Hemodynamic Management of Patients During Endovascular Treatment of Acute Ischemic Stroke Under Conscious Sedation: A Retrospective Cohort Study

Measuring Quantitative Cerebral Blood Flow in Healthy Children: A Systematic Review of Neuroimaging Techniques

Cerebral blood flow (CBF) is an important hemodynamic parameter to evaluate brain health. It can be obtained quantitatively using medical imaging modalities such as magnetic resonance imaging and positron emission tomography (PET). Although CBF in adults has been widely studied and linked with cerebrovascular and neurodegenerative diseases, CBF data in healthy children are sparse due to the challenges in pediatric neuroimaging. An understanding of the factors affecting pediatric CBF and its normal range is crucial to determine the optimal CBF measuring techniques in pediatric neuroradiology. This review focuses on pediatric CBF studies using neuroimaging techniques in 32 articles including 2668 normal subjects ranging from birth to 18 years old. A systematic literature search was conducted in PubMed, Embase, and Scopus and reported following the preferred reporting items for systematic reviews and meta-analyses (PRISMA). We identified factors (such as age, gender, mood, sedation, and fitness) that have significant effects on pediatric CBF quantification. We also investigated factors influencing the CBF measurements in infants. Based on this review, we recommend best practices to improve CBF measurements in pediatric neuroimaging. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

The influence of pre-reperfusion blood pressure on outcomes following mechanical thrombectomy for anterior circulation large vessel occlusion

BACKGROUND

We evaluated how systolic blood pressure (SBP) and mean arterial pressure (MAP) parameters between presentation and reperfusion influence functional status and intracranial hemorrhage (ICH).

METHODS

All patients who underwent MT for LVO at a single institution were reviewed. Independent variables included SBP and MAP measurements obtained on presentation, between presentation and reperfusion (pre-reperfusion), and between groin puncture and reperfusion (thrombectomy). Mean, minimum, maximum, and standard deviations (SD) for SBP and MAP were calculated. Outcomes included 90-day favorable functional status, radiographic ICH (rICH), and symptomatic ICH (sICH).

RESULTS

305 patients were included. Higher pre-reperfusion SBP_max was associated with rICH (OR 1.41, 95% CI 1.08-1.85) and sICH (OR 1.84, 95% CI 1.26-2.72). Higher SBP_SD was also associated with rICH (OR 1.38, 95% CI 1.06-1.81) and sICH (OR 1.59, 95% CI 1.12-2.26). Greater SBP_max (OR 0.64, 95% CI 0.47-0.86), MAP_max (OR 0.72, 95% CI 0.52-0.97), SBP_SD (OR 0.63, 95% CI 0.46-0.86), and MAP_SD (0.63, 95% CI 0.45-0.84) during thrombectomy were associated with lower odds of 90-day favorable functional status. In a subgroup analysis, these associations were primarily limited to patients with intact collateral circulation. Optimal SBP_max cutoffs for predicting rICH were 171 (pre-reperfusion) and 179 mmHg (thrombectomy). Cutoffs for predicting sICH were 178 (pre-reperfusion) and 174 mmHg (thrombectomy).

CONCLUSION

Greater maximum BP and variability in BP during the pre-reperfusion period are associated with unfavorable functional status and ICH after MT for anterior circulation LVO.

Effect of supraglottic airway devices versus endotracheal intubation general anesthesia on outcomes in patients undergoing mechanical thrombectomy: A prospective randomized clinical trial

BACKGROUND

There are still controversies about the optimal anesthesia protocol for patients with acute ischemic stroke (AIS) undergoing mechanical thrombectomy (MT). The aim of this study was to explore the effect of supraglottic airway device (SAD) versus endotracheal intubation (EI) general anesthesia on clinical and angiographic outcomes in patients with AIS undergoing MT.

METHODS

One hundred sixteen patients with large-vessel occlusion stroke were randomized to receive either SAD or EI general anesthesia. The primary outcome was the rate of occurrence of >20% fall in mean arterial pressure (MAP). Secondary outcomes included hemodynamics, successful recanalization, time metrics, satisfaction score of neurointerventionalist, number of passes performed, the conversion rate from SAD to EI, the National Institutes of Health Stroke Scale score, and Alberta Stroke Program Early CT Score before and 24 hours after surgery, length of stay in the stroke unit and hospital, complications and functional independence at discharge, and 90 days after stroke.

RESULTS

Both the lowest systolic blood pressure and lowest diastolic blood pressure were significantly lower in the EI group (P = .001). The consumption of vasoactive agents, the occurrence of >20% reduction in MAP and time spent with >20% fall in MAP were significantly higher in the EI group (P < .05). Compared with the EI group, the time for door-to-puncture was significantly shorter in the SAD group (P = .015). There were no significant differences with respect to puncture-to-reperfusion time, number of passes performed, rates of successful recanalization, National Institutes of Health Stroke Scale score, and Alberta Stroke Program Early CT Score 24 hours after surgery. The satisfaction score of neurointerventionalist was significantly lower in the EI group (P = .043). Conversion rate from SAD to EI was 7.41%. There were no significant differences with respect to complications, mortality, and mean Modified Rankin Scale scores both at discharge and 90-day after stroke. However, length of stroke unit and hospital stays were significantly shorter in the SAD group (P < .05).

CONCLUSION

AIS patients undergoing MT with SAD general anesthesia led to more stable hemodynamics, higher satisfaction score of neurointerventionalist, shorter door-to-puncture time, length of stroke unit, and hospital stay. However, there were no significant differences between the 2 groups on the angiographic and functional outcomes both at discharge and 90 days after stroke.

Pressor therapy in acute ischaemic stroke: an updated systematic review

Background

Low blood pressure (BP) in acute ischaemic stroke (AIS) is associated with poor functional outcome, death, or severe disability. Increasing BP might benefit patients with post-stroke hypotension including those with potentially salvageable ischaemic penumbra. This updated systematic review considers the present evidence regarding the use of vasopressors in AIS.

Methods

We searched the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE and trial databases using a structured search strategy. We examined reference lists of relevant publications for additional studies examining BP elevation in AIS.

Results

We included 27 studies involving 1886 patients. Nine studies assessed increasing BP during acute reperfusion therapy (intravenous thrombolysis, mechanical thrombectomy, intra-arterial thrombolysis or combined). Eighteen studies tested BP elevation alone. Phenylephrine was the most commonly used agent to increase BP (n = 16 studies), followed by norepinephrine (n = 6), epinephrine (n = 3) and dopamine (n = 2). Because of small patient numbers and study heterogeneity, a meta-analysis was not possible. Overall, BP elevation was feasible in patients with fluctuating or worsening neurological symptoms, large vessel occlusion with labile BP, sustained post-stroke hypotension and ineligible for intravenous thrombolysis or after acute reperfusion therapy. The effects on functional outcomes were largely unknown and close monitoring is advised if such intervention is undertaken.

Conclusion

Although theoretical arguments support increasing BP to improve cerebral blood flow and sustain the ischaemic penumbra in selected AIS patients, the data are limited and results largely inconclusive. Large, randomised controlled trials are needed to identify the optimal BP target, agent, duration of treatment and effects on clinical outcomes.

Periprocedural Management During Stroke Thrombectomy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Blood Pressure Thresholds and Neurologic Outcomes After Endovascular Therapy for Acute Ischemic Stroke: An Analysis of Individual Patient Data From 3 Randomized Clinical Trials

Importance

The optimal blood pressure targets during endovascular therapy (EVT) for acute ischemic stroke (AIS) are unknown.

Objective

To study whether procedural blood pressure parameters, including specific blood pressure thresholds, are associated with neurologic outcomes after EVT.

Design, Setting, and Participants

This retrospective cohort study included adults with anterior-circulation AIS who were enrolled in randomized clinical trials assessing anesthetic strategy for EVT between February 2014 and February 2017. The trials had comparable blood pressure protocols, and patients were followed up for 90 days. A total of 3630 patients were initially approached, and 3265 patients were excluded.

Exposure

Endovascular therapy.

Main Outcomes and Measures

The primary efficacy variable was functional outcome as defined by the modified Rankin Scale (mRS) score at 90 days. Associations of blood pressure parameters and time less than and greater than mean arterial blood pressure (MABP) thresholds with outcome were analyzed.

Results

Of the 365 patients included in the analysis, the mean (SD) age was 71.4 (13.0) years, 163 were women (44.6%), and the median National Institutes of Health Stroke Scale score was 17 (interquartile range [IQR], 14-21). For the entire cohort, 182 (49.9%) received general anesthesia and 183 (50.1%) received procedural sedation. A cumulated period of minimum 10 minutes with less than 70 mm Hg MABP (adjusted OR, 1.51; 95% CI, 1.02-2.22) and a continuous episode of minimum 20 minutes with less than 70 mm Hg MABP (adjusted OR, 2.30; 95% CI, 1.11-4.75) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 4, respectively. A cumulated period of minimum 45 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.49; 95% CI, 1.11-2.02) and a continuous episode of minimum 115 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.89; 95% CI, 1.01-3.54) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 6, respectively.

Conclusions and Relevance

Critical MABP thresholds and durations for poor outcome were found to be MABP less than 70 mm Hg for more than 10 minutes and MABP greater than 90 mm Hg for more than 45 minutes, both durations with a number needed to harm of 10 patients. Mean arterial blood pressure may be a modifiable therapeutic target to prevent or reduce poor functional outcome after EVT.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Posterior reversible encephalopathy syndrome coexists with acute cerebral infarction: challenges of blood pressure management

Hypertension is the most common cause of posterior reversible encephalopathy syndrome (PRES) and acute cerebral infarction. Due to the lack of randomized controlled clinical trials (RCTs), early antihypertensive methods are diverse, even contradictory. So far, there is no consensus on the method of blood pressure (BP) management when the 2 diseases coexist. Generally, antihypertensive therapy should be initiated quickly in the acute phase of PRES, as most patients have elevated BP. However, various factors must be considered before the administration of early antihypertensive therapy in acute cerebral infarction. The coexistence of PRES and acute cerebral infarction is uncommon clinically, and more complicated subsequent BP management. This article reports a case of PRES coexisting with acute lacunar cerebral infarction, which was caused by hypertension. We have analyzed and summarized the antihypertensive principles in PRES and different phases of acute cerebral ischemic injury. We assert that when PRES and acute cerebral infarction coexist, the antihypertensive treatment should be individualized, and careful consideration should be given to the various influencing factors.

Blood Pressure During Endovascular Treatment Under Conscious Sedation or Local Anesthesia

Objective

To evaluate the role of blood pressure (BP) as mediator of the effect of conscious sedation (CS) compared to local anesthesia (LA) on functional outcome after endovascular treatment (EVT).

Methods

Patients treated in the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry centers with CS or LA as preferred anesthetic approach during EVT for ischemic stroke were analyzed. First, we evaluated the effect of CS on area under the threshold (AUT), relative difference between baseline and lowest procedural mean arterial pressure (∆LMAP), and procedural BP trend, compared to LA. Second, we assessed the association between BP and functional outcome (modified Rankin Scale [mRS]) with multivariable regression. Lastly, we evaluated whether BP explained the effect of CS on mRS.

Results

In 440 patients with available BP data, patients treated under CS (n = 262) had larger AUTs (median 228 vs 23 mm Hg*min), larger ∆LMAP (median 16% vs 6%), and a more negative BP trend (−0.22 vs −0.08 mm Hg/min) compared to LA (n = 178). Larger ∆LMAP and AUTs were associated with worse mRS (adjusted common odds ratio [acOR] per 10% drop 0.87, 95% confidence interval [CI] 0.78–0.97, and acOR per 300 mm Hg*min 0.89, 95% CI 0.82–0.97). Patients treated under CS had worse mRS compared to LA (acOR 0.59, 95% CI 0.40–0.87) and this association remained when adjusting for ∆LMAP and AUT (acOR 0.62, 95% CI 0.42–0.92).

Conclusions

Large BP drops are associated with worse functional outcome. However, BP drops do not explain the worse outcomes in the CS group.

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

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

Effect of Conscious Sedation vs. General Anesthesia on Outcomes in Patients Undergoing Mechanical Thrombectomy for Acute Ischemic Stroke: A Prospective Randomized Clinical Trial

Background: Although several studies have compared conscious sedation (CS) with general anesthesia (GA) in patients undergoing mechanical thrombectomy (MT), there has been no affirmative conclusion. We conducted this trial to assess whether CS is superior to GA for patients undergoing MT for acute ischemic stroke (AIS).

Methods: Acute ischemic stroke patients with anterior circulation large vascular occlusion were randomized into two groups. The primary outcome was modified Rankin scale score (0–2) at 90 days after stroke. Secondary outcomes included intraprocedural hemodynamics, time metrics, successful recanalization, neurointerventionalist satisfaction score, National Institutes of Health Stroke Scale (NIHSS) score, and Alberta Stroke Program Early CT Score (ASPECTS) at 48 h post-intervention, mortality at discharge and 3 months after stroke, and complications.

Results: Compared with the CS group, heart rate was significantly lower at T1–T8 in the GA group except at T4 (P < 0.05). Mean arterial pressure (MAP) and systolic blood pressure were significantly lower in the GA group at T4–T6 and T9 (P < 0.05). Pulse oxygen saturation was significantly higher at T2–T9 in the GA group (P < 0.05). There were no significant differences in time metrics, vasoactive drug use, occurrence of >20% fall in MAP, pre-recanalization time spent with >20% fall in MAP, neurointerventionalist satisfaction, successful recanalization rate, NIHSS, and ASPECTS scores at 48 h post-intervention, and mortality rate at discharge and 3 months after stroke (P > 0.05). The cerebral infarction rate at 30 days was greater in the CS group, but not significantly (P > 0.05). There were no differences in complication rates except for pneumonia (P > 0.05). Conversion rate from CS to GA was 9.52%.

Conclusion: Anesthetic management with GA or CS during MT had no differential impact on the functional outcomes and mortality at discharge or 3 months after stroke in AIS patients, but CS led to more stable hemodynamics and lower incidence of pneumonia.

Neuroanesthesiology Update

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

Association of Blood Pressure With Outcomes in Acute Stroke Thrombectomy

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

Assessment of Anesthesia Practice Patterns for Endovascular Therapy for Acute Ischemic Stroke: A Society for Neuroscience in Anesthesiology and Critical Care (SNACC) Member Survey

BACKGROUND

The choice of general anesthesia (GA) or conscious sedation (CS) may impact neurological outcomes of patients undergoing endovascular therapy (EVT) for acute ischemic stroke (AIS). The aim of this survey was to describe the practice patterns of members of the Society for Neuroscience in Anesthesiology and Critical Care (SNACC) for anesthetic management of AIS.

METHODS

Following institutional review board approval, a 16-question online survey assessing anesthetic management of patients with AIS undergoing EVT was circulated to members of SNACC.

RESULTS

A total of 76 SNACC members from 52 institutions and 11 countries completed the survey (12.5% response rate). Overall, 33% of institutions reported dedicated neuroanesthesia teams for EVT. Patients treated with GA ranged from 5% to 100% between centers. In total 51% and 49% of centers in the United States reported preferentially providing GA and CS, respectively, compared with 34% and 66%, respectively, in European centers. Reported anesthetic induction agents are propofol (64%), etomidate (4%) and either medication (33%). For maintenance of GA, volatile anesthetic is used more often (54%) than propofol (16%). There was wide variation in medications used for CS. Arterial catheter placement was reported by 75% and 43% of respondents for patients undergoing GA and CS, respectively. Systolic blood pressure >140 mm Hg was targeted by 35.7% of respondents, with others targeting mean arterial pressure within 10%, 20% or 30% of baseline values. Phenylephrine and norepinephrine were the most commonly used vasopressors.

CONCLUSIONS

There is wide variation in anesthesia technique and hemodynamic management during EVT for AIS, and no consensus on the choice of, or preferred medications for, GA or CS, or target blood pressure and management of hypotension during the procedure.

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

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

Acute ischaemic stroke: challenges for the intensivist

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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