Effect of fludrocortisone acetate in patients with subarachnoid hemorrhage

Update on the management of subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease. Outcome after SAH is mainly determined by the initial severity of the hemorrhage. Neuroimaging, in particular computed tomography, and aneurysm repair techniques, such as coiling and clipping, as well as neurocritical care management, have improved during the last few years. The management of a patient with SAH should have an interdisciplinary approach with case discussions between the neurointensivist, interventionalist and the neurosurgeon. The patient should be treated in a specialized neurointensive care unit of a center with sufficient SAH case volume. Poor-grade patients can be observed for complications and delayed cerebral ischemia through continuous monitoring techniques in addition to transcranial Doppler ultrasonography such as continuous electroencephalography, brain tissue oxygenation, cerebral metabolism, cerebral blood flow and serial vascular imaging. Neurocritical care should focus on neuromonitoring for delayed cerebral ischemia, management of hydrocephalus, seizures and intracranial hypertension, as well as of medical complications such as hyperglycemia, fever and anemia.

An update on neurocritical care for the patient with kidney disease

Patients with kidney disease have increased rates of neurologic illness such as intracerebral hemorrhage and ischemic stroke. The acute care of patients with critical neurologic illness and concomitant kidney disease requires unique management considerations including attention to hyponatremia, renal replacement modalities in the setting of high intracranial pressure, reversal of coagulopathy, and seizure management to achieve good neurologic outcomes.

Comparison of lumbar drainage and external ventricular drainage for clearance of subarachnoid clots after Guglielmi detachable coil embolization for aneurysmal subarachnoid hemorrhage

OBJECTIVE

Subarachnoid clots play an important role in development of delayed vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to compare clearance of subarachnoid clots using external ventricular drainage (EVD) or lumbar drainage (LD) after Guglielmi detachable coil (GDC) embolization for aneurysmal SAH.

METHODS

The subjects were 51 treated with GDC coil embolization for aneurysmal Fisher group 3 SAH within 72 h of ictus. Software-based volumetric quantification of the subarachnoid clots was performed on CT scans and the hemoglobin (Hb) level was measured in CSF drained from each catheter.

RESULTS

Clearance of subarachnoid clots was more rapid in patients treated with LD (n=34) compared to those treated with EVD (n=17). The Hb level in CSF was significantly higher in the LD group on Days 4-5 after onset of SAH (P<0.05), but was higher in the EVD group on Days 8-9. The incidence of symptomatic vasospasm did not differ between the two groups. The rate of occurrence of a new low density area on CT scans was higher in patients treated with EVD, but not significantly higher than the rate in the LD group.

CONCLUSION

GDC embolization followed by lumbar drainage accelerates the reduction of subarachnoid clots, but EVD may contribute to stasis of hemorrhage within subarachnoid spaces.

Clinical management guidelines for subarachnoid haemorrhage. Diagnosis and treatment

OBJECTIVE

To update the Spanish Society of Neurology's guidelines for subarachnoid haemorrhage diagnosis and treatment.

MATERIAL AND METHODS

A review and analysis of the existing literature. Recommendations are given based on the level of evidence for each study reviewed.

RESULTS

The most common cause of spontaneous subarachnoid haemorrhage (SAH) is cerebral aneurysm rupture. Its estimated incidence in Spain is 9/100 000 inhabitants/year with a relative frequency of approximately 5% of all strokes. Hypertension and smoking are the main risk factors. Stroke patients require treatment in a specialised centre. Admission to a stroke unit should be considered for SAH patients whose initial clinical condition is good (Grades I or II on the Hunt and Hess scale). We recommend early exclusion of aneurysms from the circulation. The diagnostic study of choice for SAH is brain CT (computed tomography) without contrast. If the test is negative and SAH is still suspected, a lumbar puncture should then be performed. The diagnostic tests recommended in order to determine the source of the haemorrhage are MRI (magnetic resonance imaging) and angiography. Doppler ultrasonography studies are very useful for diagnosing and monitoring vasospasm. Nimodipine is recommended for preventing delayed cerebral ischaemia. Blood pressure treatment and neurovascular intervention may be considered in treating refractory vasospasm.

CONCLUSIONS

SAH is a severe and complex disease which must be managed in specialised centres by professionals with ample experience in relevant diagnostic and therapeutic processes.

Urea for treatment of acute SIADH in patients with subarachnoid hemorrhage: a single-center experience

Background

Hyponatremia occurring as a result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or cerebral salt wasting syndrome is a common complication in patients with subarachnoid hemorrhage (SAH). The efficacy and safety of urea as treatment for SIADH-induced hyponatremia has not been reported in this population.

Methods

This is a retrospective analysis of all patients admitted to our department for nontraumatic SAH between January 2003 and December 2008 (n = 368). All patients with SIADH-induced hyponatremia (plasma sodium < 135 mEq/L, urine sodium > 20 mEq/L, and osmolality > 200 mOsm/kg; absence of overt dehydration or hypovolemia; no peripheral edema or renal failure; no history of adrenal or thyroid disease) routinely received urea per os when hyponatremia was associated with clinical deterioration or remained less than 130 mEq/L despite saline solution administration.

Results

Forty-two patients developed SIADH and were treated with urea. Urea was started after a median of 7 (IQR, 5–10) days and given orally at doses of 15–30 g tid or qid for a median of 5 (IQR, 3–7) days. The median plasma sodium increase over the first day of treatment was 3 (IQR, 1–6) mEq/L. Hyponatremia was corrected in all patients, with median times to Na⁺ >130 and >135 mEq/L of 1 (IQR, 1–2) and 3 (IQR, 2–4) days, respectively. Urea was well tolerated, and no adverse effects were reported.

Conclusions

Oral urea is an effective and well-tolerated treatment for SIADH-induced hyponatremia in SAH patients.

Endocrine function following acute SAH

Disruption of the hypothalamic-pituitary-adrenal axes may occur after aneurysmal subarachnoid hemorrhage, resulting in hypopituitarism. An electronic literature search was conducted to identify articles with English-language abstracts published between 1980 and March 2011, which addressed hypothalamic-pituitary-adrenal axis insufficiency and hormone replacement. A total of 18 observational and prospective, randomized studies were selected for this review. Limited data are available, evaluating pituitary effects during the acute stage after subarachnoid hemorrhage, with inconsistent results being reported. Overall, after acute subarachnoid hemorrhage, cortisol levels may initially be supranormal, decreasing toward normal levels over time. During the months to years after subarachnoid hemorrhage, pituitary deficiency may occur in one out of three patients. Limited data suggest modest outcome benefits with fludrocortisone and no benefit or harm from corticosteroids.

SAH pituitary adrenal dysfunction

Disruption of the hypothalamic-pituitary-adrenal axis may occur after aneurysmal subarachnoid hemorrhage, resulting in hypopituitarism. An electronic literature search was conducted to identify articles with English-language abstracts published between 1980 and March 2011 that addressed hypothalamic-pituitary-adrenal axis insufficiency and hormone replacement. A total of 18 observational and prospective, randomized studies were selected for this review. Limited data are available evaluating pituitary effects during the acute stage after subarachnoid hemorrhage, with inconsistent results reported. Overall, acutely after subarachnoid hemorrhage, cortisol levels may initially be supranormal, decreasing toward normal levels over time. During the months to years after subarachnoid hemorrhage, pituitary deficiency may occur in up to one in three patients. Limited data suggest modest outcome benefits with fludrocortisone and no benefit or harm from corticosteroids.

Corticosteroids for acute ischaemic stroke

BACKGROUND

The majority of strokes are due to cerebral infarction. Ischaemic cerebral tissue tends to develop cytotoxic oedema which, if the blood-brain barrier is disrupted, may be followed by vasogenic oedema. Large infarcts can develop life-threatening massive oedema. Early treatment with corticosteroids could theoretically help reduce both cytotoxic and vasogenic oedema and so improve the clinical outcome after a stroke.

OBJECTIVES

To assess the effect of corticosteroids in acute presumed ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched: 17 February 2011).

SELECTION CRITERIA

Published randomised trials comparing corticosteroids with placebo or a control group in people with acute (presumed or definite) ischaemic stroke. Trials were included if treatment began within 48 hours of stroke onset and if clinical outcomes were assessed.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, assessed trial quality and extracted the data.

MAIN RESULTS

Eight trials involving 466 people were included. Details of trial quality that may relate to bias were not available for most trials. No difference was shown in the odds of death within one year (odds ratio (OR) 0.87, 95% confidence interval (CI) 0.57 to 1.34). Treatment did not appear to improve functional outcome in survivors. Seven trials reported neurological impairment but pooling the data was impossible because no common scale or time interval was used. The results were inconsistent between individual trials. The only adverse effects reported were small numbers of gastrointestinal bleeds, infections and deterioration of hyperglycaemia across both groups. The results are unchanged since the previous update.

AUTHORS' CONCLUSIONS

There is not enough evidence to evaluate corticosteroid treatment for people with acute presumed ischaemic stroke. The conclusions are unchanged since the previous update.

Critical care management of subarachnoid hemorrhage

Successful critical care management of patients with aneurysmal subarachnoid hemorrhage (SAH) requires a thorough understanding of the disease and its complications and a familiarity with modern multimodality neuromonitoring technology. This article reviews the natural history of aneurysmal SAH and strategies for disease management in the acute setting, including available tools for monitoring brain function. Intensive care management of patients with SAH focuses on prevention of further neurologic injury. Aneurysmal rebleeding, hydrocephalus, seizures, and delayed ischemic injury represent major threats. There is increasing awareness of extracerebral complications, including electrolyte disturbances (eg, cerebral salt wasting) and cardiac dysfunction. Prompt recognition and treatment of these disorders maximizes the odds of a good functional outcome. Technologic advances hold the promise of improved detection and treatment of secondary neurologic insults.

Hyponatremia is predictable in patients with aneurysmal subarachnoid hemorrhage--clinical significance of serum atrial natriuretic peptide

PURPOSE

Serum atrial natriuretic peptide (ANP) that is elevated after aneurysmal subarachnoid hemorrhage (SAH) causes diuresis and natriuresis (cerebral salt wasting) and might exacerbate delayed ischemic neurological deficit (DIND). We investigated relationships among hyponatremia, serum ANP elevation, and the onset of DIND after SAH.

MATERIALS AND METHODS

Thirty-nine consecutive patients (15 women and 24 men) with SAH were assigned to a normonatremia group or a group that developed hyponatremia after SAH. Serum ANP and brain natriuretic peptide were assessed after SAH. All patients remained normovolemic and normotensive. We attributed DIND to vasospasm only in the absence of other causes and when supported by cerebral angiography.

RESULTS

Hyponatremia developed after SAH in 11 patients (28.2%), among whom serum ANP concentrations at 0 and 3 days thereafter were significantly increased. Furthermore, DIND developed in five (45.5%) and two (7.1%) hyponatremic and normonatremic patients, respectively (P < 0.05). The serum ANP levels on day 0 after SAH were higher in Hunt and Kosnik grades 3-4 than in 1-2 and in Fisher groups 3-4 than in 1-2 (P < 0.05).

CONCLUSIONS

Increasing serum ANP concentrations were independently associated with hyponatremia resulting in DIND. Early treatment of hyponatremia might prevent DIND in patients after SAH.

Non-aneurysm subarachnoid hemorrhage in young adults

OBJECTIVE

The incidence of subarachnoid hemorrhage (SAH) in the young is increasing recently. Among the young patients, some of them do not have detectable aneurysms, so the cause of the disease may be non-aneurysmal. In this study, we analyzed some clinical cases of subarachnoid hemorrhage in young adults and discussed the possible causes other than present aneurysm and arteriovenous malformation (AVM).

METHODS

We reviewed 11 patients with SAH below 45 years of age enrolled in our hospital from January 2007 to June 2008. Their clinical characteristics, imaging examination results were analyzed in details: nine patients were found with no obvious cause for their hemorrhage. Four of them were followed up for 1 year and the other three were followed up for half a year. We telephoned the seven patients to gain the information on their recovery by questionnaire.

RESULTS

With an average onset age of 38 years old, all patients had similar symptoms and onset behavior according to their clinical characteristics. Based on the imaging results, two had confirmed vascular malformation; the other nine did not present detectable aneurysm or AVM, but with different morphological changes of their cerebral arteries. By 1-year or half-year follow-up, the seven patients were found to have good recovery.

CONCLUSION

Pathological changes of cerebral vessels due to smoking, genetic, or as an early version of formation of aneurysm, might be contributed to SAH in the young. Repeated angiogram is necessary for young patients to confirm the cause of SAH.

Sodium Disturbances Commonly Encountered in the Neurologic Intensive Care Unit

Disorders of sodium and water balance are common in patients with central nervous system (CNS) disease. These disorders frequently complicate the treatment course by precipitating or worsening neurological symptoms. These patients are not only at risk for symptoms secondary to dysnatremia but also at risk from the consequences of treatment. If not treated properly, this electrolyte disturbance can vastly increase morbidity and can even lead to death. Appropriate diagnosis and intervention requires an understanding of the physiologic and pathophysiologic mechanisms involved in sodium and water homeostasis.

Management of post-subarachnoid hemorrhage vasospasm

Permanent neurologic injury and death remain common outcomes following aneurysmal subarachnoid hemorrhage. Although many sophisticated techniques are evolving for securing intracranial aneurysms to prevent rebleeding, progress is lagging in the management of posthemorrhagic complications, particularly cerebral vasospasm. Vasospasm can be defined either angiographically, by visible reduction in arterial lumen diameters, or clinically, with signs of focal or regional cerebral ischemia. The relationship between angiographic and clinical vasospasm is not straightforward. The most important known risk factors for developing posthemorrhagic vasospasm include volume and distribution of subarachnoid blood, and no preventive measures have proven effective. Established treatment strategies for vasospasm include hyperdynamic therapy, angioplasty, and selective intra-arterial injection of vasodilators. The vasodilatory approach has been called into question by recent data suggesting that reduction of arterial luminal diameters may be due largely to a proliferative arteriopathy. Novel treatment strategies have focused on protecting the cerebrum, targeting components of the inflammatory cascade, and identifying genetic factors predisposing toward vasospasm, all of which may soon yield new treatment modalities.

Cerebral salt wasting: pathophysiology, diagnosis, and treatment

Cerebral salt wasting (CSW) is a syndrome of hypovolemic hyponatremia caused by natriuresis and diuresis. The mechanisms underlying CSW have not been precisely delineated, although existing evidence strongly implicates abnormal elevations in circulating natriuretic peptides. The key in diagnosis of CSW lies in distinguishing it from the more common syndrome of inappropriate secretion of antidiuretic hormone. Volume status, but not serum and urine electrolytes and osmolality, is crucial for making this distinction. Volume and sodium repletion are the goals of treatment of patients with CSW, and this can be performed using some combination of isotonic saline, hypertonic saline, and mineralocorticoids.

Hyponatremia in patients with neurologic disorders

The kidney and the brain play a major role in maintaining normal homeostasis of the extracellular fluid by neuroendocrine regulation of sodium and water balance. Therefore, disturbances of sodium balance are common in patients with central nervous system (CNS) disorders and clinicians should focus not only on the CNS lesion, but also on the potentially deleterious complications. Hyponatremia is the most common and important electrolyte disorder affecting patients with critical neurologic diseases. In these patients, the maladaptation to hyponatremia by impaired osmoregulation in pathologic lesions of brain may cause more aggressive cerebral edema and increased intracranial pressure due to hypoosmolality induced by hyponatremia. Furthermore, hyponatremia accompanied by CNS disorders has shown to increase delayed cerebral ischemia and mortality rates. Two main pathophysiologies of hyponatremia, excluding iatrogenic causes, are inappropriate secretion of antidiuretic hormone (SIADH) and cerebral salt wasting (CSW) syndrome. Differential diagnosis between these two entities can be difficult due to considerable overlap in the laboratory findings and clinical situations. SIADH is in a volume expanded status due to inappropriately secreted arginine vasopressin (AVP) and requires water restriction. However, CSW syndrome is characterized by renal sodium wasting mainly due to increased natriuretic peptides resulting in volume depletion and follows appropriate secretion of AVP. Therefore, maintenance of volume status and sodium replacement is the mainstay of treatment in CSW syndrome. In this review, we aimed to describe the regulation of sodium and water balance, and pathophysiology, diagnosis and treatment of hyponatremia in neurologic patients, especially focusing on SIADH and CSW syndrome.

Hyponatremia in neurosurgical patients: clinical guidelines development

OBJECTIVE

Neurosurgical patients have a high risk of hyponatremia and associated complications. We critically evaluated the existing literature to identify the determinants for the development of hyponatremia and which management strategies provided the best outcomes.

METHODS

A multidisciplinary panel in the areas of neurosurgery, nephrology, critical care medicine, endocrinology, pharmacy, and nursing summarized and classified hyponatremia literature scientific studies published in English from 1950 through 2008. The panel's recommendations were used to create an evaluation and treatment protocol for hyponatremia in neurosurgical patients at the University of Florida.

RESULTS

Hyponatremia should be further investigated and treated when the serum sodium level is less than 131 mmol/L (class II). Evaluation of hyponatremia should include a combination of physical examination findings, basic laboratory studies, and invasive monitoring when available (class III). Obtaining levels of hormones such as antidiuretic hormone and natriuretic peptides is not supported by the literature (class III). Treatment of hyponatremia should be based on severity of symptoms (class III). The serum sodium level should not be corrected by more than 10 mmol/L/d (class III). Cerebral salt wasting should be treated with replacement of serum sodium and intravenous fluids (class III). Fludrocortisone may be considered in the treatment of hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm (class I). Hydrocortisone may be used to prevent natriuresis in subarachnoid hemorrhage patients (class I). Hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm should not be treated with fluid restriction (class II). Syndrome of inappropriate antidiuretic hormone may be treated with urea, diuretics, lithium, demeclocycline, and/or fluid restriction (class III).

CONCLUSION

The summarized literature on the evaluation and treatment of hyponatremia was used to develop practice management recommendations for hyponatremia in the neurosurgical population. However, the practice management recommendations relied heavily on expert opinion because of a paucity of class I evidence literature on hyponatremia.

Management of aneurysmal subarachnoid hemorrhage

OBJECTIVE

Acute aneurysmal subarachnoid hemorrhage (SAH) is a complex multifaceted disorder that plays out over days to weeks. Many patients with SAH are seriously ill and require a prolonged intensive care unit stay. Cardiopulmonary complications are common. The management of patients with SAH focuses on the anticipation, prevention, and management of these secondary complications.

DATA SOURCES

Source data were obtained from a PubMed search of the medical literature.

DATA SYNTHESIS AND CONCLUSION

The rupture of an intracranial aneurysm is a sudden devastating event with immediate neurologic and cardiac consequences that require stabilization to allow for early diagnostic angiography. Early complications include rebleeding, hydrocephalus, and seizures. Early repair of the aneurysm (within 1-3 days) should take place by surgical or endovascular means. During the first 1-2 weeks after hemorrhage, patients are at risk of delayed ischemic deficits due to vasospasm, autoregulatory failure, and intravascular volume contraction. Delayed ischemia is treated with combinations of volume expansion, induced hypertension, augmentation of cardiac output, angioplasty, and intra-arterial vasodilators. SAH is a complex disease with a prolonged course that can be particularly challenging and rewarding to the intensivist.

Critical care management of subarachnoid hemorrhage

Successful critical care management of patients with aneurysmal subarachnoid hemorrhage requires a thorough understanding of the disease and its complications and a familiarity with modern multimodality neuromonitoring technology. This article reviews the natural history of aneurysmal subarachnoid hemorrhage and strategies for disease management in the acute setting. Available tools for monitoring brain function are discussed.

Medical Management of Patients with Aneurysmal Subarachnoid Haemorrhage

Treating patients with aneurysmal subarachnoid haemorrhage is taking care of acutely ill patients, and should be performed in centres where a multidisciplinary team is available 24 hours a day 7 days a week, and where enough patients are managed to maintain and improve standards of care. There is no medical management that improves outcome by reducing the risk of rebleeding, therefore occlusion of the aneurysm, nowadays preferably by means of coiling, remains an important goal in treating patients with aneurysms. Because the poor outcome after subarachnoid haemorrhage is caused to a large extent by complications other than rebleeding, proper medical management to prevent and treat these complications is therefore essential. On basis of the available evidence, oral (not intravenous) nimodipine should be standard care in patients with subarachnoid haemorrhage. It is rational to refrain from treating hypertension unless cardiac failure develops and to aim for normovolaemia, even in case of hyponatraemia. There is no evidence for prophylactic hypervolaemia, and the strategy of hypervolaemia and hypertension in patients with secondary cerebral ischaemia is based on case reports and uncontrolled observational series of patients. Magnesium sulphate and statins are promising therapies, and large trials on effectiveness in improving clinical outcome are underway. There is no evidence for prophylactic use of anti epileptic drugs, and routine use of corticosteroids should be avoided.

Tumor-related hyponatremia

Hyponatremia is an important and common electrolyte disorder in tumor patients and one that has been reported in association with a number of different primary diagnoses. The correct diagnosis of the pathophysiological basis for each patient is important because it significantly alters the treatment approach. In this article, we review the epidemiology and presentation of patients with hyponatremia, the pathophysiologic groups for the disorder with respect to sodium and water balance and the diagnostic measures for determining the correct pathophysiologic groups. We then present the various treatment options based on the pathophysiologic groups including a mathematical approach to the use of hypertonic saline in management. In cancer patients, hyponatremia is a serious comorbidity that requires particular attention as its treatment varies by pathophysiologic groups, and its consequences can have a deleterious effect on the patient's health.

Mineralocorticoid deficiency in post-operative cerebral salt wasting

Acute hyponatremia, following neurosurgery, results from inappropriate antidiuretic hormone secretion (SIADH) or cerebral salt wasting (CSW). CSW is due to abnormally high atrial or brain natriuretic peptides (ANP, BNP), which block all stimulators of zona glomerulosa steroidogenesis, resulting in mineralocorticoid deficiency. A 3 year-old girl presented CSW at day 4, after resection of craniopharyngioma and hypophysectomy. Hyponatremia, hyperkalemia and high natriuresis occurred on day 8, with low renin and aldosterone and elevated BNP 120.3 ng/ml (undetectable before surgery). Fludrocortisone 100 microg/day controlled natriuresis and restored electrolytes within 24 hours. A 5 year-old boy presented CSW at day 6 after partial resection of optic glioma. Fludocortisone 100 microg/day restored electrolytes within 8 hours. ANP was elevated, 60.6 ng/l, aldosterone and renin were low. Fludrocortisone supplementation should be considered in CSW, as excessive natriuresis is controlled, and electrolytes are easily restored, avoiding life-threatening complications of this complex disorder.

Aneurysmal subarachnoid haemorrhage and the anaesthetist

The anaesthetist may be involved at various stages in the management of subarachnoid haemorrhage (SAH). Thus, familiarity with epidemiological, pathophysiological, diagnostic, and therapeutic issues is as important as detailed knowledge of the optimal intraoperative anaesthetic management. As the prognosis of SAH remains poor, prompt diagnosis and appropriate treatment are essential, because early treatment may improve outcome. It is, therefore, important to rule out SAH as soon as possible in all patients complaining of sudden onset of severe headache lasting for longer than an hour with no alternative explanation. The three main predictors of mortality and dependence are impaired level of consciousness on admission, advanced age, and a large volume of blood on initial cranial computed tomography. The major complications of SAH include re-bleeding, cerebral vasospasm leading to immediate and delayed cerebral ischaemia, hydrocephalus, cardiopulmonary dysfunction, and electrolyte disturbances. Prophylaxis and therapy of cerebral vasospasm include maintenance of cerebral perfusion pressure (CPP) and normovolaemia, administration of nimodipine, triple-H therapy, balloon angioplasty, and intra-arterial papaverine. Occlusion of the aneurysm after SAH is usually attempted surgically ('clipping') or endovascularly by detachable coils ('coiling'). The need for an adequate CPP (for the prevention of cerebral ischaemia and cerebral vasospasm) must be balanced against the need for a low transmural pressure gradient of the aneurysm (for the prevention of rupture of the aneurysm). Effective measures to prevent or attenuate increases in intracranial pressure, brain swelling, and cerebral vasospasm throughout all phases of anaesthesia are prerequisite for optimal outcome.

Vasospasm in aneurysmal subarachnoid hemorrhage: diagnosis, prevention, and management

Cerebral vasospasm is a major cause of morbidity and mortality associated with subarachnoid hemorrhage (SAH). Advances in neuroimaging and development of newer intraparenchymal monitoring devices have improved the prediction and diagnosis of cerebral vasospasm significantly. Recent experimental and clinical trials have increased the armamentarium of preventive and treatment strategies for cerebral vasospasm. Vasospasm refractory to medical therapy usually is treated endovascularly with percutaneous transluminal balloon angioplasty (PTA) for proximal vessel vasospasm and vasodilator infusion for distal vessel vasospasm. Although vasospasm usually does not recur after PTA, recurrence is frequent after vasodilator infusion. The development of newer microballoon catheters has led to improvements in treatment of not only proximal but also distal vessel vasospasm with balloon angioplasty. This article reports on current knowledge in the diagnosis, prediction, prevention, and management of cerebral vasospasm.

Evidence-based cerebral vasospasm management

Cerebral vasospasm and delayed cerebral ischemia remain common complications of aneurysmal subarachnoid hemorrhage (SAH), and yet therapies for cerebral vasospasm are limited. Despite a large number of clinical trials, only calcium antagonists have strong evidence supporting their effectiveness. The purpose of this work was to perform a systematic review of the literature on the treatment of cerebral vasospasm. A literature search for randomized controlled trials of therapies used for prevention or treatment of cerebral vasospasm and/or delayed cerebral ischemia was conducted, and 41 articles meeting the review criteria were found. Study characteristics and primary results of these articles are reviewed. Key indicators of quality were poor when averaged across all studies, but have improved greatly over time. The only proven therapy for vasospasm is nimodipine. Tirilazad is not effective, and studies of hemodynamic maneuvers, magnesium, statin medications, endothelin antagonists, steroid drugs, anticoagulant/antiplatelet agents, and intrathecal fibrinolytic drugs have yielded inconclusive results. The following conclusions were made: nimodipine is indicated after SAH and tirilazad is not effective. More study of hemodynamic maneuvers, the effectiveness of other calcium channel antagonists such as nicardipine delivered by other routes (for example intrathecally), magnesium, statin drugs, endothelin antagonists, and intrathecal fibrinolytic therapy is warranted. There is less enthusiasm for the study of steroid drugs and anticoagulant/antiplatelet agents because they entail more risks and investigations so far have shown little evidence of efficacy. The study of rescue therapy such as balloon angioplasty and intraarterial vasodilating agents will be difficult. The quality of clinical trials should be improved.

Hyponatremia in neurologic patients: consequences and approaches to treatment

BACKGROUND

Hyponatremia is a common fluid-electrolyte disturbance, particularly in patients with neurologic disorders, in part because of the major role the central nervous system (CNS) plays in the regulation of sodium and water homeostasis.

REVIEW SUMMARY

The classification of hyponatremia is based on an assessment of serum sodium concentration ([Na+]), serum and urine osmolality, and body volume status. In most cases, hyponatremia is associated with hypotonicity, which causes water to move into the brain. Adaptive responses limit the impact of cerebral edema in chronic hyponatremia, but CNS symptoms and death may occur in response to rapid or large decreases in serum [Na+]. The prompt correction of serum [Na+] is mandatory in symptomatic patients, but overly rapid correction must be avoided to limit the risk of myelinolysis. In neurologic disorders, euvolemic hyponatremia (usually caused by the syndrome of inappropriate secretion of antidiuretic hormone) must be distinguished from hypovolemic states such as cerebral salt wasting because the treatment of the 2 conditions differs. Vasopressin antagonists represent a new approach to the treatment of euvolemic and hypervolemic hyponatremia secondary to arginine vasopressin dysregulation.

CONCLUSION

The optimal treatment of hyponatremia is controversial, but appropriate treatment must be determined according to the osmolality and volume status of the patient. If left untreated, serious CNS complications and adverse outcomes, including an increased risk of death, can occur.

Disturbances of sodium in critically ill adult neurologic patients: a clinical review

Disorders of sodium and water balance are common in critically ill adult neurologic patients. Normal aspects of sodium and water regulation are reviewed. The etiology of possible causes of sodium disturbance is discussed in both the general inpatient and the neurologic populations. Areas of importance are highlighted with regard to the differential diagnosis of sodium disturbance in neurologic patients, and management strategies are discussed. Specific discussions of the etiology, diagnosis, and management of cerebral salt wasting syndrome, the syndrome of inappropriate antidiuretic hormone secretion, and central diabetes insipidus are presented, as well as the problems of overtreatment. The importance of diagnosis at an early stage of these diseases is stressed, with a recommendation for conservative management of milder cases.

Controversies in the management of aneurysmal subarachnoid hemorrhage*

BACKGROUND

The care of patients with aneurysmal subarachnoid hemorrhage has evolved significantly with the advent of new diagnostic and therapeutic modalities. Although it is believed that these advances have contributed to improved outcomes, considerable uncertainty persists regarding key areas of management.

OBJECTIVE

To review selected controversies in the management of aneurysmal subarachnoid hemorrhage, with a special emphasis on endovascular vs. surgical techniques for securing aneurysms, the diagnosis and therapy of cerebral vasospasm, neuroprotection, antithrombotic and anticonvulsant agents, cerebral salt wasting, and myocardial dysfunction, and to suggest venues for further clinical investigation.

DATA SOURCE

Search of MEDLINE and Cochrane databases and manual review of article bibliographies.

DATA SYNTHESIS AND CONCLUSIONS

Many aspects of care in patients with aneurysmal subarachnoid hemorrhage remain highly controversial and warrant further resolution with hypothesis-driven clinical or translational research. It is anticipated that the rigorous evaluation and implementation of such data will provide a basis for improvements in short- and long-term outcomes.

Corticosteroids for aneurysmal subarachnoid haemorrhage and primary intracerebral haemorrhage

BACKGROUND

Corticosteroids, particularly dexamethasone, are commonly used for treatments in patients with subarachnoid haemorrhage (SAH) and primary intracerebral haemorrhage (PICH) despite the lack of evidence.

OBJECTIVES

This review aimed: (1) to determine whether corticosteroid therapy reduces the proportion of patients who die or have a poor outcome at one to six months after the onset of SAH or PICH; (2) to determine whether corticosteroid therapy reduces the frequency of delayed cerebral ischaemia (DCI) in patients with SAH; (3) to determine the frequency of adverse effects of corticosteroid therapy in patients with SAH or PICH within six months of the onset of the event.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched November 2003). In addition, we searched MEDLINE (1966 to March 2004) and EMBASE (1980 to March 2004), and searched reference lists of relevant studies identified. We also made an attempt to identify any relevant ongoing and published or unpublished studies by contacting trialists and pharmaceutical companies.

SELECTION CRITERIA

We sought to identify all randomised or quasi-randomised clinical trials of corticosteroid therapy, in patients with SAH or PICH, that have a placebo or standard strategy arm as control. Patients of any age and either gender with clinically (bed-side) diagnosed PICH and cerebrospinal fluid documented SAH were included in the analysis. The data were analysed both separately and combined for computed tomography (CT)/magnetic resonance imaging (MRI)/autopsy/angiography verified patients.

DATA COLLECTION AND ANALYSIS

Data extracted from eligible clinical trials included: (1) death and poor outcome (death, severe disability, or vegetative state) within the first one to six months of the event onset (primary outcomes); (2) development of delayed cerebral ischaemia (as defined by the trialists) in patients with SAH; and (3) adverse effects of the treatment during the scheduled treatment or follow-up period (secondary outcomes). A pooled estimate of the effect size was computed, and the test for heterogeneity between trial results was carried out using The Cochrane Collaboration's Review Manager software, RevMan 4.2. Intention-to-treat analysis was carried out whenever possible.

MAIN RESULTS

Eight trials that fulfilled the eligibility criteria were identified, with a total of 256 randomised patients in three SAH trials, and 206 patients in five PICH trials. The studies differed substantially with regard to the study populations and drugs, and methodological quality. The number of patients allocated to either hydrocortisone or fludrocortisone acetate treatment in patients with SAH, or to dexamethasone treatment in patients with PICH, was too small to make any definitive conclusions (confidence intervals were wide for any of the outcome estimates).

AUTHORS' CONCLUSIONS

Overall, there is no evidence of a beneficial or adverse effect of corticosteroids in patients with either SAH or PICH. Confidence intervals are wide and include clinically significant effects in both directions.

Hyponatraemia and hypovolemic shock with tuberculous meningitis

A 12-year-old boy with tuberculous meningitis and hydrocephalous, after undergoing revision of ventriculo-peritoneal shunt had persistent impairment of sensorium and episodes of hyponatremia (serum sodium 104 to 125 mmol/l), accompanied by polyuria, signs of poor peripheral, perfusion hypotension and low CVP, and high urinary sodium excretion (114-60 mmol/l). A diagnosis of cerebral salt wasting syndrome (CSWS) was made and was treated with saline replacement and fludrocortisone (10 microg/kg/day). Within next 3 days the sensorium, signs of shock, urine output and serum and urinary sodium returned to normal. The case illustrates that life-threatening hyponatremia in a child with neurological illness could be caused by CSWS, which must be differentiated from Syndrome of inappropriate antidiuretic hormone secretion (SIADH), as CSWS requires rigorous salt and volume replacement in contrast to fluid restriction in SIADH.

Cerebral salt wasting: truths, fallacies, theories, and challenges

BACKGROUND

The reported prevalence of cerebral salt wasting has increased in the past three decades. A cerebral lesion and a large natriuresis without a known stimulus to excrete so much sodium (Na ) constitute its essential two elements.

OBJECTIVES

To review the topic of cerebral salt wasting. There is a diagnostic problem because it is difficult to confirm that a stimulus for the renal excretion of Na is absent.

DESIGN

Review article.

INTERVENTION

None.

MAIN RESULTS

Three fallacies concerning cerebral salt wasting are stressed: first, cerebral salt wasting is a common disorder; second, hyponatremia should be one of its diagnostic features; and third, most patients have a negative balance for Na when the diagnosis of cerebral salt wasting is made. Three causes for the large natriuresis were considered: first, a severe degree of extracellular fluid volume expansion could down-regulate transporters involved in renal Na resorption; second, an adrenergic surge could cause a pressure natriuresis; and third, natriuretic agents might become more potent when the effective extracellular fluid volume is high.

CONCLUSIONS

Cerebral salt wasting is probably much less common than the literature suggests. With optimal treatment in the intensive care unit, hyponatremia should not develop.

Prognostic significance of hypernatremia and hyponatremia among patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

Abnormal serum sodium levels (hyponatremia and hypernatremia) are frequently observed during the acute period after aneurysmal subarachnoid hemorrhage (SAH) and may worsen cerebral edema and mass effect. We performed this study to determine the prognostic significance of serum sodium concentration abnormalities.

METHODS

We analyzed prospectively collected data for the placebo treatment group in a clinical trial conducted at 54 neurosurgical centers in North America. The presence of hypernatremia (serum sodium concentration of >145 mmol/L) and hyponatremia (serum sodium concentration of <135 mmol/L) was determined with serum sodium measurements obtained at admission and 3, 6, and 9 days after SAH. The effects of hypernatremia and hyponatremia on the risk of symptomatic vasospasm and on 3-month outcomes were analyzed after adjustment for the following potential confounding factors: age, sex, preexisting hypertension, admission Glasgow Coma Scale score, initial mean arterial pressure, subarachnoid clot thickness, intraventricular blood or intraparenchymal hematoma, ventricular dilation, and aneurysm size and location.

RESULTS

Of 298 patients in the analysis, 58 (19%) developed hypernatremia and 88 (30%) developed hyponatremia. Hypernatremia was significantly associated with poor outcomes (odds ratio, 2.7; 95% confidence interval, 1.2-6.1). A positive correlation was observed between the highest sodium values recorded and Glasgow Outcome Scale scores at 3 months (P < 0.0001 by analysis of variance). Hyponatremia was not associated with 3-month outcomes (odds ratio, 1.9; 95% confidence interval, 0.9-4.3). Neither hypernatremia nor hyponatremia was associated with the risk of symptomatic vasospasm.

CONCLUSION

Hyponatremia seems to be more common than hypernatremia after SAH. However, hypernatremia after SAH is independently associated with poor outcomes, and this association is independent of previously identified outcome predictors, including age and admission Glasgow Coma Scale scores. Further studies are needed to define the underlying mechanism of this association.

Hyponatremia in acute brain disease: the cerebral salt wasting syndrome

Hyponatremia in acute brain disease is a common occurrence, especially after an aneurysmal subarachnoid hemorrhage. Originally, excessive natriuresis, called cerebral salt wasting, and later the syndrome of inappropriate antidiuretic hormone secretion (SIADH), were considered to be the causes of hyponatremia. In recent years, it has become clear that most of these patients are volume-depleted and have a negative sodium balance, consistent with the original description of cerebral salt wasting. Elevated plasma concentrations of atrial or brain natriuretic peptide have been identified as the putative natriuretic factor. Hyponatremia and volume depletion may aggravate neurological symptoms, and timely treatment with adequate replacement of water and NaCl is essential. The use of fludrocortisone to increase sodium reabsorption by the renal tubules may be an alternative approach.

Corticosteroids for acute ischaemic stroke

BACKGROUND

Much of the brain swelling in ischaemic stroke is due to cytotoxic oedema, which is related to cell membrane dysfunction. Early treatment with corticosteroids may help reduce the swelling and improve the outcomes after a stroke.

OBJECTIVES

The objective of this review was to assess the effect of corticosteroids in acute presumed ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched: 10 April 2001) and contacted investigators in the field.

SELECTION CRITERIA

Published randomised trials comparing corticosteroids with placebo or control in people with acute (presumed or definite) ischaemic stroke. Trials were included if treatment began within 48 hours of stroke onset and if clinical outcome was assessed.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied the inclusion criteria, assessed trial quality and extracted the data.

MAIN RESULTS

Seven trials involving 453 people were included. Details of trial quality that may relate to bias were not available from most trials. No difference was shown in the odds of death within one year (odds ratio 1.08, 95% confidence interval 0.68 to 1.72). Treatment did not appear to improve functional outcome in survivors. Six trials reported neurological impairment but pooling the data was impossible because no common scale or time interval was used. The results were inconsistent between individual trials. The only adverse effects reported were small numbers of gastrointestinal bleeds, infections and deterioration of hyperglycaemia across both groups. Results unchanged since last update.

REVIEWER'S CONCLUSIONS

There is not enough evidence to evaluate corticosteroid treatment for people with acute presumed ischaemic stroke. Conclusions unchanged since last update.

The syndrome of inappropriate secretion of antidiuretic hormone and fluid restriction in meningitis--how strong is the evidence?

In patients with meningitis, fluid restriction is recommended to counter the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and to reduce cerebral oedema. However, any effects of an increased plasma level of ADH upon cerebral oedema would be due not to fluid retention but to hypoosmolality. In a literature review of fluid and electrolyte disturbances and the effect of fluid therapy in bacterial/tuberculous meningitis, the prevalence of hyponatraemia, hypoosmolality and SIADH varied considerably; apparently, non-osmotic stimuli for the secretion of ADH, e.g. intracranial hypertension and hypovolaemia, were present in most patients. Neither clinical nor experimental studies have confirmed that fluid restriction reduces the cerebral oedema in meningitis. Furthermore, compared with maintenance therapy, fluid restriction did not improve outcome in a randomized controlled study. Thus, we find no evidence to support the use of fluid restriction in patients with meningitis. Fluid therapy in acute bacterial meningitis should aim at avoiding hypovolaemia and hypoosmolality based on the assumptions that (i) ADH is increased by non-osmotic stimuli; (ii) elevated ADH is less important for cerebral oedema than severe hypoosmolality, which may in itself induce or aggravate oedema; (iii) maintenance fluid therapy aiming at isoosmolality will not worsen neurological outcome; and (iv) hypovolaemia is difficult to detect, and detrimental for cerebral perfusion, in these patients.

Improved efficiency of hypervolemic therapy with inhibition of natriuresis by fludrocortisone in patients with aneurysmal subarachnoid hemorrhage

OBJECT

To reduce the risk of ischemic complications in patients with subarachnoid hemorrhage (SAH), hypervolemic therapy is generally advocated. However, such conventional treatment cannot always ensure the maintenance of an effective intravascular volume expansion, because excessive natriuresis and osmotic diuresis occur after SAH. In this prospective study the authors examined the effects of inhibition of natriuresis with fludrocortisone acetate on intravascular volume expansion during hypervolemic therapy.

METHODS

Thirty patients with SAH were randomized and divided into two groups: controls (Group 1, 15 patients) and patients treated with 0.3 mg/day of fludrocortisone (Group 2, 15 patients). In all patients sodium and fluid intake levels were in excess of maintenance requirements in an attempt to maintain a positive water balance and a central venous pressure (CVP) of 8 to 12 cm H2O. The mean sodium and water intake levels for 14 days after SAH were significantly reduced by fludrocortisone in Group 2 (487+/-34.52 mEq/day and 5159.2+/-249.29 ml/day, respectively; p<0.01) compared with Group 1 (634.2+/-42.86 mEq/day and 6611.7+/-365.67 ml/day). Fludrocortisone significantly reduced the urinary sodium excretion (p<0.01) and urine volume (p<0.01) in parallel, and effectively prevented a negative shift in the sodium as well as water balance (p<0.01). The serum sodium level tended to decrease in Group 1, reaching 135 mEq/L on average, but not in Group 2 (p<0.01). Hyponatremia in Group 1 was always observed at the optimal range of CVP values. A decrease in serum potassium level within the range of 2.8 to 3.5 mEq/L was transiently noted in 11 patients (73.3%) of Group 2, but was easily corrected. Possible side effects of fludrocortisone, such as pulmonary edema, were not encountered.

CONCLUSIONS

Intravascular volume expansion in the presence of excessive natriuresis requires a large sodium and water intake and is often associated with hyponatremia. Inhibition of natriuresis with fludrocortisone can effectively reduce the sodium and water intake required for hypervolemia and prevent hyponatremia at the same time.

Intracranial aneurysms and subarachnoid hemorrhage management of the poor grade patient

Between 20 and 30% of patients who suffer cerebral aneurysm rupture are in poor clinical grade when first evaluated. Management of these patients is controversial and challenging but can be successful with an aggressive proactive approach that begins with in the field resuscitation and continues through rehabilitation. In this article we review the epidemiology, pathology and pathophysiology, clinical features, evaluation, surgical and endovascular management, critical care, cost, and outcome prediction of patients in poor clinical grade after subarachnoid hemorrhage.

Effect of 5% albumin solution on sodium balance and blood volume after subarachnoid hemorrhage

OBJECTIVE

Subarachnoid hemorrhage (SAH) predisposes patients to excessive natriuresis and volume contraction. We studied the effects of postoperative administration of 5% albumin solution on sodium balance and blood volume after SAH. We also sought to identify physiological variables that influence renal sodium excretion after SAH.

METHODS

Forty-three patients with acute SAH were randomly assigned to receive hypervolemia or normovolemia treatment for a period of 7 days after aneurysm clipping. In addition to a base line infusion of normal saline solution (80 ml/hr), 250 ml of 5% albumin solution was administered every 2 hours for central venous pressure (CVP) values of < or =8 mm Hg (hypervolemia group, n = 19) or < or =5 mm Hg (normovolemia group, n = 24).

RESULTS

Both groups demonstrated relative volume expansion in base line measurements. The hypervolemia group received significantly more total fluid, sodium, and 5% albumin solution than did the normovolemia group and had higher CVP values and serum albumin levels (all P < 0.02). Cumulative sodium balance was even in the hypervolemia group and persistently negative in the normovolemia group, because of sodium losses that occurred on Postoperative Days 2 and 3 (P = 0.03). In a multiple-regression analysis of all patients, 24-hour sodium balance correlated negatively with glomerular filtration rate (GFR) and positively with serum albumin levels, after correction for sodium intake (P < 0.0001). Hypervolemia therapy seemed to paradoxically lower GFR (P = 0.10) and had no effect on blood volume, which declined by 10% in both groups. Pulmonary edema requiring diuresis occurred in only one patient in the hypervolemia group.

CONCLUSION

Supplemental 5% albumin solution given to maintain CVP values of >8 mm Hg prevented sodium and fluid losses but did not have an impact on blood volume in our patients, who were hypervolemic in base line measurements. The natriuresis that occurs after SAH may be mediated in part by elevations of GFR. In addition to acting as a colloid volume expander, 5% albumin solution lowers the GFR and promotes renal sodium retention after SAH. These properties may limit the amount of total fluid required to maintain a given CVP value and hence may minimize the frequency of pulmonary edema.

Cerebral salt wasting syndrome: a review

Hyponatremia is frequently seen in neurosurgical patients and is often attributed to inappropriate secretion of antidiuretic hormone. A number of studies in recent years have shown that hyponatremia in many patients with intracranial disease may actually be caused by cerebral salt wasting, in which a renal loss of sodium leads to hyponatremia and a decrease in extracellular fluid volume. The appropriate treatment of cerebral salt wasting fluid and salt replacement, is opposite from the usual treatment of hyponatremia caused by inappropriate secretion of antidiuretic hormone. This review summarizes the evidence in favor of cerebral salt wasting in patients with intracranial disease, examines the possible mechanisms responsible for this phenomenon, and discusses methods for diagnosis and treatment.