Current and future treatment considerations in the management of aneurysmal subarachnoid hemorrhage

Enhanced Renal Clearance in Patients With Hemorrhagic Stroke

OBJECTIVES

To evaluate enhanced renal clearance over time in patients with aneurysmal subarachnoid hemorrhage or intracerebral hemorrhage via measured creatinine clearance and to compare measured creatinine clearance to creatinine clearance calculated by the Cockcroft-Gault equation and estimated glomerular filtration rate calculated by the Modification of Diet in Renal Diseases equation.

DESIGN

Prospective, observational study.

SETTING

Neurosciences ICU in a tertiary care academic medical center.

PATIENTS

Study participants had an admission diagnosis of aneurysmal subarachnoid hemorrhage or intracerebral hemorrhage, an expected neurosciences ICU length of stay greater than 48 hours, no evidence of renal dysfunction (admission serum creatinine < 1.5 mg/dL), and no history of chronic kidney disease.

INTERVENTIONS

Eight-hour urine collections to measure creatinine clearance were collected daily as the primary method of measuring renal function. Creatinine clearance was also calculated using the Cockcroft-Gault equation and estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease equation. Enhanced renal clearance was defined as a measured creatinine clearance greater than the calculated creatinine clearance via Cockcroft-Gault and estimated glomerular filtration rate via Modification of Diet in Renal Disease. Augmented renal clearance was defined by a measured creatinine clearance greater than or equal to 130 mL/min/1.73 m. Relevant demographic, clinical, and outcome data were recorded.

MEASUREMENTS AND MAIN RESULTS

Fifty aneurysmal subarachnoid hemorrhage patients and 30 intracerebral hemorrhage patients were enrolled, contributing 590 individual measurements. Patients with aneurysmal subarachnoid hemorrhage had a higher mean measured creatinine clearance compared with the mean calculated creatinine clearance based on the Cockcroft-Gault equation (147.9 ± 50.2 vs 109.1 ± 32.7 mL/min/1.73 m; p < 0.0001) and higher mean measured creatinine clearance compared with the mean calculated estimated glomerular filtration rate based on the Modification of Diet in Renal Disease equation (147.9 ± 50.2 vs 126.0 ± 41.9 mL/min/1.73 m; p = 0.04). Ninety-four percent of participants with aneurysmal subarachnoid hemorrhage experienced augmented renal clearance on at least 1 day. In patients with intracerebral hemorrhage, there was a higher mean measured creatinine clearance over the study period compared with the mean calculated creatinine clearance (119.5 ± 57.2 vs 77.8 ± 27.6 mL/min/1.73 m; p < 0.0001) and higher mean measured creatinine clearance compared with the mean calculated estimated glomerular filtration rate based on the Modification of Diet in Renal Disease equation (119.5 ± 57.2 vs 93.0.0 ± 32.8 mL/min/1.73 m; p = 0.02). Fifty percent of participants with intracerebral hemorrhage experienced augmented renal clearance on at least 1 day.

CONCLUSIONS

A substantial group of patients with aneurysmal subarachnoid hemorrhage or intracerebral hemorrhage experienced enhanced renal clearance, which may be otherwise unknown to clinicians. Enhanced renal clearance may lead to increased renal solute elimination over what is expected, resulting in subtherapeutic renally eliminated drug concentrations. This may result in underexposure to critical medications, leading to treatment failure and other medical complications.

Association between seizures and mortality in patients with aneurysmal subarachnoid hemorrhage: A nationwide retrospective cohort analysis

PURPOSE

The impact of seizures on outcomes in patients with subarachnoid hemorrhage (SAH) is not well understood, with conflicting results published in the literature.

METHOD

For this retrospective cohort analysis, data from the Nationwide Inpatient Samples (NIS) for 2006-2011 were utilized. All patients aged ≥18 years with a primary admitting diagnosis of subarachnoid hemorrhage were included. Patients with a diagnosis of seizure were segregated from the initial cohort. Multivariable logistic regression modeled the risk of death while adjusting for severity of SAH as well as co-morbidities. The primary outcome of this analysis was in-hospital mortality.

RESULTS

12,647 patients met inclusion criteria for the study, of which 1336 had a diagnosis of seizures. The unadjusted in-hospital mortality was higher for patients with seizures compared to those without (16.2% vs 11.6%, p<0.01). Compared to patients without seizures, patients with seizures were younger (52.4 years SD 13.9 vs 54.8 years, SD 13.6; p<0.01), more likely to be male (35.6% vs 31.0%, p<0.01) and had longer hospital stays (18.3 days, IQR 12.0-27.5 vs 14.8 days, IQR 10.0-21.9; p<0.01). After adjusting for the severity of SAH, seizures were found to be associated with increased mortality (OR 1.57, 95% CI 1.32-1.87, p<0.01).

CONCLUSION

In this large nationwide analysis, the presence of seizures in patients with SAH was associated with higher in-hospital mortality. This finding has potentially important implications for goals of care decision-making and prognostication, but further study in the area is needed.

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

BACKGROUND

Aneurysmal subarachnoid hemorrhage is a significant cause of death and disability. Nimodipine 60 mg administered enterally every 4 h improves neurologic outcomes in these patients. However, hypotension is an adverse effect of nimodipine and is believed to prompt clinicians to prescribe an unproven, nonstandard nimodipine dosing regimen.

OBJECTIVES

The primary objective was to determine the prescribing incidence of a nonstandard nimodipine dosing regimen (30 mg every 2 h) after initial prescription of the standard dose (60 mg every 4 h). The secondary objective was to determine factors associated with this dosage change.

METHODS

This retrospective cohort study evaluated participants receiving nimodipine for aneurysmal subarachnoid hemorrhage at a tertiary care teaching hospital between October 2005 and December 2011. Univariate and multivariate regression analyses were performed to identify factors associated with dosage manipulation.

RESULTS

A total of 166 eligible patients were identified. For all of these patients, nimodipine 60 mg every 4 h was prescribed initially. Subsequently, 81 (49%) of the patients were switched to nimodipine 30 mg every 2 h, whereas 85 (51%) continued on the original dosage (nimodipine 60 mg every 4 h) for the duration of their treatment. Multivariate analysis revealed that occurrence of vasospasm (odds ratio [OR] 5.30, 95% confidence interval [CI] 2.08-13.47; p < 0.001) and exposure to vasopressor therapy (OR 3.29, 95% CI 1.27-8.50; p = 0.014) were associated with increased odds of receiving the nonstandard nimodipine regimen.

CONCLUSIONS

Half of patients for whom nimodipine was prescribed for aneurysmal subarachnoid hemorrhage were exposed to an unproven regimen. Vasospasm and exposure to vasopressor therapy were associated with higher odds of receiving the nonstandard regimen. Further research is needed to evaluate whether nimodipine 30 mg every 2 h is efficacious and safe for patients in this population.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Is the circulating plasma volume sufficiently maintained? Fluid management of an aneurysmal subarachnoid hemorrhage in the acute phase

Cerebral vasospasm is a well-known cause of mortality and morbidity following aneurysmal subarachnoid hemorrhage (SAH). Prevention of symptomatic cerebral vasospasm is the basic management after SAH. Numerous pharmaceutical therapies and endovascular treatments are available against cerebral vasospasm, but none of them have so far proven to improve the outcome. We have focused on maintaining the circulation volume in order to prevent cerebral vasospasm. But to maintain the central venous pressure, huge infusion volume was required, and hyponatremia was frequently observed due to natriuresis and osmotic diuresis. Excessive natriuresis and diuresis cannot be managed through sodium and water replacement, since sodium replacement induces further natriuresis and diuresis (desalination), and water replacement induces hyponatremia. We therefore administered fludrocortisone and hydrocortisone to inhibit excessive natriuresis and diuresis. The efficacy of sodium reabsorption therapy is extremely high to maintain the circulation volume that might have a therapeutic effect to prevent cerebral vasospasm. In this article, we review our institution's experience regarding the management of patients with aneurysmal SAH and also discuss the importance of water and sodium balance when managing such patients.