Magnesium therapy within 48 hours of an aneurysmal subarachnoid hemorrhage: neuro-panacea

Safety and efficacy of magnesium-rich artificial cerebrospinal fluid for subarachnoid hemorrhage

Objectives

This study aimed to investigate the efficacy of using a newly formulated magnesium-rich artificial cerebrospinal fluid (MACSF) as an alternative to normal saline (NS) for intraoperative irrigation during aneurysm clipping in improving the prognosis of patients with Aneurysmal subarachnoid hemorrhage (aSAH).

Methods

Patients with aSAH who underwent intraoperative irrigation with MACSF or NS during the clipping in the First Affiliated Hospital of Xi 'an Jiaotong University from March 2019 to March 2022 were selected as MACSF group and NS group, respectively. The primary prognostic indicators were the incidence of favorable outcomes (mRS 0-2). The secondary outcome measures included cerebral vasospasm (CVS), mortality, total hospital stay, and intensive care unit (ICU) stay. Safety was evaluated based on the occurrence rates of hypermagnesemia, meningitis, and hydrocephalus.

Results

Overall, 34 and 37 patients were enrolled in the MACSF and NS groups, respectively. At 90 days after aSAH onset, the proportion of favorable prognosis in the MACSF group was significantly higher than that in the NS group (p = 0.035). The incidence of CVS within 14 days after surgery was significantly lower in the MACSF group than that in the NS group (p = 0.026). The mortality rate in the MACSF group was significantly lower than in the NS group (p = 0.048). The median lengths of hospital stay (p = 0.008) and ICU stay (p = 0.018) were significantly shorter in the MACSF group than in the NS group. No significant differences were observed in safety measures.

Conclusion

Using MACSF as an irrigation fluid for aneurysm clipping can significantly improve the 90-day prognosis of patients with aSAH, which may be related to the reduced incidence of CVS.

Clinical trial registration

https://www.clinicaltrials.gov, identifier NCT04358445.

Guidelines for the Neurocritical Care Management of Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The neurointensive care management of patients with aneurysmal subarachnoid hemorrhage (aSAH) is one of the most critical components contributing to short-term and long-term patient outcomes. Previous recommendations for the medical management of aSAH comprehensively summarized the evidence based on consensus conference held in 2011. In this report, we provide updated recommendations based on appraisal of the literature using the Grading of Recommendations Assessment, Development, and Evaluation methodology.

METHODS

The Population/Intervention/Comparator/Outcome (PICO) questions relevant to the medical management of aSAH were prioritized by consensus from the panel members. The panel used a custom-designed survey instrument to prioritize clinically relevant outcomes specific to each PICO question. To be included, the study design qualifying criteria were as follows: prospective randomized controlled trials (RCTs), prospective or retrospective observational studies, case-control studies, case series with a sample larger than 20 patients, meta-analyses, restricted to human study participants. Panel members first screened titles and abstracts, and subsequently full text review of selected reports. Data were abstracted in duplicate from reports meeting inclusion criteria. Panelists used the Grading of Recommendations Assessment, Development, and Evaluation Risk of Bias tool for assessment of RCTs and the "Risk of Bias In Nonrandomized Studies - of Interventions" tool for assessment of observational studies. The summary of the evidence for each PICO was presented to the full panel, and then the panel voted on the recommendations.

RESULTS

The initial search retrieved 15,107 unique publications, and 74 were included for data abstraction. Several RCTs were conducted to test pharmacological interventions, and we found that the quality of evidence for nonpharmacological questions was consistently poor. Five PICO questions were supported by strong recommendations, one PICO question was supported by conditional recommendations, and six PICO questions did not have sufficient evidence to provide a recommendation.

CONCLUSIONS

These guidelines provide recommendations for or against interventions proven to be effective, ineffective, or harmful in the medical management of patients with aSAH based on a rigorous review of the available literature. They also serve to highlight gaps in knowledge that should guide future research priorities. Despite improvements in the outcomes of patients with aSAH over time, many important clinical questions remain unanswered.

The importance of early brain injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency that accounts for 5% of all stroke cases. Individuals affected are typically in the prime of their lives (mean age 50 years). Approximately 12% of patients die before receiving medical attention, 33% within 48 h and 50% within 30 days of aSAH. Of the survivors 50% suffer from permanent disability with an estimated lifetime cost more than double that of an ischemic stroke. Traditionally, spasm that develops in large cerebral arteries 3-7 days after aneurysm rupture is considered the most important determinant of brain injury and outcome after aSAH. However, recent studies show that prevention of delayed vasospasm does not improve outcome in aSAH patients. This finding has finally brought in focus the influence of early brain injury on outcome of aSAH. A substantial amount of evidence indicates that brain injury begins at the aneurysm rupture, evolves with time and plays an important role in patients' outcome. In this manuscript we review early brain injury after aSAH. Due to the early nature, most of the information on this injury comes from animals and few only from autopsy of patients who died within days after aSAH. Consequently, we began with a review of animal models of early brain injury, next we review the mechanisms of brain injury according to the sequence of their temporal appearance and finally we discuss the failure of clinical translation of therapies successful in animal models of aSAH.

Intravenous magnesium sulfate after aneurysmal subarachnoid hemorrhage: current status

Delayed ischemic neurological deficit or clinical vasospasm remained a major cause for delayed neurological morbidity and mortality for patients with aneurysmal subarachnoid hemorrhage (SAH). Magnesium is a cerebral vasodilator. In experimental model of drug or SAH-induced vasospasm, magnesium blocks voltage-dependent calcium channels and reverses cerebral vasoconstriction. Furthermore, its antagonistic action on N-methyl-D-aspartate receptor in the brain prevents glutamate stimulation and decreases calcium influx during ischemic injury. Clinically, the protective effect of magnesium has also been found useful in women with preeclampsia, a condition thought to be due to cerebral vasospasm. Initial experimental result in human was found to safe and effective as compared to historical data. In our pilot study, 60 patients were randomly allocated to receive either magnesium sulfate infusion 80 mmol/day or saline infusion for 14 days. The incidence of symptomatic vasospasm decreased from 13/30(43%) in the saline group to 7/30(23%) in the patients receiving magnesium sulfate infusion, p = 0.10, odds ratio 0.398, 95% CI 0.131-1.211. Favorable outcome (Good recovery and moderate disability, as defined by Glasgow Outcome Scale) was achieved in 20 of 30 (67%) patients receiving magnesium sulfate infusion and 16 of 30 (53%) patients receiving placebo treatment, p = 0.292, odds ratio 1.750, 95% CI 0.616-4.974.From literature review, a total of 441 patients from four studies (including ours) were grouped for analysis. Using random effects model (Mantel-Haenszel, Robins-Breslow-Greenland), the pooled odds ratio for symptomatic vasospasm or delayed cerebral ischemia is, 0.620, 95% CI 0.389-0.987, statistically significant. Similarly, the pooled odds ratio for favorable outcome is 1.598, 95% CI 1.074-2.377, statistically significant. There are two multi-center phase III studies (IMASH and MASH2) being carried out to assess the clinical effects, in which IMASH has finished data collection on 30th June 2009.

Resistant vasospasm in subarachnoid hemorrhage treated with continuous intraarterial nimodipine infusion

Cerebral vasospasm complicating aneurysmal subarachnoid hemorrhage is a well-known medical entity. The delayed ischemic neurological deficits (DIND) as a result of vasospasm remain the main cause of morbidity among patients who manage to survive this severe disease pattern. When the traditional treatment options, either medical or interventional, fail to reverse vasospasm, continuous intraarterial infusion of nimodipine through catheters directly into the spastic arteries presents a promising treatment modality. Of 73 patients with aneurysmal subarachnoid hemorrhage between 2008 and 2009, a total of 27 had Hunt and Hess grades of 4 and 5. Fifteen percent of them showed refractory vasospasms and were treated with continuous nimodipine infusion via catheters in both internal carotid arteries. We present the method's indications and possible complications.

Metamorphosis of subarachnoid hemorrhage research: from delayed vasospasm to early brain injury

Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies.

Retrospective analysis of parenteral magnesium sulfate administration in decreased incidence of clinical and neuroradiological cerebral vasospasm: a single center experience

OBJECTIVE

Experimental work suggests a neuroprotective role for magnesium sulfate in aneurysmal subarachnoid hemorrhage. We retrospectively review the incidence of clinically relevant vasospasm in patients treated or not with continuous magnesium infusion after onset of subarachnoid hemorrhage.

METHODS

All patient records in Albany Medical Center with the diagnosis of SAH between January 1999 and June 2004 were reviewed. Patients who presented to the emergency department within 72 hours of onset were entered in the study. Patients were defined as in clinical vasospasm if there was an acute neurological change in association with abnormal trancranial Doppler (TCD), CT angiogram (CTA) or digital subtraction angiography (DSA).

RESULTS

A total of 85 patients were selected. Magnesium sulfate was infused in 43 patients. When compared with patients who did not receive MgSO(4), there was a statistically significant lower incidence of clinical and radiological vasospasm in those who had the continuous infusion of magnesium sulfate (p<0.01). There was no statistically significant difference between patients who were coiled or clipped.

CONCLUSION

Continuous magnesium sulfate infusion for the management of clinically significant cerebral vasospasm is safe and reduces the incidence of clinically significant cerebral vasospasm. Large, multicenter, controlled studies should be performed in order to determine the true effectiveness of the treatment in a controlled setting.

Use of intrathecal nicardipine for aneurysmal subarachnoid hemorrhage-induced cerebral vasospasm

BACKGROUND

Cerebral vasospasm leading to delayed ischemia is a common and serious complication of aneurysmal subarachnoid hemorrhage that often results in increased morbidity and mortality. Treatments for cerebral vasospasm, including triple-H therapy (therapeutic hypervolemia, hypertension, and hemodilution), nimodipine, balloon angioplasty, and intra-arterial vasodilators have limitations in their efficacy and safety profiles. Nicardipine, a calcium channel blocker, is available for intravenous administration for blood pressure reduction. A recent study reported its efficacy in the treatment of cerebral vasospasm when given intrathecally (IT). We present our experiences with IT nicardipine for treatment of cerebral vasospasm.

METHODS

IT nicardipine was administered to six patients with aneurysmal subarachnoid hemorrhage after prophylactic and aggressive therapeutic management for vasospasm failed.

RESULTS

In these patients, IT nicardipine treatment was followed within 8 hours by a 43.1 +/- 31.0 cm/s decrease in middle cerebral arterial flow velocity, as measured by transcranial Doppler ultrasound.

CONCLUSIONS

Based on these positive results, we believe that larger scale studies evaluating the safety and efficacy of IT nicardipine for the management of cerebral vasospasm are warranted.

Threshold to N-methyl-D-aspartate-induced seizures in mice undergoing chronic nutritional magnesium deprivation is lowered in a way partly responsive to acute magnesium and antioxidant administrations

Magnesium deficiency may be induced by a diet impoverished in magnesium. This nutritional deficit promotes chronic inflammatory and oxidative stresses, hyperexcitability and, in mice, susceptibility to audiogenic seizures. Potentiation by low-magnesium concentrations of the opening of N-methyl-d-aspartate (NMDA) receptor/calcium channel in in vitro and ex vivo studies, and responsiveness to magnesium of in vivo brain injury states are now well established. By contrast, little or no specific attention has been, however, paid to the in vivo NMDA receptor function/excitability in magnesium deficiency. The present work reports for the first time that, in mice undergoing chronic nutritional deprivation in magnesium (35 v. 930 parts per million for 27 d in OF1 mice), NMDA-induced seizure threshold is significantly decreased (38 % of normal values). The attenuation in the drop of NMDA seizure threshold (percentage of reversal) was 58 and 20 % upon acute intraperitoneal administrations of magnesium chloride hexahydrate (28 mg magnesium/kg) and the antioxidant ebselen (20 mg/kg), respectively. In nutritionally magnesium-deprived animals, audiogenic seizures are completely prevented by these compound doses. Taken as a whole, our data emphasise that chronic magnesium deprivation in mice is a nutritional in vivo model for a lowered NMDA receptor activation threshold. This nutritional model responds remarkably to acute magnesium supply and moderately to acute antioxidant administration.

Electrolyte disturbances in the intensive care unit

The development of many electrolyte disturbances in the ICU can be prevented by attention to the use of intravenous fluids and nutrition. Hyponatremia is a relative contraindication to the use of hypotonic intravenous fluids and hypernatremia calls for the administration of water. Formulae have been devised to guide the therapy of severe hyponatremia and hypernatremia. All formulae regard the patient as a closed system, and none takes into account ongoing fluid losses that are highly variable between patients. Thus, therapy of severe hyponatremia and hypernatremia must be closely monitored with serial electrolyte measurements. The significance of hypocalcemia in the critically ill is controversial. Hypokalemia, hypophosphatemia, and hypomagnesemia should be corrected.

The endovascular operating room as an extension of the intensive care unit: changing strategies in the management of neurovascular disease

Technological advances within the field of endovascular neurosurgery have influenced the management of the neurovascular patient within the intensive care unit (ICU). The endovascular operating room has, in fact, become an extension of the ICU in certain cases. Given the rapid development of new endovascular technologies, it is more important than ever for neurosurgeons to remain intimately involved with the care of their patients within the ICU. This article offers an overview of the evolution in ICU management of neurovascular disease and provides a framework for the incorporation of the endovascular operating room in the intensive care management of patients with this disease.

A review of current and future medical therapies for cerebral vasospasm following aneurysmal subarachnoid hemorrhage

✓In an effort to help clarify the current state of medical therapy for cerebral vasospasm, the authors reviewed the relevant literature on the established medical therapies used for cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH), and they discuss burgeoning areas of investigation. Despite advances in the treatment of aneurysmal SAH, cerebral vasospasm remains a common complication and has been correlated with a 1.5- to threefold increase in death during the first 2 weeks after hemorrhage. A number of medical, pharmacological, and surgical therapies are currently in use or being investigated in an attempt to reverse cerebral vasospasm, but only a few have proven to be useful. Although much has been elucidated regarding its pathophysiology, the treatment of cerebral vasospasm remains a dilemma. Although a poor understanding of SAH-induced cerebral vasospasm pathophysiology has, to date, hampered the development of therapeutic interventions, current research efforts promise the eventual production of new medical therapies.