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

Systemic tolerance of intravenous milrinone administration for cerebral vasospasm secondary to non-traumatic subarachnoid hemorrhage

PURPOSE

Delayed cerebral ischemia (DCI) is a severe subarachnoid hemorrhage (SAH) complication, closely related to cerebral vasospasm (CVS). CVS treatment frequently comprises intravenous milrinone, an inotropic and vasodilatory drug. Our objective is to describe milrinone's hemodynamic, respiratory and renal effects when administrated as treatment for CVS.

METHODS

Retrospective single-center observational study of patients receiving intravenous milrinone for CVS with systemic hemodynamics, oxygenation, renal disorders monitoring. We described these parameters' evolution before and after milrinone initiation (day - 1, baseline, day 1 and day 2), studied treatment cessation causes and assessed neurological outcome at 3-6 months.

RESULTS

Ninety-one patients were included. Milrinone initiation led to cardiac output increase (4.5 L/min [3.4-5.2] at baseline vs 6.6 L/min [5.2-7.7] at day 2, p < 0.001), Mean Arterial Pressure decrease (101 mmHg [94-110] at baseline vs 95 mmHg [85-102] at day 2, p = 0.001) norepinephrine treatment requirement increase (32% of patients before milrinone start vs 58% at day 1, p = 0.002) and slight PaO2/FiO2 ratio deterioration (401 [333-406] at baseline vs 348 [307-357] at day 2, p = 0.016). Milrinone was interrupted in 8% of patients. 55% had a favorable outcome.

CONCLUSION

Intravenous milrinone for CVS treatment seems associated with significant impact on systemic hemodynamics leading sometimes to treatment discontinuation.

CT perfusion-guided administration of IV milrinone is associated with a reduction in delayed cerebral infarction after subarachnoid hemorrhage

Delayed cerebral ischemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH) is a singular pathological entity necessitating early diagnostic approaches and both prophylactic and curative interventions. This retrospective before-after study investigates the effects of a management strategy integrating perfusion computed tomography (CTP), vigilant clinical monitoring and standardized systemic administration of milrinone on the occurrence of delayed cerebral infarction (DCIn). The "before" period included 277 patients, and the "after" one 453. There was a higher prevalence of Modified Fisher score III/IV and more frequent diagnosis of vasospasm in the "after" period. Conversely, the occurrence of DCIn was reduced with the "after" management strategy (adjusted OR 0.48, 95% CI [0.26; 0.84]). Notably, delayed ischemic neurologic deficits were less prevalent at the time of vasospasm diagnosis (24 vs 11%, p = 0.001 ), suggesting that CTP facilitated early detection. In patients diagnosed with vasospasm, intravenous milrinone was more frequently administered (80 vs 54%, p < 0.001 ) and associated with superior hemodynamics. The present study from a large cohort of aSAH patients suggests, for one part, the interest of CTP in early diagnosis of vasospasm and DCI, and for the other the efficacy of CT perfusion-guided systemic administration of milrinone in both preventing and treating DCIn.

Impact of Medical and Neurologic Complications on the Outcome of Patients with Aneurysmal Subarachnoid Hemorrhage in a Middle-Income Country

OBJECTIVE

Almost two thirds of the world's aneurysmal subarachnoid hemorrhage (aSAH) are in low- and middle-income countries. Herein, we aimed to evaluate the impact of complications on the outcome of aSAH in a middle-income country.

METHODS

Baseline data (age, sex, World Federation of Neurosurgical Society, time ictus-treatment, treatment modality) and medical and neurologic complications from a cohort in Brazil (2016-2019) were evaluated: delayed cerebral ischemia; hydrocephalus; meningitis; seizures; intracranial hypertension; infections (pneumonia, bloodstream, urinary tract infection infection of undetermined source); sodium disturbances; acute kidney injury; and cardiac and pulmonary complications. The primary outcome was the modified Rankin scale (mRS) at hospital discharge. Univariate and multivariate models were employed.

RESULTS

From 212 patients (71.7% female, age 52.7 ± 12.8), 92% developed at least 1 complication (any infection-43.9%, hydrocephalus-34.4%, intracranial hypertension-33%, infection of undetermined source-20.8%, hypernatremia-20.8%, hyponatremia-19.8%, delayed cerebral ischemia-related infarction-18.7%, pneumonia-18.4%, acute kidney injury-16.5%, and seizures-11.8%). In unadjusted analysis, all but hyponatremia and urinary tract infection were associated with mRS 3-6 at discharge; however, complications explained only 12% of the variation in functional outcome (mRS). Most patients were treated by clipping (66.5%), and 15.6% (33 patients) did not receive a definitive treatment. The median time ictus-admission and ictus-treatment were 5 and 9 days, respectively.

CONCLUSIONS

While medical and neurologic complications are a recognized opportunity to improve aSAH care, low- and middle-income countries comprise 70% of the world population and still encounter difficulties concerning early definitive aneurysm treatment, rebleeding, and human and material resources.

Management of neurological complications related to aneurysmal subarachnoid hemorrhage: A comparison of the bedside therapeutic algorithms

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is of the most serious emergencies in neurosurgical practice and continues to be associated with high morbidity and mortality. Beyond securing the ruptured aneurysm to prevent a rebleed, physicians continue to be concerned about potential complications such as cerebral vasospasm-delayed cerebral ischemia (DCI), an area where management remains highly variable. This study aimed at reviewing the most recent literature and assessing any up-to-date schemes for treating the most common aSAH neurological complications in adults that can be applied in daily clinical practice towards optimising outcomes.

METHODS

A systematic review was performed according to PRISMA guidelines on the management of aSAH neurological complications in adults. The literature surveyed was between 2016 and 2022 inclusive, using the Pubmed search engine. Comparisons between the methods suggested by existing therapeutic algorithms were discussed.

RESULTS

Six stepwise algorithms assisting the decision-making for treating cerebral vasospasm-DCI were recognised and compared. No algorithm was found for the management of any other neurological complications of aSAH. Despite differences in the algorithms, induced hypertension and endovascular therapy were common treatments in all approaches. Controversy in the therapeutic process of these complications surrounds not only the variability of methods but also their optimal application towards clinical outcome optimisation.

CONCLUSIONS

A universal approach to managing aSAH complications is lacking. Despite advances in the techniques to secure a ruptured aneurysm, there persist a high rate of neurological deficit and mortality, and several unanswered questions. More research is required towards stratification of current treatment algorithms as per the quality of their evidence.

Therapies for Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage

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

The Role of VASOGRADE as a Simple Grading Scale to Predict Delayed Cerebral Ischemia and Functional Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

The VASOGRADE is a simple aneurysmal subarachnoid hemorrhage (aSAH) grading scale that combines the modified Fisher scale (mFisher) and the World Federation of Neurological Societies (WFNS) grading system, allowing the stratification of delayed cerebral ischemia (DCI) risk. However, the VASOGRADE accuracy in predicting functional outcomes is still to be determined.

METHODS

We retrospectively evaluated a multiethnic cohort of consecutive patients with aSAH admitted to a high-volume center in Brazil from January 2016 to January 2019. Patients were classified according to the severity of the clinical presentation (WFNS), the amount of blood in the initial head computerized tomography (mFisher) scan, and the VASOGRADE (green, yellow, red). The primary outcome was to detect DCI-related cerebral infarction, and the secondary outcome was the functional outcome at hospital discharge according to the modified Rankin scale (mRs). Univariate and multivariate logistic regression models were employed.

RESULTS

A total of 212 patients (71.7% female, mean age 52.7 ± 12.8) were included. Sixty-nine patients were classified as VASOGRADE-Green (32.5%), 98 patients as VASOGRADE-Yellow (46.9%), and 45 patients as VASOGRADE-Red (20.6%). DCI-related infarction was present in 39 patients (18.9%). The proportions of patients in the VASOGRADE-Green, VASOGRADE-Yellow, and VASOGRADE-Red categories with DCI-related infarction were 7.7, 61.5, and 30.8%, respectively. After a multivariable analysis including age, sex, aneurysm location, and the VASOGRADE classification as variables, both VASOGRADE-Yellow and VASOGRADE-Red were independently associated with DCI-related infarction (odds ratio [OR] 7.69, 95% confidence interval [CI] 2.13-27.8, and OR 8.07, 95% CI 2.03-32.11, respectively) and unfavorable outcome (OR 4.16, 95% CI 1.33-13.03, and OR 25.57, 95% CI 4.45-147.1, respectively). The VASOGRADE discrimination performance for DCI-related infarction (area under the receiver operating characteristic curve) was 0.67 ± 0.04 (95% CI 0.58-0.75; p = 0.001). VASOGRADE-Red had 97.5% specificity for predicting an unfavorable mRs score at discharge (95% CI 92.8-99.5%). Conversely, VASOGRADE-Green had an excellent specificity for predicting favorable outcome at discharge (mRs score 0-2, 95% CI 82.6-95.5%).

CONCLUSIONS

In conclusion, in a multiethnic cohort of patients with aSAH, VASOGRADE-Green predicted the absence of DCI and good clinical outcome at discharge with very high specificity, and patients in this category might be selected for early intensive care unit (ICU) discharge, minimizing costs and medical complications associated with prolonged hospital stay. On the other hand, patients categorized as VASOGRADE-Yellow and VASOGRADE-Red were at the highest risk for DCI. They should, therefore, be selected as a priority for care in high-volume aSAH centers, being aggressively monitored for DCI at the ICU. Such stratification methods are crucial, especially in countries with low financial resources and high health care services demand.

Clinical Burden of Angiographic Vasospasm and Its Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

INTRODUCTION

Angiographic vasospasm (VSP), the narrowing of intracranial arteries, is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and often results in delayed cerebral ischemia (DCI) and cerebral infarction. The objective of this systematic review was to summarize the clinical burden of angiographic VSP and its related complications (DCI and cerebral infarction) after aSAH.

METHODS

Systematic searches of MEDLINE, Embase, and the Cochrane Library were conducted (in January 2021) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies reporting clinical outcomes of angiographic VSP and its related complications after aSAH. Study outcomes included measures of functional status (modified Rankin Scale [mRS], Glasgow Outcome Scale [GOS], extended Glasgow Outcome Scale [GOS-E], modified Barthel Index, or the modified National Institutes of Health Stroke Scale), cognitive status (Montreal Cognitive Assessment or the Mini Mental State Exam), clinical events (rebleeding), and mortality. Study selection, data extraction, and qualitative analyses were conducted.

RESULTS

Of 5704 abstracts reviewed, 110 studies were selected: 20 comparative and 39 regression-based studies were included in the qualitative synthesis, 51 descriptive studies were excluded. Most studies (51) were observational and conducted in a single country (53). The occurrence of angiographic VSP and its related complications after aSAH resulted in significantly poorer functional outcomes in three of nine comparative and 11 of 13 regression-based studies, measured by the mRS, and in five of six comparative and eight of nine regression-based studies, measured by the GOS and GOS-E. Angiographic VSP and its related complications were significantly associated with poor cognitive status in all five regression-based studies. Numerically or significantly higher mortality rates in patients with versus those without angiographic VSP and its related complications were reported in five of ten comparative studies and in eight of nine regression-based studies. Six studies looked at specific VSP populations (e.g., by severity or timing of VSP).

CONCLUSION

Patients with angiographic VSP and its related complications often had poor functional, neurological, and cognitive outcomes and reduced odds of survival both in hospital and at follow-up. We estimate that angiographic VSP and its related complications, DCI and cerebral infarction, lead to an approximately threefold higher odds of poor functional and cognitive outcomes, and about a twofold increase in the odds of death.

Intravenous milrinone for delayed cerebral ischaemia in aneurysmal subarachnoid haemorrhage: a systematic review

BACKGROUND

Aneurysmal subarachnoid haemorrhage (aSAH) is a major contributor to mortality worldwide, with delayed cerebral ischaemia (DCI) contributing significantly to morbidity in these patients. There are limited evidence-based therapies for DCI. A 2012 case series first recommended the use of intravenous (IV) milrinone in this patient population, stating the need for formal prospective trials. However, uptake of this therapy into clinical practice has proceeded without adequate studies for efficacy and safety.

METHODS

We sought to determine the effect of IV milrinone on DCI in patients with aSAH in terms of functional outcome through a systematic review using Embase, MEDLINE, and Cochrane Library databases. Quality assessment was performed using MINORS criteria.

RESULTS

A total of 2429 studies were screened, with ten studies included in the review. Of these, no randomized trials were identified. Three observational comparative studies were included, and the remaining seven studies were non-comparative in nature, and mainly retrospective. Overall, the quality of evidence for non-comparative studies was poor.

CONCLUSIONS

This study reveals a paucity of evidence in the literature and highlights the need for high-quality randomized trials to investigate the safety and efficacy of IV milrinone, a commonly utilized treatment in critically ill aSAH patients with DCI. Ultimately, without evidence of efficacy and absence of harm, we caution continued use of intravenous milrinone for the treatment of DCI.

Effect of inotropic agents on oxygenation and cerebral perfusion in acute brain injury

Introduction

Tissue hypoxia and insufficient energy delivery is one of the mechanisms behind the occurrence of several complications in acute brain injured patients. Several interventions can improve cerebral oxygenation; however, the effects of inotropic agents remain poorly characterized.

Methods

Retrospective analysis including patients suffering from acute brain injury and monitored with brain oxygen pressure (PbtO2) catheter, in whom inotropic agents were administered according to the decision of the treating physician's decision; PbtO2 values were collected before, 1 and 2 h after the initiation of therapy from the patient data monitoring system. PbtO2 “responders” were patients with a relative increase in PbtO2 from baseline values of at least 20%.

Results

A total of 35 patients were included in this study. Most of them (31/35, 89%) suffered from non-traumatic subarachnoid hemorrhage (SAH). Compared with baseline values [20 (14–24) mmHg], PbtO2 did not significantly increase over time [19 (15–25) mmHg at 1 h and 19 (17–25) mmHg at 2 h, respectively; p = 0.052]. A total of 12/35 (34%) patients were PbtO2 “responders,” in particular if low PbtO2 was observed at baseline. A PbtO2 of 17 mmHg at baseline had a sensibility of 84% and a specificity of 91% to predict a PbtO2 responder. A significant direct correlation between changes in PbtO2 and cardiac output [r = 0.496 (95% CI 0.122 to 0.746), p = 0.01; n = 25] and a significant negative correlation between changes in PbtO2 and cerebral perfusion pressure [r = −0.389 (95% CI −0.681 to −0.010), p = 0.05] were observed.

Conclusions

In this study, inotropic administration significantly increased brain oxygenation in one third of brain injured patients, especially when tissue hypoxia was present at baseline. Future studies should highlight the role of inotropic agents in the management of tissue hypoxia in this setting.

Updates on aneurysmal subarachnoid hemorrhage: is there anything really new?

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe disease, with systemic involvement and complex diagnosis and treatment. Since the current guidelines were published by the AHA/ASA, Neurocritical Care Society and the European Stroke Organization in 2012-2013,there has been an evolution in the comprehension of SAH-associated brain injury and its multiple underlying mechanisms. As a result, several clinical and translational trials were developed or are underway. Objective: The aim of this article is to review some updates in the diagnosis and treatment of neurological complications of SAH. Methods: A review of PubMed (May, 2010 to February, 2022) was performed. Data was summarized. Results: Content of five meta-analyses, nine review articles and 23 new clinical trials, including pilots, were summarized. Conclusions:Advances in the comprehension of pathophysiology and improvements in critical care have been reflected in the reduction of mortality in SAH. However, despite the number of publications, the only treatments shown to be effective in adequate, well-controlled clinical trials are nimodipine and repair of the ruptured aneurysm. Thus, doubts about the optimal management of SAH still persist.

Subarachnoid Hemorrhage, Delayed Cerebral Ischemia and Milrinone Use in Canada

INTRODUCTION

Delayed cerebral ischemia (DCI) is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and is associated with significant morbidity and mortality. There is little high-quality evidence available to guide the management of DCI. The Canadian Neurosurgery Research Collaborative (CNRC) is comprised of resident physicians who are positioned to capture national, multi-site data. The objective of this study was to evaluate practice patterns of Canadian physicians regarding the management of aSAH and DCI.

METHODS

We performed a cross-sectional survey of Canadian neurosurgeons, intensivists, and neurologists who manage aSAH. A 19-question electronic survey (Survey Monkey) was developed and validated by the CNRC following a DCI-related literature review (PubMed, Embase). The survey was distributed to members of the Canadian Neurosurgical Society and to Canadian members of the Neurocritical Care Society. Responses were analyzed using quantitative and qualitative methods.

RESULTS

The response rate was 129/340 (38%). Agreement among respondents was limited to the need for intensive care unit admission, use of clinical and radiographic monitoring, and prophylaxis for the prevention of DCI. Several inconsistencies were identified. Indications for starting hyperdynamic therapy varied. There was discrepancy in the proportion of patients who felt to require IV milrinone, IA vasodilators, or physical angioplasty for treatment of DCI. Most respondents reported their facility does not utilize a standardized definition for DCI.

CONCLUSION

DCI is an important clinical entity for which no homogeneity and standardization exists in management among Canadian practitioners. The CNRC calls for the development of national standards in the definition, identification, and treatment of DCI.

Left Ventricular Outflow Tract Obstruction in Patients Treated With Milrinone for Cerebral Vasospasm: Case Report and Literature Review

Subarachnoid hemorrhage is associated with high morbidity and mortality, and cerebral arterial vasospasm is one of its main complications that determines neurological prognosis. The use of intravenous milrinone is becoming more common in the treatment of vasospasm. This molecule has positive inotropic and vasodilating properties by inhibiting phosphodiesterase-3. Its most described side effects are cardiac arrhythmias and arterial hypotension. In this paper, we raise a new issue concerning milrinone and discuss an undescribed side effect of this treatment, left ventricular outflow tract obstruction (LVOTO). Dynamic LVOTO is a clinical situation favored by hypovolemia, decreased left ventricular afterload, and excessive inotropism that can lead to severe hemodynamic failure and pulmonary edema. To our knowledge, this is the first study describing milrinone-induced LVOTO. This could compromise cerebral perfusion and therefore the neurological prognosis of patients. While it is known that catecholamines may induce LVOTO, milrinone-induced LVOTO appears to be a new pathophysiological entity of which neurosurgical intensivists should be aware.

Cerebral vasospasm in children with subarachnoid hemorrhage: frequency, diagnosis, and therapeutic management

BACKGROUND

The present study explores the frequency, diagnostic approach, and therapeutic management of cerebral vasospasm in a cohort of children with moderate-to-severe traumatic and nontraumatic subarachnoid hemorrhage (SAH).

METHODS

This was a single-center retrospective study performed over a 10-year period, from January 2010 to December 2019. Children aged from one month to 18 years who were admitted to the pediatric or adult intensive care unit with a diagnosis of SAH were eligible. Cerebral vasospasm could be suspected by clinical signs or transcranial Doppler (TCD) criteria (mean blood flow velocity > 120 cm/s or an increase in mean blood flow velocity by > 50 cm/s within 24 h) and then confirmed on cerebral imaging (with a reduction to less than 50% of the caliber of the cerebral artery).

RESULTS

Eighty patients aged 8.6 years (3.3-14.8 years, 25-75th centiles) were admitted with an initial Glasgow Coma Scale score of 8 (4-12). SAH was nontraumatic in 21 (26%) patients. A total of 14/80 patients (18%) developed cerebral vasospasm on brain imaging on day 6 (5-10) after admission, with a predominance of nontraumatic SAH (12/14). The diagnosis of cerebral vasospasm was suspected on clinical signs and/or significant temporal changes in TCD monitoring (7 patients) and then confirmed on cerebral imaging. Thirteen of 14 patients with vasospasm were successfully treated using a continuous intravenous infusion of milrinone. The Pediatric Cerebral Performance Category score at discharge from the intensive care unit was comparable between children with vasospasm (score of 2 [1-4]) vs. children without vasospasm (score of 4 [2-4]) (p = 0.09).

CONCLUSIONS

These findings indicate that cerebral vasospasm exists in pediatrics, particularly after nontraumatic SAH. The use of TCD and milrinone may help in the diagnostic and therapeutic management of cerebral vasospasm.

Intravenous Milrinone for Cerebral Vasospasm in Subarachnoid Hemorrhage: The MILRISPASM Controlled Before-After Study

BACKGROUND

Intravenous (IV) milrinone, in combination with induced hypertension, has been proposed as a treatment option for cerebral vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). However, data on its safety and efficacy are scarce.

METHODS

This was a controlled observational study conducted in an academic hospital with prospectively and retrospectively collected data. Consecutive patients with cerebral vasospasm following aSAH and treated with both IV milrinone (0.5 µg/kg/min^-1, as part of a strict protocol) and induced hypertension were compared with a historical control group receiving hypertension alone. Multivariable analyses aimed at minimizing potential biases. We assessed (1) 6-month functional disability (defined as a score between 2 and 6 on the modified Rankin Scale) and vasospasm-related brain infarction, (2) the rate of first-line or rescue endovascular angioplasty for vasospasm, and (3) immediate tolerance to IV milrinone.

RESULTS

Ninety-four patients were included (41 and 53 in the IV milrinone and the control group, respectively). IV milrinone infusion was independently associated with a lower likelihood of 6-month functional disability (adjusted odds ratio [aOR] = 0.28, 95% confidence interval [CI] = 0.10-0.77]) and vasospasm-related brain infarction (aOR = 0.19, 95% CI 0.04-0.94). Endovascular angioplasty was less frequent in the IV milrinone group (6 [15%] vs. 28 [53%] patients, p = 0.0001, aOR = 0.12, 95% CI 0.04-0.38). IV milrinone (median duration of infusion, 5 [2-8] days) was prematurely discontinued owing to poor tolerance in 12 patients, mostly (n = 10) for "non/hardly-attained induced hypertension" (mean arterial blood pressure < 100 mmHg despite 1.5 µg/kg/min^-1 of norepinephrine). However, this event was similarly observed in IV milrinone and control patients (n = 10 [24%] vs. n = 11 [21%], respectively, p = 0.68). IV milrinone was associated with a higher incidence of polyuria (IV milrinone patients had creatinine clearance of 191 [153-238] ml/min^-1) and hyponatremia or hypokalemia, whereas arrhythmia, myocardial ischemia, and thrombocytopenia were infrequent.

CONCLUSIONS

Despite its premature discontinuation in 29% of patients as a result of its poor tolerance, IV milrinone was associated with a lower rate of endovascular angioplasty and a positive impact on long-term neurological and radiological outcomes. These preliminary findings encourage the conduction of confirmatory randomized trials.

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.

Kinetics of cerebral blood flow velocities during treatment for delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage

BACKGROUND

In aneurysmal subarachnoid hemorrhage (aSAH), one of the main determinants of prognosis is delayed cerebral ischemia (DCI). Transcranial Doppler (TCD) is used to monitor vasospasm and DCI. We aimed to better understand cerebral hemodynamics response to hypertension induction (HI) with norepinephrine (NE) and inotropic therapy with milrinone so that TCD can be a bedside tool in helping to guide DCI therapies. Our primary objective was to determine TCD blood flow velocity (BFV) kinetics during HI and inotropic therapy for DCI treatment. Secondly, we performed an analysis by treatment subgroups and evaluated clinical response to therapies.

METHODS

We performed a prospective observational cohort study in a Brazilian high-volume center for aSAH. Patients with aSAH admitted between 2016 and 2018 who received NE or milrinone for DCI treatment were included. TCDs were performed before therapy initiation (t0) and 45 (t1) and 90 min (t2) from the onset of therapy. For each DCI event, we analyzed the highest mean flow velocity (MFV) and the mean MFV and compared their kinetics over time. The National Institutes of Health Stroke Scale was determined at t0, t1, and t2.

RESULTS

Ninety-eight patients with aSAH were admitted during the study period. Twenty-one (21.4%) developed DCI, of whom six had DCI twice, leading to a total of 27 analyzed DCI events (12 treated with HI and 15 with milrinone). Patients treated with NE had their mean arterial pressure raised (85 mm Hg in t0, 112 mm Hg in t2 [p < 0.001]), whereas those treated with milrinone had a significant decrease in mean arterial pressure over treatment (94 mm Hg in t0, 88 mm Hg in t2 [p = 0.004]). Among all treated patients, there was a significant drop from t0 to t2 but not to t1 in the highest MFV and in the highest mean MFV. Among those treated with HI, there were no significant changes from t0 to t1 or t2 (highest MFV in t0 163.2 cm/s, in t1 172.9 cm/s [p = 0.27], and in t2 164 cm/s [p = 0.936]). Conversely, in those treated with milrinone, there was a significant decrease from t0 to t1 and to t2 (highest MFV in t0 197.1 cm/s, in t1 172.8 cm/s [p = 0.012], in t2 159 cm/s [p = 0.002]). Regarding clinical outcomes, we observed a significant improvement in mean National Institutes of Health Stroke Scale scores from 17 to 16 in t1 (p < 0.001) and to 15 in t2 (p = 0.002).

CONCLUSIONS

BFV analyzed by TCD in patients with aSAH who developed DCI and were treated with milrinone or NE significantly decreased in a time-dependent way. Milrinone effectively decrease cerebral BFV, whereas NE do not. Clinical improvement was achieved with both treatment strategies.

Treatment of Subarachnoid Hemorrhage-associated Delayed Cerebral Ischemia With Milrinone: A Review and Proposal

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage continues to be associated with high levels of morbidity and mortality. This complication had long been thought to occur secondary to severe cerebral vasospasm, but expert opinion now favors a multifactorial etiology, opening the possibility of new therapies. To date, no definitive treatment option for DCI has been recommended as standard of care, highlighting a need for further research into potential therapies. Milrinone has been identified as a promising therapeutic agent for DCI, possessing a mechanism of action for the reversal of cerebral vasospasm as well as potentially anti-inflammatory effects to treat the underlying etiology of DCI. Intra-arterial and intravenous administration of milrinone has been evaluated for the treatment of DCI in single-center case series and cohorts and appears safe and associated with improved clinical outcomes. Recent results have also brought attention to the potential outcome benefits of early, more aggressive dosing and titration of milrinone. Limitations exist within the available data, however, and questions remain about the generalizability of results across a broader spectrum of patients suffering from DCI. The development of a standardized protocol for milrinone use in DCI, specifically addressing areas requiring further clarification, is needed. Data generated from a standardized protocol may provide the impetus for a multicenter, randomized control trial. We review the current literature on milrinone for the treatment of DCI and propose a preliminary standardized protocol for further evaluation of both safety and efficacy of milrinone.

The Use of Standardized Management Protocols for Critically Ill Patients with Non-traumatic Subarachnoid Hemorrhage: A Systematic Review

The use of standardized management protocols (SMPs) may improve patient outcomes for some critical care diseases. Whether SMPs improve outcomes after subarachnoid hemorrhage (SAH) is currently unknown. We aimed to study the effect of SMPs on 6-month mortality and neurologic outcomes following SAH. A systematic review of randomized control trials (RCTs) and observational studies was performed by searching multiple indexing databases from their inception through January 2019. Studies were limited to adult patients (age ≥ 18) with non-traumatic SAH reporting mortality, neurologic outcomes, delayed cerebral ischemia (DCI) and other important complications. Data on patient and SMP characteristics, outcomes and methodologic quality were extracted into a pre-piloted collection form. Methodologic quality of observational studies was assessed using the Newcastle-Ottawa scale, and RCT quality was reported as per the Cochrane risk of bias tool. A total of 11,260 studies were identified, of which 37 (34 full-length articles and 3 abstracts) met the criteria for inclusion. Two studies were RCTs and 35 were observational. SMPs were divided into four broad domains: management of acute SAH, early brain injury, DCI and general neurocritical care. The most common SMP design was control of DCI, with 22 studies assessing this domain of care. Overall, studies were of low quality; most described single-center case series with small patient sizes. Definitions of key terms and outcome reporting practices varied significantly between studies. DCI and neurologic outcomes in particular were defined inconsistently, leading to significant challenges in their interpretation. Given the substantial heterogeneity in reporting practices between studies, a meta-analysis for 6-month mortality and neurologic outcomes could not be performed, and the effect of SMPs on these measures thus remains inconclusive. Our systematic review highlights the need for large, rigorous RCTs to determine whether providing standardized, best-practice management through the use of a protocol impacts outcomes in critically ill patients with SAH.Trial registration Registration number: CRD42017069173.

Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a neurologic emergency that requires immediate patient stabilization and prompt diagnosis and treatment. Early measures should focus on principles of advanced cardiovascular life support. The aneurysm should be evaluated and treated in a comprehensive stroke center by a multidisciplinary team capable of endovascular and, operative approaches. Once the aneurysm is secured, the patient is best managed by a dedicated neurocritical care service to prevent and manage complications, including a syndrome of delayed neurologic decline. The goal of such specialized care is to prevent secondary injury, reduce length of stay, and improve outcomes for survivors of the disease.

Long-term outcome in patients with aneurysmal subarachnoid hemorrhage requiring mechanical ventilation

BACKGROUND

Patients affected with aneurysmal subarachnoid hemorrhage (aSAH) often require intensive care, and then present distinctive outcome from less severe patients. We aimed to specify their long-term outcome and to identify factors associated with poor outcome.

METHODS

We conducted a retrospective study in a French university hospital intensive care unit. Patients with aSAH requiring mechanical ventilation hospitalized between 2010 and 2015 were included. At least one year after initial bleeding, survival and degree of disability were assessed using the modified Rankin Scale (mRS) via telephone interviews. A multivariable logistic regression analysis was performed to determine independent factors associated with poor outcome defined as mRS≥3.

RESULTS

Two-hundred thirty-six patients were included. Among them, 7 were lost to follow-up, and 229 were analyzed: 73 patients (32%) had a good outcome (mRS<3), and 156 (68%) had a poor outcome (mRS≥3). The estimated 1-year survival rate was 63%. One-hundred sixty-three patients patients (71%) suffered from early brain injuries (EBI), 33 (14%) from rebleeding, 80 (35%) from vasospasm and 63 (27%) from delayed cerebral ischemia (DCI). Multivariable logistic regression identified independent factors associated with poor outcome including delay between aSAH diagnosis and mRS assessment (OR, 0.96; 95% CI, 0.95-0.98; p<.0001), age (OR per 10 points, 1.57; 95% CI, 1.12-2.19; p = 0.008), WFNS V versus WFNS III (OR, 5.71; 95% CI 1.51-21.61; p = 0.004), subarachnoid rebleeding (OR, 6.47; 95% CI 1.16-36.06; p = 0.033), EBI (OR, 4.52; 95% CI 1.81-11.29; p = 0.001) and DCI (OR, 4.73; 95% CI, 1.66-13.49; p = 0.004).

CONCLUSION

Among aSAH patients requiring assisted ventilation, two-third of them survived at one year, and one-third showed good long-term outcome. As it appears as an independant factor associated with poor outcome, DCI shoud retain particular attention in future studies beyond angiographic vasospasm.

Intravenous milrinone for treatment of delayed cerebral ischaemia following subarachnoid haemorrhage: a pooled systematic review

Small trials have demonstrated promising results utilising intravenous milrinone for the treatment of delayed cerebral ischaemia (DCI) after subarachnoid haemorrhage (SAH). Here we summarise and contextualise the literature and discuss the future directions of intravenous milrinone for DCI. A systematic, pooled analysis of literature was performed in accordance with the PRISMA statement. Methodological rigour was analysed using the MINORS criteria. Extracted data included patient population; treatment protocol; and clinical, radiological, and functional outcome. The primary outcome was clinical resolution of DCI. Eight hundred eighteen patients from 10 single-centre, observational studies were identified. Half (n = 5) of the studies were prospective and all were at high risk of bias. Mean age was 52 years, and females (69%) outnumbered males. There was a similar proportion of low-grade (WFNS 1-2) (49.7%) and high-grade (WFNS 3-5) (50.3%) SAH. Intravenous milrinone was administered to 523/818 (63.9%) participants. Clinical resolution of DCI was achieved in 375/424 (88%), with similar rates demonstrated with intravenous (291/330, 88%) and combined intra-arterial-intravenous (84/94, 89%) therapy. Angiographic response was seen in 165/234 (71%) receiving intravenous milrinone. Hypotension (70/303, 23%) and hypokalaemia (31/287, 11%) were common drug effects. Four cases (0.5%) of drug intolerance occurred. Good functional outcome was achieved in 271/364 (74%) patients. Cerebral infarction attributable to DCI occurred in 47/250 (19%), with lower rates in asymptomatic spasm. Intravenous milrinone is a safe and feasible therapy for DCI. A signal for efficacy is demonstrated in small, low-quality trials. Future research should endeavour to establish the optimal protocol and dose, prior to a phase-3 study.

Neurovascular disease, diagnosis, and therapy: Subarachnoid hemorrhage and cerebral vasospasm

The worldwide incidence of spontaneous subarachnoid hemorrhage is about 6.1 per 100,000 cases per year (Etminan et al., 2019). Eighty-five percent of cases are due to intracranial aneurysms. The mean age of those affected is 55 years, and two-thirds of the patients are female. The prognosis is related mainly to the neurologic condition after the subarachnoid hemorrhage and the age of the patient. Overall, 15% of patients die before reaching the hospital, another 20% die within 30 days, and overall 75% are dead or remain disabled. Case fatality has declined by 17% over the last 3 decades. Despite the improvement in outcome probably due to improved diagnosis, early aneurysm repair, administration of nimodipine, and advanced intensive care support, the outcome is not very good. Even among survivors, 75% have permanent cognitive deficits, mood disorders, fatigue, inability to return to work, and executive dysfunction and are often unable to return to their premorbid level of functioning. The key diagnostic test is computed tomography, and the treatments that are most strongly supported by scientific evidence are to undertake aneurysm repair in a timely fashion by endovascular coiling rather than neurosurgical clipping when feasible and to administer enteral nimodipine. The most common complications are aneurysm rebleeding, hydrocephalus, delayed cerebral ischemia, and medical complications (fever, anemia, and hyperglycemia). Management also probably is optimized by neurologic intensive care units and multidisciplinary teams.

Milrinone Ameliorates the Neuroinflammation and Memory Function of Alzheimer's Disease in an APP/PS1 Mouse Model

PURPOSE

Alzheimer's disease (AD) is a complex neurodegenerative disorder, which is characterized by memory loss and cognitive deficits. The neuroprotective role of milrinone on the injury of spinal cord or cerebral ischemia-reperfusion has been confirmed. However, the accurate function of milrinone on AD pathogeny is still unclear.

METHODS

APP/PS1 transgenic mouse was used to explore the role of milrinone in behaviour tests, and the effects on histopathologic features of AD such as the formation of neuronal amyloid-β (Aβ) plaque, microglial activation, tau protein hyperphosphorylation, oxidative stress, and neuroinflammation. Lipopolysaccharide (LPS)/Aβ-treated BV-2 cells were used to understand the anti-inflammation mechanism of milrinone on AD in vitro.

RESULTS

Our in vivo results showed that milrinone ameliorates the memory functions of AD mice. Meanwhile, milrinone reduced Aβ deposits, repressed microglial activation and tau protein hyperphosphorylation, attenuated the oxidative stress, and decreased the levels of inflammatory cytokines. The in vitro results demonstrated that milrinone could inhibit the secretion of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α via regulation of NLRP3 inflammasomes and TLR4/MyD88/NF-κB signalling pathway.

CONCLUSION

Overall, milrinone could ameliorate the memory loss and cognitive deficits through repressing the multiple pathological processes of AD, suggesting that milrinone may be an underlying and effective drug for treating AD clinically.

Neuroinflammation and Microvascular Dysfunction After Experimental Subarachnoid Hemorrhage: Emerging Components of Early Brain Injury Related to Outcome

Aneurysmal subarachnoid hemorrhage has a high mortality rate and, for those who survive this devastating injury, can lead to lifelong impairment. Clinical trials have demonstrated that cerebral vasospasm of larger extraparenchymal vessels is not the sole contributor to neurological outcome. Recently, the focus of intense investigation has turned to mechanisms of early brain injury that may play a larger role in outcome, including neuroinflammation and microvascular dysfunction. Extravasated blood after aneurysm rupture results in a robust inflammatory response characterized by activation of microglia, upregulation of cellular adhesion molecules, recruitment of peripheral immune cells, as well as impaired neurovascular coupling, disruption of the blood-brain barrier, and imbalances in endogenous vasodilators and vasoconstrictors. Each of these phenomena is either directly or indirectly associated with neuronal death and brain injury. Here, we review recent studies investigating these various mechanisms in experimental models of subarachnoid hemorrhage with special emphasis on neuroinflammation and its effect on microvascular dysfunction. We discuss the various therapeutic targets that have risen from these mechanistic studies and suggest the utility of a multi-targeted approach to preventing delayed injury and improving outcome after subarachnoid hemorrhage.

Optimal intracranial pressure in patients with aneurysmal subarachnoid hemorrhage treated with coiling and requiring external ventricular drainage

Optimal management of intracranial pressure (ICP) among aneurysmal subarachnoid hemorrhage (aSAH) patients requiring external ventricular drainage (EVD) is controversial. To analyze predictors of delayed cerebral ischemia (DCI)-related cerebral infarction after aSAH and the influence of ICP values on DCI, we prospectively collected consecutive patients with aSAH receiving coiling and requiring EVD. Predictors of DCI-related cerebral infarction (new CT hypodensities developed within the first 3 weeks not related to other causes) were studied. Vasospasm and brain hypoperfusion were studied with CT angiography and CT perfusion (RAPID-software). Among 50 aSAH patients requiring EVD, 21 (42%) developed DCI-related cerebral infarction, while 27 (54%) presented vasospasm. Mean ICP ranged between 2 and 19 mmHg. On the multivariate analysis, the mean ICP (OR = 2, 95%CI = 1.01-3.9, p = 0.042) and the mean hypoperfusion volume on Tmax delay > 6 (OR = 1.2, 95%CI = 1.01-1.3, p = 0.025) were independent predictors of DCI. To predict DCI-related cerebral infarction, Tmax delay > 6 s presented the highest AUC (0.956, SE = 0.025), with a cutoff value of 18 ml showing sensitivity, specificity, PPV, NPV, and accuracy of 90.5% (95%CI = 69-98.8%), 86.2% (95%CI = 68.4-96%), 82.6% (95%CI = 65.4-92%), 92.5% (95%CI = 77-98%), and 88% (95%CI = 75-95%), respectively. The AUC of the mean ICP was 0.825 (SE = 0.057), and the best cutoff value was 6.7 mmHg providing sensitivity, specificity, PPV, NPV, and accuracy of 71.4% (95%CI = 48-89%), 62% (95%CI = 42-79%), 58% (95%CI = 44-70%), 75% (95%CI = 59-86%), and 66% (95%CI = 51-79%) for the prediction of DCI-related cerebral infarction, respectively. Among aSAH patients receiving coiling and EVD, lower ICP (< 6.7 mmHg in our study) could potentially be beneficial in decreasing DCI-related cerebral infarction. Brain hypoperfusion with a volume > 18 ml at Tmax delay > 6 s presents a high sensibility and specificity in prediction of DCI-related cerebral infarction.

Milrinone for refractory cerebral vasospasm with delayed cerebral ischemia

OBJECTIVE

Intravenous (IV) milrinone is a promising option for the treatment of cerebral vasospasm with delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH). However, data remain limited on the efficacy of treating cases that are refractory to standard therapy with IV milrinone. The aim of this study was to determine predictors of refractory vasospasm/DCI despite treatment with IV milrinone, and to analyze the outcome of rescue therapy with intraarterial (IA) milrinone and/or mechanical angioplasty.

METHODS

The authors conducted a retrospective cohort study of all patients with aSAH admitted between 2010 and 2016 to the Montreal Neurological Institute and Hospital. Patients were stratified into 3 groups: no DCI, standard therapy, and rescue therapy. The primary outcome was frequency of DCI-related cerebral infarction identified on neuroimaging before hospital discharge. Secondary outcomes included functional outcome reported as modified Rankin Scale (mRS) score, and segment reversal of refractory vasospasm.

RESULTS

The cohort included 322 patients: 212 in the no DCI group, 89 in the standard therapy group, and 21 in the rescue therapy group. Approximately half (52%, 168/322) were admitted with poor-grade aSAH at treatment decision (World Federation of Neurosurgical Societies grade III-V). Among patients with DCI and imaging assessing severity of vasospasm, 62% (68/109) had moderate/severe radiological vasospasm on DCI presentation. Nineteen percent (21/110) of patients had refractory vasospasm/DCI and were treated with rescue therapy. Targeted rescue therapy with IA milrinone reversed 32% (29/91) of the refractory vasospastic vessels, and 76% (16/21) of those patients experienced significant improvement in their neurological status within 24 hours of initiating therapy. Moderate/severe radiological vasospasm independently predicted the need for rescue therapy (OR 27, 95% CI 8.01-112). Of patients with neuroimaging before discharge, 40% (112/277) had developed new cerebral infarcts, and only 21% (23/112) of these were vasospasm-related. Overall, 65% (204/314) of patients had a favorable functional outcome (mRS score 0-2) assessed at a median of 4 months (interquartile range 2-8 months) after aSAH, and there was no difference in functional outcome between the 3 groups (p = 0.512).

CONCLUSIONS

The aggressive use of milrinone was safe and effective based on this retrospective study cohort and is a promising therapy for the treatment of vasospasm/DCI after aSAH.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Efficacy and safety of milrinone in the treatment of cerebral vasospasm after subarachnoid hemorrhage: a systematic review

Objective

To systematically review the current evidence on the efficacy of milrinone in the treatment of cerebral vasospasm after subarachnoid hemorrhage.

Methods

The Pubmed^®, Cochrane and Embase databases were screened for articles published from April 2001 to February 2019. Two independent reviewers performed the methodological quality screening and data extraction of the studies.

Results

Twenty-two studies were found to be relevant, and only one of these was a randomized control trial. Studies showed marked heterogeneity and weaknesses in key methodological criteria. Most patients presented with moderate to severe vasospasm. Angiography was the main method of diagnosing vasospasm. Intra-arterial administration of milrinone was performed in three studies, intravenous administration was performed in nine studies, and both routes of administration in six studies; the intrathecal route was used in two studies, the cisternal route in one study and endovascular administration in one study. The side effects of milrinone were described in six studies. Twenty-one studies indicated resolution of vasospasm.

Conclusion

The current evidence indicates that milrinone may have a role in treatment of vasospasm after aneurysmal subarachnoid hemorrhage. However, only one randomized control trial was performed, with a low quality level. Our findings indicate the need for future randomized control trials with patient-centered outcomes to provide definitive recommendations.

Which Protocol for Milrinone to Treat Cerebral Vasospasm Associated With Subarachnoid Hemorrhage?

BACKGROUND

Milrinone has emerged as an option to treat delayed cerebral ischemia after subarachnoid hemorrhage. However, substantial variation exists in the administration of this drug. We retrospectively assessed the effectiveness of 2 protocols in patients with angiographically proven cerebral vasospasm.

METHODS

During 2 successive periods, milrinone was administered using either a combination of intra-arterial milrinone infusion followed by intravenous administration until day 14 after initial bleeding (IA+IV protocol), or a continuous intravenous milrinone infusion for at least 7 days (IV protocol). The primary endpoint was the reversion rate of vasospastic arterial segments following the first IA infusion of milrinone (IA+IV protocol) compared with the reversion rate during the first week of IV infusion (IV protocol).

RESULTS

There were 24 and 77 consecutive patients in IA+IV and IV protocols, respectively. The reversion rate was comparable between the 2 protocols: 71% (95% confidence interval [CI], 59%-83%) in the IA+IV protocol versus 64% (95% CI, 58%-71%) in the IV protocol (P=0.36). Rescue procedures for persistence or recurrence of vasospasm, that is, mechanical angioplasty and/or IA milrinone infusion, were similar between the 2 protocols. Patients with a good neurological outcome at 1 year, that is, modified Rankin Scale scores 0-2, were comparable between the 2 protocols. Side effects of milrinone were uncommon and equally distributed within the 2 protocols.

CONCLUSIONS

These findings indicate that a continuous IV infusion of milrinone was as efficient as combined IA+IV infusion and suggest that this modality could be considered as a first easy-to-use option to treat patients with CVS.

Aneurysmal subarachnoid hemorrhage: current concepts and updates

ABSTRACT Aneurysmal subarachnoid hemorrhage is a condition with a considerable incidence variation worldwide. In Brazil, the exact epidemiology of aneurysmal SAH is unknown. The most common presenting symptom is headache, usually described as the worst headache ever felt. Head computed tomography, when performed within six hours of the ictus, has a sensitivity of nearly 100%. It is important to classify the hemorrhage based on clinical and imaging features as a way to standardize communication. Classification also has prognostic value. In order to prevent rebleeding, there still is controversy regarding the ideal blood pressure levels and the use of antifibrinolytic therapy. The importance of definitely securing the aneurysm by endovascular coiling or surgical clipping cannot be overemphasized. Hydrocephalus, seizures, and intracranial pressure should also be managed. Delayed cerebral ischemia is a severe complication that should be prevented and treated aggressively. Systemic complications including cardiac and pulmonary issues, sodium abnormalities, fever, and thromboembolism frequently happen and may have na impact upon prognosis, requiring proper management.

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.

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.

Intravenous Milrinone Salvage Therapy in Acute Internal Carotid Artery Occlusion: Case Report

Introduction

Acute internal carotid artery occlusion is a devastating form of ischemic accident with significant morbidity and possible mortality. The “threatened hemisphere” is allowed limited access to collateral circulation further worsening the ischemic burden and the overall prognosis.

Methods

We present the details of a case of a 38-year-old woman who suffered from an ischemic stroke. The clinical course of which showed a hemodynamic dependence to preserve her neurological function, prompting the use of the phosphodiesterase inhibitor milrinone to maintain her neurological function.

Result

This case represents the first case in the literature in which a medical therapy is used to salvage brain tissue in the site of acute symptomatic large vessel occlusion. This has spared the patient from a potential significant morbidity and even mortality if a revascularization procedure had been attempted.

Conclusion

This innovative use of milrinone, if applied in more captured patients with internal carotid occlusion or those with reversible hemodynamic failure, would improve our understanding of the ischemic thresholds and cerebral vascular reserves and would improve the clinical outcome of this significant ischemic insult.

[Effect of magnesium sulphate and milrinone on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a randomized study]

BACKGROUND

Aneurysmal subarachnoid hemorrhage is an important cause of premature death and disability worldwide. Magnesium sulphate is shown to have a neuroprotective effect and it reverses cerebral vasospasm. Milrinone is also used in the treatment of cerebral vasospasm. The aim of the present study was to compare the effect of prophylactic magnesium sulphate and milrinone on the incidence of cerebral vasospasm after subarachnoid hemorrhage.

METHODS

The study included 90 patients with aneurysmal subarachnoid hemorrhage classified randomly (by simple randomization) into two groups: magnesium sulphate was given as an infusion of 500mg.day^-1 without loading dose for 21 days. Group B: milrinone was given as an infusion of 0.5μg.kg^-1.min^-1 without loading dose for 21 days. The cerebral vasospasm was diagnosed by mean cerebral blood flow velocity in the involved cerebral artery (mean flow velocity≥120cm.s^-1), neurological deterioration by Glasgow coma scale, or angiography (the decrease in diameter of the involved cerebral artery >25%).

RESULTS

The mean cerebral blood flow velocity decreased significantly in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p<0.001). The incidence of cerebral vasospasm decreased significantly with magnesium compared to milrinone (p=0.007). The Glasgow coma scale significantly improved in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p=0.036, p=0.012, p=0.016, respectively). The incidence of hypotension was higher with milrinone than magnesium (p=0.012).

CONCLUSIONS

The incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage was significantly lower and Glasgow coma scale significantly better with magnesium when compared to milrinone. Milrinone was associated with a higher incidence of hypotension and requirement for dopamine and norepinephrine when compared to magnesium.

[Effect of magnesium sulphate and milrinone on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a randomized study]

BACKGROUND

Aneurysmal subarachnoid hemorrhage is an important cause of premature death and disability worldwide. Magnesium sulphate is shown to have a neuroprotective effect and it reverses cerebral vasospasm. Milrinone is also used in the treatment of cerebral vasospasm. The aim of the present study was to compare the effect of prophylactic magnesium sulphate and milrinone on the incidence of cerebral vasospasm after subarachnoid hemorrhage.

METHODS

The study included 90 patients with aneurysmal subarachnoid hemorrhage classified randomly (by simple randomization) into two groups: magnesium sulphate was given as an infusion of 500mg.day^-1 without loading dose for 21 days. Group B: milrinone was given as an infusion of 0.5μg.kg^-1.min^-1 without loading dose for 21 days. The cerebral vasospasm was diagnosed by mean cerebral blood flow velocity in the involved cerebral artery (mean flow velocity≥120cm.s^-1), neurological deterioration by Glasgow coma scale, or angiography (the decrease in diameter of the involved cerebral artery >25%).

RESULTS

The mean cerebral blood flow velocity decreased significantly in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p<0.001). The incidence of cerebral vasospasm decreased significantly with magnesium compared to milrinone (p=0.007). The Glasgow coma scale significantly improved in the magnesium group compared to milrinone group through Day 7, Day 14 and Day 21 (p=0.036, p=0.012, p=0.016, respectively). The incidence of hypotension was higher with milrinone than magnesium (p=0.012).

CONCLUSIONS

The incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage was significantly lower and Glasgow coma scale significantly better with magnesium when compared to milrinone. Milrinone was associated with a higher incidence of hypotension and requirement for dopamine and norepinephrine when compared to magnesium.

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.

Postinterventional critical care management of aneurysmal subarachnoid hemorrhage

PURPOSE OF REVIEW

Subarachnoid hemorrhage from a ruptured aneurysm (aSAH) is a complex disorder with the potential to have devastating effects on the brain as well as other organ systems. After more than 3 decades of research, the underlying pathophysiologic mechanisms remain incompletely understood and important questions remain regarding the evaluation and management of these patients. The purpose of this review is to analyze the recent literature and improve our understanding of certain key clinical aspects.

RECENT FINDINGS

Growing body of evidence highlights the usefulness of CT perfusion scans in the diagnosis of vasospasm and delayed cerebral ischemia (DCI). Hypervolemia leads to worse cardiopulmonary outcomes and does not improve DCI. The traditional triple H therapy is falling out of favor with hemodynamic augmentation alone now considered the mainstay of medical management. Randomized controlled trials have shown that simvastatin and intravenous magnesium do not prevent DCI or improve functional outcomes after aneurysmal subarachnoid hemorrhage (aSAH). Emerging data using multimodality monitoring has further advanced our understanding of the pathophysiology of DCI in poor grade aSAH.

SUMMARY

The brief review will focus on the postinterventional care of aSAH patients outlining the recent advances over the past few years.

Health Care-Associated Infections after Subarachnoid Hemorrhage

OBJECTIVE

Health care-associated infections (HAIs) after subarachnoid hemorrhage (SAH) are prevalent; however, data describing epidemiology of infection are limited. This study reports incidence rates, risk factors, and the resulting SAH patient-related outcomes.

METHODS

We studied the incidence of HAIs acquired in the intensive care unit (ICU) over a 6-year period. We used Bayesian Model Averaging to identify risk factors associated with an increased risk of HAIs, particularly urinary tract infections (UTI), pneumonia, and ventriculostomy-associated infections (VAI). We also examined the impact of HAIs on risk of vasospasm, ICU and hospital length of stay, and discharge disposition and adjusted for other risk factors.

RESULTS

Of 419 patients with SAH, 66 (15.8%) developed 79 HAI episodes. Mean HAI incidence rates (per 1000 ICU-days) were UTI, 7.1; pneumonia, 4.3; and VAI, 2.4. The admission characteristic associated with increased risk of overall HAI, UTI, and VAI was diabetes mellitus. Hunt and Hess grades III-V were associated with increased risk of overall HAI and VAI. Male gender, intraventricular hemorrhage, and blood glucose level (>10) were associated with increased risk of pneumonia, whereas the incidence was lower in the presence of steroids. HAI was associated with increased length of stay of 10 ICU-days and 22 hospital-days, but not vasospasm or poor discharge disposition.

CONCLUSIONS

HAIs are serious complications after SAH associated with prolonged ICU and hospital length of stay. Additional rigorous infection control measures aimed at patients with identifiable risk factors should trigger prevention, and early detection of nosocomial infections is warranted to further reduce the prevalence of HAIs.

CT Perfusion to Guide Placement of Invasive Cerebral Perfusion Monitor in Subarachnoid Hemorrhage Induced Vasospasm

Background

Vasospasm is a challenging component of the subarachnoid hemorrhage “syndrome” that is unpredictable and very difficult to monitor using noninvasive or invasive monitoring technologies in neurocritical units.

Methods

We describe the novel use of computerized tomography perfusion (CTP) imaging to choose proper targets for invasive cerebral blood flow monitors.

Results

A total of 3 patients are included in this report. CTP parameters were used to generate points of interest to target using invasive cerebral monitoring of the cerebral blood flow and initiate vasodilator therapy and subsequently guide its weaning.

Conclusions

CTP can be useful in localizing a specific anatomical target for invasive monitoring in subarachnoid hemorrhage patients suffering from vasospasm.

Milrinone-Associated Cardiomyopathy and Arrhythmia in Cerebral Vasospasm

BACKGROUND

Milrinone is an inotropic and vasodilatory drug proven safe for use in treatment of cerebral vasospasm. Despite its reported safety profile, its use is not free of side effects. Milrinone-associated cardiomyopathy and arrhythmia can occur in patients with cerebral vasospasm.

CASE DESCRIPTION

This is a retrospective chart review of a patient who presented with aneurysmal subarachnoid hemorrhage and developed clinical vasospasm twice over a period of 2 weeks. Sustained intravenous milrinone infusion was used in association with norepinephrine infusion during this period. The patient developed R-on-T triggered torsades de pointes and cardiogenic shock requiring resuscitation. Follow-up echocardiogram showed decreased ejection fraction from 64% to 43% consistent with cardiac remodeling. Systemic complications such as cardiotoxicity and arrhythmias with the use of intravenous milrinone can be seen particularly when used in combination with catecholamines.

CONCLUSIONS

With increased combined milrinone and catecholamine use for the treatment of cerebral vasospasm, physicians should be aware of the potential cardiac complications of these agents. Close monitoring with daily electrocardiograms may be helpful to detect changes that suggest cardiotoxicity. If changes are noted, an echocardiogram and cardiology consultation may be warranted.