Prophylactic hyperdynamic postoperative fluid therapy after aneurysmal subarachnoid hemorrhage: a clinical, prospective, randomized, controlled study

Three Pillars of Recovery After Aneurysmal Subarachnoid Hemorrhage: A Narrative Review

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating neurologic disease with high mortality and disability. There have been global improvements in survival, which has contributed to the prevalence of patients living with long-term sequelae related to this disease. The focus of active research has traditionally centered on acute treatment to reduce mortality, but now there is a great need to study the course of short- and long-term recovery in these patients. In this narrative review, we aim to describe the core pillars in the preservation of cerebral function, prevention of complications, the recent literature studying neuroplasticity, and future directions for research to enhance recovery outcomes following aSAH.

2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage: A Guideline From the American Heart Association/American Stroke Association

AIM

The "2023 Guideline for the Management of Patients With Aneurysmal Subarachnoid Hemorrhage" replaces the 2012 "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage." The 2023 guideline is intended to provide patient-centric recommendations for clinicians to prevent, diagnose, and manage patients with aneurysmal subarachnoid hemorrhage.

METHODS

A comprehensive search for literature published since the 2012 guideline, derived from research principally involving human subjects, published in English, and indexed in MEDLINE, PubMed, Cochrane Library, and other selected databases relevant to this guideline, was conducted between March 2022 and June 2022. In addition, the guideline writing group reviewed documents on related subject matter previously published by the American Heart Association. Newer studies published between July 2022 and November 2022 that affected recommendation content, Class of Recommendation, or Level of Evidence were included if appropriate. Structure: Aneurysmal subarachnoid hemorrhage is a significant global public health threat and a severely morbid and often deadly condition. The 2023 aneurysmal subarachnoid hemorrhage guideline provides recommendations based on current evidence for the treatment of these patients. The recommendations present an evidence-based approach to preventing, diagnosing, and managing patients with aneurysmal subarachnoid hemorrhage, with the intent to improve quality of care and align with patients' and their families' and caregivers' interests. Many recommendations from the previous aneurysmal subarachnoid hemorrhage guidelines have been updated with new evidence, and new recommendations have been created when supported by published data.

Brain-Lung Crosstalk: Management of Concomitant Severe Acute Brain Injury and Acute Respiratory Distress Syndrome

Purpose of Review

To summarize pathophysiology, key conflicts, and therapeutic approaches in managing concomitant severe acute brain injury (SABI) and acute respiratory distress syndrome (ARDS).

Recent Findings

ARDS is common in SABI and independently associated with worse outcomes in all SABI subtypes. Most landmark ARDS trials excluded patients with SABI, and evidence to guide decisions is limited in this population. Potential areas of conflict in the management of patients with both SABI and ARDS are (1) risk of intracranial pressure (ICP) elevation with high levels of positive end-expiratory pressure (PEEP), permissive hypercapnia due to lung protective ventilation (LPV), or prone ventilation; (2) balancing a conservative fluid management strategy with ensuring adequate cerebral perfusion, particularly in patients with symptomatic vasospasm or impaired cerebrovascular blood flow; and (3) uncertainty about the benefit and harm of corticosteroids in this population, with a mortality benefit in ARDS, increased mortality shown in TBI, and conflicting data in other SABI subtypes. Also, the widely adapted partial pressure of oxygen (P_aO₂) target of > 55 mmHg for ARDS may exacerbate secondary brain injury, and recent guidelines recommend higher goals of 80–120 mmHg in SABI. Distinct pathophysiology and trajectories among different SABI subtypes need to be considered.

Summary

The management of SABI with ARDS is highly complex, and conventional ARDS management strategies may result in increased ICP and decreased cerebral perfusion. A crucial aspect of concurrent management is to recognize the risk of secondary brain injury in the individual patient, monitor with vigilance, and adjust management during critical time windows. The care of these patients requires meticulous attention to oxygenation and ventilation, hemodynamics, temperature management, and the neurological exam. LPV and prone ventilation should be utilized, and supplemented with invasive ICP monitoring if there is concern for cerebral edema and increased ICP. PEEP titration should be deliberate, involving measures of hemodynamic, pulmonary, and brain physiology. Serial volume status assessments should be performed in SABI and ARDS, and fluid management should be individualized based on measures of brain perfusion, the neurological exam, and cardiopulmonary status. More research is needed to define risks and benefits in corticosteroids in this population.

Cerebral Microdialysis-Based Interventions Targeting Delayed Cerebral Ischemia Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI), a complication of subarachnoid hemorrhage (SAH), is linked to cerebral vasospasm and associated with poor long-term outcome. We implemented a structured cerebral microdialysis (CMD) based protocol using the lactate/pyruvate ratio (LPR) as an indicator of the cerebral energy metabolic status in the neurocritical care decision making, using an LPR ≥ 30 as a cutoff suggesting an energy metabolic disturbance. We hypothesized that CMD monitoring could contribute to active, protocol-driven therapeutic interventions that may lead to the improved management of patients with SAH.

METHODS

Between 2018 and 2020, 49 invasively monitored patients with SAH, median Glasgow Coma Scale 11 (range 3-15), and World Federation of Neurosurgical Societies scale 4 (range 1-5) on admission receiving CMD were included. We defined a major CMD event as an LPR ≥ 40 for ≥ 2 h and a minor CMD event as an LPR ≥ 30 for ≥ 2 h.

RESULTS

We analyzed 7,223 CMD samples over a median of 6 days (5-8). Eight patients had no CMD events. In 41 patients, 113 minor events were recorded, and in 23 patients 42 major events were recorded. Our local protocols were adhered to in 40 major (95%) and 98 minor events (87%), with an active intervention in 32 (76%) and 71 (63%), respectively. Normalization of energy metabolic status (defined as four consecutive samples with LPR < 30 for minor and LPR < 40 for major events) was seen after 69% of major and 59% of minor events. The incidence of DCI-related infarcts was 10% (five patients), with only two observed in a CMD-monitored brain region.

CONCLUSIONS

Active interventions were initiated in a majority of LPR events based on CMD monitoring. A low DCI incidence was observed, which may be associated with the active interventions. The potential aid of CMD in the clinical decision-making targeting DCI needs confirmation in additional SAH studies.

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.

Aneurysmal Subarachnoid Hemorrhage: Review of the Pathophysiology and Management Strategies

PURPOSE OF REVIEW

Aneurysmal subarachnoid hemorrhage remains a devastating disease process despite medical advances made over the past 3 decades. Much of the focus was on prevention and treatment of vasospasm to reduce delayed cerebral ischemia and improve outcome. In recent years, there has been a shift of focus onto early brain injury as the precursor to delayed cerebral ischemia. This review will focus on the most recent data surrounding the pathophysiology of aneurysmal subarachnoid hemorrhage and current management strategies.

RECENT FINDINGS

There is a paucity of successful trials in the management of subarachnoid hemorrhage likely related to the targeting of vasospasm. Pathophysiological changes occurring at the time of aneurysmal rupture lead to early brain injury including cerebral edema, inflammation, and spreading depolarization. These events result in microvascular collapse, vasospasm, and ultimately delayed cerebral ischemia. Management of aneurysmal subarachnoid hemorrhage has remained the same over the past few decades. No recent trials have resulted in new treatments. However, our understanding of the pathophysiology is rapidly expanding and will advise future therapeutic targets.

Cerebral Autoregulation in Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating stroke subtype with a high rate of mortality and morbidity. The poor clinical outcome can be attributed to the biphasic course of the disease: even if the patient survives the initial bleeding emergency, delayed cerebral ischemia (DCI) frequently follows within 2 weeks time and levies additional serious brain injury. Current therapeutic interventions do not specifically target the microvascular dysfunction underlying the ischemic event and as a consequence, provide only modest improvement in clinical outcome. SAH perturbs an extensive number of microvascular processes, including the “automated” control of cerebral perfusion, termed “cerebral autoregulation.” Recent evidence suggests that disrupted cerebral autoregulation is an important aspect of SAH-induced brain injury. This review presents the key clinical aspects of cerebral autoregulation and its disruption in SAH: it provides a mechanistic overview of cerebral autoregulation, describes current clinical methods for measuring autoregulation in SAH patients and reviews current and emerging therapeutic options for SAH patients. Recent advancements should fuel optimism that microvascular dysfunction and cerebral autoregulation can be rectified in SAH patients.

Impaired Cerebral Autoregulation After Subarachnoid Hemorrhage: A Quantitative Assessment Using a Mouse Model

Subarachnoid hemorrhage (SAH) is a common form of hemorrhagic stroke associated with high rates of mortality and severe disability. SAH patients often develop severe neurological deficits days after ictus, events attributed to a phenomenon referred to as delayed cerebral ischemia (DCI). Recent studies indicate that SAH-induced DCI results from a multitude of cerebral circulatory disturbances including cerebral autoregulation malfunction. Cerebral autoregulation incorporates the influence of blood pressure (BP) on arterial diameter in the homeostatic regulation of cerebral blood flow (CBF), which is necessary for maintaining constant brain perfusion during physiological swings in systemic BP. In this study, we quantitatively examined the impact of SAH on cerebral autoregulation using a mouse endovascular perforation model and a newly developed approach combining absolute and relative CBF measurements. This method enables a direct quantitative comparison of cerebral autoregulation between individual animals (e.g., SAH vs. control or sham-operated mice), which cannot be done solely using relative CBF changes by laser Doppler flowmetry. Here, absolute CBF was measured via injection of fluorescent microspheres at a baseline BP. In separate groups of animals, in vivo laser Doppler flowmetry was used to measure relative CBF changes over a range of BP using phlebotomy and the pressor phenylephrine to lower and raise BP, respectively. Absolute CBF measurements from microspheres were then used to calibrate laser Doppler measurements to calculate the relationship between CBF and BP, i.e., “cerebral autoregulation curves.” Un-operated and sham-operated groups exhibited similar cerebral autoregulatory curves, showing comparable levels of relatively constant CBF over a range of BP from ~80 mmHg to ~130 mmHg. In contrast, SAH animals exhibited a narrower autoregulatory range of BP, which was primarily due to a decrease in the upper limit of BP whereby cerebral autoregulation was maintained. Importantly, SAH animals also exhibited a marked decrease in CBF throughout the entire range of BP. In sum, this study provides evidence of the dramatic reduction in cortical CBF and the diminished range of autoregulation after SAH. Furthermore, this novel methodology should pave the way for future studies examining pathological mechanisms and/or therapeutic strategies targeting impaired cerebral autoregulation, a pathology common to many cardiovascular and cerebrovascular disorders.

Hybrid microcatheter angioplasty for refractory cerebral vasospasm

Cerebral vasospasm is a significant cause of morbidity and mortality associated with aneurysmal subarachnoid hemorrhage (aSAH). Intra-arterial chemical and mechanical angioplasty, performed alone or in combination, have been shown to ameliorate cerebral vasospasm and improve patient outcomes. Few options exist for patients who fail these traditional endovascular tactics. We propose a hybrid microcatheter technique that combines the mechanical benefit of transient high pressure induced by microcatheter fluid bolus with a low-dose vasodilator infusion. Five patients with moderate to severe symptomatic vasospasm who failed medical and traditional endovascular management were treated using a hybrid microcatheter technique. All angioplasty procedures were technically successful, and the degree of vasospasm improved following angioplasty. There were no complications related to the cerebral angioplasty procedures. None of the patients required repeat endovascular intervention. Hybrid microcatheter angioplasty may be a useful complement to mechanical or pharmacological techniques in the endovascular management of intractable cerebral vasospasm after aSAH.

[Clinical efficacy of restrictive fluid management in patients with severe traumatic brain injury]

OBJECTIVE

To investigate the effects of restrictive fluid management in patients with severe traumatic brain injury (sTBI).

METHODS

Between January, 2019 and June, 2020, we randomly assigned 51 postoperative patients (stay in the ICU of no less than 7 days) with sTBI into treatment group (n=25) with restrictive fluid management and the control group (n=26) with conventional fluid management. The data of optic nerve sheath diameter (ONSD), middle cerebral artery pulsatility index (MAC- PI), neuron-specific enolase (NSE) level, inferior vena cava (IVC) diameter, Glascow Coma Scale (GCS) score, mean arterial blood pressure, heart rate, and fluid balance of the patients were collected at ICU admission and at 1, 3 and 7 days after ICU admission, and the duration of mechanical ventilation, ICU stay, and 28-day mortality were recorded.

RESULTS

The cumulative fluid balance of the two groups were positive on day 1 and negative on days 3 and 7 after ICU admission; at the same time points, the patients in the treatment group had significantly greater negative fluid balance than those in the control group (P < 0.05). In both of the groups, the ONSD and MCA-PI values were significantly higher on day 1 than the baseline (P < 0.05), reached the peak levels on day 3, and decreased on day 7; at the same time point, these values were significantly lower in the treatment group than in the control group (P < 0.05). No significant difference was found in NSE level on day 1 between the two groups (P>0.05); on day 3, NSE level reached the peak level and was significantly higher in the control group (P < 0.05); on day 7, NSE level was lowered the level of day 1 in the treatment group but remained higher than day 1 level in the control group. The 28-day mortality rate did not differ significantly between the two groups (16.00% vs 23.08%, P>0.05); the duration of mechanical ventilation, length of ICU stay, and the number of tracheotomy were all significantly shorter or lower in the treatment group than in the control group (P < 0.05).

CONCLUSIONS

Restrictive fluid management can reduce cerebral edema and improve the prognosis but does not affect the 28-day mortality of patients with sTBI.

Randomized, placebo-controlled, double-blind, pilot trial to investigate safety and efficacy of Cerebrolysin in patients with aneurysmal subarachnoid hemorrhage

Background

There are limited neuroprotective treatment options for patients with aneurysmal subarachnoid hemorrhage (SAH). Cerebrolysin, a brain-specific proposed pleiotropic neuroprotective agent, has been suggested to improve global functional outcomes in ischemic stroke. We investigated the efficacy, safety and feasibility of administering Cerebrolysin for SAH patients.

Methods

This was a prospective, randomized, double-blind, placebo-controlled, single-center, parallel-group pilot study. Fifty patients received either daily Cerebrolysin (30 ml/day) or a placebo (saline) for 14 days (25 patients per study group). The primary endpoint was a favorable Extended Glasgow Outcome Scale (GOSE) of 5 to 8 (moderate disability to good recovery) at six-months. Secondary endpoints included the modified Ranking Scale (mRS), the Montreal Cognitive Assessment (MOCA) score, occurrence of adverse effects and the occurrence of delayed cerebral ischemia (DCI).

Results

No severe adverse effects or mortality attributable to Cerebrolysin were observed. No significant difference was detected in the proportion of patients with favorable six-month GOSE in either study group (odds ratio (OR): 1.49; 95% confidence interval (CI): 0.43–5.17). Secondary functional outcome measures for favorable six-month recovery i.e. a mRS of 0 to 3 (OR: 3.45; 95% CI 0.79–15.01) were comparable for both groups. Similarly, there was no difference in MOCA neurocognitive performance (p-value: 0.75) and in the incidence of DCI (OR: 0.85 95% CI: 0.28–2.59).

Conclusions

Use of Cerebrolysin in addition to standard-of-care management of aneurysmal SAH is safe, well tolerated and feasible. However, the neutral results of this trial suggest that it does not improve the six-month global functional performance of patients.

Clinical trial registration

Name of Registry: ClinicalTrials.gov

Trial Registration Number: NCT01787123.

Date of Registration: 8th February 2013.

Bioreactance-Based Noninvasive Fluid Responsiveness and Cardiac Output Monitoring: A Pilot Study in Patients with Aneurysmal Subarachnoid Hemorrhage and Literature Review

Management of volume status, arterial blood pressure, and cardiac output are core elements in approaching the patients with aneurysmal subarachnoid hemorrhage (SAH). For the prevention and treatment of delayed cerebral ischemia (DCI), euvolemia is advocated and caution is made towards the avoidance of hypervolemia. Induced hypertension and cardiac output augmentation are the mainstays of medical management during active DCI, whereas the older triple-H paradigm has fallen out of favor due to lack of demonstrable physiological or clinical benefits and serious concern for adverse effects such as pulmonary edema and multiorgan system dysfunction. Furthermore, insight into clinical hemodynamics of patients with SAH becomes salient when one considers the frequently associated cardiac and pulmonary manifestations of the disease such as SAH-associated cardiomyopathy and neurogenic pulmonary edema. In terms of fluid and volume targets, less attention has been paid to dynamic markers of fluid responsiveness despite the well-established, in the general critical care literature, superiority of these as compared to traditionally used static markers such as central venous pressure (CVP). Based on this literature and sound pathophysiologic reasoning, reliance on static markers (such as CVP) is unjustified when one attempts to assess strategies augmenting stroke volume (SV), arterial blood pressure, and oxygen delivery. There are several options for continuous bedside cardiorespiratory monitoring and optimization of SAH patients. We, here, review a noninvasive monitoring technique based on thoracic bioreactance and focusing on continuous cardiac output and fluid responsiveness markers.

Assessment of two prophylactic fluid strategies in aneurysmal subarachnoid hemorrhage: A randomized trial

OBJECTIVE

To compare the effect of two prophylactic euvolemic fluid strategy regimens on the incidence of cerebral vasospasm and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Ninety-six patients with a basal intravenous intake of 15 mL/kg/day of Ringer's lactate solution were included, and an additional 15 to 50 mL/kg/day Ringer's lactate (RL-group) or hydroxyethyl starch 130/0.4 solution (HES-group) was administered to maintain the targeted mean arterial pressure. The primary end point was the occurrence of cerebral vasospasm during the first 14 days. The secondary end points were case fatality, Barthel's index, and Glasgow Outcome Scores (GOS) at 30 days after SAH.

RESULTS

Cerebral vasospasm developed in 42 patients (43.7%), and nine of these events were severe. The vasospasm rate among the RL- and HES-based groups was 25/48 and 17/48, respectively. For the secondary endpoint, four patients (4%) died by the end of follow-up (two in each group). Unfavorable outcome cases were not different in the RL and HES groups (9 vs. 14, respectively). There was no difference between the Barthel's scores at 30 days between the two groups.

CONCLUSIONS

Using starches in a prophylactic treatment strategy in aneurysmal SAH in not supported by the study.The trial was registered at Clinicaltrials.gov under the number NCT02064075.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be associated with significant morbidity and mortality despite advances in care and aneurysm treatment strategies. Cerebral vasospasm continues to be a major source of clinical worsening in patients. We intended to review the clinical and experimental aspects of aSAH and identify strategies that are being evaluated for the treatment of vasospasm. A literature review on aSAH and cerebral vasospasm was performed. Available treatments for aSAH continue to expand as research continues to identify new therapeutic targets. Oral nimodipine is the primary medication used in practice given its neuroprotective properties. Transluminal balloon angioplasty is widely utilized in patients with symptomatic vasospasm and ischemia. Prophylactic "triple-H" therapy, clazosentan, and intraarterial papaverine have fallen out of practice. Trials have not shown strong evidence supporting magnesium or statins. Other calcium channel blockers, milrinone, tirilazad, fasudil, cilostazol, albumin, eicosapentaenoic acid, erythropoietin, corticosteroids, minocycline, deferoxamine, intrathecal thrombolytics, need to be further investigated. Many of the current experimental drugs may have significant roles in the treatment algorithm, and further clinical trials are needed. There is growing evidence supporting that early brain injury in aSAH may lead to significant morbidity and mortality, and this needs to be explored further.

Endovascular treatment of cerebral vasospasm after subarachnoid hemorrhage

Objective

Delayed cerebral ischemia (DCI) is strongly associated with poor outcome after subarachnoid hemorrhage (SAH). Cerebral vasospasm is a major contributor to DCI and requires special attention. To evaluate the effect of vasospasm management on SAH outcome, we performed a pooled analysis of 2 observational SAH cohorts.

Materials

Data from 2 institutional databases with consecutive patients with SAH treated between 2005 and 2012 were pooled. The effect of 2 institutional standards of conservative and endovascular vasospasm treatment (EVT) on the rates of DCI (new cerebral infarcts not visible on the post-treatment imaging) and unfavorable outcome (modified Rankin Scale score >2) at 6 months follow-up was analyzed.

Results

The final analysis included 1,057 patients with SAH. There was no difference regarding demographic (age and sex), clinical (Hunt & Hess grades, acute hydrocephalus, treatment modality, and infections), and radiographic (Fisher grades and aneurysm location) characteristics of the populations. However, there was a significant difference in the rate (24.4% [121/495] vs 14.4% [81/562], p < 0.0001) and timing (first treatment on day 6 vs 8.9 after SAH, p < 0.0001) of EVT. The rates of DCI (20.8% vs 29%, p = 0.0001) and unfavorable outcome (44% vs 50.6%, p = 0.04) were lower in the cohort with more frequent and early EVT. Multivariate analysis confirmed independent effect of EVT standard on DCI risk and outcome.

Conclusions

A preventive strategy utilizing frequent and early EVT seems to reduce the risk of DCI in patients with SAH and improve their functional outcome. We recommend prospective evaluation of the value of preventive EVT strategy on SAH.

Classification of evidence

This study provides Class III evidence that for patients with SAH, a frequent and early EVT to treat vasospasm reduces the risk of DCI and improves functional outcome.

Intravenous administration of Milrinone, as an alternative approach to treat vasospasm in subarachnoid hemorrhage: A case report of transcranial Doppler monitoring

This case illustrates the importance and potential of having TCD monitoring in intensive care. This easy-to-use, safe, low-cost, and bedside tool allows evaluation of the safety and feasibility of an alternative treatment of VSP in SCH and demonstrates the potential to avoid the use of angiography, a high cost, invasive procedure.

The downside of aggressive volume administration in critically ill patients-"aggressive" may lead to "excessive"

Management of fluid therapy in an intensive care unit (ICU) tends to be volume restriction after initial fluid resuscitation, since it has been the consensus that volume overload is associated with complications and poor clinical outcomes. Aggressive volume administration without cautious monitoring should be avoided in the ICU, because it could lead to excessive volume administration. However, there are limited consensus on determining the completion of resuscitation phase, in other words, when to stop aggressive infusion and initiate infusion restriction.

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.

Endovascular Treatment for Vasospasm after Aneurysmal Subarachnoid Hemorrhage Based on Data of JR-NET3

Endovascular treatments for vasospasm after subarachnoid hemorrhage are typically performed for patients who are refractory to recommended medical therapies. We analyzed the current status of endovascular treatments based on the data of Japanese Registry of Neuroendovascular Therapy (JR-NET)3, and evaluated factors related to improvement of imaging findings and neurological condition, and to mechanical hemorrhage complications. We collected data of 1211 treatments performed from 2010 to 2014. Target vessels for treatments were anterior circulation (n = 1079), posterior circulation (n = 91), and both (n = 32); the distribution of vasospasm was the proximal vessel (n = 754) to the Circle of Willis, distal vessel (n = 329), and both (n = 119). Of the treatments, 948 cases (78.3%) were intra-arterial administration of vasodilators and 259 (21.4%) were percutaneous transluminal angioplasty (PTA); 879 cases were the first intervention. The treatment time from onset was within 3 h in 378 (31.2%) cases, between 3 and 6 h in 349 (28.8%) cases, and over 6 h in 245 (20.2%) cases. The statistically significant factors associated with improvement on imaging findings was the first treatment, and treatment within 3 h from onset compared with that after 6 h. Additionally, the first and early treatments after the symptoms were associated with significantly improved neurological condition. All complications of mechanical hemorrhage occurred along with PTA. The findings show that endovascular treatment for vasospasm was effective, especially for cases who suffered from symptomatic vasospasm with a short interval after onset.

Improvement in Sonographic Vasospasm Following Intravenous Milrinone in a Subarachnoid Hemorrhage Patient with Normal Cardiac Function

Cerebral vasospasm and delayed cerebral ischemia are well-known complications of an aneurysmal subarachnoid hemorrhage (aSAH), generally occurring days to weeks after hemorrhagic ictus. Management strategies for these complications are controversial and vary in efficacy. There is a growing interest in supporting the use of intravenous (IV) milrinone to manage vasospasm. A 31-year-old male presented to the hospital after being found down outside his home. Computed tomography (CT) of the head and subsequent CT angiogram revealed a Fisher Grade 4 aneurysmal subarachnoid hemorrhage (aSAH). Six hours after admission, he became hypotensive and his neurological examination declined. A repeat CT head showed a new, left frontoparietal intracerebral hemorrhage (ICH) along with increasing SAH. He was stabilized with vasopressors and underwent emergent decompressive hemicraniectomy with subsequent clipping of the aneurysm. Approximately one week later, transcranial Doppler (TCD) showed increasing mean flow velocities in the bilateral anterior and middle cerebral arteries consistent with cerebral vasospasm. He was treated with intravenous milrinone. Repeat TCD 6.5 hours after the initial TCD showed improved mean flow velocities. His cardiac function by echocardiogram assessment was normal. The decrease in TCD velocity following treatment with milrinone indicates an improvement in the cerebral vasospasm regardless of cardiac output in a patient with subarachnoid hemorrhage. This case suggests that augmenting cardiac output may not be the only mechanism for the therapeutic benefit of milrinone.

Cerebral artery myogenic reactivity: The next frontier in developing effective interventions for subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating cerebral event that kills or debilitates the majority of those afflicted. The blood that spills into the subarachnoid space stimulates profound cerebral artery vasoconstriction and consequently, cerebral ischemia. Thus, once the initial bleeding in SAH is appropriately managed, the clinical focus shifts to maintaining/improving cerebral perfusion. However, current therapeutic interventions largely fail to improve clinical outcome, because they do not effectively restore normal cerebral artery function. This review discusses emerging evidence that perturbed cerebrovascular "myogenic reactivity," a crucial microvascular process that potently dictates cerebral perfusion, is the critical element underlying cerebral ischemia in SAH. In fact, the myogenic mechanism could be the reason why many therapeutic interventions, including "Triple H" therapy, fail to deliver benefit to patients. Understanding the molecular basis for myogenic reactivity changes in SAH holds the key to develop more effective therapeutic interventions; indeed, promising recent advancements fuel optimism that vascular dysfunction in SAH can be corrected to improve outcome.

Delayed Cerebral Ischemia after Subarachnoid Hemorrhage: Beyond Vasospasm and Towards a Multifactorial Pathophysiology

PURPOSE OF REVIEW

Delayed cerebral ischemia (DCI) is common after subarachnoid hemorrhage (SAH) and represents a significant cause of poor functional outcome. DCI was mainly thought to be caused by cerebral vasospasm; however, recent clinical trials have been unable to confirm this hypothesis. Studies in humans and animal models have since supported the notion of a multifactorial pathophysiology of DCI. This review summarizes some of the main mechanisms under investigation including cerebral vascular dysregulation, microthrombosis, cortical spreading depolarizations, and neuroinflammation.

RECENT FINDINGS

Recent guidelines have differentiated between DCI and angiographic vasospasm and have highlighted roles of the microvasculature, coagulation and fibrinolytic systems, cortical spreading depressions, and the contribution of the immune system to DCI. Many therapeutic interventions are underway in both preclinical and clinical studies to target these novel mechanisms as well as studies connecting these mechanisms to one another. Clinical trials to date have been largely unsuccessful at preventing or treating DCI after SAH. The only successful pharmacologic intervention is the calcium channel antagonist, nimodipine. Recent studies have provided evidence that cerebral vasospasm is not the sole contributor to DCI and that additional mechanisms may play equal if not more important roles.

High Early Fluid Input After Aneurysmal Subarachnoid Hemorrhage: Combined Report of Association With Delayed Cerebral Ischemia and Feasibility of Cardiac Output-Guided Fluid Restriction

BACKGROUND

Guidelines on the management of aneurysmal subarachnoid hemorrhage (aSAH) recommend euvolemia, whereas hypervolemia may cause harm. We investigated whether high early fluid input is associated with delayed cerebral ischemia (DCI), and if fluid input can be safely decreased using transpulmonary thermodilution (TPT).

METHODS

We retrospectively included aSAH patients treated at an academic intensive care unit (2007-2011; cohort 1) or managed with TPT (2011-2013; cohort 2). Local guidelines recommended fluid input of 3 L daily. More fluids were administered when daily fluid balance fell below +500 mL. In cohort 2, fluid input in high-risk patients was guided by cardiac output measured by TPT per a strict protocol. Associations of fluid input and balance with DCI were analyzed with multivariable logistic regression (cohort 1), and changes in hemodynamic indices after institution of TPT assessed with linear mixed models (cohort 2).

RESULTS

Cumulative fluid input 0 to 72 hours after admission was associated with DCI in cohort 1 (n=223; odds ratio [OR] 1.19/L; 95% confidence interval 1.07-1.32), whereas cumulative fluid balance was not. In cohort 2 (23 patients), using TPT fluid input could be decreased from 6.0 ± 1.0 L before to 3.4 ± 0.3 L; P = .012), while preload parameters and consciousness remained stable.

CONCLUSION

High early fluid input was associated with DCI. Invasive hemodynamic monitoring was feasible to reduce fluid input while maintaining preload. These results indicate that fluid loading beyond a normal preload occurs, may increase DCI risk, and can be minimized with TPT.

Accuracy of Daily Lung Ultrasound for the Detection of Pulmonary Edema Following Subarachnoid Hemorrhage

BACKGROUND

Early detection of pulmonary edema is vital to appropriate fluid management following subarachnoid hemorrhage (SAH). Lung ultrasound (LUS) has been shown to accurately identify pulmonary edema in patients with acute respiratory failure (ARF). Our objective was to determine the accuracy of daily screening LUS for the detection of pulmonary edema following SAH.

METHODS

Screening LUS was performed in conjunction with daily transcranial doppler for SAH patients within the delayed cerebral ischemia (DCI) risk period in our neuroICU. We reviewed records of SAH patients admitted 7/2012-5/2014 who underwent bilateral LUS on at least 5 consecutive days. Ultrasound videos were reviewed by an investigator blinded to the final diagnosis. "B+ lines" were defined as ≥3 B-lines on LUS. Two other investigators blinded to ultrasound results determined whether pulmonary edema with ARF (PE-ARF) was present during the period of evaluation on the basis of independent chart review, with a fourth investigator performing adjudication in the event of disagreement. The diagnostic accuracy of B+ lines for the detection of PE-ARF and RPE was determined.

RESULTS

Of 59 patients meeting criteria for inclusion, 21 (36%) had PE-ARF and 26 (44%) had B+ lines. Kappa for inter-rater agreement was 0.821 (p < 0.0001) for clinical diagnosis of PE-ARF between the two investigators. B+ lines demonstrated sensitivity 90% (95% CI 70-99%) and specificity 82% (66-92%), for PE-ARF. Median days from B+ lines onset to PE-ARF was 1 (IQR 0-1).

CONCLUSION

Screening LUS was a sensitive test for the detection of symptomatic pulmonary edema following SAH and may assist with fluid titration during the risk period for DCI.

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.

Fluid management of the neurological patient: a concise review

Maintenance fluids in critically ill brain-injured patients are part of routine critical care. Both the amounts of fluid volumes infused and the type and tonicity of maintenance fluids are relevant in understanding the impact of fluids on the pathophysiology of secondary brain injuries in these patients. In this narrative review, current evidence on routine fluid management of critically ill brain-injured patients and use of haemodynamic monitoring is summarized. Pertinent guidelines and consensus statements on fluid management for brain-injured patients are highlighted. In general, existing guidelines indicate that fluid management in these neurocritical care patients should be targeted at euvolemia using isotonic fluids. A critical appraisal is made of the available literature regarding the appropriate amount of fluids, haemodynamic monitoring and which types of fluids should be administered or avoided and a practical approach to fluid management is elaborated. Although hypovolemia is bound to contribute to secondary brain injury, some more recent data have emerged indicating the potential risks of fluid overload. However, it is acknowledged that many factors govern the relationship between fluid management and cerebral blood flow and oxygenation and more research seems warranted to optimise fluid management and improve outcomes.

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.

Poor outcome is associated with less negative fluid balance in patients with aneurysmal subarachnoid hemorrhage treated with prophylactic vasopressor-induced hypertension

Background

Aneurysmal subarachnoid hemorrhage (SAH) is a serious condition associated with high mortality rates and long-term disability. We investigated the impact of fluid balance on neurologic outcome after adjustment for possible confounders related to intensive care therapy and extra-cerebral organ failure during the early phase after SAH.

Methods

In this retrospective study, we analyzed data from all 142 adult patients admitted to our university hospital surgical intensive care unit (ICU) with SAH between March 2004 and November 2010.

Results

The mean patient age was 54 ± 14 years, 62.7 % were female, and the median Hunt and Hess score was 3. The proportions of patients with poor outcome (Glasgow Outcome Score ≤3) were 58.4, 54.2, and 52.1 % at 3, 6, and 12 months, respectively, after the SAH. The ICU and hospital mortality rates were both 12.7 %, and the median lengths of stay in the ICU and the hospital were 16 (IQ 7–25) and 26 (IQ 18–34) days, respectively. In multivariable analysis, older age and greater cumulative fluid balance within the first 7 days in the ICU were independently associated with a greater risk of poor outcome.

Conclusion

In this cohort of patients, older age and greater cumulative fluid balance were independently associated with a greater risk of poor outcome up to 1 year after the initial insult. Our data suggest that mild hypovolemia may be beneficial in the management of these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0128-6) contains supplementary material, which is available to authorized users.

The critical care management of poor-grade subarachnoid haemorrhage

Aneurysmal subarachnoid haemorrhage is a neurological syndrome with complex systemic complications. The rupture of an intracranial aneurysm leads to the acute extravasation of arterial blood under high pressure into the subarachnoid space and often into the brain parenchyma and ventricles. The haemorrhage triggers a cascade of complex events, which ultimately can result in early brain injury, delayed cerebral ischaemia, and systemic complications. Although patients with poor-grade subarachnoid haemorrhage (World Federation of Neurosurgical Societies 4 and 5) are at higher risk of early brain injury, delayed cerebral ischaemia, and systemic complications, the early and aggressive treatment of this patient population has decreased overall mortality from more than 50% to 35% in the last four decades. These management strategies include (1) transfer to a high-volume centre, (2) neurological and systemic support in a dedicated neurological intensive care unit, (3) early aneurysm repair, (4) use of multimodal neuromonitoring, (5) control of intracranial pressure and the optimisation of cerebral oxygen delivery, (6) prevention and treatment of medical complications, and (7) prevention, monitoring, and aggressive treatment of delayed cerebral ischaemia. The aim of this article is to provide a summary of critical care management strategies applied to the subarachnoid haemorrhage population, especially for patients in poor neurological condition, on the basis of the modern concepts of early brain injury and delayed cerebral ischaemia.

A multicenter prospective cohort study of volume management after subarachnoid hemorrhage: circulatory characteristics of pulmonary edema after subarachnoid hemorrhage

OBJECT Subarachnoid hemorrhage (SAH) is often accompanied by pulmonary complications, which may lead to poor outcomes and death. This study investigated the incidence and cause of pulmonary edema in patients with SAH by using hemodynamic monitoring with PiCCO-plus pulse contour analysis. METHODS A total of 204 patients with SAH were included in a multicenter prospective cohort study to investigate hemodynamic changes after surgical clipping or coil embolization of ruptured cerebral aneurysms by using a PiCCO-plus device. Changes in various hemodynamic parameters after SAH were analyzed statistically. RESULTS Fifty-two patients (25.5%) developed pulmonary edema. Patients with pulmonary edema (PE group) were significantly older than those without pulmonary edema (non-PE group) (p = 0.017). The mean extravascular lung water index was significantly higher in the PE group than in the non-PE group throughout the study period. The pulmonary vascular permeability index (PVPI) was significantly higher in the PE group than in the non-PE group on Day 6 (p = 0.029) and Day 10 (p = 0.011). The cardiac index of the PE group was significantly decreased biphasically on Days 2 and 10 compared with that of the non-PE group. In the early phase (Days 1-5 after SAH), the daily water balance of the PE group was slightly positive. In the delayed phase (Days 6-14 after SAH), the serum C-reactive protein level and the global end-diastolic volume index were significantly higher in the PE group than in the non-PE group, whereas the PVPI tended to be higher in the PE group. CONCLUSIONS Pulmonary edema that occurs in the early and delayed phases after SAH is caused by cardiac failure and inflammatory (i.e., noncardiogenic) conditions, respectively. Measurement of the extravascular lung water index, cardiac index, and PVPI by PiCCO-plus monitoring is useful for identifying pulmonary edema in patients with SAH.

Rescue therapy for refractory vasospasm after subarachnoid hemorrhage

Vasospasm and delayed cerebral ischemia remain to be the common causes of increased morbidity and mortality after aneurysmal subarachnoid hemorrhage. The majority of clinical vasospasm responds to hemodynamic augmentation and direct vascular intervention; however, a percentage of patients continue to have symptoms and neurological decline. Despite suboptimal evidence, clinicians have several options in treating refractory vasospasm in aneurysmal subarachnoid hemorrhage (aSAH), including cerebral blood flow enhancement, intra-arterial manipulations, and intra-arterial and intrathecal infusions. This review addresses standard treatments as well as emerging novel therapies aimed at improving cerebral perfusion and ameliorating the neurologic deterioration associated with vasospasm and delayed cerebral ischemia.

Effect of triple-h prophylaxis on global end-diastolic volume and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Although prophylactic triple-H therapy has been used in a number of institutions globally to prevent delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH), limited evidence is available for the effectiveness of triple-H therapy on hemodynamic variables. Recent studies have suggested an association between low global end-diastolic volume index (GEDI), measured using a transpulmonary thermodilution method, and DCI onset. The current study aimed at assessing the effects of prophylactic triple-H therapy on GEDI.

METHODS

This prospective multicenter study included aneurysmal SAH patients admitted to 9 hospitals in Japan. The decision to administer prophylactic triple-H therapy and the management protocols were left to the physician in charge (physician-directed therapy) of each participating institution. The primary endpoints were the changes in the hemodynamic variables as analyzed using a generalized linear mixed model.

RESULTS

Of 178 patients, 62 (34.8 %) received prophylactic triple-H therapy and 116 (65.2 %) did not. DCI was observed in 35 patients (19.7 %), with no significant difference between the two groups [15 (24.2 %) vs. 20 (17.2 %), p = 0.27]. Although a greater amount of fluid (p < 0.001) and a higher mean arterial pressure (p = 0.005) were observed in the triple-H group, no significant difference was observed between the groups in GEDI (p = 0.81) or cardiac output (p = 0.62).

CONCLUSIONS

Physician-directed prophylactic triple-H administration was not associated with improved clinical outcomes or quantitative hemodynamic indicators for intravascular volume. Further, GEDI-directed intervention studies are warranted to better define management algorithms for SAH patients with the aim of preventing DCI.

Severe Dextran-Induced Anaphylactic Shock during Induction of Hypertension-Hypervolemia-Hemodilution Therapy following Subarachnoid Hemorrhage

Dextran is a colloid effective for volume expansion; however, a possible side effect of its use is anaphylaxis. Dextran-induced anaphylactoid reaction (DIAR) is a rare but severe complication, with a small dose of dextran solution sufficient to induce anaphylaxis. An 86-year-old female who underwent clipping for a ruptured cerebral aneurysm was admitted to the intensive care unit. Prophylactic hypertension-hypervolemia-hemodilution therapy was induced for cerebral vasospasm following a subarachnoid hemorrhage. The patient went into severe shock after administration of dextran for volume expansion, and dextran administration was immediately discontinued. The volume administered at that time was only 0.8 mL at the most. After fluid resuscitation with a crystalloid solution, circulatory status began to recover. However, cerebral vasospasm occurred and the patient's neurological condition deteriorated. Five weeks after the shock, she was diagnosed with hypersensitivity to dextran by a skin test. When severe hypotension occurs after dextran administration, appropriate treatments for shock should be performed immediately with discontinuation of dextran solution. Although colloid administration is recommended in some guidelines and researches, it is necessary to consider concerning the indication for volume expansion as well as the risk of colloid administration.

Cerebral Vasospasm in Critically III Patients with Aneurysmal Subarachnoid Hemorrhage: Does the Evidence Support the Ever-Growing List of Potential Pharmacotherapy Interventions?

The occurrence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is a significant event resulting in decreased cerebral blood flow and oxygen delivery. Prevention and treatment of cerebral vasospasm is vital to avert neurological damage and reduced functional outcomes. A variety of pharmacotherapy interventions for the prevention and treatment of cerebral vasospasm have been evaluated. Unfortunately, very few large randomized trials exist to date, making it difficult to make clear recommendations regarding the efficacy and safety of most pharmacologic interventions. Considerable debate exists regarding the efficacy and safety of hypervolemia, hemodilution, and hypertension (triple-H therapy), and the implementation of each component varies substantially amongst institutions. There is a new focus on euvolemic-induced hypertension as a potentially preferred mechanism of hemodynamic augmentation. Nimodipine is the one pharmacologic intervention that has demonstrated favorable effects on patient outcomes and should be routinely administered unless contraindications are present. Intravenous nicardipine may offer an alternative to oral nimodipine. The addition of high-dose magnesium or statin therapy has shown promise, but results of ongoing large prospective studies are needed before they can be routinely recommended. Tirilazad and clazosentan offer new pharmacologic mechanisms, but clinical outcome results from prospective randomized studies have largely been unfavorable. Locally administered pharmacotherapy provides a targeted approach to the treatment of cerebral vasospasm. However, the paucity of data makes it challenging to determine the most appropriate therapy and implementation strategy. Further studies are needed for most pharmacologic therapies to determine whether meaningful efficacy exists.

Current options for the management of aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm: a comprehensive review of the literature

OBJECTIVES

Cerebral vasospasm is one of the leading causes of morbi-mortality following aneurysmal subarachnoid hemorrhage. The aim of this article is to discuss the current status of vasospasm therapy with emphasis on endovascular treatment.

METHODS

A comprehensive review of the literature obtained by a PubMed search. The most relevant articles related to medical, endovascular and alternative therapies were selected for discussion.

RESULTS

Current accepted medical options include the oral nimodipine and 'triple-H' therapy (hypertension, hypervolemia and hemodilution). Nimodipine remains the only modality proven to reduce the incidence of infarction. Although widely used, 'triple-H' therapy has not been demonstrated to significantly change overall outcome after cerebral vasospasm. Indeed, both induced hypervolemia and hemodilution may have deleterious effects, and more recent physiologic data favor normovolemia with induced hypertension or optimization of cardiac output. Endovascular options include percutaneous transluminal balloon angioplasty (PTA) and intra-arterial (IA) infusion of vasodilators. Multiple case reports and case series have been encountered in the literature using different drug regimens with diverse mechanisms of action. Compared with PTA, IA drug infusion has the advantages of distal penetration and a better safety profile. Its main disadvantages are the more frequent need for repeat treatments and its systemic hemodynamic repercussions. Alternative options using intraventricular/cisternal drug therapy and flow augmentation strategies have also shown possible benefits; however, their use is not yet as well established.

CONCLUSION

Blood pressure or cardiac output optimization should be the mainstay of hyperdynamic therapy. Endovascular treatment appears to have a positive impact on neurological outcome compared with the natural history of the disease. The role of intraventricular therapy and flow augmentation strategies in association with medical and endovascular treatment may, in the future, play a growing role in the management of patients with severe refractory vasospasm.

Treatment of intracranial vasospasm following subarachnoid hemorrhage

Vasospasm has been a long known source of delayed morbidity and mortality in aneurysmal subarachnoid hemorrhage patients. Delayed ischemic neurologic deficits associated with vasospasm may account for as high as 50% of the deaths in patients who survive the initial period after aneurysm rupture and its treatment. The diagnosis and treatment of vasospasm has still been met with some controversy. It is clear that subarachnoid hemorrhage is best cared for in tertiary care centers with modern resources and access to cerebral angiography. Ultimately, a high degree of suspicion for vasospasm must be kept during ICU care, and any signs or symptoms must be investigated and treated immediately to avoid permanent stroke and neurologic deficit. Treatment for vasospasm can occur through both ICU intervention and endovascular administration of intra-arterial vasodilators and balloon angioplasty. The best outcomes are often attained when these methods are used in conjunction. The following article reviews the literature on cerebral vasospasm and its treatment and provides the authors’ approach to treatment of these patients.

The effects of fluid balance and colloid administration on outcomes in patients with aneurysmal subarachnoid hemorrhage: a propensity score-matched analysis

BACKGROUND

Delayed ischemic neurological deficit (DIND) following aneurysmal subarachnoid hemorrhage (SAH) remains a significant cause of mortality and disability. The administration of colloids and the induction of a positive fluid balance during the vasospasm risk period remain controversial. Here, we compared DIND and outcomes among propensity score-matched cohorts who did and did not receive colloids and also tested the effect of a positive fluid balance on these endpoints.

METHODS

Exploratory analysis was performed on 413 patients enrolled in CONSCIOUS-1, a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. Propensity score matching was performed on the basis of age, gender, pre-existing heart conditions, hypertension, nicotine use, World Federation of Neurosurgical Societies scores, aneurysm location, clazosentan treatment, subarachnoid clot burden, and severity of angiographic vasospasm. Inferential statistics were used for group-wise comparisons.

RESULTS

One hundred twenty-three subjects were matched (41 received colloids, whereas 82 did not). The covariate balance and propensity score distributions were acceptable. There was no difference between the groups with respect to DIND (17 vs. 22%; p = 0.64) or the presence (48 vs. 51%; p = 0.71) or volume of delayed infarcts (volume >7.5 cm3; 62 vs. 48%; p = 0.41). Similarly, no differences were found on multivariate analysis between patients who did and did not have a positive fluid balance, although patients with severe angiographic vasospasm had more delayed infarcts with a negative fluid balance (p = 0.01). Among all subjects, the administration of colloids and a positive fluid balance were associated with worse outcomes on the NIHSS (p = 0.04) and modified Rankin (p = 0.02) scales, respectively.

CONCLUSIONS

Colloid administration and induction of a positive fluid balance during the vasospasm risk period may be associated with poor outcomes in specific patient groups. Patient selection is of utmost importance when managing the fluid status of patients with aneurysmal SAH.

Challenges in collecting pharmacokinetic and pharmacodynamic information in an intensive care setting: PK/PD modelling of clazosentan in patients with aneurysmal subarachnoid haemorrhage

PURPOSE

This paper describes the pharmacokinetic/pharmacodynamic modelling of clazosentan in patients with aneurysmal subarachnoid haemorrhage (aSAH), and the impact of collecting data in an intensive care unit (ICU) setting. Factors influencing data quality, analysis, and interpretation are provided with recommendations for future clinical studies in ICU settings.

METHODS

CONSCIOUS-2 was a phase III study involving 1,157 patients with aSAH. Secured by surgical clipping, patients were infused with clazosentan or placebo for up to 14 days post-aSAH. Clazosentan exposure relationships with vital signs, QT intervals, and AST/ALT values as well as efficacy and safety endpoints were characterised using population PK/PD and logistic regression models.

RESULTS

Clazosentan clearance was influenced by age, sex, Asian origin, and disease status at baseline, and increased with time. Volume of distribution showed a sex difference. Exposure had no relationship with any efficacy endpoint or ALT/AST values, but was related to the increasing probability of lung complications. Blood pressure decreased proportionally to clazosentan concentrations, and the presence of clazosentan was associated with QT interval increases. Implausible values in the concentration data reflect the specific ICU challenges, possibly arising from PK sampling from the infusion arm or haemodilution.

CONCLUSIONS

Population PK/PD modelling of CONCIOUS-2 data provided clinically relevant knowledge about various effects of clazosentan in the aSAH patient population in a real clinical setting. The quality of data and analyses could be improved by the collection of additional data and stricter training of study personnel. Differences in clinical practice between sites and geographical regions are more challenging to overcome.

Brain ischemia in patients with intracranial hemorrhage: pathophysiological reasoning for aggressive diagnostic management

Patients with intracranial hemorrhage have to be managed aggressively to avoid or minimize secondary brain damage due to ischemia, which contributes to high morbidity and mortality. The risk of brain ischemia, however, is not the same in every patient. The risk of complications associated with an aggressive prophylactic therapy in patients with a low risk of brain ischemia can outweigh the benefits of therapy. Accurate and timely identification of patients at highest risk is a diagnostic challenge. Despite the availability of many diagnostic tools, stroke is common in this population, mostly because the pathogenesis of stroke is frequently multifactorial whereas diagnosticians tend to focus on one or two risk factors. The pathophysiological mechanisms of brain ischemia in patients with intracranial hemorrhage are not yet fully elucidated and there are several important areas of ongoing research. Therefore, this review describes physiological and pathophysiological aspects associated with the development of brain ischemia such as the mechanism of oxygen and carbon dioxide effects on the cerebrovascular system, neurovascular coupling and respiratory and cardiovascular factors influencing cerebral hemodynamics. Consequently, we review investigations of cerebral blood flow disturbances relevant to various hemodynamic states associated with high intracranial pressure, cerebral embolism, and cerebral vasospasm along with current treatment options.

Current controversies in the prediction, diagnosis, and management of cerebral vasospasm: where do we stand?

Aneurysmal subarachnoid hemorrhage occurs in approximately 30,000 persons in the United States each year. Around 30 percent of patients with aneurysmal subarachnoid hemorrhage suffer from cerebral ischemia and infarction due to cerebral vasospasm, a leading cause of treatable death and disability following aneurysmal subarachnoid hemorrhage. Methods used to predict, diagnose, and manage vasospasm are the topic of recent active research. This paper utilizes a comprehensive review of the recent literature to address controversies surrounding these topics. Evidence regarding the effect of age, smoking, and cocaine use on the incidence and outcome of vasospasm is reviewed. The abilities of different computed tomography grading schemes to predict vasospasm in the aftermath of subarachnoid hemorrhage are presented. Additionally, the utility of different diagnostic methods for the detection and visualization of vasospasm, including transcranial Doppler ultrasonography, CT angiography, digital subtraction angiography, and CT perfusion imaging is discussed. Finally, the recent literature regarding interventions for the prophylaxis and treatment of vasospasm, including hyperdynamic therapy, albumin, calcium channel agonists, statins, magnesium sulfate, and endothelin antagonists is summarized. Recent studies regarding each topic were reviewed for consensus recommendations from the literature, which were then presented.

Is asymptomatic vasospasm associated with poor outcome in subarachnoid hemorrhage?

BACKGROUND

Vasospasm occurs in up to 70% of aneurysmal subarachnoid hemorrhage (aSAH), but only half becomes symptomatic. It is unclear whether asymptomatic vasospasm (AV) detected by noninvasive testing affects outcome. Prophylactic hemodilutional, hypertensive, and hypervolemic (HHH) therapy is widely used but the benefit remains unproven. We aim to determine whether AV increases the risk of poor outcome and whether HHH is safe.

METHODS

A total of 175 consecutive patients with aSAH without clinical vasospasm were included. Patients with sonographic (transcranial doppler) or radiologic (computed tomography [CT] Angiography) vasospasm were assigned to AV group, while those without were assigned to no vasospasm (NV) group. Logistic regression was used to determine the association between AV and HHH on poor outcome, defined as modified Rankin scale (mRS) >3 at discharge or 3 to 6 months' follow-up.

RESULTS

In all, 106 patients had NV and 25 received HHH. A total of 69 patients had AV and 54 received HHH. Asymptomatic vasospasm compared to NV was not associated with poor outcome (odds ratio [OR] 2.6, 95% confidence interval [CI]: 0.75-8.9; P = .1). Hemodilutional, hypertensive, and hypervolemic use in patients with AV did not improve the outcome (OR 0.16, 95%CI: 0.009-2.84; P = .2). In patients with NV, HHH use showed trend toward poor outcome after multivariable adjustment (OR 12.6, 95%CI: 1.08-146.5 P = .04).

CONCLUSION

Asymptomatic vasospasm does not appear to be associated with poor outcome in aSAH. Hemodilutional, hypertensive, and hypervolemic therapy in AV was not associated with improved outcome and may be harmful to patients who do not have vasospasm. Further research is needed to validate this finding.

[Delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: prevention, diagnostics and therapy]

Delayed cerebral ischemia (DCI) is the second most important impacting factor for functional outcome after aneurysmal subarachnoid hemorrhage (SAH) following the initial severity of the bleeding. In contrast to the initial SAH severity the presence and consequences of DCI can be managed with prophylactic and therapeutic interventions. The previous notion of treatment of angiographically observed vasospasm has not been shown to be successful.This article covers prevention, monitoring and therapeutic concepts for patients with SAH with emphasis on the efficacy for DCI and current and ongoing research projects.

Dissociation of vasospasm-related morbidity and outcomes in patients with aneurysmal subarachnoid hemorrhage treated with clazosentan: a meta-analysis of randomized controlled trials

OBJECT

Clazosentan therapy after aneurysmal subarachnoid hemorrhage (SAH) has been found to be effective in reducing the incidence of vasospasm in randomized controlled trials. However, while vasospasm-related morbidity, including delayed ischemic neurological deficits (DINDs) and delayed cerebral infarctions, was consistently decreased, statistical significance was not demonstrated and outcomes were not affected by clazosentan treatment. The objective of this meta-analysis was to determine whether clazosentan treatment after aneurysmal SAH significantly reduced the incidence of DINDs and delayed cerebral infarctions and improved outcomes.

METHODS

All randomized controlled trials investigating the effect of clazosentan were retrieved via searches with sensitive and specific terms. Six variables were abstracted after the assessment of the methodological quality of the trials. Analyses were performed following the method guidelines of the Cochrane Back Review Group.

RESULTS

Four randomized, placebo-controlled trials met eligibility criteria, enrolling a total of 2181 patients. The meta-analysis demonstrated a significant decrease in the incidence of DINDs (relative risk [RR] 0.76 [95% CI 0.62-0.92]) and delayed cerebral infarction (RR 0.79 [95% CI 0.63-1.00]) in patients treated with clazosentan after aneurysmal SAH. However, this treatment regimen was not shown to outcomes including functional outcomes measured by Glasgow Outcome Scale-Extended (RR 1.12 [95% CI 0.96-1.30]) or mortality (RR 1.02 [95%CI 0.70-1.49]). Adverse events, including pulmonary complications, anemia, and hypotension, were all significantly increased in patients who received clazosentan therapy.

CONCLUSIONS

The results of the present meta-analysis show that treatment with clazosentan after aneurysmal SAH significantly reduced the incidence of the vasospasm-related DINDs and delayed cerebral infarctions, but did not improve poor neurological outcomes in patients with aneurysmal SAH. Further study is required to elucidate the dissociation between vasospasm-related morbidity and outcomes.

Medical Management of Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage: A Review of Current and Emerging Therapeutic Interventions

Cerebral vasospasm is a major source of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH). Evidence suggests a multifactorial etiology and this concept remains supported by the assortment of therapeutic modalities under investigation. The authors provide an updated review of the literature for previous and recent clinical trials evaluating medical treatments in patients with cerebral vasospasm secondary to aSAH. Currently, the strongest evidence supports use of prophylactic oral nimodipine and initiation of triple-H therapy for patients in cerebral vasospasm. Other agents presented in this report include magnesium, statins, endothelin receptor antagonists, nitric oxide promoters, free radical scavengers, thromboxane inhibitors, thrombolysis, anti-inflammatory agents and neuroprotectants. Although promising data is beginning to emerge for several treatments, few prospective randomized clinical trials are presently available. Additionally, future investigational efforts will need to resolve discrepant definitions and outcome measures for cerebral vasospasm in order to permit adequate study comparisons. Until then, definitive recommendations cannot be made regarding the safety and efficacy for each of these therapeutic strategies and medical management practices will continue to be implemented in a wide-ranging manner.

Clinical trials in cardiac arrest and subarachnoid hemorrhage: lessons from the past and ideas for the future

Introduction. Elevated intracranial pressure that occurs at the time of cerebral aneurysm rupture can lead to inadequate cerebral blood flow, which may mimic the brain injury cascade that occurs after cardiac arrest. Insights from clinical trials in cardiac arrest may provide direction for future early brain injury research after subarachnoid hemorrhage (SAH). Methods. A search of PubMed from 1980 to 2012 and clinicaltrials.gov was conducted to identify published and ongoing randomized clinical trials in aneurysmal SAH and cardiac arrest patients. Only English, adult, human studies with primary or secondary mortality or neurological outcomes were included. Results. A total of 142 trials (82 SAH, 60 cardiac arrest) met the review criteria (103 published, 39 ongoing). The majority of both published and ongoing SAH trials focus on delayed secondary insults after SAH (70%), while 100% of cardiac arrest trials tested interventions within the first few hours of ictus. No SAH trials addressing treatment of early brain injury were identified. Twenty-nine percent of SAH and 13% of cardiac arrest trials showed outcome benefit, though there is no overlap mechanistically. Conclusions. Clinical trials in SAH assessing acute brain injury are warranted and successful interventions identified by the cardiac arrest literature may be reasonable targets of the study.

The association between fluid balance and outcomes after subarachnoid hemorrhage

BACKGROUND

We sought to determine the association between early fluid balance and neurological/vital outcome of patients with subarachnoid hemorrhage.

METHODS

Hospital admission, imaging, ICU and outcome data were retrospectively collected from the medical records of adult patients with aneurysmal SAH admitted to a level-1 trauma and stroke referral center during a 5-year period. Two groups were identified based on cumulative fluid balance by ICU day 3: (i) patients with a positive fluid balance (n = 221) and (ii) patients with even or negative fluid balance (n = 135). Multivariable logistic regression was used to adjust for age, Hunt-Hess and Fisher scores, mechanical ventilation and troponin elevation (>0.40 ng/ml) at ICU admission. The primary outcome was a composite of hospital mortality or new stroke.

RESULTS

Patients with positive fluid balance had worse admission GCS and Hunt-Hess score, and by ICU day 3 had cumulatively received more IV fluids, but had less urine output when compared with the negative fluid balance group. There was no difference in the odds of hospital death or new stroke (adjusted OR: 1.47, 95%CI: 0.85, 2.54) between patients with positive and negative fluid balance. However, positive fluid balance was associated with increased odds of TCD vasospasm (adjusted OR 2.25, 95%CI: 1.37, 3.71) and prolonged hospital length of stay.

CONCLUSIONS

Although handling of IV fluid administration was not an independent predictor of mortality or new stroke, patients with early positive fluid balance had worse clinical presentation and had greater resource use during the hospital course.

Pulmonary complications in patients with severe brain injury

Pulmonary complications are prevalent in the critically ill neurological population. Respiratory failure, pneumonia, acute lung injury and the acute respiratory distress syndrome (ALI/ARDS), pulmonary edema, pulmonary contusions and pneumo/hemothorax, and pulmonary embolism are frequently encountered in the setting of severe brain injury. Direct brain injury, depressed level of consciousness and inability to protect the airway, disruption of natural defense barriers, decreased mobility, and secondary neurological insults inherent to severe brain injury are the main cause of pulmonary complications in critically ill neurological patients. Prevention strategies and current and future therapies need to be implemented to avoid and treat the development of these life-threatening medical complications.

Milrinone and homeostasis to treat cerebral vasospasm associated with subarachnoid hemorrhage: the Montreal Neurological Hospital protocol

INTRODUCTION

For the treatment of cerebral vasospasm, current therapies have focused on increasing blood flow through blood pressure augmentation, hypervolemia, the use of intra-arterial vasodilators, and angioplasty of proximal cerebral vessels. Through a large case series, we present our experience of treating cerebral vasospasm with a protocol based on maintenance of homeostasis (correction of electrolyte and glucose disturbances, prevention and treatment of hyperthermia, replacement of fluid losses), and the use of intravenous milrinone to improve microcirculation (the Montreal Neurological Hospital protocol). Our objective is to describe the use milrinone in our practice and the neurological outcomes associated with this approach.

METHODS

Large case series based on the review of all patients diagnosed with delayed ischemic neurologic deficits after aneurysmal subarachnoid hemorrhage between April 1999 and April 2006.

RESULTS

88 patients were followed for a mean time of 44.6 months. An intravenous milrinone infusion was used for a mean of 9.8 days without any significant side effects. No medical complications associated with this protocol were observed. There were five deaths; of the surviving patients, 48.9 % were able to go back to their previous baseline and 75 % had a good functional outcome (modified Rankin scale ≤ 2).

CONCLUSION

A protocol using intravenous milrinone, and the maintenance of homeostasis is simple to use and requires less intensive monitoring and resources than the standard triple H therapy. Despite the obvious limitations of this study's design, we believe that it would be now appropriate to proceed with formal prospective studies of this protocol.