To Tube or Not to Tube? The Role of Intubation during Stroke Thrombectomy

A retrospect and outlook on the neuroprotective effects of anesthetics in the era of endovascular therapy

Studies on the neuroprotective effects of anesthetics were carried out more than half a century ago. Subsequently, many cell and animal experiments attempted to verify the findings. However, in clinical trials, the neuroprotective effects of anesthetics were not observed. These contradictory results suggest a mismatch between basic research and clinical trials. The Stroke Therapy Academic Industry Roundtable X (STAIR) proposed that the emergence of endovascular thrombectomy (EVT) would provide a proper platform to verify the neuroprotective effects of anesthetics because the haemodynamics of patients undergoing EVT is very close to the ischaemia–reperfusion model in basic research. With the widespread use of EVT, it is necessary for us to re-examine the neuroprotective effects of anesthetics to guide the use of anesthetics during EVT because the choice of anesthesia is still based on team experience without definite guidelines. In this paper, we describe the research status of anesthesia in EVT and summarize the neuroprotective mechanisms of some anesthetics. Then, we focus on the contradictory results between clinical trials and basic research and discuss the causes. Finally, we provide an outlook on the neuroprotective effects of anesthetics in the era of endovascular therapy.

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.

Stroke thrombectomy perioperative anesthetic and hemodynamic management

There is an ongoing debate about the optimal anesthetic and hemodynamic management of acute stoke patients with large vessel occlusion undergoing endovascular mechanical thrombectomy. Several prospective and retrospective analyses, and randomized controlled trials, attempted to address the challenges of using different anesthetic modalities in acute stroke patients requiring mechanical thrombectomy. We review the advantages and disadvantages of monitored anesthesia care, local anesthesia, conscious sedation, and general anesthesia, along with the relevance of hemodynamic management and perioperative oxygenation status in these complex patients.

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.

Risk Factors for General Anesthesia Conversion in Anterior Circulation Stroke Patients Undergoing Endovascular Treatment

BACKGROUND AND PURPOSE

No current consensus exists on the best anesthetic management of ischemic stroke patients undergoing mechanical thrombectomy. Both conscious sedation (CS) and general anesthesia (GA) are currently considered valid anesthetic strategies, yet patients managed under CS may require emergent conversion to GA, which has been associated with worse outcomes. The aim of this study was to analyze the conversion rate and potential risk factors for GA conversion during mechanical thrombectomy.

METHODS

Two-hundred and twenty-seven patients with consecutive acute anterior circulation ischemic stroke treated with mechanical thrombectomy and initiated under CS or local anesthesia were included in this retrospective analysis. Conversion rate to GA was calculated, while univariate and multivariate analysis were used to identify risk factors.

RESULTS

Twenty patients (8.8%) were switched to GA. Multivariate analysis identified procedure duration (odds ratio [OR] 1.01, 95% confidence interval [CI] 1.00-1.02, p value 0.028), tandem stroke (OR 8.57, 95% CI 2.06-35.7, p value 0.003), Sequential Organ Failure Assessment (SOFA) (OR 1.76, 95% CI 1.19-2.61, p value 0.005), and number of pharmacological agents used (OR 5.76, 95% CI 2.49-13.3, p value <0.001) as independently associated with conversion to GA.

CONCLUSION

In our study, tandem occlusion, longer endovascular procedures, SOFA, and number of pharmacological agents used predicted the risk of emergent conversion to GA in stroke patients undergoing endovascular treatment. Prospective studies investigating optimal CS strategies are deemed necessary.

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.

Ideal sedation for stroke thrombectomy: a prospective pilot single-center observational study

OBJECTIVESeveral retrospective studies have supported the use of conscious sedation (CS) over general anesthesia (GA) as the preferred methods of sedation for stroke thrombectomy, but a recent randomized controlled trial showed no difference in outcomes after CS or GA. The purpose of the Ideal Sedation for Stroke Thrombectomy (ISST) study was to evaluate the difference in time and outcomes in the reperfusion of anterior circulation in ischemic stroke using GA and monitored anesthesia care (MAC).METHODSThe ISST study was a prospective, open-label registry. A total of 40 patients who underwent mechanical thrombectomy for anterior circulation ischemic stroke were enrolled. Informed consent was obtained from each patient before enrollment. The primary endpoint included the interval between the patient's arrival to the interventional radiology room and reperfusion time. Secondary endpoints were evaluated to estimate the effects on the outcome of patients between the 2 sedation methods.RESULTSOf the 40 patients, 32 received thrombectomy under MAC and 8 patients under GA. The male-to-female ratio was 18:14 in the MAC group and 4:4 in the GA group. The mean time from interventional radiology room arrival to reperfusion in the GA group was 2 times higher than that in the MAC group. Complete reperfusion (TICI grade 3) was achieved in more than 50% of patients in both groups. The mean modified Rankin Scale score at 3 months was < 2 in the MAC group and > 3 in the GA group (p = 0.021).CONCLUSIONSThe findings from the pilot study showed a significantly shorter time interval between IR arrival and reperfusion and better outcomes in patients undergoing reperfusion for ischemic stroke in the anterior circulation using MAC compared with GA.Clinical trial registration no.: NCT03036631 (clinicaltrials.gov).

Site of Occlusion May Influence Decision to Perform Thrombectomy Under General Anesthesia or Conscious Sedation

BACKGROUND

Although mechanical thrombectomy has become the standard of care for large-vessel occlusion, the role of conscious sedation versus general anesthesia (GA) with intubation during thrombectomy remains controversial. Aphasia may increase patient agitation or apparent uncooperativeness/confusion and thereby lead to higher use of GA. The purpose of this study was to identify risk factors for GA and determine if the side of vessel occlusion potentially impacts GA rates.

MATERIALS AND METHODS

Patients who underwent mechanical thrombectomy of the middle cerebral artery (MCA) for acute ischemic stroke at our institution between April 2014 and July 2017 were retrospectively reviewed. Patient characteristics, procedural factors, and outcomes were assessed using multivariate regression analyses. Mediation analysis was utilized to investigate whether aphasia lies on the causal pathway between left-sided MCA stroke and GA.

RESULTS

Overall, 112 patients were included: 62 with left-sided and 50 with right-sided MCA occlusion. Patients with left-sided MCA occlusion presented with aphasia significantly more often those with right-sided occlusion (90.3% vs. 32.0%; P<0.001). GA rates were significantly higher for patients with left-sided compared with right-sided MCA occlusion (45.2% vs. 20.0%; P=0.028). Aphasia mediated 91.3% of the effect of MCA stroke laterality on GA (P=0.02). GA was associated with increased door-to-groin-puncture time (106.4% increase; 95% confidence interval, 24.1%-243.4%; P=0.006) and adverse discharge outcome (odds ratio, 1.04; 95% confidence interval, 1.01-1.07; P=0.019).

CONCLUSIONS

Patients who had a stroke with left-sided MCA occlusion are more likely to undergo GA for mechanical thrombectomy than those with right-sided MCA occlusion. Aphasia may mediate this effect and understanding this relationship may decrease GA rates through modification of management protocols, potentially leading to improved clinical outcomes. Our study suggests that GA should preferentially be considered for the subset of patients with acute ischemic stroke undergoing mechanical thrombectomy for left-sided MCA occlusion.

[Periinterventional management of acute endovascular stroke treatment]

Mechanical thrombectomy (MT) is more effective than standard medical treatment with or without intravenous thrombolysis alone for treating acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) in the anterior circulation. MT is therefore recommended in current international guidelines, and many acute-care hospitals and stroke centers will have to prepare for providing this treatment in an optimal way. Beside successful recanalization, management before, during, and after the intervention represents significant challenges. One unresolved matter is whether the choice of anesthetic strategy, including airway management, affects functional outcome. Based on current data, treatment under general anesthesia (GA)-respecting predefined safety criteria and contraindications-seem seems to be equivalent to treating the patient in conscious sedation (CS) and not necessarily disadvantageous. Aspects of periinterventional management of MT, including pragmatic recommendations concerning logistics, monitoring, postprocedural steps, and follow-up imaging, will be summarized in this overview.

Review article: Emergency endotracheal intubation in non-traumatic brain pathologies: A systematic review and meta-analysis

Endotracheal intubation is an advanced airway procedure performed in the ED and the out-of-hospital setting for acquired brain injuries that include non-traumatic brain pathologies such as stroke, encephalopathies, seizures and toxidromes. Controlled trial evidence supports intubation in traumatic brain injuries, but it is not clear that this evidence can be applied to non-traumatic brain pathologies. We sought to analyse the impact of emergency intubation on survival in non-traumatic brain pathologies and also to quantify the prevalence of intubation in these pathologies. We conducted a systematic literature search of Medline, Embase and the Cochrane Library. Eligibility, data extraction and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model pooled prevalence of intubation in non-traumatic brain pathologies. Forty-six studies were included in this systematic review. No studies were suitable for meta-analysis the primary outcome of survival. Thirty-nine studies reported the prevalence of intubation in non-traumatic brain pathologies and a meta-analysis showed that emergency intubation was used in 12% (95% CI 0-33) of pathologies. Endotracheal intubation was used commonly in haemorrhagic stroke 79% (95% CI 47-100) and to a lesser extent for seizures 18% (95% CI 10-27) and toxidromes 25% (95% CI 6-48). This systematic review shows that there is no high-quality clinical evidence to support or refute emergency intubation in non-traumatic brain pathologies. Our analysis shows that intubation is commonly used in non-traumatic brain pathologies, and the need for rigorous evidence is apparent.

Different strategies to initiate and maintain hyperventilation: their effect on continuous estimates of dynamic cerebral autoregulation

OBJECTIVE

Capnography is a key monitoring intervention in several neurologically vulnerable clinical states. Cerebral autoregulation (CA) describes the ability of the cerebrovascular system to maintain a near constant cerebral blood flow throughout fluctuations in systemic arterial blood pressure, with the partial pressure of arterial carbon dioxide known to directly influence CA. Previous work has demonstrated dysautoregulation lasting around 30 s prior to the anticipated augmentation of hyperventilation-associated hypocapnia. In order assess to potential benefit of hypocapnic interventions in an acute stroke setting, minimisation of dysregulation is paramount.

APPROACH

Hyperventilation strategies to induce and maintain hypocapnia were performed in 61 healthy participants, effects on temporal estimates of dynamic cerebral autoregulation (autoregulation index, ARI) were assessed to validate the most effective strategy for inducing and maintaining hypocapnia.

MAIN RESULTS

The extent of initial decrease was significantly smaller in the continuous metronome strategy compared to the delayed metronome and voluntary strategies (▵ARI 0.33  ±  1.18, 2.80  ±  3.33 and 3.69  ±  2.79 respectively, p   <  0.017).

SIGNIFICANCE

The use of a continuous metronome to induce hypocapnia rather than the sudden inception of an auditory stimulus appears to reduce the initial decrease in autoregulatory capacity seen in previous studies. Dysautoregulation can be minimised by continuous metronome use during hyperventilation-induced hypocapnia. This advancement in understanding of the behaviour of CA during hypocapnia permits safer delivery of CA targeted interventions, particularly in neurologically vulnerable patient populations.

Blood pressure control for acute severe ischemic and hemorrhagic stroke

PURPOSE OF REVIEW

Severe ischemic or hemorrhagic stroke is a devastating cerebrovascular disease often demanding critical care. Optimal management of blood pressure (BP) in the acute phase is controversial. The purpose of this review is to display insights from recent studies on BP control in both conditions.

RECENT FINDINGS

BP control in acute ischemic stroke has recently been investigated with regard to endovascular recanalizing therapies. Decreases from baseline BP and hypotension during the intervention have been found detrimental. Overall, a periinterventional SBP between 140 and 160 mmHg appeared favorable in several studies. In acute hemorrhagic stroke, the recently completed Antihypertensive Treatment of Acute Cerebral Hemorrhage II trial confirmed feasibility of early aggressive BP reduction but failed to demonstrate a reduction in hematoma growth or a clinical benefit.

SUMMARY

Recent findings do not support benefits of intensive BP lowering in both acute hemorrhagic and ischemic stroke, with the possible exception of the postinterventional phase after successful endovascular recanalization of large-vessel occlusions. Although optimal ranges of BP values remain to be defined, high BP should still be treated according to guidelines. As stroke patients requiring critical care are underrepresented in most studies on BP, caution in transferring these findings is warranted and prospective research in that patient population needed.

Association of Blood Pressure With Short- and Long-Term Functional Outcome After Stroke Thrombectomy: Post Hoc Analysis of the SIESTA Trial

BACKGROUND AND PURPOSE

Outcome after mechanical thrombectomy for ischemic stroke may be influenced by blood pressure (BP). This study aims to assess the association of BP changes during general anesthesia versus conscious sedation with functional outcome after mechanical thrombectomy.

METHODS

SIESTA (Sedation vs Intubation for Endovascular Stroke Treatment) was a monocentric randomized trial of general anesthesia versus conscious sedation during mechanical thrombectomy involving BP target protocols. In this post hoc analysis, BP measurements were divided into 4 phases: preintervention, prerecanalization, postrecanalization, and postintervention. We examined the association between BP and functional outcomes (defined by improvement of 24-hour National Institutes of Health Stroke Scale [NIHSS] and 3-month modified Rankin Scale).

RESULTS

We found no association between the difference in systolic BP, diastolic BP, and mean arterial pressure from baseline to the different phases of intervention and NIHSS change after 24 hours. Only baseline diastolic BP was associated with a reduced improvement in NIHSS (β=0.17, P<0.01). There was no association of BP drops with a change in modified Rankin Scale at 3 months. About sedation, only baseline mean arterial pressure preintervention revealed significant associations (β=0.16, P<0.01) with less change in 24-hour NIHSS in conscious sedation group. Otherwise, there was no association for differences of any of the BP measurements with a change in 24-hour NIHSS and long-term functional outcome either in general anesthesia or the conscious sedation group when analyzed separately, consistent with our findings in the entire cohort. Doses of propofol (β=0.84, P=0.04) and norepinephrine (β=1.87, P=0.01) administered during intervention before recanalization were associated with reduced improvement of NIHSS at 24 hours.

CONCLUSIONS

In a setting, where both sedation regimes general anesthesia and conscious sedation were performed according to strict protocols directed at avoiding BP extremes, our findings suggest that peri-interventional BP drops were not associated with either early neurological improvement or long-term functional outcome.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02126085.

National survey on perioperative anaesthetic management in the endovascular treatment of acute ischaemic stroke

OBJECTIVE

To assess the anaesthetic management of treatment for endovascular acute ischaemic stroke (AIS) in Spain.

MATERIALS AND METHOD

A survey was designed by the SEDAR Neuroscience Section and sent to the Spanish anaesthesiology departments with a primary stroke centre between July and November 2016.

RESULTS

Of the 47 hospitals where endovascular treatment of AIS is performed, 37 anaesthesiology departments participated. Thirty responses were obtained; three of which were eliminated due to duplication (response rate of 72.9%). Health coverage for AIS endovascular treatment was available 24hours a day in 63% of the hospitals. The anaesthesiologist in charge of the procedure was physically present in the hospital in 55.3%. There was large inter-hospital variability in non-standard monitoring and type of anaesthesia. The most important criterion for selecting type of anaesthesia was multidisciplinary choice made by the anaesthesiologist, neurologist and neuroradiologist (59.3%). The duration of time from arrival to arterial puncture was 10-15minutes in 59.2%. In 44.4%, systolic blood pressure was maintained between 140-180mmHg, and diastolic blood pressure<105mmHg. Glycaemic levels were taken in 81.5% of hospitals. Intravenous heparinisation was performed during the procedure in 66.7% with different patterns of action. In cases of moderate neurological deterioration with no added complications, 85.2% of the included hospitals awakened and extubated the patients.

CONCLUSIONS

The wide variability observed in the anaesthetic management and the organization of the endovascular treatment of AIS demonstrates the need to create common guidelines for anaesthesiologists in Spain.

Wide Variability in Prethrombectomy Workflow Practices in the United States: A Multicenter Survey

BACKGROUND AND PURPOSE

Clinical outcomes in patients with acute ischemic stroke caused by large vessel occlusion depend on the speed and quality of workflows leading to mechanical thrombectomy. In the absence of universally accepted best practices for workflow, developing stroke hospitals can benefit from improved awareness of real-world workflows in effect at experienced centers. To this end, we surveyed prethrombectomy workflow practices at stroke centers throughout the United States.

MATERIALS AND METHODS

E-mail and phone interviews were conducted with neurointerventional team members at 30 experienced, endovascular-capable stroke centers. Questions were chosen to reflect workflow components of triage, team activation, transport, case setup, and anesthesia.

RESULTS

There is wide variation in prethrombectomy workflows. At 53% of institutions, nonphysician staff respond to stroke alerts alongside physicians. Imaging triage involves noninvasive angiography or perfusion imaging at 97% and 63% of institutions, respectively. Neurointerventional consultation is initiated before the completion of neuroimaging at 86% of institutions, and the team is activated before a final treatment decision at 59%. The neurointerventional team most commonly arrives within 30 minutes. Patients may be transported to the neuroangiography suite before team arrival at 43% of institutions. Procedural trays are set up in advance of team arrival at 13% of centers; additional thrombectomy devices are centrally stored at 54%. A power injector for angiographic runs is consistently used at 43% of institutions. Anesthesiology routinely supports thrombectomies at 67% of institutions.

CONCLUSIONS

Prethrombectomy workflows vary widely between experienced centers. Improved awareness of real-world workflows and their variations may help to guide institutions in designing their own protocols of care.

Impact of Anesthesia on the Outcome of Acute Ischemic Stroke after Endovascular Treatment with the Solitaire Stent Retriever

BACKGROUND AND PURPOSE

General anesthesia during endovascular treatment of acute ischemic stroke may have an adverse effect on outcome compared with conscious sedation. The aim of this study was to examine the impact of the type of anesthesia on the outcome of patients with acute ischemic stroke treated with the Solitaire stent retriever, accounting for confounding factors.

MATERIALS AND METHODS

Four-hundred one patients with consecutive acute anterior circulation stroke treated with a Solitaire stent retriever were included in this prospective analysis. Outcome was assessed after 3 months by the modified Rankin Scale.

RESULTS

One-hundred thirty-five patients (31%) underwent endovascular treatment with conscious sedation, and 266 patients (69%), with general anesthesia. Patients under general anesthesia had higher NIHSS scores on admission (17 versus 13, P < .001) and more internal carotid artery occlusions (44.6% versus 14.8%, P < .001) than patients under conscious sedation. Other baseline characteristics such as time from symptom onset to the start of endovascular treatment did not differ. Favorable outcome (mRS 0-2) was more frequent with conscious sedation (47.4% versus 32%; OR, 0.773; 95% CI, 0.646-0.925; P = .002) in univariable but not multivariable logistic regression analysis (P = .629). Mortality did not differ (P = .077). Independent predictors of outcome were age (OR, 0.95; 95% CI, 0.933-0.969; P < .001), NIHSS score (OR, 0.894; 95% CI, 0.855-0.933; P < .001), time from symptom onset to the start of endovascular treatment (OR, 0.998; 95% CI, 0.996-0.999; P = .011), diabetes mellitus (OR, 0.544; 95% CI, 0.305-0.927; P = .04), and symptomatic intracerebral hemorrhage (OR, 0.109; 95% CI, 0.028-0.428; P = .002).

CONCLUSIONS

In this single-center study, the anesthetic management during stent retriever thrombectomy with general anesthesia or conscious sedation had no impact on the outcome of patients with large-vessel occlusion in the anterior circulation.

Optimizing Outcomes for Mechanically Ventilated Patients in an Era of Endovascular Acute Ischemic Stroke Therapy

Endovascular mechanical thrombectomy is a new standard of care for acute ischemic stroke (AIS). The majority of these patients receive mechanical ventilation (MV), which has been associated with poor outcomes. The implication of this is significant, as most neurointerventionalists prefer general compared to local anesthesia during the procedure. Consequences of hemodynamic and respiratory perturbations during general anesthesia and MV are thought to contribute significantly to the poor outcomes that are encountered. In this review, we first describe the unique risks associated with MV in the specific context of AIS and then discuss evidence of brain goal-directed approaches that may mitigate these risks. These strategies include an individualized approach to hemodynamic parameters (eg, adherence to a minimum blood pressure goal and adequate volume resuscitation), respiratory parameters (eg, arterial carbon dioxide optimization), and the use of ventilator settings that optimize neurological outcomes (eg, arterial oxygen optimization).

[Peri-interventional management of acute endovascular stroke treatment]

Due to the ground breaking consistent evidence that supports the effect of endovascular stroke treatment (EST), many acute care hospitals and stroke centers will have to be prepared to provide this treatment in an optimal way within the coming years. In addition to the intervention itself, patient preparation, stabilization and monitoring during the treatment as well as the aftercare represent significant challenges and have mostly not yet been sufficiently investigated. Under these aspects, the questions of optimal sedation and airway management have received the highest attention. Based on retrospective study results it already seems to be justified, respecting certain criteria, to prefer EST with the patient under conscious sedation (CS) in comparison to general anesthesia (GA) and to only switch to GA in cases of emergency until this question has been clarified by prospective studies. This and other aspects of peri-interventional management, such as logistics, monitoring, blood pressure, ventilation settings, postprocedural steps of intensive or stroke unit care and imaging follow-up are summarized in this overview. The clinical and radiological selection of patients and thus the decision for intervention or technical aspects of the intervention itself will not be part of this article.

Clinical Impact of Ventilation Duration in Patients with Stroke Undergoing Interventional Treatment under General Anesthesia: The Shorter the Better?

BACKGROUND AND PURPOSE

Whether general anesthesia for neurothrombectomy in patients with ischemic stroke has a negative impact on clinical outcome is currently under discussion. We investigated the impact of early extubation and ventilation duration in a cohort that underwent thrombectomy under general anesthesia.

MATERIALS AND METHODS

We analyzed 103 consecutive patients from a prospective stroke registry. They met the following criteria: CTA-proved large-vessel occlusion in the anterior circulation, ASPECTS above 6 on presenting cranial CT, revascularization by thrombectomy with the patient under general anesthesia within 6 hours after onset of symptoms, and available functional outcome (mRS) 90 days after onset.

RESULTS

The mean ventilation time was 128.07 ± 265.51 hours (median, 18.5 hours; range, 1-1244.7 hours). Prolonged ventilation was associated with pneumonia during hospitalization and unfavorable functional outcome (mRS ≥3) and death at follow-up (Mann-Whitney U test; P ≤ .001). According to receiver operating characteristic analysis, a cutoff after 24 hours predicted unfavorable functional outcome with a sensitivity and specificity of 60% and 78%, respectively. Our results imply that delayed extubation was not associated with a less favorable clinical outcome compared with immediate extubation after the procedure.

CONCLUSIONS

Short ventilation times are associated with a lower pneumonia rate and more favorable clinical outcome. Cautious interpretation of our data implies that whether patients are extubated immediately after the procedure is irrelevant for clinical outcome as long as ventilation does not exceed 24 hours.

Mechanical thrombectomy in acute ischemic stroke: Consensus statement by ESO-Karolinska Stroke Update 2014/2015, supported by ESO, ESMINT, ESNR and EAN

The original version of this consensus statement on mechanical thrombectomy was approved at the European Stroke Organisation (ESO)-Karolinska Stroke Update conference in Stockholm, 16–18 November 2014. The statement has later, during 2015, been updated with new clinical trials data in accordance with a decision made at the conference. Revisions have been made at a face-to-face meeting during the ESO Winter School in Berne in February, through email exchanges and the final version has then been approved by each society. The recommendations are identical to the original version with evidence level upgraded by 20 February 2015 and confirmed by 15 May 2015. The purpose of the ESO-Karolinska Stroke Update meetings is to provide updates on recent stroke therapy research and to discuss how the results may be implemented into clinical routine. Selected topics are discussed at consensus sessions, for which a consensus statement is prepared and discussed by the participants at the meeting. The statements are advisory to the ESO guidelines committee. This consensus statement includes recommendations on mechanical thrombectomy after acute stroke. The statement is supported by ESO, European Society of Minimally Invasive Neurological Therapy (ESMINT), European Society of Neuroradiology (ESNR), and European Academy of Neurology (EAN).

Management of the Interventional Stroke Patient

OPINION STATEMENT

The acute treatment of major ischemic stroke has been revolutionized by strong and consistent evidence from multiple randomized trials. Endovascular treatment by mechanical thrombectomy will be increasingly chosen as an adjunctive or alternative to intravenous thrombolysis. To apply this form of stroke treatment is associated with the challenge of optimal periinterventional treatment. The patient has to be identified, counselled, prepared, monitored, cardiovascularly stabilized, possibly sedated and ventilated, and postprocedurally treated in the optimal way. However, most aspects of periinterventional treatment have as yet not been clarified and require prospective research. Among these, the question of general anesthesia vs conscious sedation has received most attention and may be the most crucial one. Based on a great amount of retrospective data, it appears reasonable to start the intervention under conscious sedation of the non-intubated patient with standby measures for emergent intubation, until prospective randomized trials have clarified that issue. Periinterventional management will significantly affect the success of recanalization.

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.