Stefan Helwig

Is Prehospital Treatment of Acute Stroke too Expensive An Economic Evaluation Based on the First Trial

Background: Recently, a strategy for treating stroke directly at the emergency site was developed. It was based on the use of an ambulance equipped with a scanner, a point-of-care laboratory, and telemedicine capabilities (Mobile Stroke Unit). Despite demonstrating a marked reduction in the delay to thrombolysis, this strategy is criticized because of potentially unacceptable costs. Methods: We related the incremental direct costs of prehospital stroke treatment based on data of the first trial on this concept to one year direct cost savings taken from published research results. Key parameters were configuration of emergency medical service personnel, operating distance, and population density. Model parameters were varied to cover 5 different relevant emergency medical service scenarios. Additionally, the effects of operating distance and population density on benefit-cost ratios were analyzed. Results: Benefits of the concept of prehospital stroke treatment outweighed its costs with a benefit-cost ratio of 1.96 in the baseline experimental setting. The benefit-cost ratio markedly increased with the reduction of the staff and with higher population density. Maximum benefit-cost ratios between 2.16 and 6.85 were identified at optimum operating distances in a range between 43.01 and 64.88 km (26.88 and 40.55 miles). Our model implies that in different scenarios the Mobile Stroke Unit strategy is cost-efficient starting from an operating distance of 15.98 km (9.99 miles) or from a population density of 79 inhabitants per km2 (202 inhabitants per square mile). Conclusion: This study indicates that based on a one-year benefit-cost analysis that prehospital treatment of acute stroke is highly cost-effective across a wide range of possible scenarios. It is the highest when the staff size of the Mobile Stroke Unit can be reduced, for example, by the use of telemedical support from hospital experts. Although efficiency is positively related to population density, benefit-cost ratios can be greater than 1 even in rural settings.

Prehospital Imaging-Based Triage of Head Trauma with a Mobile Stroke Unit: First Evidence and Literature Review.

An ambulance equipped with a computed tomography (CT) scanner, point‐of‐care laboratory, and telemedicine capabilities (Mobile Stroke Unit [MSU]) has been shown to enable delivery of thrombolysis to stroke patients at the emergency site, thereby significantly decreasing time to treatment. However, the MSU frequently assesses patients with cerebral disorders other than stroke. For some of these disorders, prehospital CT scanning may also be beneficial.

First Automated Stroke Imaging Evaluation via Electronic Alberta Stroke Program Early CT Score in a Mobile Stroke Unit.

Background: Recently, a mobile stroke unit (MSU) was shown to facilitate acute stroke treatment directly at the emergency site. The neuroradiological expertise of the MSU is improved by its ability to detect early ischemic damage via automatic electronic (e) evaluation of CT scans using a novel software program that calculates the electronic Alberta Stroke Program Early CT Score (e-ASPECTS). Methods: The feasibility of integrating e-ASPECTS into an ambulance was examined, and the clinical integration and utility of the software in 15 consecutive cases evaluated. Results: Implementation of e-ASPECTS onto the MSU and into the prehospital stroke management was feasible. The values of e-ASPECTS matched with the results of conventional neuroradiologic analysis by the MSU team. The potential benefits of e-ASPECTS were illustrated by three cases. In case 1, excluding early infarct signs supported the decision to directly perform prehospital thrombolysis. In case 2, in which stroke was caused by large-vessel occlusion, the high e-ASPECTS value supported the decision to initiate intra-arterial treatment and triage the patient to a comprehensive stroke center. In case 3, the e-ASPECTS value was 10, indicating the absence of early infarct signs despite pre-existing cerebral microangiopathy and macroangiopathy, a finding indicating the programs robustness against artefacts. Conclusions: This study on the integration of e-ASPECTS into the prehospital stroke management via a MSU showed for the first time that such integration is feasible, and aids both decision regarding the treatment option and the triage regarding the most appropriate target hospital.

Standard operating procedures improve acute neurologic care in a sub-Saharan African setting

Objective: Quality of neurologic emergency management in an under-resourced country may be improved by standard operating procedures (SOPs). Methods: Neurologic SOPs were implemented in a large urban (Banjul) and a small rural (Brikama) hospital in the Gambia. As quality indicators of neurologic emergency management, performance of key procedures was assessed at baseline and in the first and second implementation years. Results: At Banjul, 100 patients of the first-year intervention group exhibited higher rates of general procedures of emergency management than 105 control patients, such as neurologic examination (99.0% vs 91.4%; p < 0.05) and assessments of respiratory rate (98.0% vs 81.9%, p < 0.001), temperature (60.0% vs 36.2%; p < 0.001), and glucose levels (73.0% vs 58.1%; p < 0.05), in addition to written directives by physicians (96.0% vs 88.6%, p < 0.05), whereas assessments of other vital signs remained unchanged. In stroke patients, rates of stroke-related procedures increased: early CT scanning (24.3% vs 9.9%; p < 0.05), blood count (73.0% vs 49.3%; p < 0.01), renal and liver function tests (50.0% vs 5.6%, p < 0.001), aspirin prophylaxis (47.3% vs 9.9%; p < 0.001), and physiotherapy (41.9% vs 4.2%; p < 0.001). Most effects persisted until the second-year evaluation. SOP implementation was similarly feasible and beneficial at the Brikama hospital. However, outcomes did not significantly differ in the hospitals. Conclusions: Implementing SOPs is a realistic, low-cost option for improving process quality of neurologic emergency management in under-resourced settings. Classification of evidence: This study provides Class IV evidence that, for patients with suspected neurologic emergencies in sub-Saharan Africa, neurologic SOPs increase the rate of performance of guideline-recommended procedures.

Dosage Calculation for Intravenous Thrombolysis of Ischemic Stroke: To Weigh or to Estimate

Background: Estimation is a widely used method of assessing the weight of patients with acute stroke. Because the dosage of tissue plasminogen activator (tPA) is weight-dependent, errors in estimation lead to incorrect dosing. Methods: We installed a ground-level scale in the computed tomography (CT) suite of our hospital and also integrated a scale into the CT table of our Mobile Stroke Unit in order to prospectively assess the differences between reported, estimated, and measured weights of acute stroke patients. An independent rater asked patients to report their weight. The patients’ weights were also estimated by the treating physician and measured with a scale. Differences between reported, estimated, and measured weights were analyzed statistically. Results: For 100 consecutive patients, weighing was possible without treatment delays. Weights estimated by the physician diverged from measured weights by 10% or more for 27 patients and by 20% or more for 6 patients. Weights reported by the patient diverged from measured weights by 10% or more for 12 patients. Weights reported by the patients differed significantly less from measured weights (mean, 4.1 ± 3.1 kg) than did weights estimated by the physician (5.7 ± 4.4 kg; p = 0.003). Conclusion: This first prospective study of weight assessment in acute stroke shows that the use of an easily accessible scale makes it feasible to weigh patients with acute stroke without the treatment delay associated with additional patient transfers. Physicians’ estimates of patients’ weights demonstrated substantial aberrations from measured weights. Avoiding these deviations would improve the accuracy of tPA dosage.

Prehospital Computed Tomography Angiography in Acute Stroke Management

Background: An ambulance equipped with a computed tomography (CT) scanner, a point-of-care laboratory, and telemedicine capabilities (mobile stroke unit [MSU]) has been shown to enable the delivery of thrombolysis to stroke patients directly at the emergency site, thereby significantly decreasing time to treatment. However, work-up in an MSU that includes CT angiography (CTA) may also potentially facilitate triage of patients directly to the appropriate target hospital and specialized treatment, according to their individual vascular pathology. Methods: Our institution manages a program investigating the prehospital management of patients with suspicion of acute stroke. Here, we report a range of scenarios in which prehospital CTA could be relevant in triaging patients to the appropriate target hospital and to the individually required treatment. Results: Prehospital CTA by use of an MSU allowed to detect large vessel occlusion of the middle cerebral artery in one patient with ischemic stroke and occlusion of the basilar artery in another, thereby allowing rational triage to comprehensive stroke centers for immediate intra-arterial treatment. In complementary cases, prehospital imaging not only allowed diagnosis of parenchymal hemorrhage with a spot sign indicating ongoing bleeding in one patient and of subarachnoid hemorrhage in another but also clarified the underlying vascular pathology, which was relevant for subsequent triage decisions. Conclusion: Defining the vascular pathology by CTA directly at the emergency site may be beneficial in triaging patients with various cerebrovascular diseases to the most appropriate target hospital and specialized treatment.

Author response: Standard operating procedures improve acute neurologic care in a sub-Saharan African setting

We thank Dr. Chin for the comments on our article.1 We agree that the study was performed under experimental conditions. This limitation, aimed to be minimized by assessment conditions that were similar before and after standard operating procedure (SOP) implementation and by the absence of provision of additional resources, was discussed.1 The statement that sub-Saharan African countries face crucial challenges that are, in the end, associated with the severe financial constrains is true. This was documented in our study,1 including the problem of CT performance due to unsettled payment questions. SOPs are only one of several steps, among which are long-term international financial support and cooperation, structural measures (such as health insurance systems), and systematic training of neurologists (thereby avoiding brain drain). Yet, what can be done today? As long as the financial support and the structural frameworks remain suboptimal, SOPs to make better use of the still available, although limited, personnel and technical resources (e.g., adjustment of physiologic measures, aspirin prophylaxis, or physiotherapy) are a relevant step towards guideline-recommended stroke management. As suggested by Dr. Chin, these might be complemented by further SOPs that focus on postemergency management and measures for prevention.2

Mobile Stroke Units - Cost-Effective or Just an Expensive Hype?

Purpose of ReviewAcute stroke is a treatable disease. Nevertheless, only a minority of patients obtain guideline-adjusted therapy. One major reason is the small time window in which therapies have to be administered in order to reverse or mitigate brain injury and prevent disability. The Mobile Stroke Unit (MSU) concept, available for a decade now, is spreading worldwide, comprising ambulances, fully equipped with computed tomography, laboratory unit and telemedicine connection to the stroke centre and staffed with a specialised stroke team. Besides its benefits, this concept adds a relevant amount of costs to health services.Recent FindingsThe feasibility of the MSU and its impact on reducing treatment times have been proven by several research trials. In addition, pre-hospital stroke diagnosis including computed tomographic angiography analysis facilitates correct triage of patients, needing mechanical recanalization, thereby reducing the number of secondary or inter-hospital transfers. Even so, the concept is not yet fully implemented on a broad scale. One reason is the still open question of cost-effectiveness. There are assumptions based on the randomised trials of MSUs hinting towards an acceptable amount of money per quality-adjusted life years and overall cost-effectiveness. Up to now, neither a prospective analysis nor a consideration of secondary transfer avoidance is available.SummaryThe MSU concept is an innovative and impactful strategy to improve stroke management, especially in times of constraints in healthcare economics and health care professionals. Prospective information is needed to answer the cost-effectiveness question satisfactorily.