Incidence of and factors associated with manipulation of nimodipine dosage in patients with aneurysmal subarachnoid hemorrhage

Effects of early high-dose vasopressor administration in patients after aneurysmal subarachnoid hemorrhage: a retrospective single-center study

BACKGROUND

Although the use of vasopressors is recommended after aneurysmal subarachnoid hemorrhage (aSAH) to maintain adequate cerebral perfusion pressure, data on potential adverse effects on delayed cerebral ischemia (DCI) are lacking. The aim of this study was to evaluate the effects of early high-dose vasopressor therapy with norepinephrine alone or additional vasopressin on the subsequent occurrence of DCI, DCI-related infarction and functional outcomes.

METHODS

Retrospective evaluation of aSAH patients admitted between January 2010 and December 2022. Demographic, clinical and outcome data as well as daily norepinephrine equivalent (NEE) scores were collected. Potential risk factors for DCI, DCI-related infarction and functional outcome 3 months after discharge were assessed by logistic regression analyses.

RESULTS

A total of 288 patients were included. 208 patients (72%) received vasopressor therapy during the first 14 postictal days with a mean NEE score of 3.8 µg/kgBW/h. The highest NEE scores were observed in the acute phase after hemorrhage and mainly in poor-grade patients. The mean NEE score during the postictal days 1-4 was significantly higher in patients who developed DCI or DCI-related infarction and who had an unfavorable functional outcome. Multivariable logistic regression analysis identified a high NEE score on postictal days 1-4 as an independent predictor of DCI and unfavorable functional outcome.

CONCLUSIONS

Vasopressor use is common in aSAH patients in the acute phase after hemorrhage. Our results suggest that high NEE scores during the first 4 days after ictus represent an independent prognostic factor and might aggravate the complex cerebral sequelae associated with the disease.

Pharmacological Prevention of Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Causes of morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH) include early brain injury and delayed neurologic deterioration, which may result from delayed cerebral ischemia (DCI). Complex pathophysiological mechanisms underlie DCI, which often includes angiographic vasospasm (aVSP) of cerebral arteries.

METHODS

Despite the study of many pharmacological therapies for the prevention of DCI in aSAH, nimodipine-a dihydropyridine calcium channel blocker-remains the only drug recommended universally in this patient population. A common theme in the research of preventative therapies is the use of promising drugs that have been shown to reduce the occurrence of aVSP but ultimately did not improve functional outcomes in large, randomized studies. An example of this is the endothelin antagonist clazosentan, although this agent was recently approved in Japan.

RESULTS

The use of the only approved drug, nimodipine, is limited in practice by hypotension. The administration of nimodipine and its counterpart nicardipine by alternative routes, such as intrathecally or formulated as prolonged release implants, continues to be a rational area of study. Additional agents approved in other parts of the world include fasudil and tirilazad.

CONCLUSIONS

We provide a brief overview of agents currently being studied for prevention of aVSP and DCI after aSAH. Future studies may need to identify subpopulations of patients who can benefit from these drugs and perhaps redefine acceptable outcomes to demonstrate impact.

Risks of nimodipine dose reduction during the high-risk period for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Nimodipine dose reduction is recommended in case of high vasopressor demand after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess potential adverse effects of nimodipine reduction during the high-risk period for delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) between days 5 and 10 after hemorrhage. Demographic and clinical data as well as daily nimodipine dose of aSAH patients admitted between 2010 and 2019 were retrospectively analyzed. Univariable and multivariable regression analyses were performed to identify factors associated with DCI, angiographic CVS, DCI-related infarction, and unfavorable outcome. A total of 205 patients were included. Nimodipine dose reduction occurred in 108 (53%) patients ('nimodipine reduction group'), while 97 patients (47%) received the full dose ('no nimodipine reduction group'), Patients in the 'nimodipine reduction group' had significant worse WFNS and Fisher grades and developed significantly more often DCI and angiographic CVS. DCI-related infarction and unfavorable outcome were also significantly increased in the 'nimodipine reduction group.' 'Reduced nimodipine dose' was the only independent predictor for the occurrence of DCI and angiographic CVS in multivariable regression analysis. 'Poor WFNS grade' and 'reduced nimodipine dose' were identified as independent risk factors for DCI-related infarction while 'older age,' 'poor WFNS grade,' and 'reduced nimodipine dose' were associated with unfavorable outcome at 3 months after discharge. Nimodipine dose reduction during the high-risk period of DCI and CVS between days 5 and 10 after hemorrhage might abrogate the positive prognostic effects of nimodipine and should be critically evaluated.

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 Effect of Oral Nimodipine on Cerebral Metabolism and Hemodynamic Parameters in Patients Suffering Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION

Nimodipine is routinely administered to aneurysmal subarachnoid hemorrhage patients to improve functional outcomes. Nimodipine can induce marked systemic hypotension, which might impair cerebral perfusion and brain metabolism.

METHODS

Twenty-seven aneurysmal subarachnoid hemorrhage patients having multimodality neuromonitoring and oral nimodipine treatment as standard of care were included in this retrospective study. Alterations in mean arterial blood pressure (MAP), cerebral perfusion pressure (CPP), brain tissue oxygen tension (pbtO2), and brain metabolism (cerebral microdialysis), were investigated up to 120 minutes after oral administration of nimodipine (60 mg or 30 mg), using mixed linear models.

RESULTS

Three thousand four hundred twenty-five oral nimodipine administrations were investigated (126±59 administrations/patient). After 60 mg of oral nimodipine, there was an immediate statistically significant (but clinically irrelevant) drop in MAP (relative change, 0.97; P<0.001) and CPP (relative change: 0.97; P<0.001) compared with baseline, which lasted for the whole 120 minutes observation period (P<0.001). Subsequently, pbtO2 significantly decreased 50 minutes after administration (P=0.04) for the rest of the observation period; the maximum decrease was -0.6 mmHg after 100 minutes (P<0.001). None of the investigated cerebral metabolites (glucose, lactate, pyruvate, lactate/pyruvate ratio, glutamate, glycerol) changed after 60 mg nimodipine. Compared with 60 mg nimodipine, 30 mg induced a lower reduction in MAP (relative change, 1.01; P=0.02) and CPP (relative change, 1.01; P=0.03) but had similar effects on pbtO2 and cerebral metabolism (P>0.05).

CONCLUSIONS

Oral nimodipine reduced MAP, which translated into a reduction in cerebral perfusion and oxygenation. However, these changes are unlikely to be clinically relevant, as the absolute changes were minimal and did not impact cerebral metabolism.