Single mean arterial blood pressure drops during stroke thrombectomy under general anaesthesia are associated with poor outcome

The effect of anesthesia on hemodynamics and outcome of patients undergoing thrombectomy after acute ischemic stroke: a retrospective analysis

BACKGROUND

Anesthesia during thrombectomy remains a matter of debate. We retrospectively investigated the influence of intraprocedural blood pressure and type of anaesthetic agent on 3-month functional outcome and mortality in stroke patients undergoing mechanical thrombectomy under general anesthesia in a single center study.

METHODS

All patients suffering from stroke who presented between January 2019 and July 2021 at Ziekenhuis Oost-Limburg Genk, Belgium and who received thrombectomy were included. Patient's characteristics and outcome data had been collected for benchmarking. Detailed perioperative data were exported from the electronic anesthesia records and clinically validated. Patients were stratified by peri-operative presence of hypotension (MAP < 65 mmHg at any time point) versus no-hypotension (MAP ≥ 65 mmHg).

RESULTS

All 98 patients received mechanical thrombectomy under general anesthesia. Thirty-six percent (n = 35) was hypotensive peri-operatively at any time point. Proportion of sevoflurane use was higher in non-hypotensive patients compared to hypotensive patients (73% (n = 45) vs. 51% (n = 18), p = 0.04). Peri-operative use of vasopressors was higher in the hypotensive group compared to non-hypotensive (88% (n = 30) vs. 63% (n = 39), p = 0.008). Proportion of patients with good functional outcome at 3 months (mRS 0-2) was higher in non-hypotensive patients compared to hypotensive patients 44% (n = 27) vs. 24% (n = 8), p < 0.05. 90-day mortality was lower in non-hypotensive patients compared to hypotensive patients 21% (n = 13) vs. 43% (n = 15), (p = 0.02).

CONCLUSION

Patients who are hypotensive at any given time during thrombectomy under general anesthesia may have worse neurological outcome compared to non-hypotensive patients. The best anaesthetic management for mechanical thrombectomy needs to be clarified prospectively in large multicenter studies.

Strict blood pressure control following thrombectomy is associated with neuronal injury and poor functional outcome

OBJECTIVE

Mechanical thrombectomy (MT) has become standard treatment in acute ischemic stroke due to large vessel occlusion (LVO). However, optimal blood pressure (BP) management following successful recanalization remains unclear. We aim to investigate the association of strictly achieving BP targets of ≤160/90 mmHg with the extent of neuronal loss and functional outcome.

METHODS

In patients prospectively enrolled in the Gutenberg-Stroke-Study (May 2018-November 2019), BP was measured half-hourly for 24 h following MT. Based on achieving BP target of ≤160/90 mmHg, patients with successful recanalization of LVO were divided into "low-BP" group (BP ≤ 160/90 mmHg) or "high-BP" group (BP > 160/90 mmHg). Neuronal loss was quantified by serum-based measurement of neurofilament light chain (sNfL) after three days. BP groups and association of BP parameters with sNfL were investigated by correlation analyses and multiple regression modeling.

RESULTS

Of 253 enrolled patients (mean age 73.1 ± 12.9 years, 53.4% female), 165 met inclusion criteria. 21.2% (n = 35) strictly achieved "low-BP" target. "low-BP" was associated with unfavorable functional outcome at 90-day follow-up (aOR [95%CI]: 5.88 [1.88-18.32], p = 0.002) and decreased health-related quality of life (mean EQ-5D-index 0.45 ± 0.28 vs 0.63 ± 0.31, p = 0.009). sNfL levels were increased in "low-BP" patients (median [IQR] 239.7 [168.4-303.4] vs 118.8 [52.5-220.5] pg/mL, p = 0.026). Hypotensive episodes were more frequent in the "low-BP" group (48.6% vs 29.2%, p = 0.031). sNfL level could identify patients who had experienced hypotensive episodes with high discriminative ability (AUC [95%CI]: 0.68 [0.56-0.78], p = 0.007).

INTERPRETATION

Strict BP control (≤160/90 mmHg) within 24 h following successful recanalization of LVO by MT is associated with increased neuronal injury, displayed by higher sNfL levels, and poorer functional outcome, potentially indicating hypotension-induced neuronal loss during post-MT phase.

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.

Occurrence of secondary insults during endovascular treatment of acute ischemic stroke and impact on outcome: the SIR-STROKE prospective observational study

BACKGROUND

Neurological outcome after endovascular treatment (EVT) of acute ischemic stroke (AIS) may depend on both patient-specific and procedural factors. We hypothesized that altered systemic homeostasis might be frequent and affect outcome in these patients. The aim of this study was to analyze secondary insults during EVT of AIS and its association with outcome and anesthesiologic regimen.

METHODS

This was a single-center prospective observational study on patients undergoing EVT for AIS under local anesthesia (LA), conscious sedation (CS), or general anesthesia (GA). Altered systemic parameters were recorded and quantified as secondary insults. The primary endpoint was to evaluate number, duration, and severity of secondary insults during EVT. Secondary endpoints were to analyze association of insults with modified Rankin Scale at 90 days and anesthesiologic regimen.

RESULTS AND CONCLUSIONS

One hundred twenty patients were enrolled. Overall, 78% of patients experienced at least one episode of hypotension, 21% hypertension, 54% hypoxemia, 16% bradycardia, and 13% tachycardia. In patients monitored with capnometry, 70% experienced hypocapnia and 21% hypercapnia. LA was selected in 24 patients, CS in 84, and GA in 12. Hypotension insult was more frequent during GA than LA and CS (p = 0.0307), but intraprocedural blood pressure variation was higher during CS (p = 0.0357). Hypoxemia was more frequent during CS (p = 0.0087). Proportion of hypotension duration was higher in unfavorable outcome but secondary insults did not remain in the final model of multivariable analysis. Secondary insults occurred frequently during EVT for AIS but the main predictors of outcome were age, NIHSS at admission, and prompt and successful recanalization.

Anesthesia, Blood Pressure, and Socioeconomic Status in Endovascular Thrombectomy for Acute Stroke: A Single Center Retrospective Case Cohort

INTRODUCTION

Mechanical thrombectomy (MT) is standard for acute ischemic stroke (AIS), with early studies suggesting that general anesthesia (GA) is associated with worse outcomes than monitored anesthesia care (MAC). Socioeconomic deprivation is also a risk factor for worse AIS outcomes. With improvements in MT and blood pressure (BP) management, it remains unclear if GA or socioeconomic deprivation are risk factors for worse outcomes after MT.

METHODS

We retrospectively analyzed 125 consecutive AIS patients presenting for MT at a comprehensive stroke center serving patients with high levels of socioeconomic deprivation. The primary objective was impact of GA versus MAC on functional independence at 90 days. Secondary outcomes included procedural BP, and impact of BP and socioeconomic deprivation (assessed by the area of deprivation index) on outcomes.

RESULTS

A 90-day outcomes were similar in patients undergoing MT with GA or MAC. The area of deprivation index was similar in GA and MAC groups and in patients with good versus poor 90-day outcomes. There were similar numbers of patients with mean arterial pressure (MAP) <60 mm Hg in the MAC and GA groups (8 vs. 11; P =0.21), but more patients with MAP <70 mm Hg in the GA group (28 vs. 9; P <0.001). Median (interquartile range) duration of MAP <70 mm Hg was 10 (5 to 15) and 20 (10 to 36) minutes in the MAC and GA groups, respectively ( P <0.001); however, these MAPs were not associated with worse 90-day outcomes.

CONCLUSION

Anesthesia and MAP did not affect MT outcomes. The cohort is unique based on an area of deprivation index in the higher deciles in the United States. While the area of deprivation index was not associated with worse outcomes, further study is warranted.

Comparison of Anesthetic Agents Dexmedetomidine and Midazolam During Mechanical Thrombectomy

OBJECTIVES

The ideal anesthetic for mechanical thrombectomy (MT) is a subject of debate. Recent studies have supported the use of monitored anesthesia care (MAC), but few have attempted to compare MAC neuroanesthetics. Our study directly compares midazolam and dexmedetomidine (DEX) on blood pressure control during thrombectomy and functional outcomes at discharge.

MATERIALS AND METHODS

We performed a retrospective review of an MT database, which consisted of 612 patients admitted between 2010-2019 to our tertiary stroke center. 193 patients who received either midazolam or DEX for MAC induction were identified. Primary and secondary outcomes were >20% maximum decrease in mean arterial pressure during MT and functional independence respectively.

RESULTS

146 patients were administered midazolam, while 47 were administered DEX. Decrease in blood pressure (BP) during MT was associated with lower rates of functional independence at last follow-up (p=0.034). When compared to midazolam, DEX had significantly higher rates of intraprocedural decrease in MAP at the following cut-offs: >20% (p<0.001), >30% (p=0.001), and >40% (p=0.006). On multivariate analysis, DEX was an independent predictor of >20% MAP decrease (OR 7.042, p<0.001). At time of discharge, NIHSS scores and functional independence (mRS 0-2) were statistically similar between DEX and midazolam. Functional independence at last known follow-up was statistically similar between DEX and midazolam (p = 0.643).

CONCLUSIONS

Use of DEX during MT appears to be associated with increased blood pressure volatility when compared to midazolam. Further investigation is needed to determine the impact of MAC agents on functional independence.

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

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

Impact of Early Blood Pressure Lowering in Patients Presenting with Acute Ischemic Stroke

Purpose of Review

In this review article we will discuss the acute hypertensive response in the context of acute ischemic stroke and present the latest evidence-based concepts of the significance and management of the hemodynamic response in acute ischemic stroke.

Recent Findings

Acute hypertensive response is considered a common hemodynamic physiologic response in the early setting of an acute ischemic stroke. The significance of the acute hypertensive response is not entirely well understood. However, in certain types of acute ischemic strokes, the systemic elevation of the blood pressure helps to maintain the collateral blood flow in the penumbral ischemic tissue. The magnitude of the elevation of the systemic blood pressure that contributes to the maintenance of the collateral flow is not well established. The overcorrection of this physiologic hemodynamic response before an effective vessel recanalization takes place can carry a negative impact in the final clinical outcome. The significance of the persistence of the acute hypertensive response after an effective vessel recanalization is poorly understood, and it may negatively affect the final outcome due to reperfusion injury.

Summary

Acute hypertensive response is considered a common hemodynamic reaction of the cardiovascular system in the context of an acute ischemic stroke. The reaction is particularly common in acute brain embolic occlusion of large intracranial vessels. Its early management before, during, and immediately after arterial reperfusion has a repercussion in the final fate of the ischemic tissue and the clinical outcome.

Acute ischemic stroke & emergency mechanical thrombectomy: The effect of type of anesthesia on early outcome

BACKGROUND

Endovascular mechanical thrombectomy (EMT) is the standard of care for acute ischemic stroke (AIS) caused by proximal large vessel occlusions. There is conflicting evidence on outcome of patients undergoing EMT under procedural sedation (PS) or general anesthesia (GA). In this retrospective study we analyze the effect of GA and PS on the functional outcome of patients undergoing EMT.

METHODS

Patients who have been admitted at our institute AIS and were treated with EMT under GA or PS between January 2015 and September 2018 were included in the study. Primary end point was the proportion of patients with good functional outcome as defined by a modified Rankin score (mRS) 0-2 at discharge.

RESULTS

A total of 155 patients were analyzed in this study including 45 (29.03 %) patients who received 97 GA, 110 (70.9 %) PS and 31 of these received Dexmedetomidine/Remifentanil. The median (IQR) 98 mRS at discharge was 4.0 (1.0-4.0) in the GA group Vs 3.00, (1.00-4.00) in the PS group. Among the secondary outcomes the lowest MAP recorded was significantly less in GA group (64.56 100 ± 18.70) compared to PS group (70.86 ± 16.30); p = 0.03. The PS group had a lower odd of mRS 3-5 (after adjustment), however, this finding was statistically not significant (OR 0.52 [0.07-3.5] 102 p = 0.5).

CONCLUSIONS

Our retrospective analysis did not find any influence of GA compared to PS whenever this was delivered by target controlled infusion (TCI) of propofol or by remifentanil/dexmedetomidine (REX) on early functional outcome.

Blood Pressure Management in Acute Ischemic Stroke

PURPOSE OF REVIEW

Abrupt blood pressure (BP) rise is the most common clinical symptom of acute ischemic stroke (AIS). However, BP alterations during AIS reflect many diverse mechanisms, both stroke-related and nonspecific epiphenomena, which change over time and across patients. While extremes of BP as well as high BP variability have been related with worse outcomes in observational studies, optimal BP management after AIS remains challenging.

RECENT FINDINGS

This review discusses the complexity of the factors linking BP changes to the clinical outcomes of patients with AIS, depending on the treatment strategy and local vessel status and, in particular, the degree of reperfusion achieved. The evidence for possible additional clinical markers, including the presence of arterial hypertension, and comorbid organ dysfunction in individuals with AIS, as informative and helpful factors in therapeutic decision-making concerning BP will be reviewed, as well as recent data on neurovascular monitoring targeting person-specific local cerebral perfusion and metabolic demand, instead of the global traditional parameters (BP among others) alone. The individualization of BP management protocols based on a complex evaluation of the homeostatic response to focal cerebral ischemia, including but not limited to BP changes, may be a valuable novel goal proposed in AIS, but further trials are warranted.