Endovascular Treatment of Acute Ischemic Stroke Under General Anesthesia: Predictors of Good Outcome

The Effect of Anesthetic Agent and Mean Arterial Pressure on Functional Outcome After General Anesthesia for Endovascular Thrombectomy

BACKGROUND

The optimal general anesthetic (GA) technique for stroke patients undergoing endovascular thrombectomy (ET) is unclear. We compared favorable outcomes and mortality in patients receiving propofol or volatile GA during ET and assessed associations between mean arterial pressure (MAP) and outcome.

METHODS

Ninety-three patients with anterior circulation stroke who received propofol or volatile GA during ET between February 2015 and February 2018 were included in this retrospective study. Ninety-day modified Rankin scores were compared and mortality was adjusted for intravenous thrombolysis and diabetes. We performed ordinal logistic regression analyses containing MAP time/exposure thresholds.

RESULTS

There was no difference in the rate of favorable outcome (modified Rankin scores 0-2) in the volatile and propofol groups (48.8% vs. 55.8%, respectively; P =0.5). Ninety-day mortality was lower in patients receiving propofol (11.5%) than in those receiving volatile GA (29.3%) (odds ratio, 0.32; 95% confidence interval, 0.11 to 0.94; P =0.03); this mortality benefit was greater in patients that did not receive intravenous thrombolysis before ET (odds ratio for survival, 6; 95% confidence interval, 1.13 to 31.74). There was no difference in MAP between groups and a (nonsignificant) trend towards the benefit of MAP <90 mm Hg but not <70 mm Hg.

CONCLUSIONS

Favorable outcome rates were similar in stroke patients receiving propofol or volatile GA during ET. Propofol was associated with lower mortality, an effect magnified in patients that did not receive intravenous thrombolysis. MAP time/exposure thresholds were associated with outcome but independent of the anesthetic agent. Our data suggest that a difference in outcome related to an anesthetic agent may exist; this hypothesis needs to be tested in a prospective study.

Effect of Individualized Versus Standardized Blood Pressure Management During Endovascular Stroke Treatment on Clinical Outcome: A Randomized Clinical Trial

BACKGROUND

Optimal blood pressure (BP) management during endovascular stroke treatment is not well established. We studied whether an individualized approach for managing BP during endovascular stroke treatment gives a better clinical outcome than an approach with standardized systolic BP targets.

METHODS

The INDIVIDUATE study (Individualized Blood Pressure Management During Endovascular Treatment of Acute Ischemic Stroke Under Procedural Sedation) is a randomized clinical trial with a prospective randomized open blinded end point (PROBE) design. Patients were recruited between October 1, 2020 and July 7, 2022 at a single center at a tertiary care university hospital. Patients were eligible, when they were suffering from acute ischemic stroke of the anterior circulation with occlusions of the internal carotid artery and middle cerebral artery and a National Institutes of Health Stroke Scale score of ≥8 receiving endovascular stroke treatment in procedural sedation. The intervention consists of an individualized BP management strategy, where preinterventional baseline systolic BP (SBP) values are used as intraprocedural BP targets. As a control, the standard treatment aims to maintain the intraprocedural SBP between 140 and 180 mm Hg. The main prespecified outcome is the proportion of favorable functional outcomes 90 days after stroke, defined as a modified Rankin Scale score of 0 to 2.

RESULTS

Two hundred fifty patients were enrolled and included in the analysis, mean (SD) age was 77 (12) years, 142 (57%) patients were women, and mean (SD) National Institutes of Health Stroke Scale score on admission was 17 (5.2). In all, 123 (49%) patients were treated with individualized and 127 (51%) with standard BP management. Mean (SD) intraprocedural SBP was similar in the individualized versus standard BP management group (157 [19] versus 154 [18] mm Hg; P=0.16). The rate of favorable functional outcome after 3 months was not significantly different between the individualized versus the standard BP management group (25% versus 24%; adjusted odds ratio, 0.81 [95% CI, 0.41-1.61]; P=0.56).

CONCLUSIONS

Among patients treated with endovascular stroke treatment due to an acute ischemic stroke of the anterior circulation, no significant difference was seen between the individualized BP management strategy, where intraprocedural SBP was targeted to baseline values, and the standardized regimen of targeting SBP between 140 and 180 mm Hg.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04578288.

Carbon dioxide and MAPK signalling: towards therapy for inflammation

Inflammation, although necessary to fight infections, becomes a threat when it exceeds the capability of the immune system to control it. In addition, inflammation is a cause and/or symptom of many different disorders, including metabolic, neurodegenerative, autoimmune and cardiovascular diseases. Comorbidities and advanced age are typical predictors of more severe cases of seasonal viral infection, with COVID-19 a clear example. The primary importance of mitogen-activated protein kinases (MAPKs) in the course of COVID-19 is evident in the mechanisms by which cells are infected with SARS-CoV-2; the cytokine storm that profoundly worsens a patient's condition; the pathogenesis of diseases, such as diabetes, obesity, and hypertension, that contribute to a worsened prognosis; and post-COVID-19 complications, such as brain fog and thrombosis. An increasing number of reports have revealed that MAPKs are regulated by carbon dioxide (CO2); hence, we reviewed the literature to identify associations between CO2 and MAPKs and possible therapeutic benefits resulting from the elevation of CO2 levels. CO2 regulates key processes leading to and resulting from inflammation, and the therapeutic effects of CO2 (or bicarbonate, HCO3-) have been documented in all of the abovementioned comorbidities and complications of COVID-19 in which MAPKs play roles. The overlapping MAPK and CO2 signalling pathways in the contexts of allergy, apoptosis and cell survival, pulmonary oedema (alveolar fluid resorption), and mechanical ventilation-induced responses in lungs and related to mitochondria are also discussed. Video Abstract.

Ventilation Targets for Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review

Mechanical thrombectomy (MT) has become a standard treatment for acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). Recent evidence suggests that general anesthesia (GA) and mechanical ventilation do not lead to inferior neurologic outcomes if compared to non-GA. However, the guidelines lack specific recommendations for ventilation targets during MT under GA. This systematic review aims to identify ventilation strategies correlating with better neurological outcomes in AIS patients undergoing MT, particularly focusing on oxygenation and carbon dioxide (CO2) targets. A systematic search of multiple databases was conducted to identify human studies reporting the correlation between ventilation strategies and neurological outcomes in MT for AIS. Eligible studies included clinical trials, observational studies, and case-control studies. Out of 157 studies assessed, 11 met the inclusion criteria. Five studies investigated oxygenation targets, while six studies explored CO2 targets. The published studies highlighted the controversial role of supplemental normobaric oxygen therapy and its potential association with worse outcomes. Regarding CO2 targets, the studies identified a potential association between end tidal CO2 levels and functional outcomes, with hypocapnia being unfavorable. This systematic review demonstrates that the current available evidence still lacks strength to suggest specific ventilation targets, but it highlights the potential risks of hyperoxia and hypocapnia in this specific cohort of patients.

Anaesthetic and peri-operative management for thrombectomy procedures in stroke patients

PURPOSE

To provide recommendations for the anaesthetic and peri-operative management for thrombectomy procedure in stroke patients DESIGN: A consensus committee of 15 experts issued from the French Society of Anaesthesia and Intensive Care Medicine (Société Française d'Anesthésie et Réanimation, SFAR), the Association of French-language Neuro-Anaesthetists (Association des Neuro-Anesthésistes Réanimateurs de Langue Francaise, ANARLF), the French Neuro-Vascular Society (Société Francaise de Neuro-Vasculaire, SFNV), the French Neuro-Radiology Society (Société Francaise de Neuro-Radiologie, SFNR) and the French Study Group on Haemostasis and Thrombosis (Groupe Français d'Études sur l'Hémostase et la Thrombose, GFHT) was convened, under the supervision of two expert coordinators from the SFAR and the ANARLF. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guideline elaboration process was conducted independently of any industry funding. The authors were required to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide their assessment of quality of evidence.

METHODS

Four fields were defined prior to the literature search: (1) Peri-procedural management, (2) Prevention and management of secondary brain injuries, (3) Management of antiplatelet and anticoagulant treatments, (4) Post-procedural management and orientation of the patient. Questions were formulated using the PICO format (Population, Intervention, Comparison, and Outcomes) and updated as needed. Analysis of the literature was then conducted and the recommendations were formulated according to the GRADE methodology.

RESULTS

The SFAR/ANARLF/SFNV/SFNR/GFHT guideline panel drew up 18 recommendations regarding anaesthetic management of mechanical thrombectomy procedures. Due to a lack of data in the literature allowing to conclude with high certainty on relevant clinical outcomes, the experts decided to formulate these guidelines as "Professional Practice Recommendations" (PPR) rather than "Formalized Expert Recommendations". After two rounds of rating and several amendments, a strong agreement was reached on 100% of the recommendations. No recommendation could be formulated for two questions.

CONCLUSIONS

Strong agreement among experts was reached to provide a sizable number of recommendations aimed at optimising anaesthetic management for thrombectomy in patients suffering from stroke.

Anesthetic considerations for endovascular treatment in stroke therapy

PURPOSE OF REVIEW

The introduction of clot removement by endovascular treatment (EVT) in 2015 has improved the clinical outcome of patients with acute ischemic stroke (AIS) due to a large vessel occlusion (LVO). Anesthetic strategies during EVT vary widely between hospitals, with some departments employing local anesthesia (LA), others performing conscious sedation (CS) or general anesthesia (GA). The optimal anesthetic strategy remains debated. This review will describe the effects of anesthetic strategy on clinical and radiological outcomes and hemodynamic parameters in patients with AIS undergoing EVT.

RECENT FINDINGS

Small single-center randomized controlled trails (RCTs) found either no difference or favored GA, while large observational cohort studies favored CS or LA. RCTs using LA as separate comparator arm are still lacking and a meta-analysis of observational studies failed to show differences in functional outcome between LA vs. other anesthetic strategies. Advantages of LA were shorter door-to-groin time in patients and less intraprocedural hypotension, which are both variables that are known to impact functional outcome.

SUMMARY

The optimal anesthetic approach in patients undergoing EVT for stroke therapy is still unclear, but based on logistics and peri-procedural hemodynamics, LA may be the optimal choice. Multicenter RCTs are warranted comparing LA, CS and GS with strict blood pressure targets and use of the same anesthetic agents to minimize confounding variables.

Periprocedural Management During Stroke Thrombectomy

PURPOSE OF REVIEW

Endovascular therapy (EVT) for acute ischemic stroke caused by large vessel occlusion is a powerful and evidence-based tool to achieve reperfusion and results in improved neurologic outcome. Focus has now shifted toward optimizing the procedure. We reviewed the relevant current literature on periprocedural stroke care such as pretreatment with IV tissue plasminogen activator (tPA), choice of anesthesia, ventilation strategy, and blood pressure management.

RECENT FINDINGS

IV tPA should not be withheld in a patients with stroke eligible for EVT. A meta-analysis of randomized trials on general anesthesia (GA) vs procedural sedation has shown better neurologic outcomes with protocol-based GA in centers with dedicated neuroanesthesia teams. There are no data from randomized trials on blood pressure control, but according to available evidence, systolic blood pressure should probably be held at >140 mm Hg during the procedure and <160 mm Hg after reperfusion. In ventilated patients, extreme deviations from normoxemia and normocapnia should be avoided.

SUMMARY

Periprocedural care influences the outcome after EVT for large vessel ischemic stroke. More evidence from prospective ongoing and future studies is urgently needed to identify its optimization.

Individualized blood pressure management during endovascular treatment of acute ischemic stroke under procedural sedation (INDIVIDUATE) - An explorative randomized controlled trial

BACKGROUND

Optimal blood pressure is not well established during endovascular therapy of acute ischemic stroke. Applying standardized blood pressure target values for every stroke patient might be a suboptimal approach.

AIM

To assess whether an individualized intraprocedural blood pressure management with individualized blood pressure target ranges might pose a better strategy for the outcome of the patients than standardized blood pressure targets.Sample size: Randomization of 250 patients 1:1 to receive either standard or individualized blood pressure management approach.

METHODS AND DESIGN

We conduct an explorative single-center randomized controlled trial with a PROBE (parallel-group, open-label randomized controlled trial with blinded endpoint evaluation) design. In the control group, intraprocedural systolic blood pressure target range is 140-180 mmHg. The intervention group is the individualized approach, which is maintaining the intraprocedural systolic blood pressure at the level on presentation (±10 mmHg).Study outcomes: The primary endpoint is the modified Rankin scale assessed 90 days +/- 2 weeks after stroke onset, dichotomized by 0-2 (favorable outcome) to 3-6 (unfavorable outcome). Secondary endpoints include early neurological improvement, infarction size, and systemic physiology monitor parameters.

DISCUSSION

An individualized approach for blood pressure management during thrombectomy could lead to a better outcome for stroke patients. The trial is registered at clinicaltrials.gov as 'Individualized Blood Pressure Management During Endovascular Stroke Treatment (INDIVIDUATE)' under NCT04578288.

Hemodynamics of Leptomeningeal Collaterals after Large Vessel Occlusion and Blood Pressure Management with Endovascular Treatment

Endovascular therapy (EVT) is an effective treatment for ischemic stroke due to large vessel occlusion (LVO). Unlike intravenous thrombolysis, EVT enables visualization of the restoration of blood flow, also known as successful reperfusion in real time. However, until successful reperfusion is achieved, the survival of the ischemic brain is mainly dependent on blood flow from the leptomeningeal collaterals (LMC). It plays a critical role in maintaining tissue perfusion after LVO via pre-existing channels between the arborizing pial small arteries or arterioles overlying the cerebral hemispheres. In the ischemic territory where the physiologic cerebral autoregulation is impaired and the pial arteries are maximally dilated within their capacity, the direction and amount of LMC perfusion rely on the systemic perfusion, which can be estimated by measuring blood pressure (BP). After the EVT procedure, treatment focuses on mitigating the risk of hemorrhagic transformation, potentially via BP reduction. Thus, BP management may be a key component of acute care for patients with LVO stroke. However, the guidelines on BP management during and after EVT are limited, mostly due to the scarcity of high-level evidence on this issue. In this review, we aim to summarize the anatomical and physiological characteristics of LMC to maintain cerebral perfusion after acute LVO, along with a landscape summary of the literature on BP management in endovascular treatment. The objective of this review is to describe the mechanistic association between systemic BP and collateral perfusion after LVO and thus provide clinical and research perspectives on this topic.

Perioperative Care of Patients at High Risk for Stroke During or After Non-cardiac, Non-neurological Surgery: 2020 Guidelines From the Society for Neuroscience in Anesthesiology and Critical Care

Perioperative stroke is associated with considerable morbidity and mortality. Stroke recognition and diagnosis are challenging perioperatively, and surgical patients receive therapeutic interventions less frequently compared with stroke patients in the outpatient setting. These updated guidelines from the Society for Neuroscience in Anesthesiology and Critical Care provide evidence-based recommendations regarding perioperative care of patients at high risk for stroke. Recommended areas for future investigation are also proposed.

Choice of ANaesthesia for EndoVAScular treatment of acute ischaemic stroke at posterior circulation (CANVAS II): protocol for an exploratory randomised controlled study

INTRODUCTION

Observational and interventional studies indicate that the type of anaesthesia may be associated with the postprocedural neurological function in patients with anterior circulation acute ischaemic stroke undergoing endovascular treatment. Patients with acute posterior circulation ischaemic stroke may experience different physiological changes and result in severe neurological outcome. However, the effect of the type of anaesthesia on postprocedure neurological function remained unclear in this population.

METHODS AND ANALYSIS

This is an exploratory randomised controlled trial that will be carried out at Beijing Tiantan Hospital, Capital Medical University. Patients with acute posterior circulation ischaemic stroke and deemed suitable for emergency endovascular recanalisation will be recruited in this trial. Eighty-four patients will be randomised to receive either general anaesthesia or conscious sedation with 1:1 allocation ratio. The primary endpoint is the 90-day modified Rankin Scale.

ETHICS AND DISSEMINATION

The study has been reviewed by and approved by Ethics Committee of Beijing Tiantan Hospital of Capital Medical University (KY2017-074-02). If the results are positive, the study will indicate whether the type of anaesthesia affects neurological outcome after endovascular treatment of posterior stroke. The findings of the study will be published in peer-reviewed journals and presented at national or international conferences.

TRIAL REGISTRATION NUMBER

NCT03317535.

Early blood pressure management for endovascular therapy in acute ischemic stroke: A review of the literature

The perioperative optimal blood pressure targets during mechanical thrombectomy for acute ischemic stroke are uncertain, and randomized controlled trials addressing this issue are lacking. There is still no consensus on the optimal target for perioperative blood pressure in acute ischemic stroke patients with large vessel occlusion. In addition, there are many confounding factors that can influence the outcome including the patient's clinical history and stroke characteristics. We review the factors that have an impact on perioperative blood pressure change and discuss the influence of perioperative blood pressure on functional outcome after mechanical thrombectomy. In conclusion, we suggest that blood pressure should be carefully and flexibly managed perioperatively in patient-received mechanical thrombectomy. Blood pressure changes during mechanical thrombectomy were independently correlated with poor prognosis, and blood pressure should be maintained in a normal range perioperatively. Postoperative blood pressure control is associated with recanalization status in which successful recanalization requires normal range blood pressure (systolic blood pressure 120-140 mmHg), while non-recanalization requires higher blood pressure (systolic blood pressure 160-180 mmHg). The preoperative blood pressure targets for mechanical thrombectomy should be tailored based on the patient's clinical history (systolic blood pressure ≤185 mmHg). Blood pressure should be carefully and flexibly managed intraoperatively (systolic blood pressure 140-180 mmHg) in patient-received endovascular therapy.

Physiologic predictors of collateral circulation and infarct growth during anesthesia - Detailed analyses of the GOLIATH trial

Collateral circulation plays a pivotal role in acute ischemic stroke due to large vessel occlusion (LVO) and may be affected by multiple variables during sedation for endovascular therapy (EVT). We conducted detailed analyses of the GOLIATH trial to identify predictors of collateral circulation grade and infarct growth. We also modified the ASITN collateral grading scale and sought to determine its impact on clinical outcome and infarct growth. Multivariable analysis was used to identify predictors of collaterals and infarct growth. Ordinal analysis demonstrated nominal, but non-significant association between modified ASITN scale and infarct growth. Among all analyzed baseline clinical and procedural variables, the most significant predictors of infarct growth at 24 h were phenylephrine dose (estimate 6.78; p = 0.014) and baseline infarct volume (estimate 0.93; p = 0.03). The most significant predictors of worse collateral grade were mean arterial pressure (MAP) <70 mmHg (OR 0.35; p = 0.048) and baseline infarct volume (OR 0.96; p = 0.003). Hypotension during sedation for EVT for LVO negatively impacts collateral circulation, while higher pressor dose is a strong predictor of infarct growth. Avoidance of anesthesia-induced hypotension and consequent need for pressor therapy may prevent collateral failure and minimize infarct growth.

Effect of Steady and Dynamic Blood Pressure Parameters During Thrombectomy According to the Collateral Status

Background and Purpose- Guidelines regarding blood pressure (BP) management during endovascular therapy (EVT) for anterior circulation strokes are questionable since the optimal BP target is a matter of debate. To evaluate the importance of hemodynamic control during EVT, we investigated the impact of dynamic and steady BP parameters during EVT on functional outcome (part 1) and according to the collateral status (CS; part 2). Methods- We performed a post hoc analysis of the ASTER trial (Contact Aspiration Versus Stent Retriever for Successful Recanalization). BP was measured noninvasively during EVT and CS assessed on the angiographic run before EVT. We studied dynamic BP parameter using BP variability (coefficient of variation) and steady BP parameter (hypotension time defined as systolic BP <140 mm Hg and mean arterial pressure <90 mm Hg). The primary outcome was favorable outcome defined as a 3-month modified Rankin Scale score between 0 and 2. Results- Among the 381 patients of the ASTER study, 172 patients were included in part 1 and 159 in part 2. Systolic BP, diastolic BP, and mean arterial pressure variability were negatively associated with favorable outcome regardless of CS: per 10-unit increase, adjusted odds ratios were 0.45 (95% CI, 0.20-0.98), 0.37 (95% CI, 0.19-0.72), and 0.35 (95% CI, 0.16-0.76), respectively. According to CS, the hypotension time with periprocedural mean arterial pressure <90 mm Hg was negatively associated with favorable outcome in patients with poor CS (adjusted odds ratio, 0.88 [95% CI, 0.72-1.09]) but not in patients with good CS (adjusted odds ratio, 1.24 [95% CI, 0.91-1.67]; P_het=0.047). Conclusions- The CS did not modify the association between dynamic parameters and functional outcomes, but some findings suggest that the CS modifies the association between steady parameter and functional outcomes. Hypotension time according to the CS was not statistically predictive of poor outcomes but displayed a trend toward worse outcomes for patients with poor CS only.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Association of Blood Pressure With Outcomes in Acute Stroke Thrombectomy

Limited data exist evaluating the effect of blood pressure (BP) on clinical outcomes among patients with acute ischemic stroke with large vessel occlusion treated with mechanical thrombectomy (MT). We sought to evaluate the association of BP levels on clinical outcomes among patients with acute ischemic stroke with large vessel occlusion treated with MT. Studies were identified that reported the association of systolic BP (SBP) or diastolic BP levels before, during, or after MT on the outcomes of patients with acute ischemic stroke treated with MT. Unadjusted and adjusted analyses of studies reporting odds ratios (OR_adj) per 10 mm Hg BP increment were performed. Our analysis included 25 studies comprising 6474 patients. Higher pre-MT mean SBP (P=0.008) and post-MT maximum SBP (P=0.009) levels were observed in patients who died within 3 months. Patients with 3-month functional independence were noted to have lower pre-MT (P<0.001) and post-MT maximum SBP levels (P<0.001). In adjusted analyses, increasing post-MT maximum SBP and diastolic BP levels were associated with 3-month mortality (OR_adj, 1.19 [95% CI,1.00-1.43]; I²=78%, P value for Cochran Q test: 0.001) and symptomatic intracranial hemorrhage (OR_adj, 1.65 [95% CI, 1.11-2.44]; I²=0%, P value for Cochran Q test: 0.80), respectively. Increasing pre- and post-MT mean SBP levels were associated with lower odds of 3-month functional independence (OR_adj, 0.86 [95% CI, 0.77-0.96]; I²=18%, P value for Cochran Q test: 0.30) and (OR_adj, 0.80 [95% CI, 0.72-0.89]; I²=0%, P value for Cochran Q test: 0.51), respectively. In conclusion, elevated BP levels before and after MT are associated with adverse outcomes among patients with acute ischemic stroke with large vessel occlusion.

Anesthetic Management of Emergency Endovascular Thrombectomy for Acute Ischemic Stroke, Part 1: Patient Characteristics, Determinants of Effectiveness, and Effect of Blood Pressure on Outcome

In the United States, stroke ranks fifth among all causes of death and is the leading cause of serious long-term disability. 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 within 6 hours of symptom onset or within 6-24 hours 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 patients treated with endovascular thrombectomy. Part 1 (this article) reviews the development of endovascular thrombectomy and the determinants of endovascular thrombectomy effectiveness irrespective of method of anesthesia. The first aim of part 1 is to explain why rapid workflow and maintenance of blood pressure are necessary to help support the ischemic brain until, as a result of endovascular thrombectomy, reperfusion is accomplished. The second aim of part 1, understanding the nonanesthesia factors determining endovascular thrombectomy effectiveness, is necessary to identify numerous biases present in observational reports regarding anesthesia for endovascular thrombectomy. With this background, in part 2 (the companion to this article), the observational literature is briefly summarized, largely to identify its weaknesses, but also to develop hypotheses derived from it that have been recently tested in 3 randomized clinical trials of sedation versus general anesthesia for endovascular thrombectomy. In part 2, these 3 trials are reviewed both from a functional outcomes perspective (meta-analysis) and a methodological perspective, providing specifics regarding anesthesia and hemodynamic management. Part 2 concludes with a pragmatic approach to anesthesia decision making (sedation versus general anesthesia) and acute phase anesthesia management of patients treated with endovascular thrombectomy.

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.

Anesthesia practice for endovascular therapy of acute ischemic stroke in Europe

PURPOSE OF REVIEW

Anesthetic assistance is often required during endovascular therapy (EVT) of large vessel occlusion in patients with acute ischemic stroke. It is currently debated whether EVT should be performed under general anesthesia or conscious sedation. This review will summarize the recent literature with emphasis on the influence of anesthesia method on neurological outcome.

RECENT FINDINGS

Recent randomized trials have reported no difference in outcome after EVT performed under either conscious sedation or general anesthesia. This is in contrast to a substantial number of retrospective studies, which found that EVT performed under general anesthesia was associated with a worse neurologic outcome compared with conscious sedation. Anesthetic drugs affect vessel tone and the level of blood pressure may influence outcome. The most favorable choice of anesthetic agents and ventilatory strategy is still debated.

SUMMARY

The optimal anesthetic practice for EVT remains to be identified. Currently, conscious sedation is often an easy first-line strategy, but general anesthesia can be considered an equal and safe alternative to conscious sedation when there is a carefully administered anesthetic that maintains strict hemodynamic control. Attention to ventilation is advocated. The presence of a specialized neuroanesthesiologist or otherwise dedicated anesthesia personnel is highly recommended.

Association of Blood Pressure During Thrombectomy for Acute Ischemic Stroke With Functional Outcome: A Systematic Review

Background and Purpose- Optimal blood pressure (BP) targets during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are unknown, and randomized controlled trials addressing this issue are lacking. We aimed to perform a systematic review of studies evaluating the influence of periprocedural BP on functional outcome after MT. Methods- Studies assessing periprocedural BP effect on functional outcome published after January 1st, 2012 were included in the systematic review. The PRISMA checklist and flow diagram were followed for the design and reporting of this work. Results- Nine studies were included, for a total of 1037 patients. The heterogeneity in findings with respect to BP monitoring and studied parameters precluded a meta-analysis. Mean arterial pressure was the most frequently reported parameter to describe BP variability during MT, and systolic BP was the main parameter used to define periprocedural BP targets. Five studies suggested an association between 3 types of BP drops as predictors of poor functional outcome at 3 months: >40% drop in mean arterial pressure compared with baseline (odds ratio=2.8; [1.09-7.19]; P=0.032), lowest mean arterial pressure before recanalization (odds ratio=1.28; [1.01-1.62] per 10 mm Hg drop below 100 mm Hg; P=0.04), and MAP drops (odds ratio=4.38; [1.53-12.6] for drops >10%). Four studies did not show an association between BP during MT and functional outcome, including 3 studies with strict periprocedural systolic BP targets (within a 140-180 mm Hg). Conclusions- BP drops during MT may be associated with a worse functional outcome. When strict systolic BP targets are achieved, no association between BP and functional outcome was also noted. Both conclusions require further evaluation in randomized studies.

Acute ischaemic stroke: challenges for the intensivist

PURPOSE

To provide an update about the rapidly developing changes in the critical care management of acute ischaemic stroke patients.

METHODS

A narrative review was conducted in five general areas of acute ischaemic stroke management: reperfusion strategies, anesthesia for endovascular thrombectomy, intensive care unit management, intracranial complications, and ethical considerations.

RESULTS

The introduction of effective reperfusion strategies, including IV thrombolysis and endovascular thrombectomy, has revolutionized the management of acute ischaemic stroke and transformed outcomes for patients. Acute therapeutic efforts are targeted to restoring blood flow to the ischaemic penumbra before irreversible tissue injury has occurred. To optimize patient outcomes, secondary insults, such as hypotension, hyperthermia, or hyperglycaemia, that can extend the penumbral area must also be prevented or corrected. The ICU management of acute ischaemic stroke patients, therefore, focuses on the optimization of systemic physiological homeostasis, management of intracranial complications, and neurological and haemodynamic monitoring after reperfusion therapies. Meticulous blood pressure management is of central importance in improving outcomes, particularly in patients that have undergone reperfusion therapies.

CONCLUSIONS

While consensus guidelines are available to guide clinical decision making after acute ischaemic stroke, there is limited high-quality evidence for many of the recommended interventions. However, a bundle of medical, endovascular, and surgical strategies, when applied in a timely and consistent manner, can improve long-term stroke outcomes.

General Anesthesia Versus Conscious Sedation for Intracranial Mechanical Thrombectomy: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background

Endovascular therapy is the standard of care for severe acute ischemic stroke caused by large‐vessel occlusion in the anterior circulation, but there is uncertainty regarding the optimal anesthetic approach during this therapy. Meta‐analyses of observational studies suggest that general anesthesia increases morbidity and mortality compared with conscious sedation. We performed a systematic review and meta‐analysis of randomized clinical trials to examine the effect of anesthetic strategy during endovascular treatment for acute ischemic stroke.

Methods and Results

Systematic review and meta‐analysis according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) guidelines has been registered with the PROSPERO (International Prospective Register of Ongoing Systematic Reviews) (CRD42018103684). Medline, EMBASE, and CENTRAL databases were searched through August 1, 2018. Meta‐analyses were conducted using a random‐effects model to pool odds ratio with corresponding 95% CI. The primary outcome was 90‐day functional independence (modified Rankin Scale 0–2). In the results, 3 trials with a total of 368 patients were selected. Among patients with ischemic stroke undergoing endovascular therapy, general anesthesia was significantly associated with higher odds of functional independence (odds ratio 1.87, 95% CI 1.15–3.03, I²=17%) and successful recanalization (odds ratio 1.94, 95% CI 1.13–3.3) compared with conscious sedation. However, general anesthesia was associated with a higher risk of 20% mean arterial pressure decrease (odds ratio 10.76, 95% CI 5.25–22.07). There were no significant differences in death, symptomatic intracranial hemorrhage, anesthesiologic complication, intensive care unit length of stay, pneumonia, and interventional complication.

Conclusions

Moderate‐quality evidence suggests that general anesthesia results in significantly higher rates of functional independence than conscious sedation in patients with ischemic stroke undergoing endovascular therapy. Large randomized clinical trials are required to confirm the benefit.

Neuroanesthesiology Update

This review provides a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, traumatic brain injury, neuromonitoring, neurotoxicity, and perioperative disorders of cognitive function.