Neurocritical Care of Emergent Large-Vessel Occlusion: The Era of a New Standard of Care

Cerebral Ischemic Reperfusion Injury: Preventative and Therapeutic Strategies

Acute ischemic stroke is a leading cause of morbidity and mortality in the United States. Treatment goals remain focused on restoring blood flow to compromised areas. However, a major concern arises after reperfusion occurs. Cerebral ischemic reperfusion injury is defined as damage to otherwise salvageable brain tissue occurring with the reestablishment of the vascular supply to that region. The pool of eligible patients for revascularization continues to grow, especially with the recently expanded endovascular therapeutic window. Neurointensivists should understand and manage complications of successful recanalization. In this review, we examine the pathophysiology, diagnosis, and potential management strategies in cerebral ischemic reperfusion injury.

Predictive Factors of Perioperative Stroke-Related Mortality Following Vascular Surgery: A Retrospective Analysis

OBJECTIVE

Vascular surgical procedures have one of the highest risks of perioperative stroke and stroke-related mortality, yet the independent risk factors contributing to this increased mortality have not been described. Perioperative strokes are thought to result from a combination of embolism and hypoperfusion mechanisms. The purpose of this study is to describe the independent predictors of perioperative stroke-related mortality in the vascular surgical population using the Pennsylvania Health Care Cost Containment Council (PHC4) database which collects cause of death data.

METHODS

This retrospective, case-control study evaluated 4,128 patients aged 18-99 who underwent a vascular, non-carotid surgical procedure and subsequently suffered perioperative mortality. Common surgical comorbidities and risk factors for perioperative stroke, including carotid stenosis and atrial fibrillation, were evaluated in multivariate regression analysis.

RESULTS

Patients with carotid stenosis were 2.6 (aOR, 95% CI 1.4-4.5) times more likely to suffer perioperative mortality from stroke than from other causes. Additionally, in-hospital stroke, history of stroke, admission from a healthcare facility, and cancer were all positive predictive factors, whereas atrial fibrillation, emergency admission, hypertension, and diabetes were associated with decreased risk of perioperative stroke-related mortality.

CONCLUSIONS

Identification of vascular surgical population-specific predictors of stroke-related mortality can help to enhance preoperative risk-stratification tools and guide perioperative management of identified high-risk patients. Increased neurophysiologic monitoring in the perioperative period to prevent delays in diagnosis of perioperative stroke offers a strategy to reduce risk of perioperative stroke-related mortality in vascular surgical patients.

Care of the Patient With Acute Ischemic Stroke (Endovascular/Intensive Care Unit-Postinterventional Therapy): Update to 2009 Comprehensive Nursing Care Scientific Statement: A Scientific Statement From the American Heart Association

Ischemic stroke remains the fifth leading cause of death in the United States. Nurses play a pivotal role in the care of patients throughout the continuum. With the advances in stroke care, including mechanical thrombectomy, the American Heart Association/American Stroke Association charged the writing panel to complement the 2009 clinical practice guideline, "Comprehensive Overview of Nursing and Interdisciplinary Care of the Acute Ischemic Stroke Patient," with current evidence-based nursing care. This update is 1 of a 3-part series focusing on emergency medical services/emergency care, endovascular/intensive care unit care, and postacute care. The aim of this scientific statement is to review and present current evidence, complications, best practices, and clinical practice strategies to provide current comprehensive scientific information for nursing care in the neuroendovascular area and intensive care unit in conjunction with medical treatments, including intravenous thrombolysis and mechanical thrombectomy.

Perioperative stroke-related mortality after non-cardiovascular, non-neurological procedures: A retrospective risk factor evaluation of common surgical comorbidities

BACKGROUND

Perioperative stroke-related mortality in the non-cardiovascular, non-neurological surgery population is an uncommon, yet devastating outcome. A combination of emboli and hypoperfusion may cause large vessel occlusions leading to perioperative strokes and mortality. Identifying independent risk factors for perioperative stroke-related mortality may enhance risk-stratification algorithms and preventative therapies.

OBJECTIVES

This study utilised cause-of-death data to determine independent risk scores for common surgical comorbidities that may lead to perioperative stroke-related mortality, including atrial fibrillation and asymptomatic carotid stenosis.

METHODS

This retrospective, IRB-exempt, case-control study evaluated non-cardiovascular, non-neurological surgical patients in a claims-based database. ICD-10-CM and ICD-9-CM codes identified cause of death and comorbidity incidences, respectively. A multivariate regression analysis then established adjusted independent risk scores of each comorbidity in relation to perioperative stroke-related mortality.

RESULTS

Patients with atrial fibrillation were more likely (1.7 aOR, 95% CI (1.1, 2.8) p = 0.02) to die from perioperative stroke-related mortality than from other causes. No association was found with asymptomatic carotid stenosis. Further, in-hospital strokes (25.9 aOR, 95% CI (16.0, 41.8) p < 0.001) or diabetes (1.8 aOR, 95% CI (1.1, 2.9) p = 0.02) may increase perioperative stroke-related mortality risk.

CONCLUSIONS

Atrial fibrillation, diabetes and in-hospital strokes may be independent risk factors for perioperative stroke-related mortality in the non-cardiovascular, non-neurological surgery population.

Blood Pressure Management Before, During, and After Endovascular Thrombectomy for Acute Ischemic Stroke

There is an absence of specific evidence or guideline recommendations on blood pressure management for large vessel occlusion stroke patients. Until randomized data are available, the periprocedural blood pressure management of patients undergoing endovascular thrombectomy can be viewed in two phases relative to the achievement of recanalization. In the hyperacute phase, prior to recanalization, hypotension should be avoided to maintain adequate penumbral perfusion. The American Heart Association guidelines should be followed for the upper end of prethrombectomy blood pressure: ≤185/110 mm Hg, unless post-tissue plasminogen activator administration when the goal is <180/105 mm Hg. After successful recanalization (thrombolysis in cerebral infarction [TICI]: 2b-3), we recommend a target of a maximum systolic blood pressure of < 160 mm Hg, while the persistently occluded patients (TICI < 2b) may require more permissive goals up to <180/105 mm Hg. Future research should focus on generating randomized data on optimal blood pressure management both before and after endovascular thrombectomy, to optimize patient outcomes for these divergent clinical scenarios.

Anesthetic Management of Emergency Endovascular Thrombectomy for Acute Ischemic Stroke, Part 2: Integrating and Applying Observational Reports and Randomized Clinical Trials

The 2018 American Heart Association stroke care guidelines consider endovascular thrombectomy to be the standard of care for patients who have acute ischemic stroke in the anterior circulation when arterial puncture can be made: (1) within 6 h of symptom onset; or (2) within 6-24 h of symptom onset when specific eligibility criteria are satisfied. The aim of this 2-part review is to provide practical perspective on the clinical literature regarding anesthesia care of endovascular thrombectomy patients. In the preceding companion article (part 1), the rationale for rapid workflow and maintenance of blood pressure before reperfusion were reviewed. Also in part 1, the key patient and procedural factors determining endovascular thrombectomy effectiveness were identified. In this article (part 2), the observational literature regarding anesthesia for endovascular thrombectomy is summarized briefly, largely to identify its numerous biases, but also to develop hypotheses regarding sedation versus general anesthesia pertaining to workflow, hemodynamic management, and intra- and post-endovascular thrombectomy adverse events. These hypotheses underlie the conduct and outcome measures of 3 recent randomized clinical trials of sedation versus general anesthesia for endovascular thrombectomy. A meta-analysis of functional outcomes from these 3 trials show, when managed according to trial protocols, sedation and general anesthesia result in outcomes that are not significantly different. Details regarding anesthesia and hemodynamic management from these 3 trials are provided. This article concludes with a pragmatic approach to real-time anesthesia decision-making (sedation versus general anesthesia) and the goals and methods of acute phase anesthesia management of endovascular thrombectomy patients.

Postinterventional Sedation Worsens Functional Outcomes in Patients with Acute Ischemic Stroke Treated with Endovascular Therapy

BACKGROUND

Postinterventional sedation is commonly used in clinical practice to ensure patient safety and comfort. Although sedation or anesthesia during thrombectomy has been well studied, the association between postinterventional sedation and functional outcomes in endovascularly treated patients with acute ischemic stroke (AIS) has yet to be investigated. We describe the association between postinterventional sedation and functional outcomes in patients with AIS treated with endovascular therapy (EVT).

METHODS

This observational study was based on a prospective registry. Patients with AIS treated with EVT from January 2013 to August 2017 at Xuanwu Hospital, Capital Medical University were included. Patients receiving postinterventional sedation were compared with patients not receiving sedation. The primary outcome was the 3 months modified Rankin Scale score.

RESULTS

A total of 268 patients were eligible for study: 112 patients (41.8%) receiving postinterventional sedation and 156 patients (58.2%) without sedation. At 3 months follow-up, the median modified Rankin Scale score was 4 (interquartile range, 3-6) in the sedation group and 2 (interquartile range, 1-4) in the nonsedation group (P < 0.001). Multivariable regression analysis suggested that the need for postinterventional sedation was associated with unfavorable outcomes, with an odds ratio of 0.20 for functional independence (95% confidence interval [CI], 0.078-0.487; P < 0.001), 0.06 for freedom from disability (95% CI, 0.017-0.228; P < 0.001), and 8.37 for death (95% CI, 2.196-31.889; P = 0.002).

CONCLUSIONS

Postinterventional sedation worsens functional outcomes in patients with AIS with large-vessel occlusions treated with EVT. Whether the sedation is a causative factor or a surrogate for poor functional outcomes remains to be determined.

Mandatory Neuroendovascular Evolution: Meeting the New Demands

Background

Traditionally, patients undergoing acute ischemic strokes were candidates for mechanical thrombectomy if they were within the 6-h window from onset of symptoms. This timeframe would exclude many patient populations, such as wake-up strokes. However, the most recent clinical trials, DAWN and DEFUSE3, have expanded the window of endovascular treatment for acute ischemic stroke patients to within 24 h from symptom onset. This expanded window increases the number of potential candidates for endovascular intervention for emergent large vessel occlusions and raises the question of how to efficiently screen and triage this increase of patients.

Summary

Abbreviated pre-hospital stroke scales can be used to guide EMS personnel in quickly deciding if a patient is undergoing a stroke. Telestroke networks connect remote hospitals to stroke specialists to improve the transportation time of the patient to a comprehensive stroke center for the appropriate level of care. Mobile stroke units, mobile interventional units, and helistroke reverse the traditional hub-and-spoke model by bringing imaging, tPA, and expertise to the patient. Smartphone applications and social media aid in educating patients and the public regarding acute and long-term stroke care.

Key Messages

The DAWN and DEFUSE3 trials have expanded the treatment window for certain acute ischemic stroke patients with mechanical thrombectomy and subsequently have increased the number of potential candidates for endovascular intervention. This expansion brings patient screening and triaging to greater importance, as reducing the time from symptom onset to decision-to-treat and groin puncture can better stroke patient outcomes. Several strategies have been employed to address this issue by reducing the time of symptom onset to decision-to-treat time.

Improving mechanical thrombectomy time metrics in the angiography suite: Stroke cart, parallel workflows, and conscious sedation

Purpose Earlier reperfusion of large-vessel occlusion (LVO) stroke improves functional outcomes. We hypothesize that use of a stroke cart in the angiography suite, containing all commonly used procedural equipment in a mechanical thrombectomy, combined with parallel staff workflows, and use of conscious sedation when possible, improve mechanical thrombectomy time metrics. Methods We identified 47 consecutive LVO patients who underwent mechanical thrombectomy at our center, retrospectively and prospectively from implementation of these three workflow changes (19 pre- and 28 post-). For each patient, last known normal, NIHSS, angiography suite in-room time, type of anesthesia, groin puncture time, on-clot time, recanalization time, LVO location, number of passes, device(s) used, mTICI score, and outcome (mRS) were recorded. Between-group comparisons of time metrics and multivariate regression were performed. Results Stroke cart, parallel workflows, and primary use of conscious sedation decreased in-room time to groin puncture (-21.3 min, p < 0.0001), in-room to on-clot time (-24.1 min, p = 0.001), and in-room to reperfusion time (-29.5 min, p = 0.01). In a multivariate analysis, endotracheal intubation and general anesthesia were found to significantly increase in-room to on-clot time ( p = 0.01), in-room to reperfusion time ( p = 0.01), and groin puncture to on-clot time ( p = 0.05). The number of patients achieving a good outcome (mRS 0-2), however, did not significantly differ between the two groups (9/18 (47%) vs 14/28 (50%), p = 0.60). Conclusions Use of a stroke cart, parallel workflows by neurointerventionalists, technologists, and nursing staff, and use of conscious sedation may be useful to other institutions in efforts to improve procedural times.

Blood pressure levels post mechanical thrombectomy and outcomes in large vessel occlusion strokes

Objective:

There are limited data evaluating the effect of post mechanical thrombectomy (MT) blood pressure (BP) levels on early outcomes of patients with large vessel occlusions (LVO). We sought to investigate the association of BP course following MT with early outcomes in LVO.

Methods:

Consecutive patients with LVO treated with MT during a 3-year period were evaluated. Hourly systolic BP (SBP) and diastolic BP (DBP) values were recorded for 24 hours following MT and maximum SBP and DBP levels were identified. LVO patients with complete reperfusion following MT were stratified in 3 groups based on post-MT achieved BP goals: <140/90 mm Hg (intensive), <160/90 mm Hg (moderate), and <220/110 mm Hg or <180/105 mm Hg when pretreated with IV thrombolysis (permissive hypertension). Three-month functional independence was defined as modified Rankin Scale score of 0–2.

Results:

A total of 217 acute ischemic stroke patients with LVO were prospectively evaluated. A 10 mm Hg increment in maximum SBP documented during the first 24 hours post MT was independently (p = 0.001) associated with a lower likelihood of 3-month functional independence (odds ratio [OR] 0.70; 95% confidence interval [CI] 0.56–0.87) and a higher odds of 3-month mortality (OR 1.49; 95% CI 1.18–1.88) after adjusting for potential confounders. In addition, achieving a BP goal of <160/90 mm Hg during the first 24 hours following MT was independently associated with a lower likelihood of 3-month mortality (OR 0.08; 95% CI 0.01–0.54; p = 0.010) in comparison to permissive hypertension.

Conclusions:

High maximum SBP levels following MT are independently associated with increased likelihood of 3-month mortality and functional dependence in LVO patients. Moderate BP control is also related to lower odds of 3-month mortality in comparison to permissive hypertension.

A decrease in blood pressure is associated with unfavorable outcome in patients undergoing thrombectomy under general anesthesia

BACKGROUND

Up to two-thirds of patients are either dependent or dead 3 months after thrombectomy for acute ischemic stroke (AIS). Loss of cerebral autoregulation may render patients with AIS vulnerable to decreases in mean arterial pressure (MAP).

OBJECTIVE

To determine whether a fall in MAP during intervention under general anesthesia (GA) affects functional outcome.

METHODS

This subgroup analysis included patients from the MR CLEAN trial treated with thrombectomy under GA. The investigated variables were the difference between MAP at baseline and average MAP during GA (ΔMAP) as well as the difference between baseline MAP and the lowest MAP during GA (ΔLMAP). Their association with a shift towards better outcome on the modified Rankin Scale (mRS) after 90 days was determined using ordinal logistic regression with adjustment for prognostic baseline variables.

RESULTS

Sixty of the 85 patients treated under GA in MR CLEAN had sufficient anesthetic information available for the analysis. A greater ΔMAP was associated with worse outcome (adjusted common OR (acOR) 0.95 per point mm Hg, 95% CI 0.92 to 0.99). An average MAP during GA 10 mm Hg lower than baseline MAP constituted a 1.67 times lower odds of a shift towards good outcome on the mRS. For ΔLMAP this association was not significant (acOR 0.97 per mm Hg, 95% CI 0.94 to 1.00, p=0.09).

CONCLUSIONS

A decrease in MAP during intervention under GA compared with baseline is associated with worse outcome.

TRIAL REGISTRATION NUMBER

NTR1804; ISRCTN10888758; post-results.