of patients receiving thrombolytic therapy (Spearman’s correlation coefficient -0.90, p < 0.001).

Discussion

In our study, we found prehospital notification was associated with faster door-to-CT scan and shorter DTN time in patients presenting within 3 hours of symptom onset. Such a close collaboration between hospitals and the EMS system gives citizens an in-time emergency care network. Our study revealed that, like in other countries, prehospital notification for stroke patients improved in-hospital stroke care in Taiwan. Our study showed that the sensitivity and PPV of prenotification decisions according to our CPSS-based criteria was comparable with those in other studies. Our study also found that DTN time was shorter in the hospital that treated a greater volume of patients with thrombolytic therapy. A multicenter collaboration program is needed to help those hospitals with relatively lower stroke patient volume to set up interventions that have been proven to improve stroke care.

Conclusions

Prehospital notification of stroke can significantly shorten door-to-CT time and improve acute stroke care in Taiwan.

Acute Stroke: Current Evidence-based Recommendations for Prehospital Care

Introduction

In the United States, emergency medical services (EMS) protocols vary widely across jurisdictions. We sought to develop evidence-based recommendations for the prehospital evaluation and treatment of a patient with a suspected stroke and to compare these recommendations against the current protocols used by the 33 EMS agencies in the state of California.

Methods

We performed a literature review of the current evidence in the prehospital treatment of a patient with a suspected stroke and augmented this review with guidelines from various national and international societies to create our evidence-based recommendations. We then compared the stroke protocols of each of the 33 EMS agencies for consistency with these recommendations. The specific protocol components that we analyzed were the use of a stroke scale, blood glucose evaluation, use of supplemental oxygen, patient positioning, 12-lead electrocardiogram (ECG) and cardiac monitoring, fluid assessment and intravenous access, and stroke regionalization.

Results

Protocols across EMS agencies in California varied widely. Most used some sort of stroke scale with the majority using the Cincinnati Prehospital Stroke Scale (CPSS). All recommended the evaluation of blood glucose with the level for action ranging from 60 to 80mg/dL. Cardiac monitoring was recommended in 58% and 33% recommended an ECG. More than half required the direct transport to a primary stroke center and 88% recommended hospital notification.

Conclusion

Protocols for a patient with a suspected stroke vary widely across the state of California. The evidence-based recommendations that we present for the prehospital diagnosis and treatment of this condition may be useful for EMS medical directors tasked with creating and revising these protocols.

Patient characteristics affecting stroke identification by emergency medical service providers in Brooklyn, New York

Early identification of stroke should begin in the prehospital phase because the benefits of thrombolysis and clot extraction are time dependent. This study aims to identify patient characteristics that affect prehospital identification of stroke by Long Island college hospital (LICH) emergency medical services (EMS). All suspected strokes brought to LICH by LICH ambulances from January 1, 2010 to December 31, 2011 were included in the study. We compared prehospital care report-based diagnosis against the get with the guidelines (GWTG) database. Age-adjusted logistic regression models were used to study that the effect of individual patient characteristics have on EMS providers' diagnosis. Included in the study were 10,384 patients with mean age 43.9 years. Of whom, 75 had a GWTG cerebrovascular diagnosis: 53 were ischemic strokes, 7 transient ischemic attacks, 3 subarachnoid hemorrhage, and 12 intercerebral bleeds. LICH EMS correctly identified 44 of 75 GWTG strokes. Fifty-one patients were overcalled as stroke by the EMS. Overall EMS sensitivity was 58.7 % and specificity was 99.5 %. Dispatcher call type of altered mental status, stroke, unconsciousness, and increasing prehospital blood pressure quartile were found to be significantly predictive of a true stroke diagnosis. Patients with a past medical history and EMS providers' impression of seizures were more likely to be overcalled as a stroke in the field. More than a third of actual stroke patients were missed in the field in our study. Our results show that the patients' past medical history, dispatcher collected information and prehospital vital sign measurements are associated with a true diagnosis of stroke.

Brain attacks and stroke in children

Emergency physicians are often the first point of contact in children presenting with acute neurological disorders. Differentiating serious disorders, such as stroke, from benign disorders, such as migraine, can be challenging. Clinical assessment influences decision-making, in particular the need for emergent neuroimaging to confirm diagnosis. This review describes the spectrum of disorders causing 'brain attack' symptoms, or acute onset focal neurological dysfunction, with particular emphasis on childhood stroke, because early recognition is essential to improve access to thrombolytic treatments, which have improved outcomes in adults. Clues to diagnosis of specific conditions are discussed. Symptoms and signs, which discriminate stroke from mimics, are described, highlighting differences to adults. Haemorrhagic and ischaemic stroke have different presenting features, which influence choice of the most appropriate imaging modality to maximise diagnostic accuracy. Improvements in the care of children with brain attacks require coordinated approaches and system improvements similar to those developed in adults.

Comparison of stroke recognition and stroke severity scores for stroke detection in a single cohort

OBJECTIVE

First, to determine the sensitivity and specificity of six stroke recognition scores in a single cohort to improve interscore comparability. Second, to test four stroke severity scores repurposed to recognise stroke in parallel.

METHODS

Of 9154 emergency runs, 689 consecutive cases of preclinically 'suspected central nervous system disorder' admitted to the emergency room (ER) of the Heidelberg University Hospital were included in the validation cohort. Using data abstracted from the neurological ER medical reports, retrospective assessment of stroke recognition scores became possible for the Cincinnati Prehospital Stroke Scale (CPSS), Face Arm Speech Test (FAST), Los Angeles Prehospital Stroke Screen (LAPSS), Melbourne Ambulance Stroke Screen (MASS), Medic Prehospital Assessment for Code Stroke (Med PACS) and Recognition of Stroke in the Emergency Room score (ROSIER), and that of stroke severity scores became possible for the Kurashiki Prehospital Stroke Scale (KPSS), Los Angeles Motor Scale (LAMS) and shortened National Institutes of Health Stroke Scale (sNIHSS)-8/sNIHSS-5. Test characteristics were calculated using the hospital discharge diagnosis as the reference standard.

RESULTS

The CPSS and FAST had a sensitivity of 83% (95% CI 76 to 88) and 85% (78% to 90%) and a specificity of 69% (64% to 73%) and 68% (63% to 72%), respectively. The more complex LAPSS, MASS and Med PACS had a high specificity (92% to 98%) but low sensitivity (44% to 71%). In the ROSIER, sensitivity (80%, 73 to 85) and specificity (79%, 75 to 83) were similar. Test characteristics for KPSS, sNIHSS-8 and sNIHSS-5 were similar to the simple recognition scores (sensitivity 83% to 86%, specificity 60% to 69%). The LAMS offered only low sensitivity.

CONCLUSIONS

The simple CPSS and FAST scores provide good sensitivity for stroke recognition. More complex scores do not result in better diagnostic performance. Stroke severity scores can be repurposed to recognise stroke at the same time because test characteristics are comparable with pure stroke recognition scores. Particular shortcomings of the individual scores are discussed.

Prehospital Stroke Identification: Factors Associated with Diagnostic Accuracy

BACKGROUND

Stroke patients misdiagnosed by emergency medical services (EMS) providers have been shown to receive delayed in-hospital care. We aim at determining the diagnostic accuracy of Fire Department of New York (FDNY) EMS providers for stroke and identifying potential reasons for misdiagnosis.

METHODS

Prehospital care reports of all patients transported by FDNY EMS to 3 hospitals from January 1, 2010, to December 31, 2011, were compared against the American Heart Association Get With The Guidelines (GWTG) database (reference standard) for the diagnosis of stroke. Age-adjusted logistic regression models were generated to explore prehospital patient characteristics which are associated with stroke misdiagnosis.

RESULTS

Of 72,984 patient transports during the study period, 750 had a GWTG diagnosis of stroke, 468 (62%) of which were identified correctly in the field and 282 (38%) were missed. An additional 268 patients were misdiagnosed as stroke when in fact they had an alternative diagnosis. Overall sensitivity was 62.4% (95% confidence interval [CI], 58.9-65.8) and specificity was 99.6% (95% CI, 99.6-99.7). No patients who presented with unilateral weakness, facial weakness, or speech problems were missed, whereas patients with atypical complaints like general malaise, dizziness, and headache were more likely to be missed. Seizures led the EMS providers to both overcall a stroke and miss the diagnosis.

CONCLUSIONS

FDNY EMS care providers missed more than a third of stroke cases. Seizures and other atypical presentations contribute significantly to stroke misdiagnosis in the field. Our findings highlight the need for better prehospital stroke identification methods.

The accuracy of prehospital diagnosis of acute cerebrovascular accidents: an observational study

INTRODUCTION

Time to treatment is the key factor in stroke care. Although the initial medical assessment is usually made by a non-neurologist or a paramedic, it should ensure correct identification of all acute cerebrovascular accidents (CVAs). Our aim was to evaluate the accuracy of the physician-made prehospital diagnosis of acute CVA in patients referred directly to the neurological emergency department (ED), and to identify conditions mimicking CVAs.

MATERIAL AND METHODS

This observational study included consecutive patients referred to our neurological ED by emergency physicians with a suspicion of CVA (acute stroke, transient ischemic attack (TIA) or a syndrome-based diagnosis) during 12 months. Referrals were considered correct if the prehospital diagnosis of CVA proved to be stroke or TIA.

RESULTS

The prehospital diagnosis of CVA was correct in 360 of 570 cases. Its positive predictive value ranged from 100% for the syndrome-based diagnosis, through 70% for stroke, to 34% for TIA. Misdiagnoses were less frequent among ambulance physicians compared to primary care and outpatient physicians (33% vs. 52%, p < 0.001). The most frequent mimics were vertigo (19%), electrolyte and metabolic disturbances (12%), seizures (11%), cardiovascular disorders (10%), blood hypertension (8%) and brain tumors (5%). Additionally, 6% of all admitted CVA cases were referred with prehospital diagnoses other than CVA.

CONCLUSIONS

Emergency physicians appear to be sensitive in diagnosing CVAs but their overall accuracy does not seem high. They tend to overuse the diagnosis of TIA. Constant education and adoption of stroke screening scales may be beneficial for emergency care systems based both on physicians and on paramedics.

Improved performance of new prenotification criteria for acute stroke patients

BACKGROUND/PURPOSE

We aim to evaluate the accuracy of the new prehospital notification criteria for patients with potential acute stroke in the prehospital setting.

METHODS

We conducted a retrospective observational study from March 2011 to February 2013 of potential acute stroke patients prenotified using the new criteria which were: (1) positive Cincinnati Prehospital Stroke Scale (CPSS); (2) symptom onset within 3 hours; and (3) blood glucose level > 60 mg/dL. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the new criteria were calculated and outcomes of acute stroke patients were reported. Data of all patients with stroke or transient ischemic attack (TIA) transported to the destination hospital were also obtained to evaluate the compliance of emergency medical technicians.

RESULTS

There were 2888 patients suspected of stroke by emergency medical technicians and 221 patients prenotified due to meeting the criteria. The PPV, NPV, sensitivity, and specificity of the new criteria were 76.9%, 96.6%, 64.9%, and 98.1%, respectively. Onset time > 3 hours (24/51, 47.1%) and seizure (27.5%) were the two most common conditions leading to false prenotification. Of all prenotified patients, 23.1% (51/221) received thrombolytic therapy. Hemorrhagic stroke or ischemic stroke with hemorrhagic transformation (53.8%) and minor symptoms or rapid recovery (26.9%) were the most common reasons excluding correctly prenotified patients from thrombolytic therapy.

CONCLUSION

The accuracy of the new prehospital stroke criteria has higher PPV and specificity compared to previous CPSS validation studies.

Clinical signs in young patients with stroke related to FAST: results of the sifap1 study

OBJECTIVES

The present study aimed to evaluate the frequency of warning signs in younger patients with stroke with a special regard to the 'FAST' scheme, a public stroke recognition instrument (face, arm, speech, timely).

SETTING

Primary stroke care in participating centres of a multinational European prospective cross-sectional study (Stroke in Young Fabry Patients; sifap1). Forty-seven centres from 15 European countries participate in sifap1.

PARTICIPANTS

5023 acute patients with stroke (aged 18-55 years) patients (96.5% Caucasians) were enrolled in the study between April 2007 and January 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

sifap1 was originally designed to investigate the relation of juvenile stroke and Fabry disease. A secondary aim of sifap1 was to investigate stroke patterns in this specific group of patients. The present investigation is a secondary analysis addressing stroke presenting symptoms with a special regard to signs included in the FAST scheme.

RESULTS

4535 patients with transient ischaemic attack (TIA; n=1071), ischaemic stroke (n=3396) or other (n=68) were considered in the presented analysis. FAST symptoms could be traced in 76.5% of all cases. 35% of those with at least one FAST symptom had all three symptoms. At least one FAST symptom could be recognised in 69.1% of 18-24 years-old patients, in 74% of those aged 25-34 years, in 75.4% of those aged 35-44 years, and 77.8% in 45-55 years-old patients. With increasing stroke severity signs included in the FAST scheme were more prevalent (National Institute of Health Stroke Scale, NIHSS<5: 69%, NIHSS 6-15: 98.9%, NIHSS>15: 100%). Clustering clinical signs according to FAST lower percentages of strokes in the posterior circulation (65.2%) and in patients with TIA (62.3%) were identified.

CONCLUSIONS

FAST may be applied as a useful and rapid tool to identify stroke symptoms in young individuals aged 18-55 years. Especially in patients eligible for thrombolysis FAST might address the majority of individuals.

STUDY REGISTRATION

The study was registered in http://www.clinicaltrials.gov (No. NCT00414583).

Prehospital stroke scales in urban environments: a systematic review

OBJECTIVE

To identify and compare the operating characteristics of existing prehospital stroke scales to predict true strokes in the hospital.

METHODS

We searched MEDLINE, EMBASE, and CINAHL databases for articles that evaluated the performance of prehospital stroke scales. Quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We abstracted the operating characteristics of published prehospital stroke scales and compared them statistically and graphically.

RESULTS

We retrieved 254 articles from MEDLINE, 66 articles from EMBASE, and 32 articles from CINAHL Plus database. Of these, 8 studies met all our inclusion criteria, and they studied Cincinnati Pre-Hospital Stroke Scale (CPSS), Los Angeles Pre-Hospital Stroke Screen (LAPSS), Melbourne Ambulance Stroke Screen (MASS), Medic Prehospital Assessment for Code Stroke (Med PACS), Ontario Prehospital Stroke Screening Tool (OPSS), Recognition of Stroke in the Emergency Room (ROSIER), and Face Arm Speech Test (FAST). Although the point estimates for LAPSS accuracy were better than CPSS, they had overlapping confidence intervals on the symmetric summary receiver operating characteristic curve. OPSS performed similar to LAPSS whereas MASS, Med PACS, ROSIER, and FAST had less favorable overall operating characteristics.

CONCLUSIONS

Prehospital stroke scales varied in their accuracy and missed up to 30% of acute strokes in the field. Inconsistencies in performance may be due to sample size disparity, variability in stroke scale training, and divergent provider educational standards. Although LAPSS performed more consistently, visual comparison of graphical analysis revealed that LAPSS and CPSS had similar diagnostic capabilities.

Face Arm Speech Time Test use in the prehospital setting, better in the ambulance than in the emergency medical communication center

BACKGROUND

Prehospital identification of acute stroke increases the possibility of early treatment and good outcome. To increase identification of stroke, the Face Arm Speech Time (FAST) test was introduced in the Emergency Medical Communication Center (EMCC). This substudy aims to evaluate the implementation of the FAST test in the EMCC and the ambulance service.

METHODS

The study was conducted in the region of Stockholm, Sweden during 6 months. The study population consisted of all calls to the EMCC concerning patients presenting at least one FAST symptom or a history/finding making the EMCC or ambulance personnel to suspect stroke within 6 h. Positive FAST was compared to diagnosis at discharge. Positive predictive values (PPV) for a stroke diagnosis at discharge were calculated.

RESULTS

In all, 900 patients with a median age of 71 years were enrolled, 667 (74%) by the EMCC and 233 (26%) by the ambulances. At discharge, 472 patients (52%) were diagnosed with stroke/transient ischemic attack (TIA), 337 identified by the EMCC (71%) and 135 (29%) by the ambulances. The PPV for a discharge diagnosis of stroke/TIA was 51% (CI 47-54%) in EMCC-enrolled and 58% (CI 52-64%) in ambulance-enrolled patients. With a positive FAST the PPV of a correct stroke/TIA diagnosis increased to 56% (CI 52-61%) and 73% (CI 66-80%) in EMCC- and ambulance-enrolled patients, respectively. Positive FAST from EMCC was also found in 44% of patients with a nonstroke diagnosis at discharge. A stroke/TIA diagnosis at discharge but negative FAST was found in 58 and 27 patients enrolled by the EMCC and ambulances, respectively.

CONCLUSIONS

The PPV of FAST is higher when used on the scene by ambulance than by EMCC. FAST may be a useful prehospital tool to identify stroke/TIA but has limitations as the test can be negative in true strokes, can be positive in nonstrokes, and FAST symptoms may be present but not identified in the emergency call. For the prehospital care situation better identification tools are needed.

The use of Cincinnati Prehospital Stroke Scale during telephone dispatch interview increases the accuracy in identifying stroke and transient ischemic attack symptoms

BACKGROUND

Timely and appropriate hospital treatment of acute cerebrovascular diseases (stroke and Transient Ischemic Attacks - TIA) improves patient outcomes. Emergency Medical Service (EMS) dispatchers who can identify cerebrovascular disease symptoms during telephone requests for emergency service also contribute to these improved outcomes. The Italian Ministry of Health issued guidelines on the management of AC patients in pre-hospital emergency service, including Cincinnati Prehospital Stroke Scale (CPSS) use.We measured the sensitivity and Positive Predictive Value (PPV) of EMS dispatchers' ability to recognize stroke/TIA symptoms and evaluated whether the CPSS improves accuracy.

METHODS

A cross-sectional multicentre study was conducted to collect data from 38 Italian emergency operative centres on all cases identified with stroke/TIA symptoms at the time of dispatch and all cases with stroke/TIA symptoms identified on the scene by the ambulance personnel from November 2010 to May 2011.

RESULTS

The study included 21760 cases: 18231 with stroke/TIA symptoms at dispatch and 9791 with symptoms confirmed on the scene. The PPV of the dispatch stroke/TIA symptoms identification was 34.3% (95% CI 33.7-35.0; 6262/18231) and the sensitivity was 64.0% (95% CI 63.0-64.9; 6262/9791). Centres using CPSS more often (>10% of cases) had both higher PPV (56%; CI 95% 57-60 vs 18%; CI 95% 17-19) and higher sensitivity (71%; CI 95% 87-89 vs 52%; CI 95% 51-54).In the multivariate regression a centre's CPSS use was associated with PPV (beta 0.48 p = 0.014) and negatively associated with sensitivity (beta -0.36; p = 0.063); centre sensitivity was associated with CPSS (beta 0.32; p = 0.002), adjusting for PPV.

CONCLUSIONS

Centres that use CPSS more frequently during phone dispatch showed greater agreement with on-the-scene prehospital assessments, both in correctly identifying more cases with stroke/TIA symptoms and in giving fewer false positives for non-stroke/TIA cases. Our study shows an extreme variability in the performance among OCs, highlighting that form many centres there is room for improvement in both sensitivity and positive predictive value of the dispatch. Our results should be used for benchmarking proposals in the effort to identify best practices across the country.

Validation of the Los Angeles pre-hospital stroke screen (LAPSS) in a Chinese urban emergency medical service population

Background and purpose

Early and accurate diagnosis of stroke by emergency medical service (EMS) paramedics is critical for reducing pre-hospital delays. The Los Angeles pre-hospital stroke screen (LAPSS) has been widely used as a validated screening tool for early identifying stroke patients by EMS paramedics. However, validation of LAPSS has never been performed in Chinese stroke population. This study is aimed to verify the LAPSS for early identifying stroke patients in a Chinese urban EMS.

Methods

76 paramedics of five urban first aid stations attached to Beijing 120 EMS were involved. The paramedics were trained by professionals to quickly screen patients based on LAPSS. Potential “target stroke” individuals who met the base LAPSS screen criteria were identified. Sensitivity and specificity analyses of the LAPSS were calculated.

Results

From June 10, 2009 to June 10, 2010, paramedics transported a total of 50,220 patients. 1550 patients who met the baseline screen criteria were identified as the potential “target stroke” population. 1130 patients had the completed LAPSS information datasheet and 997 patients were clinically diagnosed with stroke. The average time of completing the LAPSS was 4.3±3.0 minutes (median, 5 minutes). The sensitivity and specificity of the LAPSS in this study was 78.44% and 90.22%, respectively. After adjusting for age factor by excluding patients of >45 years old, the sensitivity was significantly increased to 82.95% with specificity unchanged.

Conclusion

The paramedics of Beijing 120 EMS could efficiently use LAPSS as a screening tool for early identifying stroke patients. While the sensitivity of LAPSS in Chinese urban patient population was lower than those reported in previous LAPSS validation studies, the specificity was consistent with these studies. After excluded the item of “Age>45 years”, the sensitivity was improved.

National characteristics of emergency medical services responses in the United States

OBJECTIVE

Despite its long history and current prominence in U.S. communities, only limited data describe the national characteristics of emergency medical services (EMS) care in the United States. We sought to characterize out-of-hospital EMS care in the United States.

METHODS

We conducted an analysis of the 2010 National Emergency Medical Services Information System (NEMSIS) research data set, encompassing EMS emergency response data from 29 states. From these data, we estimated the national number and incidence of EMS responses. We also characterized EMS responses and the patients receiving care.

RESULTS

There were 7,563,843 submitted EMS responses, corresponding to an estimated national incidence of 17.4 million EMS emergency responses per year (56 per 1,000 person-years). The EMS response incidence varied by U.S. Census region (South 137.4 per 1,000 population per year, Northeast 85.2, West 39.7, and Midwest 33.3). The use of lights and sirens varied across Census regions (Northeast 90.3%, South 76.7%, West 68.8%, and Midwest 67.5%). The percentage of responses resulting in patient contact varied across Census regions (range 78.4% to 95.7%). The EMS time intervals were similar between Census regions; response median 5 minutes (interquartile range [IQR] 3-9), scene 14 minutes (10-20), and transport 11 minutes (7-19). Underserved populations (the elderly, minorities, rural residents, and the uninsured) were large users of EMS resources.

CONCLUSION

These data highlight the breadth and diversity of EMS demand and care in the United States.

Non-stroke admissions to a hyperacute stroke unit

A significant proportion of patients presenting to hyperacute stroke units (HSUs) are diagnosed with non-stroke (NS). This study aimed to assess the rate and diagnoses of NS patients admitted to a HSU and the implications for clinical service provision. Admissions to the HSU at the Southern General Hospital, Glasgow, were retrospectively assessed (March 2007-September 2007). NS patients were identified by two parallel ascertainment methods and NS diagnosis was confirmed by case-note and discharge letter review. Of 375 presentations, 116 (31%) were due to NS. NS diagnosis was more likely for local referrals than from regional hospitals (41% versus 19%; P = 0.0002). Compared with stroke/transient ischaemic attack patients, NS patients were significantly younger, more likely to have an magnetic resonance imaging (MRI) scan and had a shorter length of hospital stay. Common NS diagnoses were migraine (22%), functional neurological disorder (14%), syncope (12%) and seizure (6%). NS patients who had an MRI scan were more likely to have a length of stay ≥2 days (75% versus 53%; P = 0.03). NS makes up one-third of acute stroke-like presentations with a high frequency of neurological conditions. NS patients tend to be younger and require significant investigation. The increased use of MRI and neurological services has implications for providing a hyperacute stroke service.