Poisson Modeling Predicts Acute Telestroke Patient Call Volume.

Background: Predicting the frequency of calls for telestroke and emergency teleneurology consultation is essential to prepare staffing for the immediate management of time-sensitive strokes. In this study, we evaluate Poisson distribution count data using a generalized linear model that predicts the volume of hourly telestroke calls over a 24-h period. Methods: We performed an Institutional Review Board approved retrospective cohort review of patients (January 2019-December 2022) from an institutional telestroke database at a large nonprofit multihospital system in the United States. All patients ≥18 years with a telestroke activation were included. Telestroke calls were quantified in frequency per day and analyzed by multiple time and date intervals. Poisson probability mass function (PMF) and cumulative distribution function (CDF) were used to predict call probabilities. A univariable Poisson regression model was fit to predict call volumes. Results: A total of 8,499 patients at 21 hospitals met inclusion criteria, the mean calls/day were 5.82 ± 2.54, and mean calls/day within each hour increment ranged from a minimum of 0.07 from 5 a.m. to 6 a.m. to a maximum of 0.45 from 7 p.m. to 8 p.m. The Poisson distribution was the most appropriate parametric probability model for these data, confirmed by the fit of the data to the expected distributions corresponding to the calculated means. The predicted probabilities of call frequencies by hour were calculated using the Poisson PMF and CDF; the probability of two or fewer calls/day by hour ranged from 98.9% to 99.9%. Univariable Poisson regression modeled an increase of future calls/day from 6.7 calls/day in July 2023 to 7.6 calls/day in October 2025. Conclusion: Poisson modeling closely fits telestroke call volumes, predicts the future volumes, and can be applied to any health system in which the mean call volume is known, which may inform the number of physicians needed to cover calls in real-time.

Extended Window Thrombolytics for Ischemic Stroke: A Telestroke versus In-person Experience.

Background and Purpose: Telestroke evaluation of patients with acute ischemic stroke is supported by American Heart and Stroke Association Guidelines. However, there is no data on outcomes or safety of administering IV thrombolytic stroke therapy using extended window criteria (>4.5 h since onset of symptoms with a hyperacute MRI diffusion T2/FLAIR mismatch) via telestroke. Here, we report adverse events and outcomes of extended-window thrombolysis by telestroke vs in-person care. Methods: We performed a retrospective cohort review from 2020 to 2022 of prospectively collected multinstitutional databases from a large, not-for-profit health system with both in-person stroke and telestroke care. The primary outcome was frequency of symptomatic intracranial hemorrhage (sICH). Secondary outcomes were favorable functional outcome at hospital discharge (modified Rankin Scale, mRS, 0-3) and discharge disposition. Results: A total of 33 patients were treated with extended-window thrombolysis (n = 20 in-person, n = 13 telestroke). The median NIH stroke scale was 6, and time since last known normal was similar (median [95% CI]: in-person 13 h [11-15 h] vs telestroke 12 h [9-16 h], P = .33). The sICH frequency was low and occurred in one patient (4.8% in-person vs 0% by telestroke). Favorable outcome at discharge was not different between in-person and telestroke care (median mRS [95% CI]: 2 [1-3] vs 1 [0-2], OR .0 [.0-1.8], P = .27), and discharge deposition was also similar. Conclusions: In patients eligible for extended window acute stroke treatment with thrombolytics, there was no difference in adverse events between telestroke and in-person care.

Teleneurocritical care is associated with equivalent billable charges to in-person neurocritical care for patients with acute stroke.

INTRODUCTION: Teleneurocritical care (TNCC) provides virtual care for hospitals who do not have continuous neurointensivist coverage. It is not known if TNCC is cost effective nor which variables impact the total billed charges per patient encounter. We characterize cost, defined by charge characteristics of TNCC compared to in-person neurocritical care (NCC), for patients with acute ischemic or hemorrhagic stroke requiring ICU care. METHODS: We performed a retrospective review from 2018 to 2021 of prospectively collected multinstitutional databases from a large, integrated, not-for-profit health system with an in-person NCC and spoke TNCC sites. The primary outcome was the total billable charge per TNCC patient with acute ischemic or hemorrhagic stroke compared to in-person NCC. Secondary outcomes were functional outcome, transfer rate, and length of stay (LOS). RESULTS: A total of 1779 patients met inclusion criteria, 1062 at the hub in-person NCC hospital and 717 at spoke TNCC hospitals. Total billed patient charges of TNCC were similar to in-person NCC (median 104% of the cost per in-person NCC patient, 95% CI: 99%-108%). From 2018 to 2021, the charge difference between TNCC and NCC was not different (r2 = 0.71, p = 0.16). Both age and length stay were independently predictive of charges: for every year older the charge increased by US $6.3, and every day greater LOS the charge increased by $2084.3 (p < 0.001, both). TNCC transfer rates were low, and TNCC had shorter LOS and greater favorable functional outcome. DISCUSSION: TNCC was associated with similar patient financial charges as compared to in-person NCC. Standardization of care and the integrated hub-spoke value-focused operational procedures of TNCC may be applicable to other healthcare systems, however, further prospective study is needed.

Teleneurocritical Care for Patients with Large Vessel Occlusive Ischemic Stroke Treated by Thrombectomy.

BACKGROUND: Teleneurocritical care (TNCC) provides 24/7 virtual treatment of patients with neurological disease in the emergency department or intensive care unit. However, it is not known if TNCC is safe, effective, or associated with similar outcomes compared with in-person neurocritical care. We aim to determine the effect of daily inpatient consults from TNCC on the outcomes of patients with large vessel occlusive acute ischemic stroke treated by thrombectomy. METHODS: A multicenter, retrospective cohort of consecutive patients ≥ 18 years old with acute ischemic stroke from a large vessel occlusion treated by thrombectomy were identified from 2018 to 2021 within a telehealth network of an integrated not-for-profit health care system in the United States. The primary end point was good functional outcome, i.e., modified Rankin Scale 0-3, at the time of hospital discharge in patients receiving in-person neurocritical care versus TNCC. RESULTS: A total of 437 patients met inclusion criteria, 226 at the in-person hospital (median age 67, 53% women) and 211 at the two TNCC hospitals (median age 74, 49% women). The rate of successful endovascular therapy (modified Thrombolysis in Cerebral Infarction score 2b-3) was not different among hospitals. Good functional outcome at discharge was similar between in-person neurocritical care and TNCC (in-person 31.4% vs. TNCC 33.5%, odds ratio 0.88, 95% confidence interval 0.6-1.3; p = 0.64). Only National Institutes of Health stroke scale and age were multivariable predictors of outcome. There were no differences in mortality (9.3% vs. 13.2%, p = 0.19), intensive care unit length of stay (2.1 vs. 1.9 days, p = 0.39), or rate of symptomatic intracerebral hemorrhage (6.8% vs. 6.6%, p = 0.47) between in-person neurocritical care and TNCC. CONCLUSIONS: Teleneurocritical care allows for equivalent favorable functional outcomes compared with in-person neurocritical care for patients with acute large vessel ischemic stroke receiving thrombectomy. The standardized protocols used by TNCC in this study, specifically the comprehensive 24/7 treatment of patients in the intensive care unit for the length of their stay, may be relevant for other health systems with limited in-person resources; however, additional study is required.

Insurance payment for artificial intelligence technology: Methods used by a stroke artificial intelligence system and strategies to qualify for the new technology add-on payment.

The first ever insurance reimbursement for an artificial intelligence (AI) system, which expedites triage of acute stroke, occurred in 2020 when the Centers for Medicare and Medicaid Services (CMS) granted approval for a New Technology Add-on Payment (NTAP). Key aspects of the AI system that led to its approval by the CMS included its unique mechanism of action, use of robotic process automation, and clear linkage of the system's output to clinical outcomes. The specific strategies employed encompass a first-case scenario of proving reimbursable value for improved stroke outcomes using AI. Given the rapid change in utilization of AI technology in stroke care, we describe the economic drivers of stroke AI systems in healthcare, focusing on concepts of reimbursement for value added by AI to the stroke care system. This report reviews (1) the successful approach used by the first NTAP-approved AI system, (2) economic variables in insurance reimbursement for AI, and (3) resultant strategies that may be utilized to facilitate qualification for NTAP reimbursement, which may be adopted by other AI systems used in stroke care.

Acute on Chronic Neuromuscular Respiratory Failure in the Intensive Care Unit: Optimization of Triage, Ventilation Modes, and Extubation.

Critical care management of acute respiratory failure in patients with neuromuscular disease (NMD) such as amyotrophic lateral sclerosis (ALS) is not standardized and is challenging for many critical care specialists. Progressive hypercapnic respiratory failure and ineffective airway clearance are key issues in this patient population. Often at the time of hospital presentation, patients are already supported by home mechanical ventilatory support with noninvasive ventilation (NIV) and an airway clearance regimen. Prognosis is poor once a patient develops acute respiratory failure requiring intubation and invasive mechanical ventilatory support, commonly leading to tracheostomy or palliative-focused care.  We focus on this understudied group of patients with ALS without tracheostomy and incorporate existing data to propose a technical approach to the triage and management of acute respiratory failure, primarily for those who require intubation and mechanical ventilatory support for reversible causes, and also for progression of end-stage disease. Optimizing management in this setting improves both quality and quantity of life. Neuromuscular patients with acute respiratory failure require protocolized and personalized triage and treatment. Here, we describe the technical methods used at our single institution. The triage phase incorporates comprehensive evaluation for new etiologies of hypoxia and hypercapnia, which are not initially presumed to be secondary to progression or end-stage neuromuscular respiratory failure. In select patients, this may involve intubation or advanced adjustments of NIV machines. Next, once the acute etiology(s) is identified and treated, the focus shifts: training and use of mechanical airway clearance to optimize pulmonary function, facilitation of NIV wean or successful extubation to NIV, and transition to a stable regimen for home ventilation. The comprehensive protocol described here incorporates multi-institutional approaches and effectively optimizes acute respiratory failure in patients with neuromuscular pulmonary disease.

Early Head Computed Tomography Abnormalities Associated with Elevated Intracranial Pressure in Severe Traumatic Brain Injury.

BACKGROUND AND PURPOSE: Intracranial pressure (ICP) monitoring is recommended in severe traumatic brain injury (sTBI), yet invasive monitoring has risks, and many patients do not develop elevated ICP. Tools to identify patients at risk for ICP elevation are limited. We aimed to identify early radiologic biomarkers of ICP elevation. METHODS: In this retrospective study, we analyzed a prospectively enrolled cohort of patients with a sTBI at an academic level 1 trauma center. Inclusion criteria were nonpenetrating TBI, age ≥16 years, Glasgow Coma Scale (GCS) score ≤8, and presence of an ICP monitor. Two independent reviewers manually evaluated 30 prespecified features on serial head computed tomography (CTs). Patient characteristics and radiologic features were correlated with elevated ICP. The primary outcome was clinically relevant ICP elevation, defined as ICP ≥ 20 mm Hg on at least 5 or more hourly recordings during postinjury days 0-7 with concurrent administration of an ICP-lowering treatment. RESULTS: Among 111 sTBI patients, the median GCS was 6 (interquartile range 3-8), and 45% had elevated ICP. Features associated with elevated ICP were younger age (every 10-year decrease, odds ratio [OR] 1.4), modified Fisher scale (mFS) score at 0-4 hours postinjury (every 1 point, OR 1.8), and combined volume of contusional hemorrhage and peri-hematoma edema (10 ml, OR 1.2) at 4-18 hours postinjury. CONCLUSIONS: Younger age, mFS score, and volume of contusion are associated with ICP elevation in patients with a sTBI. Imaging features may stratify patients by their risk of subsequent ICP elevation.

Hypoperfusion Intensity Ratio Predicts Malignant Edema and Functional Outcome in Large-Vessel Occlusive Stroke with Poor Revascularization.

BACKGROUND AND OBJECTIVE: Malignant cerebral edema (MCE) is a well-known complication in patients with acute ischemic stroke with core infarcts ≥ 80 mL caused by large-vessel occlusions. MCE can also develop in patients with smaller infarcts with moderate -to-large volume of tissue at risk who do not achieve successful revascularization with endovascular thrombectomy (ET). Features that predict the development of MCE in this population are not well-described. We aim to identify predictors of MCE and 90-day functional outcome in stroke patients with an anterior circulation large vessel occlusion (LVO) and a < 80 mL ischemic core who do not achieve complete reperfusion. METHODS: We reviewed our institutional stroke registry and included patients who achieved unsuccessful revascularization, mTICI 0-2a, after ET and whose baseline imaging was notable for a core infarct < 80 mL, a Tmax > 6 s volume ≥ 80 mL, and a mismatch ratio ≥ 1.8. MCE was defined as ≥ 5 mm of midline shift on follow-up imaging, obtained 6-48 h after the pre-ET perfusion scan. RESULTS: Thirty-six patients met inclusion criteria. Unadjusted analysis demonstrated that younger age, higher systolic blood pressure, larger core volume, and higher hypoperfusion intensity ratio (HIR) were associated with MCE (all p < 0.02). In multivariate logistic regression analysis, age, HIR, and core infarct volume were independent predictors of MCE. The optimal HIR threshold to predict MCE was ≥ 0.54 (OR 14.7, 95% CI 2.4-78.0, p = 0.003). HIR was also associated with 3-month mRS (HIR ≥ 0.54 for mRS of 3-6: OR 10.8, 95% CI 1.9-44.0, p = 0.02). CONCLUSIONS: Younger age, larger core infarct volume, and higher HIR are predictive of MCE in patients with anterior circulation LVO, moderate-to-large tissue at risk, and suboptimal revascularization. HIR is correlated with three-month functional outcomes.

Rescue of Nimodipine-Induced Refractory Vasoplegia With Hydroxocobalamin in Subarachnoid Hemorrhage: A Case Report.

BACKGROUND: We report a case of refractory vasoplegia after nimodipine administration that was unresponsive to triple vasopressor therapy and was rescued by IV hydroxocobalamin. CASE SUMMARY: An 84-year-old male presented comatose from a subarachnoid hemorrhage and developed severe hypotension unresponsive to three vasopressors following a single dose of enteral nimodipine. Multisystem point-of-care ultrasonography ruled out alternate etiologies of shock, indicating that this was likely a vasoplegic state caused by nimodipine. We administered 5 grams of IV hydroxocobalamin over 15 minutes due to the possibility of impaired nitric oxide metabolism as the driver of vasoplegia. This led to immediate improvement in hemodynamics and rapid discontinuation of vasopressors. The patient experienced chromaturia but no other adverse effects due to hydroxocobalamin. CONCLUSIONS: Nimodipine administration is a standard practice for patients with aneurysmal subarachnoid hemorrhage to reduce unfavorable outcomes from cerebral vasospasm. Although mild hypotension is a common side effect of nimodipine, in rare cases, it may become profound, leading to refractory vasoplegia. There is no evidence-base for reversal agents for nimodipine-induced vasoplegia, and this case is the first to demonstrate successful use of hydroxocobalamin as a potential rescue therapy. We also propose an algorithm for treatment of vasoplegia with consideration of medications that act on nitric oxide-mediated vasodilation and their side-effect profiles.

Endovascular Treatment of Acute Carotid Stent Occlusion: Aspiration Thrombectomy and Angioplasty.

Introduction Acute carotid stent occlusion (CSO) is a rare complication of endovascular carotid stent placement that requires emergent intervention. We describe angioplasty or combined angioplasty and aspiration thrombectomy as a new endovascular technique for CSO treatment. The technique is compared to others previously described in the literature. Methods We performed a retrospective cohort study of all patients who underwent endovascular treatment (ET) of acute symptomatic CSO from January 2008 to March 2018 at our neurovascular referral center. Patient demographics, endovascular treatment details, and outcome data were determined from the electronic medical record. Primary outcome was successful stent recanalization and cerebral reperfusion (modified thrombolysis in cerebral infarction (mTICI) score IIB-III). Secondary outcomes were National Institutes of Health Stroke Scale (NIHSS) shift from presentation to discharge, mortality, and modified Rankin Scale (mRS) score at 3 months. Additionally, a literature review (years 2008-2019) was performed to characterize other techniques for ET of CSO. Results Four patients who underwent ET of acute CSO were identified. ET treatment by angioplasty (n = 1) or combined aspiration thrombectomy and angioplasty (n = 3) resulted in carotid stent recanalization in all patients. Tandem intracranial occlusions were present in three patients (75%), and successful cerebral reperfusion was achieved in all patients. Patient symptoms improved (mean NIHSS shift -5.3 ± 7.2 at discharge). One patient died of a symptomatic reperfusion hemorrhage and another died of cardiac complications by 3-month follow-up. The mRS scores of the surviving patients were 1 and 3. Previously described studies (n = 14) using different and varied techniques had moderate recanalization rates and outcomes. Conclusion Combined aspiration thrombectomy and angioplasty for the neurointerventional treatment of acute CSO leads to high rates of stent recanalization and cerebral reperfusion. The recanalization rate here is improved compared to previously reported techniques. Further multicenter studies are required to risk-stratify patients for specific ET interventions.

A Standardized Checklist Improves the Transfer of Stroke Patients from the Neurocritical Care Unit to Hospital Ward.

BACKGROUND AND PURPOSE: The transfer of patients with ischemic stroke from the intensive care unit (ICU) to noncritical care inpatient wards involves detailed information sharing between care teams. Our local transfer process was not standardized, leading to potential patient risk. We developed and evaluated an "ICU Transfer Checklist" to standardize communication between the neurocritical care team and the stroke ward team. METHODS: Retrospective review of consecutive patients with ischemic stroke admitted to the neurocritical care unit who were transferred to the stroke ward was used to characterize transfer documentation. A multidisciplinary team developed and implemented an ICU Transfer Checklist that contained a synthesis of the patient's clinical course, immediate "to-do" action items, and a system-based review of active medical problems. Postintervention checklist utilization was recorded for 8 months, and quality metrics for the postintervention cohort were compared to the preintervention cohort. Providers were surveyed pre- and postintervention to characterize perceived workflow and quality of care. RESULTS: Patients before (n = 52) and after (n = 81) ICU Transfer Checklist implementation had similar demographic and clinical characteristics. In the postchecklist implementation period, the ICU Transfer Checklist was used in over 85% of patients and median hospital length of stay (LOS) decreased (8.6 days vs 5.4 days, P = .003), while ICU readmission rate remained low. The checklist was associated with improved perceptions of safety and decreased time needed to transfer patients. CONCLUSIONS: Use of the standardized ICU Transfer Checklist was associated with decreased hospital LOS and with improvements in providers' perceptions of patient safety.

Artificial intelligence to diagnose ischemic stroke and identify large vessel occlusions: a systematic review.

BACKGROUND AND PURPOSE: Acute stroke caused by large vessel occlusions (LVOs) requires emergent detection and treatment by endovascular thrombectomy. However, radiologic LVO detection and treatment is subject to variable delays and human expertise, resulting in morbidity. Imaging software using artificial intelligence (AI) and machine learning (ML), a branch of AI, may improve rapid frontline detection of LVO strokes. This report is a systematic review of AI in acute LVO stroke identification and triage, and characterizes LVO detection software. METHODS: A systematic review of acute stroke diagnostic-focused AI studies from January 2014 to February 2019 in PubMed, Medline, and Embase using terms: 'artificial intelligence' or 'machine learning or deep learning' and 'ischemic stroke' or 'large vessel occlusion' was performed. RESULTS: Variations of AI, including ML methods of random forest learning (RFL) and convolutional neural networks (CNNs), are used to detect LVO strokes. Twenty studies were identified that use ML. Alberta Stroke Program Early CT Score (ASPECTS) commonly used RFL, while LVO detection typically used CNNs. Image feature detection had greater sensitivity with CNN than with RFL, 85% versus 68%. However, AI algorithm performance metrics use different standards, precluding ideal objective comparison. Four current software platforms incorporate ML: Brainomix (greatest validation of AI for ASPECTS, uses CNNs to automatically detect LVOs), General Electric, iSchemaView (largest number of perfusion study validations for thrombectomy), and Viz.ai (uses CNNs to automatically detect LVOs, then automatically activates emergency stroke treatment systems). CONCLUSIONS: AI may improve LVO stroke detection and rapid triage necessary for expedited treatment. Standardization of performance assessment is needed in future studies.

ICU Interventions in Ischemic Stroke Patients Treated Using Liberalized IV-tPA Criteria.

BACKGROUND AND OBJECTIVE: Current standard practice guidelines recommend ICU admission for ischemic stroke patients treated with intravenous tissue plasminogen activator (IV-tPA). More recently, the trend in stroke care is to broaden eligibility for IV thrombolysis. Two examples are a more liberal inclusion criteria known as SMART criteria (sIV-tPA), and the transfer of patients to comprehensive stroke centers (CSC). The present study characterizes ICU interventions in these patients. Understanding which stroke patients that require ICU-level care may allow for placement of patients in the appropriate level of care at hospital admission. METHODS: We performed a retrospective review of consecutive transfer and nontransfer sIV-tPA-treated patients admitted to the ICU at a CSC. We evaluated the frequency, timing, and nature of ICU interventions. RESULTS: Three hundred and thirty one patients were treated with sIV-tPA and 42% required ICU interventions during ICU admission. Of patients requiring ICU interventions, 98% had an ICU intervention performed in triage, prior to admission. National Institute of Health Stroke Scale score only had a moderate association to requirement of ICU interventions. Neither transferring patients to a CSC nor the number of standard IV-tPA contraindications increased ICU interventions. CONCLUSIONS: Liberalized IV-tPA administration did not increase ICU interventions. Nearly all patients that required ICU interventions declared this need in triage, prior to ICU admission. This timing of ICU intervention use during triage is highly sensitive for whether a patient will require ongoing ICU-level care during hospital admission. Identifying ICU intervention use in triage may allow for more effective placement of post-IV-tPA patients in the appropriate inpatient care setting, leading to better utilization of scarce ICU resources.