HIMALAIA (Hypertension Induction in the Management of AneurysmaL subArachnoid haemorrhage with secondary IschaemiA): a randomized single-blind controlled trial of induced hypertension vs. no induced hypertension in the treatment of delayed cerebral ischemia after subarachnoid hemorrhage

Prevention of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage-Summary of Existing Clinical Evidence

The 2023 International Subarachnoid Hemorrhage Conference identified a need to provide an up-to-date review on prevention methods for delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage and highlight areas for future research. A PubMed search was conducted for key factors contributing to development of delayed cerebral ischemia: anesthetics, antithrombotics, cerebrospinal fluid (CSF) diversion, hemodynamic, endovascular, and medical management. It was found that there is still a need for prospective studies analyzing the best methods for anesthetics and antithrombotics, though inhaled anesthetics and antiplatelets were found to have some advantages. Lumbar drains should increasingly be considered the first line of CSF diversion when applicable. Finally, maintaining euvolemia before and during vasospasm is recommended as there is no evidence supporting prophylactic spasmolysis or angioplasty. There is accumulating observational evidence, however, that intra-arterial spasmolysis with refractory DCI might be beneficial in patients not responding to induced hypertension. Nimodipine remains the medical therapy with the most support for prevention.

Risk factors for poor outcome after aneurysmal subarachnoid hemorrhage in patients with initial favorable neurological status

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) remains a devastating diagnosis. A poor outcome is known to be highly dependent on the initial neurological status. Our goal was to identify other parameters that favor the risk of complications and poor outcome in patients with aSAH and initially favorable neurologic status.

METHODS

Consecutive aSAH cases treated at our hospital between 01/2003 and 06/2016 with the initial World Federation of Neurosurgical Societies grades I-III were included. Data on demographic characteristics, previous medical history, initial aSAH severity, and functional outcome after aSAH were collected. The study endpoints were the occurrence of cerebral infarcts, in-hospital mortality, and unfavorable outcome at 6 months after aSAH (modified Rankin scale > 3).

RESULTS

In the final cohort (n= 582), the rate of cerebral infarction, in-hospital mortality, and unfavorable outcome was 35.1%, 8.1%, and 17.6% respectively. The risk of cerebral infarction was independently related to the presence of acute hydrocephalus (adjusted odds ratio [aOR]=2.33, p<0.0001), aneurysm clipping (aOR=1.78, p=0.003), and use of calcium channel blockers concomitant to nimodipine (aOR=2.63, p=0.002). Patients' age (>55 years, aOR=4.24, p<0.0001), acute hydrocephalus (aOR=2.43, p=0.036), and clipping (aOR=2.86, p=0.001) predicted in-hospital mortality. Baseline characteristics associated with unfavorable outcome at 6 months were age (aOR=2.77, p=<0.0001), Fisher grades III-IV (aOR=2.81, p=0.016), acute hydrocephalus (aOR=2.22, p=0.012), clipping (aOR=3.98, p<0.0001), admission C-reactive protein>1mg/dL (aOR=1.76, p=0.035), and treatment intervals (aOR=0.64 per-5-year-intervals, p=0.006).

CONCLUSIONS

Although cerebral infarction is a common complication in aSAH individuals with favorable initial clinical condition, >80% of these patients show favorable long-term outcome. The knowledge of outcome-relevant baseline characteristics might help to reduce the burden of further complications and poor outcome in aSAH patients who tolerated the initial bleeding event well.

Management of hypertensive crisis: British and Irish Hypertension Society Position document

Patients with hypertensive emergencies, malignant hypertension and acute severe hypertension are managed heterogeneously in clinical practice. Initiating anti-hypertensive therapy and setting BP goal in acute settings requires important considerations which differ slightly across various diagnoses and clinical contexts. This position paper by British and Irish Hypertension Society, aims to provide clinicians a framework for diagnosing, evaluating, and managing patients with hypertensive crisis, based on the critical appraisal of available evidence and expert opinion.

Therapies for Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is one of the most important complications of subarachnoid hemorrhage. Despite lack of prospective evidence, medical rescue interventions for DCI include hemodynamic augmentation using vasopressors or inotropes, with limited guidance on specific blood pressure and hemodynamic parameters. For DCI refractory to medical interventions, endovascular rescue therapies (ERTs), including intraarterial (IA) vasodilators and percutaneous transluminal balloon angioplasty, are the cornerstone of management. Although there are no randomized controlled trials assessing the efficacy of ERTs for DCI and their impact on subarachnoid hemorrhage outcomes, survey studies suggest that they are widely used in clinical practice with significant variability worldwide. IA vasodilators are first line ERTs, with better safety profiles and access to distal vasculature. The most commonly used IA vasodilators include calcium channel blockers, with milrinone gaining popularity in more recent publications. Balloon angioplasty achieves better vasodilation compared with IA vasodilators but is associated with higher risk of life-threatening vascular complications and is reserved for proximal severe refractory vasospasm. The existing literature on DCI rescue therapies is limited by small sample sizes, significant variability in patient populations, lack of standardized methodology, variable definitions of DCI, poorly reported outcomes, lack of long-term functional, cognitive, and patient-centered outcomes, and lack of control groups. Therefore, our current ability to interpret clinical results and make reliable recommendations regarding the use of rescue therapies is limited. This review summarizes existing literature on rescue therapies for DCI, provides practical guidance, and identifies future research needs.

Investigating the relationship between high-dose norepinephrine administration and the incidence of delayed cerebral infarction in patients with aneurysmal subarachnoid hemorrhage: A single-center retrospective evaluation

BACKGROUND

One of the longest-standing treatments to prevent delayed cerebral infarction (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) remains raising the blood pressure to a certain level of mean arterial pressure. This may require high doses of norepinephrine, which has been associated with severe end organ damage. With this study, we aimed to investigate the effects of norepinephrine on the incidence of DCI in a clinical setting.

METHODS

We conducted a retrospective evaluation of patients with aSAH admitted to our institution between November 2018 and March 2021. Potential risk factors for DCI were analyzed and significant predictors were assessed by means of a logistic regression analysis to account for potential confounders.

RESULTS

In this study, 104 patients were included. Hereof, 39 (38%) showed radiologic signs of DCI between day three and 14 post-intervention. These patients had more frequent vasospasms (n = 37 vs. 30, p = 0.022), a higher Hunt & Hess score (3 ± 2 vs. 2 ± 1, p = 0.004), a lower initial Glasgow Coma Scale score (9 ± 5 vs. 12 ± 4, p = 0.003) and received a higher median norepinephrine dose (20,356μg vs. 6,508μg, p < 0.001). A logistic regression analysis revealed that only high-dose norepinephrine administration (OR 2.84, CI 1.56-7.8) and vasospasm (OR 3.07, CI 1.2-7.84) appeared to be significant independent risk factors for DCI.

CONCLUSION

Our results indicate a significant association between higher dose norepinephrine administration and the occurrence of DCI. Future research including greater sample sizes and a prospective setting will be necessary to further investigate the relationship.

Slow recruitment in the HIMALAIA study: lessons for future clinical trials in patients with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage based on feasibility data

Background

Our randomized clinical trial on induced hypertension in patients with delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) was halted prematurely due to unexpected slow recruitment rates. This raised new questions regarding recruitment feasibility. As our trial can therefore be seen as a feasibility trial, we assessed the reasons for the slow recruitment, aiming to facilitate the design of future randomized trials in aSAH patients with DCI or other critically ill patient categories.

Methods

Efficiency of recruitment and factors influencing recruitment were evaluated, based on the patient flow in the two centers that admitted most patients during the study period. We collected numbers of patients who were screened for eligibility, provided informed consent, and developed DCI and who eventually were randomized.

Results

Of the 862 aSAH patients admitted in the two centers during the course of the trial, 479 (56%) were eligible for trial participation of whom 404 (84%) were asked for informed consent. Of these, 188 (47%) provided informed consent, of whom 50 (27%) developed DCI. Of these 50 patients, 12 (24%) could not be randomized due to a logistic problem or a contraindication for induced hypertension emerging at the time of randomization, and four (8%) were missed for randomization. Eventually, 34 patients were randomized and received intervention or control treatment.

Conclusions

Enrolling patients in a randomized trial on a treatment strategy for DCI proved unfeasible: only 1 out of 25 admitted and 1 out of 14 eligible patients could eventually be randomized. These rates, caused by a large proportion of ineligible patients, a small proportion of patients providing informed consent, and a large proportion of patients with contraindications for treatment, can be used to make sample size calculations for future randomized trials in DCI or otherwise critically ill patients. Facilitating informed consent through improved provision of information on risks, possible benefits, and study procedures may result in improved enrolment.

Trial registration

The original trial was prospectively registered with ClinicalTrials.gov (NCT01613235), date of registration 07-06-2012.

Incremental Versus Immediate Induction of Hypertension in the Treatment of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Background

Delayed cerebral ischemia (DCI) is a common complication of aneurysmal subarachnoid hemorrhage and contributes to unfavorable outcome. In patients with deterioration despite prophylactic nimodipine treatment, induced hypertension (iHTN) can be considered, although the safety and efficacy of induction are still a matter of debate. In this study, two iHTN treatment algorithms were compared with different approaches toward setting pressure targets.

Methods

In a cohort of 325 consecutive patients with subarachnoid hemorrhage, 139 patients were treated by induced hypertension as a first tier treatment. On diagnosing DCI, blood pressure was raised via norepinephrine infusion in 20-mm Hg increments in 37 patients (iHTN_incr), whereas 102 patients were treated by immediate elevation to systolic pressure above 180 mm Hg (iHTN_imm). Treatment choice was based on personal preference of the treating physician but with a gradual shift away from incremental elevation. Both groups were evaluated for DCI-caused infarction, the need of additional endovascular rescue treatment, the occurrence of pressor-treatment-related complications, and clinical outcome assessed by the extended Glasgow outcome scale after 12 months.

Results

The rate of refractory DCI requiring additional rescue therapy was comparable in both groups (48.9% in iHTN_incr, 40.0% in iHTN_imm; p = 0.332). The type of induced hypertension was not independently associated with the occurrence of DCI-related infarction in a logistic regression model (odds ratio 1.004; 95% confidence interval 0.329–3.443; p = 0.942). Similar rates of pressor-treatment-related complications were observed in both treatment groups. Favorable outcome was reached in 44 (43.1%) patients in the immediate vs. 10 (27.0%) patients in the incremental treatment group (p = 0.076). However, only Hunt and Hess grading was identified as an independent predictor variable of clinical outcome (odds ratio 0.422; 95% confidence interval 0.216–0.824; p = 0.012).

Conclusions

Immediate induction of hypertension with higher pressure targets did not result in a lower rate of DCI-related infarctions but was not associated with a higher complication rate compared with an incremental approach. Future tailored blood pressure management based on patient- and time-point-specific needs will hopefully better balance the neurological advantages versus the systemic complications of induced hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-022-01466-7.

Interventions for altering blood pressure in people with acute subarachnoid haemorrhage

BACKGROUND

Subarachnoid haemorrhage has an incidence of up to nine per 100,000 person-years. It carries a mortality of 30% to 45% and leaves 20% dependent in activities of daily living. The major causes of death or disability after the haemorrhage are delayed cerebral ischaemia and rebleeding. Interventions aimed at lowering blood pressure may reduce the risk of rebleeding, while the induction of hypertension may reduce the risk of delayed cerebral ischaemia. Despite the fact that medical alteration of blood pressure has been clinical practice for more than three decades, no previous systematic reviews have assessed the beneficial and harmful effects of altering blood pressure (induced hypertension or lowered blood pressure) in people with acute subarachnoid haemorrhage.

OBJECTIVES

To assess the beneficial and harmful effects of altering arterial blood pressure (induced hypertension or lowered blood pressure) in people with acute subarachnoid haemorrhage.

SEARCH METHODS

We searched the following from inception to 8 September 2020 (Chinese databases to 27 January 2019): Cochrane Stroke Group Trials register; CENTRAL; MEDLINE; Embase; five other databases, and five trial registries. We screened reference lists of review articles and relevant randomised clinical trials.

SELECTION CRITERIA

Randomised clinical trials assessing the effects of inducing hypertension or lowering blood pressure in people with acute subarachnoid haemorrhage. We included trials irrespective of publication type, status, date, and language.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. We assessed the risk of bias of all included trials to control for the risk of systematic errors. We performed trial sequential analysis to control for the risks of random errors. We also applied GRADE. Our primary outcomes were death from all causes and death or dependency. Our secondary outcomes were serious adverse events, quality of life, rebleeding, delayed cerebral ischaemia, and hydrocephalus. We assessed all outcomes closest to three months' follow-up (primary point of interest) and maximum follow-up.

MAIN RESULTS

We included three trials: two trials randomising 61 participants to induced hypertension versus no intervention, and one trial randomising 224 participants to lowered blood pressure versus placebo. All trials were at high risk of bias. The certainty of the evidence was very low for all outcomes. Induced hypertension versus control Two trials randomised participants to induced hypertension versus no intervention. Meta-analysis showed no evidence of a difference between induced hypertension versus no intervention on death from all causes (risk ratio (RR) 1.60, 95% confidence interval (CI) 0.57 to 4.42; P = 0.38; I2 = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analyses showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. Meta-analysis showed no evidence of a difference between induced hypertension versus no intervention on death or dependency (RR 1.29, 95% CI 0.78 to 2.13; P = 0.33; I2 = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analyses showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. Meta-analysis showed no evidence of a difference between induced hypertension and control on serious adverse events (RR 2.24, 95% CI 1.01 to 4.99; P = 0.05; I2 = 0%; 2 trials, 61 participants; very low-certainty evidence). Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. One trial (41 participants) reported quality of life using the Stroke Specific Quality of Life Scale. The induced hypertension group had a median of 47 points (interquartile range 35 to 55) and the no-intervention group had a median of 49 points (interquartile range 35 to 55). The certainty of evidence was very low. One trial (41 participants) reported rebleeding. Fisher's exact test (P = 1.0) showed no evidence of a difference between induced hypertension and no intervention on rebleeding. The certainty of evidence was very low. Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. One trial (20 participants) reported delayed cerebral ischaemia. Fisher's exact test (P = 1.0) showed no evidence of a difference between induced hypertension and no intervention on delayed cerebral ischaemia. The certainty of the evidence was very low. Trial sequential analysis showed that we had insufficient information to confirm or reject our predefined relative risk reduction of 20% or more. None of the trials randomising participants to induced hypertension versus no intervention reported on hydrocephalus. No subgroup analyses could be conducted for trials randomising participants to induced hypertension versus no intervention. Lowered blood pressure versus control One trial randomised 224 participants to lowered blood pressure versus placebo. The trial only reported on death from all causes. Fisher's exact test (P = 0.058) showed no evidence of a difference between lowered blood pressure versus placebo on death from all causes. The certainty of evidence was very low.

AUTHORS' CONCLUSIONS

Based on the current evidence, there is a lack of information needed to confirm or reject minimally important intervention effects on patient-important outcomes for both induced hypertension and lowered blood pressure. There is an urgent need for trials assessing the effects of altering blood pressure in people with acute subarachnoid haemorrhage. Such trials should use the SPIRIT statement for their design and the CONSORT statement for their reporting. Moreover, such trials should use methods allowing for blinded altering of blood pressure and report on patient-important outcomes such as mortality, rebleeding, delayed cerebral ischaemia, quality of life, hydrocephalus, and serious adverse events.

The Updated Role of the Blood Brain Barrier in Subarachnoid Hemorrhage: From Basic and Clinical Studies

Subarachnoid hemorrhage (SAH) is a type of hemorrhagic stroke associated with high mortality and morbidity. The blood-brain-barrier (BBB) is a structure consisting primarily of cerebral microvascular endothelial cells, end feet of astrocytes, extracellular matrix, and pericytes. Post-SAH pathophysiology included early brain injury and delayed cerebral ischemia. BBB disruption was a critical mechanism of early brain injury and was associated with other pathophysiological events. These pathophysiological events may propel the development of secondary brain injury, known as delayed cerebral ischemia. Imaging advancements to measure BBB after SAH primarily focused on exploring innovative methods to predict clinical outcome, delayed cerebral ischemia, and delayed infarction related to delayed cerebral ischemia in acute periods. These predictions are based on detecting abnormal changes in BBB permeability. The parameters of BBB permeability are described by changes in computed tomography (CT) perfusion and magnetic resonance imaging (MRI). K_ep seems to be a stable and sensitive indicator in CT perfusion, whereas K^trans is a reliable parameter for dynamic contrast-enhanced MRI. Future prediction models that utilize both the volume of BBB disruption and stable parameters of BBB may be a promising direction to develop practical clinical tools. These tools could provide greater accuracy in predicting clinical outcome and risk of deterioration. Therapeutic interventional exploration targeting BBB disruption is also promising, considering the extended duration of post-SAH BBB disruption.

Fluid management concepts for severe neurological illness: an overview

PURPOSE OF REVIEW

The acute care of a patient with severe neurological injury is organized around one relatively straightforward goal: avoid brain ischemia. A coherent strategy for fluid management in these patients has been particularly elusive, and a well considered fluid management strategy is essential for patients with critical neurological illness.

RECENT FINDINGS

In this review, several gaps in our collective knowledge are summarized, including a rigorous definition of volume status that can be practically measured; an understanding of how electrolyte derangements interact with therapy; a measurable endpoint against which we can titrate our patients' fluid balance; and agreement on the composition of fluid we should give in various clinical contexts.

SUMMARY

As the possibility grows closer that we can monitor the physiological parameters with direct relevance for neurological outcomes and the various complications associated with neurocritical illness, we may finally move away from static therapy recommendations, and toward individualized, precise therapy. Although we believe therapy should ultimately be individualized rather than standardized, it is clear that the monitoring tools and analytical methods used ought to be standardized to facilitate appropriately powered, prospective clinical outcome trials.

Prospective Multicenter Study of Changes in MTT after Aneurysmal SAH and Relationship to Delayed Cerebral Ischemia in Patients with Good- and Poor-Grade Admission Status

BACKGROUND AND PURPOSE

Patients with aneurysmal SAH and good clinical status at admission are considered at a lower risk for delayed cerebral ischemia. Prolonged MTT may be associated with an increased risk. It is unclear whether this is dependent on clinical status. Our purpose was to determine whether increased MTT within 3 days of aneurysmal SAH compared with baseline is associated with a higher risk of delayed cerebral ischemia in patients with good (World Federation of Neurosurgical Societies I-III) versus poor (World Federation of Neurosurgical Societies IV-V) admission status.

MATERIALS AND METHODS

This prolonged MTT was a multicenter, prospective cohort investigation of 87 patients with aneurysmal SAH. MTT was measured at admission before aneurysm treatment (MTT1) and following repair (MTT2) within 3 days of admission; MTT_diff was calculated as the difference between MTT2 and MTT1. Changes in MTT across time were assessed with repeated measures analyses. Risk of delayed cerebral ischemia or death was determined with multivariate logistic regression analysis.

RESULTS

In patients with a good grade (n = 49), MTT was prolonged in patients who developed delayed cerebral ischemia, with MTT_diff significantly greater (0.82 ± 1.5) compared with those who did not develop delayed cerebral ischemia (-0.14 ± 0.98) (P = .03). Prolonged MTT was associated with a significantly higher risk of delayed cerebral ischemia or death (OR = 3.1; 95% CI, 1.3-7.4; P = .014) on multivariate analysis. In patients with poor grades (n = 38), MTT_diff was not greater in patients who developed delayed cerebral ischemia; MTT1 was significantly prolonged compared with patients with a good grade.

CONCLUSIONS

Patients in good clinical condition following aneurysmal SAH but with increasing MTT in the first few days after aneurysmal SAH are at high risk of delayed cerebral ischemia and warrant close clinical monitoring.

Changes in Cerebral Perfusion with Induced Hypertension in Aneurysmal Subarachnoid Hemorrhage: A Pilot and Feasibility Study

BACKGROUND

The effects of induced hypertension (IH) on cerebral perfusion after subarachnoid hemorrhage (SAH) are unclear. The objectives of this investigation are to: (1) determine whether there are differences in cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) measured with computed tomography perfusion (CTP) before and after IH; (2) evaluate differences in the presence of infarction and clinical outcome between patients with and without IH.

METHODS

We performed a retrospective cohort analysis of 25 aneurysmal SAH patients. IH was initiated as per the standard institutional protocol when patients showed clinical symptoms of delayed cerebral ischemia (DCI). Differences in CBF, CBV, and MTT between early (<72 h after aneurysm rupture) and late (7-10 days after aneurysm rupture) CTP were quantified in patients with (n = 13) and without IH (n = 12). Outcome measures included cerebral infarction and clinical outcome at 3 months.

RESULTS

Early MTT was significantly greater in the IH group compared to the no-IH group. There was no difference in early or late CBV or CBF between the two groups. In patients that received IH, there was a significant decrease in MTT between the early (7.0 ± 1.2 s) and late scans (5.8 ± 1.6 s; p = 0.005). There was no difference in the incidence of infarction (5/13 vs. 2/11) or poor outcome (3/11 vs. 6/13) between the IH and no-IH groups, respectively (p > 0.05).

CONCLUSIONS

Elevated MTT is a significant factor for the development of DCI in patients eventually requiring IH therapy and is improved by IH treatment. Therapies to prevent DCI and improve clinical outcome may need to be initiated earlier, when cerebral perfusion abnormalities are first identified.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Medically induced hypertension, hypervolaemia and haemodilution for the treatment and prophylaxis of vasospasm following aneurysmal subarachnoid haemorrhage: systematic review

PURPOSE

Arterial vasospasm is a major cause of death and long-term disability following subarachnoid haemorrhage (SAH). The use of medically induced hypertension, hypervolaemia and/or haemodilution is widely practiced for prophylaxis and treatment of vasospasm following SAH. We aimed to determine if the quality of available research is adequate to inform use of haemodynamic management strategies to prevent or treat vasospasm following SAH.

METHODS

Individual searches of the following databases were conducted: The Cochrane Database of Systematic Reviews, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and OpenSIGLE. Pertinent randomised clinical trials and cohort studies comparing any element or combination thereof: medically induced hypertension, hypervolaemia, and haemodilution were included. Data were extracted using standardised proformas and risk of bias assessed using a domain-based risk of bias assessment tool.

RESULTS

348 study reports were identified by our literature search. Eight studies were included, three of which examined both volume expansion and medically induced hypertension. Three randomised clinical trials and two cohort studies examining prophylactic volume expansion were included. Two trials of prophylactic medically induced hypertension and two cohort studies were included. One trial and one cohort study of medically induced hypertension for treatment of established vasospasm was included. These trials demonstrated no significant difference in any of the clinical outcome measures studied. No trials of blood transfusion were included.

CONCLUSIONS

There is currently insufficient evidence to determine the efficacy or non-efficacy of intravenous volume expansion, medically induced hypertension or blood transfusion for the treatment or prophylaxis of vasospasm following SAH. All of these approaches have been associated with adverse events, of unclear incidence. The current evidence base therefore cannot be used to reliably inform clinical practice. This is a priority for further research.

Effect of recombinant adeno-associated virus expressing calcitonin gene-related peptide on chick embryo umbilical artery vasospasm model

In the present study, a recombinant adeno-associated virus vector containing the calcitonin gene related peptide gene (rAAV-CGRP) was constructed and the therapeutic effect of rAAV-CGRP on a chick umbilical artery vasospasm model induced by chick embryo allantoic cavity hemorrhage was investigated. Fresh specific pathogen-free fertilized chicken eggs were randomly divided into a rAAV-CGRP group, an empty vector virus (AAV) group, and a control group, with 24 eggs in each group. An umbilical arterial vasospasm model was established using a needle puncture method on a vein in the chorioallantoic membrane to induce a hemorrhage in the allantoic cavity of 11-day-old chicken embryonated eggs. A total of 24 h after model establishment, 1 ml of rAAV-CGRP and empty vector virus solution of rAAV-CGRP and empty vector virus solution was, respectively, injected into the allantoic cavity in the rAAV-CGRP and AAV groups. Experimental results showed that after 72 h of model establishment, the mortality rates of the 3-, 5- and 7-day subgroups in the rAAV-CGRP group were lower than in the subgroups of the AAV injection group. After 3, 5 and 7 days of model establishment in the rAAV-CGRP group, the cross-sectional area of the inner diameter of the umbilical arteries was larger than that of the AAV group; the vessel wall thicknesses of the rAAV-CGRP group were thinner than in the AAV group. In addition, the concentration of CGRP in chick embryo allantoic fluid significantly increased and was several times higher than in the AAV group (P<0.05). In conclusion, administration of rAAV-CGRP through the allantoic cavity may increase the viability of a vasospasm model induced by chick allantoic cavity hemorrhage, significantly improve umbilical artery vasospasm, and increase CGRP expression in the chick embryo allantoic cavity. This approach also provides a novel experimental model for identifying other target genes for the gene therapy of vasospasm.

Induced Hypertension for Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Induced hypertension is widely used to treat delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage, but a literature review shows that its presumed effectiveness is based on uncontrolled case-series only. We here report clinical outcome of aneurysmal subarachnoid hemorrhage patients with DCI included in a randomized trial on the effectiveness of induced hypertension.

METHODS

Aneurysmal subarachnoid hemorrhage patients with clinical symptoms of DCI were randomized to induced hypertension or no induced hypertension. Risk ratios for poor outcome (modified Rankin Scale score >3) at 3 months, with 95% confidence intervals, were calculated and adjusted for age, clinical condition at admission and at time of DCI, and amount of blood on initial computed tomographic scan with Poisson regression analysis.

RESULTS

The trial aiming to include 240 patients was ended, based on lack of effect on cerebral perfusion and slow recruitment, when 21 patients had been randomized to induced hypertension, and 20 patients to no hypertension. With induced hypertension, the adjusted risk ratio for poor outcome was 1.0 (95% confidence interval, 0.6-1.8) and the risk ratio for serious adverse events 2.1 (95% confidence interval, 0.9-5.0).

CONCLUSIONS

Before this trial, the effectiveness of induced hypertension for DCI in aneurysmal subarachnoid hemorrhage patients was unknown because current literature consists only of uncontrolled case series. The results from our premature halted trial do not add any evidence to support induced hypertension and show that this treatment can lead to serious adverse events.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01613235.

Subarachnoid Hemorrhage: An Update

Subarachnoid hemorrhage (SAH) is a debilitating, although uncommon, type of stroke with high morbidity, mortality, and economic impact. Modern 30-day mortality is as high as 40%, and about 50% of survivors have permanent disability. Care at high-volume centers with dedicated neurointensive care units is recommended. Euvolemia, not hypervolemia, should be targeted, and the aneurysm should be secured early. Neither statin therapy nor magnesium infusions should be initiated for delayed cerebral ischemia. Cerebral vasospasm is just one component of delayed cerebral edema. Hyponatremia is common in subarachnoid hemorrhage and is associated with longer length of stay, but not increased mortality.

Continuous EEG Monitoring for Early Detection of Delayed Cerebral Ischemia in Subarachnoid Hemorrhage: A Pilot Study

INTRODUCTION

Early identification of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) is a major challenge. The aim of this study was to investigate whether quantitative EEG (qEEG) features can detect DCI prior to clinical or radiographic findings.

METHODS

A prospective cohort study was performed in aSAH patients in whom continuous EEG (cEEG) was recorded. We studied 12 qEEG features. We compared the time point at which qEEG changed with the time point that clinical deterioration occurred or new ischemia was noted on CT scan.

RESULTS

Twenty aSAH patients were included of whom 11 developed DCI. The alpha/delta ratio (ADR) was the most promising feature that showed a significant difference in change over time in the DCI group (median -62% with IQR -87 to -39%) compared to the control group (median +27% with IQR -32 to +104%, p = 0.013). Based on the ROC curve, a threshold was chosen for a combined measure of ADR and alpha variability (AUC: 91.7, 95% CI 74.2-100). The median time that elapsed between change of qEEG and clinical DCI diagnosis was seven hours (IQR -11-25). Delay between qEEG and CT scan changes was 44 h (median, IQR 14-117).

CONCLUSION

In this study, ADR and alpha variability could detect DCI development before ischemic changes on CT scan was apparent and before clinical deterioration was noted. Implementation of cEEG in aSAH patients can probably improve early detection of DCI.

Management of delayed cerebral ischemia after subarachnoid hemorrhage

For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization. Prevention of DCI primarily relies on nimodipine administration and optimization of blood volume and cardiac performance. Neurological monitoring is essential for early DCI detection and intervention. Serial clinical examination combined with intermittent transcranial Doppler ultrasonography and CT angiography (with or without perfusion) is the most commonly used monitoring paradigm, and usually suffices in good grade patients. By contrast, poor grade patients (WFNS grades 4 and 5) require more advanced monitoring because stupor and coma reduce sensitivity to the effects of ischemia. Greater reliance on CT perfusion imaging, continuous electroencephalography, and invasive brain multimodality monitoring are potential strategies to improve situational awareness as it relates to detecting DCI. Pharmacologically-induced hypertension combined with volume is the established first-line therapy for DCI; a good clinical response with reversal of the presenting deficit occurs in 70 % of patients. Medically refractory DCI, defined as failure to respond adequately to these measures, should trigger step-wise escalation of rescue therapy. Level 1 rescue therapy consists of cardiac output optimization, hemoglobin optimization, and endovascular intervention, including angioplasty and intra-arterial vasodilator infusion. In highly refractory cases, level 2 rescue therapies are also considered, none of which have been validated. This review provides an overview of current state-of-the-art care for DCI management.

Precision medicine of aneurysmal subarachnoid hemorrhage, vasospasm and delayed cerebral ischemia

INTRODUCTION

Precision medicine provides individualized treatment of diseases through leveraging patient-to-patient variation. Aneurysmal subarachnoid hemorrhage carries tremendous morbidity and mortality with cerebral vasospasm and delayed cerebral ischemia proving devastating and unpredictable. Lack of treatment measures for these conditions could be improved through precision medicine. Areas covered: Discussed are the pathophysiology of CV and DCI, treatment guidelines, and evidence for precision medicine used for prediction and prevention of poor outcomes following aSAH. A PubMed search was performed using keywords cerebral vasospasm or delayed cerebral ischemia and either biomarkers, precision medicine, metabolomics, proteomics, or genomics. Over 200 peer-reviewed articles were evaluated. The studies presented cover biomarkers identified as predictive markers or therapeutic targets following aSAH. Expert commentary: The biomarkers reviewed here correlate with CV, DCI, and neurologic outcomes after aSAH. Though practical use in clinical management of aSAH is not well established, using these biomarkers as predictive tools or therapeutic targets demonstrates the potential of precision medicine.

Delayed cerebral ischaemia prevention and treatment after aneurysmal subarachnoid haemorrhage: a systematic review

: The leading cause of morbidity and mortality after surviving the rupture of an intracranial aneurysm is delayed cerebral ischaemia (DCI). We present an update of recent literature on the current status of prevention and treatment strategies for DCI after aneurysmal subarachnoid haemorrhage. A systematic literature search of three databases (PubMed, ISI Web of Science, and Embase) was performed. Human clinical trials assessing treatment strategies, published in the last 5 yr, were included based on full-text analysis. Study data were extracted using tables depicting study type, sample size, and outcome variables. We identified 49 studies meeting our inclusion criteria. Clazosentan, magnesium, and simvastatin have been tested in large high-quality trials but failed to show a beneficial effect. Cilostazol, eicosapentaenoic acid, erythropoietin, heparin, and methylprednisolone yield promising results in smaller, non-randomized or retrospective studies and warrant further investigation. Topical application of nicardipine via implants after clipping has been shown to reduce clinical and angiographic vasospasm. Methods to improve subarachnoid blood clearance have been established, but their effect on outcome remains unclear. Haemodynamic management of DCI is evolving towards euvolaemic hypertension. Endovascular rescue therapies, such as percutaneous transluminal balloon angioplasty and intra-arterial spasmolysis, are able to resolve angiographic vasospasm, but their effect on outcome needs to be proved. Many novel therapies for preventing and treating DCI after aneurysmal subarachnoid haemorrhage have been assessed, with variable results. Limitations of the study designs often preclude definite statements. Current evidence does not support prophylactic use of clazosentan, magnesium, or simvastatin. Many strategies remain to be tested in larger randomized controlled trials.

CLINICAL TRIAL REGISTRATION

This systematic review was registered in the international prospective register of systematic reviews.

PROSPERO

CRD42015019817.

Effects of Induced Hypertension on Cerebral Perfusion in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

The presumed effectiveness of induced hypertension for treating delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage is based on uncontrolled case-series only. We assessed the effect of induced hypertension on cerebral blood flow (CBF) in aneurysmal subarachnoid hemorrhage patients with delayed cerebral ischemia in a randomized clinical trial.

METHODS

Aneurysmal subarachnoid hemorrhage patients were randomized to induced or no induced hypertension (control group) at delayed cerebral ischemia onset. CBF was assessed, blinded for treatment allocation, with computed tomographic perfusion in standardized predefined regions at delayed cerebral ischemia onset and after 24 to 36 hours of study treatment. Mean arterial blood pressure was compared between groups (linear mixed model). The primary outcome measure was the difference in change in overall CBF (Mann-Whitney U test).

RESULTS

Mean arterial blood pressure was, on average, 12 mm Hg (95% confidence interval, 8.6-14.5) higher in the hypertension group (n=12) than in the control group (n=13). Change in overall CBF (mL/100g per s) was -8.5 (range, -42 to 30) in the control group and 0.1 (range, -31-43) in the hypertension group (P=0.25).

CONCLUSIONS

Change in overall CBF did not differ to a statistically significant extent between the groups. Based on our results, 225 to 250 patients per group are needed to find a statistically significant difference in change in overall CBF between induced hypertension and no hypertension.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT0161323.

[News and perspectives in neurocritical care]

Neurocritical care is an ever-evolving discipline and its implementation in intensive care leads to reduction in mortality and to improvement of functional outcome in patients with devastating injuries to the nervous system. However, the decisive elements of the complete field of neurocritical care remain relatively unclear, as well as the exact ways to optimize them. During recent years new insights have been gained and new exciting studies have been initiated from which results are soon to be expected. This review focuses on the following management aspects: neuromonitoring, airway and ventilation, endovascular therapy, cerebrospinal fluid drainage, decompressive craniectomy, hematoma evacuation, blood pressure, and targeted temperature management. The application of these measures to brain diseases and injuries frequently treated in neurointensive care units will be addressed in the context of current studies.

Treatment of subarachnoid hemorrhage

Nontraumatic subarachnoid hemorrhage from intracranial aneurysm rupture presents with sudden severe headache. Initial treatment focuses on airway management, blood pressure control, and extraventricular drain for hydrocephalus. After identifying the aneurysm, they may be clipped surgically or endovascularly coiled. Nimodipine is administered to maintain a euvolemic state and prevent delayed cerebral ischemia (DCI). Patients may receive anticonvulsants. Monitoring includes serial neurologic assessments, transcranial Doppler ultrasonography, computed tomography perfusion, and angiographic studies. Treatment includes augmentation of blood pressure and cardiac output, cerebral angioplasty, and intra-arterial infusions of vasodilators. Although early mortality is high, about one half of survivors recover with little disability.