Is periprocedural sedation during acute stroke therapy associated with poorer functional outcomes?

General anesthesia versus sedation for endovascular thrombectomy: Meta-analysis and trial sequential analysis of randomized controlled trials

Background

The endovascular thrombectomy procedure has become an established standard of care in clinical practice for the management of acute ischemic stroke. However, the anesthesia modality on endovascular thrombectomy remains controversial. The aim of this meta-analysis was to investigate the impact of general anesthesia compared to sedation on immediate and 3-month neurological outcomes in patients undergoing endovascular thrombectomy.

Methods

PubMed, Scopus, and Embase databases were systematically searched to identify randomized controlled trials (RCTs) comparing general anesthesia with sedation in patients undergoing endovascular thrombectomy. The primary outcomes assessed were immediate and 3-month neurological function as well as the rate of successful recanalization. Additionally, secondary outcomes included pulmonary infection and symptomatic intracerebral hemorrhage.

Results

The analysis included eight randomized controlled trials with a total of 1352 patients (General Anesthesia group,N = 609; Sedation group,N = 743) for endovascular thrombectomy. Pooled data revealed that general anesthesia achieved successful reperfusion in 84.3 %, whereas the sedation group had a rate of 70.7 % (RR = 1.77, 95 % CI 1.33 to 2.35, P < 0.0001). Furthermore, Trial Sequential Analysis (TSA) confirmed the significant impact of general anesthesia on achieving successful reperfusion. The meta-analyses found no differences in the rates of favorable cerebral outcome, as evaluated by the National Institutes of Health Stroke Scale (NIHSS) at 24-48 h and the modified Rankin Scale (mRS) at 3 months, between the general anesthesia (GA) and sedation groups. However, The incidence of pulmonary infection was significantly higher in the GA group compared to the sedation group (RR = 1.86, 95 % CI 1.07 to 3.23; P = 0.03). The incidence of symptomatic intracranial hemorrhage did not differ between the groups receiving general anesthesia and sedation.

Conclusion

General anesthesia enhances the efficacy of recanalization without no improvement in cerebral function, while concurrently increasing the susceptibility to pulmonary infection among patients undergoing endovascular thrombectomy for acute ischemic stroke.

Evaluation of Blood Biomarkers and Parameters for the Prediction of Stroke Survivors' Functional Outcome upon Discharge Utilizing Explainable Machine Learning

Despite therapeutic advancements, stroke remains a leading cause of death and long-term disability. The quality of current stroke prognostic models varies considerably, whereas prediction models of post-stroke disability and mortality are restricted by the sample size, the range of clinical and risk factors and the clinical applicability in general. Accurate prognostication can ease post-stroke discharge planning and help healthcare practitioners individualize aggressive treatment or palliative care, based on projected life expectancy and clinical course. In this study, we aimed to develop an explainable machine learning methodology to predict functional outcomes of stroke patients at discharge, using the Modified Rankin Scale (mRS) as a binary classification problem. We identified 35 parameters from the admission, the first 72 h, as well as the medical history of stroke patients, and used them to train the model. We divided the patients into two classes in two approaches: "Independent" vs. "Non-Independent" and "Non-Disability" vs. "Disability". Using various classifiers, we found that the best models in both approaches had an upward trend, with respect to the selected biomarkers, and achieved a maximum accuracy of 88.57% and 89.29%, respectively. The common features in both approaches included: age, hemispheric stroke localization, stroke localization based on blood supply, development of respiratory infection, National Institutes of Health Stroke Scale (NIHSS) upon admission and systolic blood pressure levels upon admission. Intubation and C-reactive protein (CRP) levels upon admission are additional features for the first approach and Erythrocyte Sedimentation Rate (ESR) levels upon admission for the second. Our results suggest that the said factors may be important predictors of functional outcomes in stroke patients.

Type of anaesthesia for acute ischaemic stroke endovascular treatment

BACKGROUND

The use of mechanical thrombectomy to restore intracranial blood flow after proximal large artery occlusion by a thrombus has increased over time and led to better outcomes than intravenous thrombolytic therapy alone. Currently, the type of anaesthetic technique during mechanical thrombectomy is under debate as having a relevant impact on neurological outcomes.

OBJECTIVES

To assess the effects of different types of anaesthesia for endovascular interventions in people with acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Specialised Register of Trials on 5 July 2022, and CENTRAL, MEDLINE, and seven other databases on 21 March 2022. We performed searches of reference lists of included trials, grey literature sources, and other systematic reviews.  SELECTION CRITERIA: We included all randomised controlled trials with a parallel design that compared general anaesthesia versus local anaesthesia, conscious sedation anaesthesia, or monitored care anaesthesia for mechanical thrombectomy in acute ischaemic stroke. We also included studies reported as full-text, those published as abstract only, and unpublished data. We excluded quasi-randomised trials, studies without a comparator group, and studies with a retrospective design.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, extracted data, and assessed the risk of bias and the certainty of the evidence using the GRADE approach. The outcomes were assessed at different time periods, ranging from the onset of the stroke symptoms to 90 days after the start of the intervention. The main outcomes were functional outcome, neurological impairment, stroke-related mortality, all intracranial haemorrhage, target artery revascularisation status, time to revascularisation, adverse events, and quality of life. All included studies reported data for early (up to 30 days) and long-term (above 30 days) time points.

MAIN RESULTS

We included seven trials with 982 participants, which investigated the type of anaesthesia for endovascular treatment in large vessel occlusion in the intracranial circulation. The outcomes were assessed at different time periods, ranging from the onset of stroke symptoms to 90 days after the procedure. Therefore, all included studies reported data for early (up to 30 days) and long-term (above 30 up to 90 days) time points. General anaesthesia versus non-general anaesthesia(early) We are uncertain about the effect of general anaesthesia on functional outcomes compared to non-general anaesthesia (mean difference (MD) 0, 95% confidence interval (CI) -0.31 to 0.31; P = 1.0; 1 study, 90 participants; very low-certainty evidence) and in time to revascularisation from groin puncture until the arterial reperfusion (MD 2.91 minutes, 95% CI -5.11 to 10.92; P = 0.48; I² = 48%; 5 studies, 498 participants; very low-certainty evidence). General anaesthesia may lead to no difference in neurological impairment up to 48 hours after the procedure (MD -0.29, 95% CI -1.18 to 0.59; P = 0.52; I² = 0%; 7 studies, 982 participants; low-certainty evidence), and in stroke-related mortality (risk ratio (RR) 0.98, 95% CI 0.52 to 1.84; P = 0.94; I² = 0%; 3 studies, 330 participants; low-certainty evidence), all intracranial haemorrhages (RR 0.92, 95% CI 0.65 to 1.29; P = 0.63; I² = 0%; 5 studies, 693 participants; low-certainty evidence) compared to non-general anaesthesia. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia (RR 0.21, 95% CI 0.05 to 0.79; P = 0.02; I² = 71%; 2 studies, 229 participants; low-certainty evidence). General anaesthesia improves target artery revascularisation compared to non-general anaesthesia (RR 1.10, 95% CI 1.02 to 1.18; P = 0.02; I² = 29%; 7 studies, 982 participants; moderate-certainty evidence). There were no available data for quality of life. General anaesthesia versus non-general anaesthesia (long-term) There is no difference in general anaesthesia compared to non-general anaesthesia for dichotomous and continuous functional outcomes (dichotomous: RR 1.21, 95% CI 0.93 to 1.58; P = 0.16; I² = 29%; 4 studies, 625 participants; low-certainty evidence; continuous: MD -0.14, 95% CI -0.34 to 0.06; P = 0.17; I² = 0%; 7 studies, 978 participants; low-certainty evidence). General anaesthesia showed no changes in stroke-related mortality compared to non-general anaesthesia (RR 0.88, 95% CI 0.64 to 1.22; P = 0.44; I² = 12%; 6 studies, 843 participants; low-certainty evidence). There were no available data for neurological impairment, all intracranial haemorrhages, target artery revascularisation status, time to revascularisation from groin puncture until the arterial reperfusion, adverse events (haemodynamic instability), or quality of life. Ongoing studies We identified eight ongoing studies. Five studies compared general anaesthesia versus conscious sedation anaesthesia, one study compared general anaesthesia versus conscious sedation anaesthesia plus local anaesthesia, and two studies compared general anaesthesia versus local anaesthesia. Of these studies, seven plan to report data on functional outcomes using the modified Rankin Scale, five studies on neurological impairment, six studies on stroke-related mortality, two studies on all intracranial haemorrhage, five studies on target artery revascularisation status, four studies on time to revascularisation, and four studies on adverse events. One ongoing study plans to report data on quality of life. One study did not plan to report any outcome of interest for this review.

AUTHORS' CONCLUSIONS

In early outcomes, general anaesthesia improves target artery revascularisation compared to non-general anaesthesia with moderate-certainty evidence. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia with low-certainty evidence. We found no evidence of a difference in neurological impairment, stroke-related mortality, all intracranial haemorrhage and haemodynamic instability adverse events between groups with low-certainty evidence. We are uncertain whether general anaesthesia improves functional outcomes and time to revascularisation because the certainty of the evidence is very low. However, regarding long-term outcomes, general anaesthesia makes no difference to functional outcomes compared to non-general anaesthesia with low-certainty evidence. General anaesthesia did not change stroke-related mortality when compared to non-general anaesthesia with low-certainty evidence. There were no reported data for other outcomes. In view of the limited evidence of effect, more randomised controlled trials with a large number of participants and good protocol design with a low risk of bias should be performed to reduce our uncertainty and to aid decision-making in the choice of anaesthesia.

Endovascular Treatment for Acute Ischemic Stroke With or Without General Anesthesia: A Matched Comparison

BACKGROUND

Endovascular treatment in large artery occlusion stroke reduces disability. However, the impact of anesthesia type on clinical outcomes remains uncertain.

METHODS

We compared consecutive patients in the Swiss Stroke Registry with anterior circulation stroke receiving endovascular treatment with or without general anesthesia (GA). The primary outcome was disability on the modified Rankin Scale after 3 months, analyzed with ordered logistic regression. Secondary outcomes included dependency or death (modified Rankin Scale score ≥3), National Institutes of Health Stroke Scale after 24 hours, symptomatic intracranial hemorrhage with ≥4 points worsening on National Institutes of Health Stroke Scale within 7 days, and mortality. Coarsened exact matching and propensity score matching were performed to adjust for indication bias.

RESULTS

One thousand two hundred eighty-four patients (GA: n=851, non-GA: n=433) from 8 Stroke Centers were included. Patients treated with GA had higher modified Rankin Scale scores after 3 months than patients treated without GA, in the unmatched (odds ratio [OR], 1.75 [1.42-2.16]; P<0.001), the coarsened exact matching (n=332-524, using multiple imputations of missing values; OR, 1.60 [1.08-2.36]; P=0.020), and the propensity score matching analysis (n=568; OR, 1.61 [1.20-2.15]; P=0.001). In the coarsened exact matching analysis, there were no significant differences in National Institutes of Health Stroke Scale after 1 day (estimated coefficient 2.61 [0.59-4.64]), symptomatic intracranial hemorrhage (OR, 1.06 [0.30-3.75]), dependency or death (OR, 1.42 [0.91-2.23]), or mortality (OR, 1.65 [0.94-2.89]). In the propensity score matching analysis, National Institutes of Health Stroke Scale after 24 hours (estimated coefficient, 3.40 [1.76-5.04]), dependency or death (OR, 1.49 [1.07-2.07]), and mortality (OR, 1.65 [1.11-2.45]) were higher in the GA group, whereas symptomatic intracranial hemorrhage did not differ significantly (OR, 1.77 [0.73-4.29]).

CONCLUSIONS

This large study showed worse functional outcome after endovascular treatment of anterior circulation stroke with GA than without GA in a real-world setting. This finding appears to be independent of known differences in patient characteristics between groups.

Oxygen Saturation and Postoperative Mortality in Patients With Acute Ischemic Stroke Treated by Endovascular Thrombectomy

BACKGROUND

Monitored anesthesia care (MAC) and general anesthesia (GA) with endotracheal intubation are the 2 most used techniques for patients with acute ischemic stroke (AIS) undergoing endovascular thrombectomy. We aimed to test the hypothesis that increased arterial oxygen concentration during reperfusion period is a mechanism underlying the association between use of GA (versus MAC) and increased risk of in-hospital mortality.

METHODS

In this retrospective cohort study, data were collected at the Cleveland Clinic between 2013 and 2018. To assess the potential mediation effect of time-weighted average oxygen saturation (Spo2) in first postoperative 48 hours between the association between GA versus MAC and in-hospital mortality, we assessed the association between anesthesia type and post-operative Spo2 tertiles (exposure-mediator relationship) through a cumulative logistic regression model and assessed the association between Spo2 and in-hospital mortality (mediator-outcome relationship) using logistic regression models. Confounding factors were adjusted for using propensity score methods. Both significant exposure-mediator and significant mediator-outcome relationships are needed to suggest potential mediation effect.

RESULTS

Among 358 patients included in the study, 104 (29%) patients received GA and 254 (71%) received MAC, with respective hospital mortality rate of 19% and 5% (unadjusted P value <.001). GA patients were 1.6 (1.2, 2.1) (P < .001) times more likely to have a higher Spo2 tertile as compared to MAC patients. Patients with higher Spo2 tertile had 3.8 (2.1, 6.9) times higher odds of mortality than patients with middle Spo2 tertile, while patients in the lower Spo2 tertile did not have significant higher odds compared to the middle tertile odds ratio (OR) (1.8 [0.9, 3.4]; overall P < .001). The significant exposure-mediator and mediator-outcome relationships suggest that Spo2 may be a mediator of the relationship between anesthetic method and mortality. However, the estimated direct effect of GA versus MAC on mortality (ie, after adjusting for Spo2; OR [95% confidence interval {CI}] of 2.1 [0.9-4.9]) was close to the estimated association ignoring Spo2 (OR [95% CI] of 2.2 [1.0-5.1]), neither statistically significant, suggesting that Spo2 had at most a modest mediator role.

CONCLUSIONS

GA was associated with a higher Spo2 compared to MAC among those treated by endovascular thrombectomy for AIS. Spo2 values that were higher than the middle tertile were associated with higher odds of mortality. However, GA was not significantly associated with higher odds of death. Spo2 at most constituted a modest mediator role in explaining the relationship between GA versus MAC and mortality.

Anesthesia modality does not affect clinical outcomes of intra-arterial vasodilator treatment in patients with symptomatic cerebral vasospasms

Background: Delayed cerebral ischemia and cerebral vasospasm remain the leading causes of poor outcome in survivors of aneurysmal subarachnoid hemorrhage. Refractory cerebral vasospasms can be treated with endovascular vasodilator therapy, which can either be performed in conscious sedation or general anesthesia. The aim of this study is to compare the effect of the anesthesia modality on long-term clinical outcomes in patients undergoing endovascular vasodilator therapy due to cerebral vasospasm and hypoperfusion.

Methods: Modified Rankin Scale (mRS) scores were retrospectively analyzed at time of discharge from the hospital and six months after aneurysmal subarachnoid hemorrhage. Additionally, National Institutes of Health Stroke Scale (NIHSS) was assessed 24 hours before, immediately before, immediately after, and 24 hours after endovascular vasodilator therapy, and at discharge and six months. Interventional parameters such as duration of intervention, choice and dosage of vasodilator and number of arteries treated were also recorded.

Results: A total of 98 patients were included in this analysis and separated into patients who had interventions in conscious sedation, general anesthesia and a mix of both. Neither mRS at discharge nor at six months showed a significant difference for functionally independent outcomes (mRS 0-2) between groups. NIHSS before endovascular vasodilator therapy was significantly higher in patients receiving interventions in general anesthesia but did not differ anymore between groups six months after the initial bleed.

Conclusion: This study did not observe a difference in outcome whether patients underwent endovascular vasodilator therapy in general anesthesia or conscious sedation for refractory cerebral vasospasms. Hence, the choice should be made for each patient individually.

Endovascular Treatment of Acute Ischemic Stroke

PURPOSE OF REVIEW

This article reviews the actual indications for mechanical thrombectomy in patients with acute ischemic stroke and how the opportunities for endovascular therapy can be expanded by using the concept of clinical-imaging or perfusion-imaging mismatch (as a surrogate for salvageable tissue) rather than time of ischemia.

RECENT FINDINGS

Six randomized controlled trials undoubtedly confirmed the benefits of using endovascular thrombectomy on the clinical outcome of patients with stroke with large vessel occlusion within 6 hours from symptom onset compared with those receiving only standard medical care. In a meta-analysis of individual patient data, the number needed to treat with endovascular thrombectomy to reduce disability by at least one level on the modified Rankin Scale for one patient was 2.6. Recently, the concept of "tissue window" versus time window has proved useful for selecting patients for mechanical thrombectomy up to 24 hours from symptom onset. The DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention) trial included patients at a median of 12.5 hours from onset and showed the largest effect in functional outcome ever described in any acute stroke treatment trial (35.5% increase in functional independence). In DEFUSE 3 (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution 3), patients treated with mechanical thrombectomy at a median of 11 hours after onset had a 28% increase in functional independence and an additional 20% absolute reduction in death or severe disability.

SUMMARY

For patients with acute ischemic stroke and a large vessel occlusion in the proximal anterior circulation who can be treated within 6 hours of stroke symptom onset, mechanical thrombectomy with a second-generation stent retriever or a catheter aspiration device should be indicated regardless of whether the patient received treatment with intravenous (IV) recombinant tissue plasminogen activator (rtPA) in patients with limited signs of early ischemic changes on neuroimaging. Two clinical trials completely disrupted the time window concept in acute ischemic stroke, showing excellent clinical outcomes in patients treated up to 24 hours from symptom onset. Time of ischemia is, on average, a good biomarker for tissue viability; however, the window of opportunity for treatment varies across different individuals because of a range of compensatory mechanisms. Adjusting time to the adequacy of collateral flow leads to the concept of tissue window, a paradigm shift in stroke reperfusion therapy.

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.

Association of General Anesthesia vs Procedural Sedation With Functional Outcome Among Patients With Acute Ischemic Stroke Undergoing Thrombectomy: A Systematic Review and Meta-analysis

IMPORTANCE

General anesthesia during thrombectomy for acute ischemic stroke has been associated with poor neurological outcome in nonrandomized studies. Three single-center randomized trials reported no significantly different or improved outcomes for patients who received general anesthesia compared with procedural sedation.

OBJECTIVE

To detect differences in functional outcome at 3 months between patients who received general anesthesia vs procedural sedation during thrombectomy for anterior circulation acute ischemic stroke.

DATA SOURCE

MEDLINE search for English-language articles published from January 1, 1980, to July 31, 2019.

STUDY SELECTION

Randomized clinical trials of adults with a National Institutes of Health Stroke Scale score of at least 10 and anterior circulation acute ischemic stroke assigned to receive general anesthesia or procedural sedation during thrombectomy.

DATA EXTRACTION AND SYNTHESIS

Individual patient data were obtained from 3 single-center, randomized, parallel-group, open-label treatment trials with blinded end point evaluation that met inclusion criteria and were analyzed using fixed-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Degree of disability, measured via the modified Rankin Scale (mRS) score (range 0-6; lower scores indicate less disability), analyzed with the common odds ratio (cOR) to detect the ordinal shift in the distribution of disability over the range of mRS scores.

RESULTS

A total of 368 patients (mean [SD] age, 71.5 [12.9] years; 163 [44.3%] women; median [interquartile range] National Institutes of Health Stroke Scale score, 17 [14-21]) were included in the analysis, including 183 (49.7%) who received general anesthesia and 185 (50.3%) who received procedural sedation. The mean 3-month mRS score was 2.8 (95% CI, 2.5-3.1) in the general anesthesia group vs 3.2 (95% CI, 3.0-3.5) in the procedural sedation group (difference, 0.43 [95% CI, 0.03-0.83]; cOR, 1.58 [95% CI, 1.09-2.29]; P = .02). Among prespecified adverse events, only hypotension (decline in systolic blood pressure of more than 20% from baseline) (80.8% vs 53.1%; OR, 4.26 [95% CI, 2.55-7.09]; P < .001) and blood pressure variability (systolic blood pressure >180 mm Hg or <120 mm Hg) (79.7 vs 62.3%; OR, 2.42 [95% CI, 1.49-3.93]; P < .001) were significantly more common in the general anesthesia group.

CONCLUSIONS AND RELEVANCE

Among patients with acute ischemic stroke involving the anterior circulation undergoing thrombectomy, the use of protocol-based general anesthesia, compared with procedural sedation, was significantly associated with less disability at 3 months. These findings should be interpreted tentatively, given that the individual trials examined were single-center trials and disability was the primary outcome in only 1 trial.

Association of Anesthetic Exposure Time With Clinical Outcomes After Endovascular Therapy for Acute Ischemic Stroke

Background: The optimal sedative regimen with general anesthesia (GA) or conscious sedation for patients undergoing endovascular therapy (EVT) remains controversial. Apart from sedative regimen, the duration of anesthetic exposure may affect clinical outcomes. We aimed to determine whether there is an association between anesthetic exposure time and clinical outcomes in mechanically ventilated stroke patients undergoing EVT for large vessel occlusion.

Methods: This was an observational study of consecutive ischemic stroke patients who underwent EVT for anterior circulation large vessel occlusion under GA from January 2016 to March 2018. To minimize confounding by indication, we restricted our analysis to patients whose anesthetic exposure lasted <72 h. Multivariable logistic regression modeling adjusted for covariates was employed to evaluate whether 90-days independent functional outcome (defined as modified Rankin Scale scores 0–2) and 90-days survival could be predicted by anesthetic exposure time.

Results: During the study period, 138 patients with ischemic stroke who underwent EVT received GA and fulfilled our study criteria: median age was 77 years (interquartile range, 65–82); 46.4% were men; median NIHSS score was 18 (15–21), median ASPECT score was 7 (6–8). Median duration of GA was 5.4 (2.5–19.7) h. Logistic regression modeling revealed an independent association between duration of anesthetic exposure and both 90-days independent functional outcome (p = 0.034) and 90-days survival (p = 0.011). Each additional 15-min of anesthetic exposure decreased the likelihood of achieving an independent functional outcome at 90 days by 1.5% and of being alive at 90 days by 1.0%.

Conclusion: Our data promotes the notion that ischemic stroke patients who require peri-interventional GA for EVT should be extubated as soon as possible after the procedure.

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.

Outcomes of general anesthesia versus conscious sedation for Stroke undergoing endovascular treatment: a meta-analysis

Background

The impact of anesthesia strategy on the outcomes of acute ischemic stroke (AIS) patients undergoing endovascular treatment is currently controversy. Thus, we performed this meta-analysis to compare the differences of clinical and angiographic outcomes between general anesthesia (GA) and conscious sedation (CS).

Methods

A literature search in PubMed, Embase, and Web of Knowledge databases through February 2019 was conducted for related records on GA and CS of AIS undergoing endovascular treatment. The results of the studies were pooled and meta-analyzed with fixed- or random-effect model based on heterogeneity test in total and subgroup analyses.

Results

Twenty-three studies including 6703 patients were analyzed in this meta-analysis. We found that patients in the GA group have lower odds of favorable functional outcome (mRS scores ≤2) compared with the CS group (odds ratio [OR] = 0.62, 95% confidence interval [CI]: 0.49–0.77), and higher risk of mortality (OR = 1.68, 95% CI: 1.49–1.90), pneumonia (OR = 1.78, 95% CI: 1.40–2.26), symptomatic intracranial hemorrhage (OR = 1.64, 95% CI: 1.13–2.37). However, no significant differences were seen between the groups in the rate of recanalization (OR = 1.07, 95% CI: 0.89–1.28), vessel dissection or perforation (OR = 1.00, 95% CI: 0.98–1.03) and asymptomatic intracranial hemorrhage (OR = 1.19, 95% CI: 0.96–1.47). While in the RCT subgroup analysis, we found patients in the GA group does not show lower rate of favorable functional outcome compared with the CS group (OR = 1.84, 95% CI: 1.17–2.89). And there was no significant difference in the rate of mortality between GA and CS groups during RCT subgroup analysis (OR = 0.74, 95% CI: 0.43–1.27).

Conclusions

AIS patients performed endovascular treatment under GA compared with CS was associated with worse functional outcome and increased rate of mortality, but differences in worsened outcomes do not exist when one looks into the GA vs. CS RCTs. Moreover, these findings are mainly based on the retrospective studies and additional multi-center randomized controlled trials to definitively address these issues is warranted.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0741-7) contains supplementary material, which is available to authorized users.

Influence of Anesthesia Type on Outcomes after Endovascular Treatment in Acute Ischemic Stroke: Meta-Analysis

PURPOSE

To assess clinical and angiographic outcomes after endovascular treatment (EVT) in ischemic stroke patients according to anesthesia types (general anesthesia vs. conscious sedation).

MATERIALS AND METHODS

A systematic literature review through an online data base between January 1990 and September 2017 was performed. A fixed effect model was used in cases of <50% heterogeneity. The primary outcomes were good clinical outcome at the 3-month follow-up and successful recanalization. A meta-regression analysis was done to estimate primary outcomes of log odds ratio (OR) on onset-to-puncture time (OTP) differences. Publication bias was determined using Begg's funnel plot and additional the Trim and Fill method.

RESULTS

Sixteen articles including 2,662 patients (general anesthesia, n=1,275; conscious sedation, n=1,387) were included. General anesthesia significantly decreased good outcomes than conscious sedation (OR, 0.564; 95% confidence interval [CI], 0.354-0.899). However, outcomes did not differ significantly in randomized controlled trials (RCTs; OR, 1.101; 95% CI, 0.395-3.071). Anesthesia type was not associated with successful recanalization (OR, 0.985; 95% CI, 0.787-1.233). General anesthesia increased the risk of mortality (OR, 1.532; 95% CI, 1.187-1.976) and pneumonia (OR, 1.613; 95% CI, 1.172-2.221), but not symptomatic intracranial hemorrhage (OR, 1.125; 95% CI, 0.767-1.652). The meta-regression analysis showed no linear relationship between OTP differences and log OR of good outcome (coefficient, 0.0004; P=0.95) or successful recanalization (coefficient, 0.0005; P=0.94), respectively.

CONCLUSION

General anesthesia seemed to be associated with adverse clinical outcome after EVT. However, its efficacy was not demonstrated in RCTs. Successful recanalization did not differ according to anesthesia type. Studies using individual patient data based on further RCTs are necessary to elucidate anesthesia effect on procedural and clinical outcomes.

Anesthesia for endovascular treatment in anterior circulation stroke: A systematic review and meta-analysis

BACKGROUND

Endovascular treatment in patients with acute anterior circulation stroke could be performed under either conscious sedation (CS) or general anesthesia (GA). Although several studies have investigated the association between the clinical outcomes and the two anesthesia methods, consensus is lacking.

METHODS

PubMed and EMBASE searches were used to select full-text articles comparing the effects of GA and CS on functional outcome and complications in patients with anterior circulation ischemic stroke. Enrolled patients were assigned to receive endovascular treatment with CS or GA, with a primary outcome of functional independency within 90 days. Secondary outcomes included intracranial hemorrhage, all-cause mortality at 90 days, pneumonia, and intraprocedural complications.

RESULTS

Thirteen studies (3 RCTs and 10 observational studies), which included 3,857 patients (CS = 2,129, GA = 1,728), were eligible for the analysis. The overall analysis including the RCTs and observational studies demonstrated that the functional independence within 90 days occurred more frequently among patients with CS compared with GA (OR, 1.42; 95% CI, 1.05-1.92, p = 0.02); and the risk of mortality was higher with GA compared with CS; furthermore, CS was associated with lower rate of intracranial hemorrhage. In RCTs, GA was associated with increased functional independence (OR, 0.55; 95% CI, 0.34-0.89, p = 0.01) and successful reperfusion (OR, 0.51; 95% CI, 0.30-0.89, p = 0.02).

CONCLUSIONS

In the overall analysis and observational studies, CS was associated with improved functional outcomes and relatively safe for anterior ischemic stroke compared with GA. While the pooled data from RCTs suggested that GA was associated with improved outcomes. The inconsistency indicated that more large-scale RCTs are required to evaluate what factors influenced the effect of the anesthesia methods on clinical outcomes.

Anesthetic management of endovascular treatment for acute ischemic stroke: Influences on outcome and complications

Background and objectives

The emerging use of endovascular therapies for acute ischemic stroke, like intra-arterial thrombectomy, compels a better understanding of the anesthetic management required and its impact in global outcomes. This article reviews the available data on the anesthetic management of endovascular treatment, comparing general anesthesia with conscious sedation, the most used modalities, in terms of anesthetic induction and procedure duration, patient mobility, occlusion location, hemodynamic parameters, outcome and safety; it also focuses on the state-of-the-art on physiologic and pharmacologic neuroprotection.

Contents

Most of the evidence on this topic is retrospective and contradictory, with only three small randomized studies to date. Conscious sedation was frequently associated with better outcomes, but the prospective evidence declared that it has no advantage over general anesthesia concerning that issue. Conscious sedation is at least as safe as general anesthesia for the endovascular treatment of acute ischemic stroke, with equivalent mortality and fewer complications like pneumonia, hypotension or extubation difficulties. It has, however, a higher frequency of patient agitation and movement, which is the main cause for conversion to general anesthesia.

Conclusions

General anesthesia and conscious sedation are both safe alternatives for anesthetic management of patients submitted to endovascular thrombectomy. No anesthetic management is universally recommended and hopefully the ongoing randomized clinical trials will shed some light on the best approach; meanwhile, the choice of anesthesia should be based on the patient's individual characteristics. Regarding neuroprotection, hemodynamic stability is currently the most important strategy, as no pharmacological method has been proven effective in humans.

"Real life" impact of anesthesia strategy for mechanical thrombectomy on the delay, recanalization and outcome in acute ischemic stroke patients

BACKGROUND AND PURPOSE

Choice of anesthesia type on outcome for mechanical thrombectomy (MT) in acute ischemic stroke remains controversial. The goal of our research was to study the impact of anesthesia strategy on the delay, angiographic and neurological outcome of MT performed under general anesthesia (GA) vs. conscious sedation (CS).

METHODS

This prospective, single-center observational study included patients with anterior circulation large vessel occlusion (ACLVO) strokes treated with MT within 6 hours of symptom onset. All time metrics were evaluated. Angiographic and clinical outcomes were assessed by recanalization rate (mTICI) and 3-month functional independence (mRs). Complications and mortality rate were recorded as safety outcomes.

RESULTS

In total, 303 consecutive thrombectomies were performed, 86.8% under GA. NIHSS was higher in GA, with median of 19.0 for GA and 16.5 for CS (P = 0.049). Median time from arrival in hospital (door) to groin puncture was 83 min (IQR = 45.0-109.5) for GA compared to 72 min (IQR = 35.0-85.3) for CS, P = 0.170). Median time from arrival in the angiosuite to groin puncture was 20 min (IQR = 15.0-29.0) for GA compared to 15 min (IQR = 10.0-20.0) for CS, P = 0.017). There were no significant differences in recanalization time metrics, successful revascularization rate, functional independence and mortality rate at three months.

CONCLUSIONS

GA induced a 5 to 10 minutes delay for groin puncture, without impact on recanalization time metrics, or neurological outcome at 3 months. Our results demonstrate that a well-organized workflow is associated with reasonable delay in performing GA for MT, without effect on outcome compared to sedation.

Initial clinical experience with the ADAPT technique: A direct aspiration first pass technique for stroke thrombectomy

BACKGROUND

The development of new revascularization devices has improved recanalization rates and time but not clinical outcomes. We report our initial results with a new technique utilizing a direct aspiration first pass technique with a large bore aspiration catheter as the primary method for vessel recanalization.

METHODS

A retrospective evaluation of a prospectively captured database of 37 patients at six institutions was performed on patients where the ADAPT technique was utilized. The data represent the initial experience with this technique.

RESULTS

The ADAPT technique alone was successful in 28 of 37 (75%) cases although six cases had large downstream emboli that required additional aspiration. Nine cases required the additional use of a stent retriever and one case required the addition of a Penumbra aspiration separator to achieve recanalization. The average time from groin puncture to at least Thrombolysis in Cerebral Ischemia (TICI) 2b recanalization was 28.1 min, and all cases were successfully revascularized. TICI 3 recanalization was achieved 65% of the time. On average, patients presented with an admitting National Institutes of Health Stroke Scale (NIHSS) score of 16.3 and improved to an NIHSS score of 4.2 by the time of hospital discharge. There was one procedural complication.

DISCUSSION

This initial experience highlights the fact that the importance of the technique with which new stroke thrombectomy devices are used may be as crucial as the device itself. The ADAPT technique is a simple and effective approach to acute ischemic stroke thrombectomy. Utilizing the latest generation of large bore aspiration catheters in this fashion has allowed us to achieve excellent clinical and angiographic outcomes.

Factors that may contribute to poor outcome despite good reperfusion after acute endovascular stroke therapy

Endovascular therapy with mechanical thrombectomy is a formidable treatment for severe acute ischemic stroke caused by occlusion of a proximal intracranial artery. Its strong beneficial effect is explained by the high rates of very good and excellent reperfusion achieved with current endovascular techniques. However, there is a sizable proportion of patients who do not experience clinical improvement despite successful recanalization of the occluded artery and reperfusion of the ischemic territory. Factors such as baseline reserve, collateral flow, anesthesia and systemic factors have been identified as potential culprits for lack of improvement in the setting of timely and successful revascularization. Older age, baseline disability and perhaps radiological markers of chronic brain injury can affect the prognosis of patients treated with endovascular therapy. Collateral flow is a major determinant of outcome after endovascular therapy and it is manifested by the size of the core in relation to the volume of the salvageable tissue. Parenchymal and vascular imaging can help assess the quality of collateral flow, but the optimal radiological strategy for daily practice (i.e. the optimal combination of rapid availability and diagnostic precision) has not been established. A sizable body of observational evidence indicates that acute hypertension, hyperglycemia and fever are associated with worse outcomes after a stroke even after optimal reperfusion with endovascular therapy. Lastly, current randomized controlled trials in anesthesia for stroke demonstrate similar rates of good functional outcome between general anesthesia and conscious sedation suggesting equipoise exists.

[Anesthetic management of endovascular treatment for acute ischemic stroke: Influences on outcome and complications]

BACKGROUND AND OBJECTIVES

The emerging use of endovascular therapies for acute ischemic stroke, like intra-arterial thrombectomy, compels a better understanding of the anesthetic management required and its impact in global outcomes. This article reviews the available data on the anesthetic management of endovascular treatment, comparing general anesthesia with conscious sedation, the most used modalities, in terms of anesthetic induction and procedure duration, patient mobility, occlusion location, hemodynamic parameters, outcome and safety; it also focuses on the state-of-the-art on physiologic and pharmacologic neuroprotection.

CONTENTS

Most of the evidence on this topic is retrospective and contradictory, with only three small randomized studies to date. Conscious sedation was frequently associated with better outcomes, but the prospective evidence declared that it has no advantage over general anesthesia concerning that issue. Conscious sedation is at least as safe as general anesthesia for the endovascular treatment of acute ischemic stroke, with equivalent mortality and fewer complications like pneumonia, hypotension or extubation difficulties. It has, however, a higher frequency of patient agitation and movement, which is the main cause for conversion to general anesthesia.

CONCLUSIONS

General anesthesia and conscious sedation are both safe alternatives for anesthetic management of patients submitted to endovascular thrombectomy. No anesthetic management is universally recommended and hopefully the ongoing randomized clinical trials will shed some light on the best approach; meanwhile, the choice of anesthesia should be based on the patient's individual characteristics. Regarding neuroprotection, hemodynamic stability is currently the most important strategy, as no pharmacological method has been proven effective in humans.

Impact of Anesthetic Management on Safety and Outcomes Following Mechanical Thrombectomy for Ischemic Stroke in SWIFT PRIME Cohort

Background and purpose: The optimal anesthetic management of acute ischemic stroke patients during mechanical thrombectomy (MT) remains controversial. In this post-hoc analysis, we investigated the impact of anesthesia type on clinical outcomes in patients included in SWIFT PRIME trial.

Methods: Ninety-seven patients treated with MT were included. Patients treated in centers with general anesthesia (GA) policy (n = 32) were compared with those treated in centers with conscious sedation (CS) policy (n = 65). Primary outcomes studied included times to treatment initiation (TTI), rates of successful recanalization (TICI 2b/3), and functional independence (mRS 0–2 at 90 days). Secondary outcomes were adverse events, lowest systolic and diastolic blood pressures (LSBP and LDBP) during MT. Univariate analysis and multivariate regression logistic modeling were conducted.

Results: The GA-policy and CS-policy groups presented comparable TTI (94 ± 36 min vs. 102 ± 48 min; p = 0.44), rates of TICI 2b/3 recanalization (22/32 [68.8%] vs. 51/65 [78.5%]; p = 0.32). CS-policy was associated to higher rate of functional independence than GA-policy, but the difference was not significant (43/65 [66.2%] vs. 16/32 [50.0%]; p = 0.18). GA-policy patients had a higher rate of postoperative pneumonia (11/32 [34.4%] vs. 8/65 [12.3%]; p = 0.02) and lower LSBP (110 [30,160] mmHg vs. 119 [77,170] mmHg; p = 0.03) and LDBP (55 (15,75) mmHg vs. 67 [40,121]; p < 0.001). When corrected for differences in baseline characteristics, GA-policy was associated with lower rate of functional independence (OR 0.32; p = 0.05). A 10-point increase in perprocedural LDBP was associated with an increased likelihood of favorable outcome (OR 1.51; p = 0.01).

Conclusions: GA-policy for MT presented comparable TTI and rates of successful revascularization to CS-policy. However, GA-policy was associated with lower rates of functional independence and with higher incidence of perprocedural hypotension and postoperative pneumonia.

Clinical Trial Registration: URL—http://www.clinicaltrials.gov. Unique identifier: NCT01657461

Ketamine reduces deleterious consequences of spreading depolarizations

Recent work has implicated spreading depolarization (SD) as a key contributor the progression of acute brain injuries, however development of interventions selectively targeting SD has lagged behind. Initial clinical intervention efforts have focused on observations that relatively high doses of the sedative agent ketamine can completely suppress SD. However, blocking propagation of SD could theoretically prevent beneficial effects of SD in surrounding brain regions. Selective targeting of deleterious consequences of SD (rather than abolition) could be a useful adjunct approach, and be achieved with lower ketamine concentrations. We utilized a brain slice model to test whether deleterious consequences of SD could be prevented by ketamine, using concentrations that did not prevent the initiation and propagation of SD. Studies were conducted using murine brain slices, with focal KCl as an SD stimulus. Consequences of SD were assessed with electrophysiological and imaging measures of ionic and synaptic recovery. Under control conditions, ketamine (up to 30 μM) did not prevent SD, but significantly reduced neuronal Ca2+ loading and the duration of associated extracellular potential shifts. Recovery of postsynaptic potentials after SD was also significantly accelerated. When SD was evoked on a background of mild metabolic compromise, neuronal recovery was substantially impaired. Under compromised conditions, the same concentrations of ketamine reduced ionic and metabolic loading during SD, sufficient to preserve functional recovery after repetitive SDs. These results suggest that lower concentrations of ketamine could be utilized to prevent damaging consequences of SD, while not blocking them outright and thereby preserving potentially protective effects of SD.

Conscious Sedation versus General Anesthesia for Patients with Acute Ischemic Stroke Undergoing Endovascular Therapy: A Systematic Review and Meta-Analysis

The aim of this study is to compare the effect of conscious sedation (CS) with general anesthesia (GA) on clinical outcomes in patients with acute ischemic stroke (AIS) undergoing endovascular therapy (EVT). MEDLINE, EMBASE, and Cochrane Central Registers of Controlled Trials (from inception to July 2017) were searched for reports on CS and GA of AIS undergoing EVT. Two reviewers assessed the eligibility of the identified studies and extracted data. Data were analyzed using the fixed-effects model, and the sources of heterogeneity were explored by sensitive analysis. Trial sequential analysis was conducted to monitor boundaries for the limitation of global type I error, and GRADE system was demonstrated to evaluate the quality of evidence. A total of thirteen studies were finally identified. Pooled analysis of the incidence of mRS score ≦ 2 after hospital discharge and one or three months in the CS group was higher than that in the GA group. The all-causing mortality of AIS patients in the CS group was lower than that in the GA group. There were no differences in the proportion of IA rtPA and thrombolysis between the two groups. Compared with AIS patients receiving GA, the all-causing mortality in the AIS patients receiving CS was decreased, while incidence of mRS score ≦ 2 at hospital discharge and one or three months was increased.

Anaesthesia for neuroradiology: thrombectomy: 'one small step for man, one giant leap for anaesthesia'

PURPOSE OF REVIEW

Endovascular management of acute thrombotic strokes is a new management technique. Anaesthesia will play a key role in the management of these patients. To date there is no established method of managing these patients from an anaesthetic perspective.

RECENT FINDINGS

In 2015, five landmark studies popularized intra-arterial clot retrieval for ischaemic strokes. Since then there have been a number of small studies investigating the best anaesthetic technique, taking into account patient, technical, and clinical factors. This review summarizes these studies and discusses the different anaesthetic options, with their relative merits and pitfalls.

SUMMARY

There is a paucity of robust evidence for the best anaesthetic practice in this cohort of patients. Airway protection seems to be an issue in 2.5% of cases. Timing of the procedure is vital, and any delay may be detrimental to neurological outcome. In a survey of neurointerventionalists, the main concern they expressed was the potential delay to revascularization posed by anaesthesia. Patients complain of pain during mechanical clot retrieval if awake. The overall consensus seems to be favouring conscious sedation over general anaesthesia in the acute setting.

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.

Challenges in the Anesthetic and Intensive Care Management of Acute Ischemic Stroke

Acute ischemic stroke (AIS) is a devastating condition with high morbidity and mortality. In the past 2 decades, the treatment of AIS has been revolutionized by the introduction of several interventions supported by class I evidence-care on a stroke unit, intravenous tissue plasminogen activator within 4.5 hours of stroke onset, aspirin commenced within 48 hours of stroke onset, and decompressive craniectomy for supratentorial malignant hemispheric cerebral infarction. There is new class I evidence also demonstrating benefits of endovascular therapy on functional outcomes in those with anterior circulation stroke. In addition, the importance of the careful management of key systemic physiological variables, including oxygenation, blood pressure, temperature, and serum glucose, has been appreciated. In line with this, the role of anesthesiologists and intensivists in managing AIS has increased. This review highlights the main challenges in the endovascular and intensive care management of AIS that, in part, result from the paucity of research focused on these areas. It also provides guidelines for the management of AIS based upon current evidence, and identifies areas for further research.

Monitored Anesthesia Care vs Intubation for Vertebrobasilar Stroke Endovascular Therapy

Importance

No consensus regarding the ideal sedation treatment for stroke endovascular therapy has been reached, and practices remain largely based on local protocols and clinician preferences. Most studies have focused on anterior circulation strokes; therefore, little is known regarding the optimal anesthesia type for vertebrobasilar occlusion strokes.

Objective

To compare clinical and angiographic outcomes between monitored anesthesia care (MAC) and general anesthesia (GA) in patients presenting with vertebrobasilar occlusion strokes.

Design, Setting, and Participants

Retrospective, matched, case-control study of consecutive vertebrobasilar occlusion strokes treated with endovascular therapy at 2 academic institutions. The study took place between September 2005 and September 2015 at University of Pittsburgh Medical Center Stroke Institute, Pittsburgh, Pennsylvania, and between September 2010 and September 2015 at the Marcus Stroke and Neuroscience Center at Grady Memorial Hospital, Atlanta, Georgia. Patients requiring emergent intubation prior to endovascular therapy were excluded. The remaining patients were categorized into (1) MAC and (2) elective intubation for the procedure (elective GA). Patients who converted from MAC to GA during the procedure were included in the MAC group. The 2 groups were matched for age, baseline National Institutes of Health Stroke Scale score, and glucose levels. Baseline characteristics and outcomes were compared.

Main Outcomes and Measures

The primary outcome measure was the shift in the degree of disability among the 2 groups as measured by the modified Rankin scale at 90 days.

Results

A total of 215 patients underwent endovascular therapy for vertebrobasilar occlusion strokes during the study period. Thirty-nine patients were excluded owing to emergent pre-endovascular therapy intubation. Sixty-three patients had MAC (36%) and 113 patients had GA (64%). The conversion rate from MAC to GA was 13% (n = 8). After matching, 61 pairs of patients (n = 122) underwent primary analysis. The 2 groups were well balanced in terms of baseline characteristics. Median age was 69 years (interquartile range, 60-75 years) in the MAC group vs 67 years (interquartile range, 55.5-78.5 years) in the GA group (P = .83). Fifty-four percent of the patients in the MAC group were men vs 41% in the GA group (P = .44). When compared with the elective GA group, patients who underwent the procedure with MAC had similar rates of successful reperfusion, good clinical outcomes, hemorrhagic complications, and mortality. The modality of anesthesia was not associated with any significant changes in the modified Rankin scale score distribution (MAC: OR, 1.52; 95% CI, 0.80-2.90; P = .19).

Conclusions and Relevance

In endovascular therapy for acute posterior circulation stroke, MAC is feasible and appears to be as safe and effective as GA. Future clinical trials are warranted to confirm our findings.

General Anesthesia Versus Conscious Sedation for Endovascular Treatment of Acute Ischemic Stroke

Background and Purpose—

Retrospective studies have found that patients receiving general anesthesia for endovascular treatment in acute ischemic stroke have worse neurological outcome compared with patients receiving conscious sedation. In this prospective randomized single-center study, we investigated the impact of anesthesia technique on neurological outcome in acute ischemic stroke patients.

Methods—

Ninety patients receiving endovascular treatment for acute ischemic stroke in 2013 to 2016 were included and randomized to general anesthesia or conscious sedation. Difference in neurological outcome at 3 months, measured as modified Rankin Scale score, was analyzed (primary outcome) and early neurological improvement of National Institutes of Health Stroke Scale and cerebral infarction volume. Age, sex, comorbidities, admission National Institutes of Health Stroke Scale score, intraprocedural blood pressure, blood glucose, Paco 2 and Pco 2 modified Thrombolysis in Cerebral Ischemia score, and relevant time intervals were recorded.

Results—

In the general anesthesia group 19 of 45 patients (42.2%) and in the conscious sedation group 18 of 45 patients (40.0%) achieved a modified Rankin Scale score ≤2 ( P =1.00) at 3 months, with no differences in intraoperative blood pressure decline from baseline ( P =0.57); blood glucose ( P =0.94); PaCO2 ( P =0.68); time intervals ( P =0.78); degree of successful recanalization, 91.1% versus 88.9% ( P =1.00); National Institutes of Health Stroke Scale score at 24 hours 8 (3–5) versus 9 (2–15; P =0.60); infarction volume, 20 (10–100) versus 20(10–54) mL ( P =0.53); and hospital mortality (13.3% in both groups; P =1.00).

Conclusions—

In endovascular treatment for acute ischemic stroke, no difference was found between general anesthesia and conscious sedation in neurological outcome 3 months after stroke.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01872884.

Choice of ANesthesia for EndoVAScular Treatment of Acute Ischemic Stroke: Protocol for a randomized controlled (CANVAS) trial

Background

Observational studies indicate that the type of anesthesia, local or general, may be associated with the post-procedural neurological function in patients with acute ischemic stroke undergoing endovascular treatment. However, these results need further confirmation, and the causal relationship has not yet been established.

Methods

This is a randomized controlled equivalence trial. Permuted block randomization stratified by culprit vessels will be used. Six hundred and forty patients with acute ischemic stroke undergoing endovascular recanalization will be randomized one to one to receive either general anesthesia or local anesthesia. The primary endpoint is the modified Rankin scale at 90 days after endovascular treatment. The secondary endpoints are the peri-procedural mortality and morbidity.

Discussion

The study aims to determine the effects of anesthetic choice on neurological outcomes in patients with acute ischemic stroke undergoing intra-arterial recanalization. If the results are positive, the study will indicate that the type of anesthesia does not affect neurological outcome after endovascular treatment. Trial registration: ClinicalTrial.gov identifier: NCT02677415

Anesthesia Technique and Outcomes of Mechanical Thrombectomy in Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

The impact of anesthesia technique on the outcomes of mechanical thrombectomy for acute ischemic stroke remains an issue of debate. We investigated the association of general anesthesia with outcomes in patients undergoing mechanical thrombectomy for ischemic stroke.

METHODS

We performed a cohort study involving patients undergoing mechanical thrombectomy for ischemic stroke from 2009 to 2013, who were registered in the New York Statewide Planning and Research Cooperative System database. An instrumental variable (hospital rate of general anesthesia) analysis was used to simulate the effects of randomization and investigate the association of anesthesia technique with case-fatality and length of stay.

RESULTS

Among 1174 patients, 441 (37.6%) underwent general anesthesia and 733 (62.4%) underwent conscious sedation. Using an instrumental variable analysis, we identified that general anesthesia was associated with a 6.4% increased case-fatality (95% confidence interval, 1.9%-11.0%) and 8.4 days longer length of stay (95% confidence interval, 2.9-14.0) in comparison to conscious sedation. This corresponded to 15 patients needing to be treated with conscious sedation to prevent 1 death. Our results were robust in sensitivity analysis with mixed effects regression and propensity score-adjusted regression models.

CONCLUSIONS

Using a comprehensive all-payer cohort of acute ischemic stroke patients undergoing mechanical thrombectomy in New York State, we identified an association of general anesthesia with increased case-fatality and length of stay. These considerations should be taken into account when standardizing acute stroke care.

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

Acute ischemic stroke continues to be one of the leading causes of morbidity and mortality worldwide. Recent advances in mechanical thrombectomy techniques combined with prereperfusion computed tomographic angiography for patient selection have revolutionized stroke care in the past year. Peri- and postinterventional neurocritical care of the patient who has had an emergent large-vessel occlusion is likely an equally important contributor to the outcome but has been relatively neglected. Critical periprocedural management issues include streamlining care to speed intervention, blood pressure optimization, reversal of anticoagulation, management of agitation, and selection of anesthetic technique (ie, general vs monitored anesthesia care). Postprocedural critical care issues that might modulate neurological outcome include blood pressure and glucose optimization, avoidance of fever or hyperoxia, fluid and nutritional management, and early integration of rehabilitation into the intensive care unit setting. In this review, we sought to lay down an evidence-based strategy for patients with acute ischemic stroke undergoing emergent endovascular reperfusion.

Improved Therapeutic Benefits by Combining Physical Cooling With Pharmacological Hypothermia After Severe Stroke in Rats

Supplemental Digital Content is available in the text.

Background and Purpose—

Therapeutic hypothermia is a promising strategy for treatment of acute stroke. Clinical translation of therapeutic hypothermia, however, has been hindered because of the lack of efficiency and adverse effects. We sought to enhance the clinical potential of therapeutic hypothermia by combining physical cooling (PC) with pharmacologically induced hypothermia after ischemic stroke.

Methods—

Wistar rats were subjected to 90-minute middle cerebral artery occlusion by insertion of an intraluminal filament. Mild-to-moderate hypothermia was induced 120 minutes after the onset of stroke by PC alone, a neurotensin receptor 1 (NTR1) agonist HPI-201 (formally ABS-201) alone or the combination of both. The outcomes of stroke were evaluated at 3 and 21 days after stroke.

Results—

PC or HPI-201 each showed hypothermic effect and neuroprotection in stroke rats. The combination of PC and HPI-201 exhibited synergistic effects in cooling process, reduced infarct formation, cell death, and blood-brain barrier damages and improved functional recovery after stroke. Importantly, coapplied HPI-201 completely inhibited PC-associated shivering and tachycardia.

Conclusions—

The centrally acting hypothermic drug HPI-201 greatly enhanced the efficiency and efficacy of conventional PC; this combined cooling therapy may facilitate clinical translation of hypothermic treatment for stroke.

[Intubation and sedation in the endovascular treatment of acute cerebral infarction]

In the past complex intracranial treatments demanded intubation and general anesthesia of the patient. With increasing rate of endovascular local treatment of acute stroke more and more neurointerventionalists report that recanalisation techniques can be performed in sedation of the patient without the need of additional intubation. Although prospective studies are lacking retrospective studies have shown that the risk of iatrogeneous vessel injuries without global anesthesia is not increased but outcomes in case of conscious sedations are better compared with intubation and general anesthesia.

Hypotension During Endovascular Treatment of Ischemic Stroke Is a Risk Factor for Poor Neurological Outcome

Background and Purpose—

In retrospective studies, patients receiving general anesthesia for endovascular treatment for acute ischemic stroke have worse neurological outcome compared with patients receiving conscious sedation. It has been suggested that this is caused by general anesthesia–associated hypotension. We investigated the effect of intraprocedural hypotension on neurological outcome.

Methods—

One hundred eight patients with acute ischemic stroke, who underwent endovascular treatment in general anesthesia between 2007 and 2012, were included. Analyzed predictors of neurological outcome were age, sex, comorbidities, baseline National Institutes of Health Stroke Scale, intraprocedural relative changes in mean arterial blood pressure from baseline, blood glucose, modified Thrombolysis in Cerebral Infarction score, and elapsed time from stroke to computed tomography, groin puncture, and recanalization/end of procedure.

Results—

A fall in mean arterial blood pressure of >40% was an independent predictor for poor neurological outcome ( P =0.032), as were higher admission National Institutes of Health Stroke Scale score ( P =0.008) and lack of recanalization ( P =0.003).

Conclusions—

Profound intraprocedural hypotension is an independent predictor for poor neurological outcome in patients with acute ischemic stroke undergoing endovascular therapy in general anesthesia.

Impact of General Anesthesia on Safety and Outcomes in the Endovascular Arm of Interventional Management of Stroke (IMS) III Trial

BACKGROUND AND PURPOSE

General anesthesia (GA) for endovascular therapy (EVT) of acute ischemic stroke may be associated with worse outcomes.

METHODS

The Interventional Management of Stroke III trial randomized patients within 3 hours of acute ischemic stroke onset to intravenous tissue-type plasminogen activator±EVT. GA use within 7 hours of stroke onset was recorded per protocol. Good outcome was defined as 90-day modified Rankin Scale ≤2. A multivariable analysis adjusting for dichotomized National Institutes of Health Stroke Scale (NIHSS; 8-19 versus ≥20), age, and time from onset to groin puncture was performed.

RESULTS

Four hundred thirty-four patients were randomized to EVT, 269 (62%) were treated under local anesthesia and 147 (33.9%) under GA; 18 (4%) were undetermined. The 2 groups were comparable except for median baseline NIHSS (16 local anesthesia versus 18 GA; P<0.0001). The GA group was less likely to achieve a good outcome (adjusted relative risk, 0.68; confidence interval, 0.52-0.90; P=0.0056) and had increased in-hospital mortality (adjusted relative risk, 2.84; confidence interval, 1.65-4.91; P=0.0002). Those with medically indicated GA had worse outcomes (adjusted relative risk, 0.49; confidence interval, 0.30-0.81; P=0.005) and increased mortality (relative risk, 3.93; confidence interval, 2.18-7.10; P<0.0001) with a trend for higher mortality with routine GA. There was no significant difference in the adjusted risks of subarachnoid hemorrhage (P=0.32) or symptomatic intracerebral hemorrhage (P=0.37).

CONCLUSIONS

GA was associated with worse neurological outcomes and increased mortality in the EVT arm; this was primarily true among patients with medical indications for GA. Relative risk estimates, though not statistically significant, suggest reduced risk for subarachnoid hemorrhage and symptomatic intracerebral hemorrhage under local anesthesia. Although the reasons for these associations are not clear, these data support the use of local anesthesia when possible during EVT.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

Sedation vs. Intubation for Endovascular Stroke TreAtment (SIESTA) – A Randomized Monocentric Trial

Background

The optimal peri-interventional management of sedation and airway for endovascular stroke treatment (EST) appears to be a crucial factor for treatment success. According to retrospective studies, the widely favored general anesthesia with intubation seems to be associated with poor functional outcome compared to a slightly sedated non-intubated condition (conscious sedation).

Method

SIESTA is a monocentric, prospective, randomized parallel-group, open-label treatment trial with blinded endpoint evaluation (PROBE design). The study compares the non-intubated with the intubated state in patients receiving endovascular treatment of acute ischemic anterior circulation stroke. The primary endpoint is early neurological improvement as by National Institutes of Health Stroke Scale (NIHSS) after 24 h (difference between NIHSS on admission and NIHSS after 24 h). Secondary endpoints include: functional outcome after three-months as by modified Rankin Scale (mRS), mortality, parameters of ventilation and critical care, feasibility, and safety, i.e. complications related to endovascular stroke treatment.

Conclusion

The aims of this study are to prospectively clarify whether the non-intubated state of conscious sedation is feasible, safe, and superior with regard to early neurological improvement compared to the intubated state of general anesthesia in patients receiving acute endovascular stroke treatment.