Brain Natriuretic Peptide Concentrations After Aneurysmal Subarachnoid Hemorrhage: Relationship with Hypovolemia and Hyponatremia

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management.

METHODS

Narrative review of the literature.

RESULTS

Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes.

CONCLUSIONS

In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Endocrine dysregulation in aneurysmal subarachnoid haemorrhage

INTRODUCTION

Aneurysmal Subarachnoid haemorrhage (aSAH) is one of the most common causes of neurocritical care admission. Consistent evidence has been suggestive of endocrine dysregulation in aSAH. This review aims to provide an up-to-date presentation of the available evidence regarding endocrine dysregulation in aneurysmal subarachnoid haemorrhage.

METHODS

A comprehensive literature search was performed using PubMed database. All available evidence related to endocrine dysregulation in hypothalamic-pituitary hormones, adrenal hormones and natriuretic peptides after aSAH, published since 2010, were reviewed.

RESULTS

There have been reports of varying prevalence of dysregulation in hypothalamic-pituitary and adrenal hormones in aSAH. The cause of this dysregulation and its pattern remain unclear. Hypothalamic-pituitary and adrenal dysregulation have been associated with higher incidence of poor neurological outcome and increased mortality. Whilst there is evidence that long-term dysregulation of these axes may also develop, it appears to be less frequent than the acute-phase dysregulation and transient in pattern. Increased levels of catecholamines have been reported in the hyper-acute phase of aSAH with reported inconsistent correlation with the outcomes and the complications of the disease. There is growing evidence that of a causal link between the endocrine dysregulation and the development of hyponatraemia and delayed cerebral ischaemia, in the acute phase of aSAH. However, the pathophysiological mechanism and pattern of endocrine dysregulation which could be causally associated with these complications still remain debatable.

CONCLUSION

The evidence, mainly from small observational and heterogeneous in methodology studies, is suggestive of adverse effects of the endocrine dysregulation on the outcome and the incidence of complications of the disease. However, the cause of this dysregulation and a pathophysiological mechanism that could link its presence with the development of acute complications and the outcome of the aSAH remain unclear. Further research is warranted to elucidate the clinical significance of endocrine dysregulation in subarachnoid haemorrhage.

Assessment of BNP and BDNF results in elective endovascular cerebral aneurysm treatment

BACKGROUND

B-type natriuretic peptide (BNP) levels increase with an increase in intracranial pressure. A decrease in BNP levels has been found to be associated with patient positive prognosis. Brain-derived neurotrophic factor (BDNF) levels decrease in patients with acute stroke.

AIMS

To compare the BNP and BDNF values in serum before and after elective endovascular cerebral aneurysm treatment (ECAT).

METHODS

A total of 50 patients who underwent elective ECAT were included in the study. Exclusion criteria were determined to be history of heart failure or heart attack (n = 8), renal failure (n = 5), subarachnoid hemorrhage (n = 4), or previous aneurysm clip procedure (n = 3). Intravenous blood samples were obtained from 30 patients who underwent elective ECAT before and after treatment. After centrifugation, the BNP and BDNF values in serum were obtained with the ELISA method and compared.

RESULTS

This study included 19 female and 11 male patients, aged between 24 and 75 years. The average age of the patients was 51.27 ± 13.31 years. The median BDNF values did not change significantly after ECAT (before the endovascular procedure: 3.1 ± 1.3 pg/dl; after the endovascular procedure: 2.8 ± 0.9 pg/dl, p = 0.16). Median BNP levels decreased significantly after ECAT (before the endovascular procedure: 617.50 ± 483.11 pg/ml; after the endovascular procedure: 395.00 ± 352.15 pg/ml, p < 0.001).

CONCLUSIONS

After elective endovascular cerebral aneurysm treatment, the BNP values in serum decreased significantly, and the BDNF values in serum did not change significantly.

Hyponatraemia and hypernatraemia: Disorders of Water Balance in Neurosurgery

Disorders of tonicity, hyponatraemia and hypernatraemia, are common in neurosurgical patients. Tonicity is sensed by the circumventricular organs while the volume state is sensed by the kidney and peripheral baroreceptors; these two signals are integrated in the hypothalamus. Volume is maintained through the renin-angiotensin-aldosterone axis, while tonicity is defended by arginine vasopressin (antidiuretic hormone) and the thirst response. Edelman found that plasma sodium is dependent on the exchangeable sodium, potassium and free-water in the body. Thus, changes in tonicity must be due to disproportionate flux of these species in and out of the body. Sodium concentration may be measured by flame photometry and indirect, or direct, ion-sensitive electrodes. Only the latter method is not affected by changes in plasma composition. Classification of hyponatraemia by the volume state is imprecise. We compare the tonicity of the urine, given by the sodium potassium sum, to that of the plasma to determine the renal response to the dysnatraemia. We may then assess the activity of the renin-angiotensin-aldosterone axis using urinary sodium and fractional excretion of sodium, urate or urea. Together, with clinical context, these help us determine the aetiology of the dysnatraemia. Symptomatic individuals and those with intracranial catastrophes require prompt treatment and vigilant monitoring. Otherwise, in the absence of hypovolaemia, free-water restriction and correction of any reversible causes should be the mainstay of treatment for hyponatraemia. Hypernatraemia should be corrected with free-water, and concurrent disorders of volume should be addressed. Monitoring for overcorrection of hyponatraemia is necessary to avoid osmotic demyelination.

Higher plasma NT-proBNP levels correlate with syndrome of inappropriate antidiuretic hormone and poor prognosis in neurological patients

Background

Hyponatremia induced by syndrome of inappropriate antidiuretic hormone secretion (SIADH) was common electrolyte disturbance encountered in critically ill neurological diseases, which has normal or increased fluid volume. Brain natriuretic peptide (BNP), which is released in equal proportion to N-terminal pro-brain natriuretic peptide (NT-proBNP), plays vital roles in regulation of volume status. The relationship between SIADH and NT-proBNP levels in neurological diseases has rarely been reported.

Methods

A retrospective cross-sectional study was conducted to analyze plasma NT-proBNP levels in 33 patients with SIADH and 23 controlled eunatremic patients with neurological diseases.

Results

Baseline NT-proBNP levels were compared between two groups [SIADH group: median 311 pg/mL, interquartile range (IQR) 110–768 pg/mL] vs. eunatremic group: median 46 pg/mL, IQR, 12–96 pg/mL) (P<0.05). Plasma NT-proBNP levels were markedly increased in hyponatremic patients who had two or more complications than those who had less complication (P<0.05). In SIADH patients, NT-proBNP levels in remission phase were lower to levels at baseline. Furthermore, no death was seen in eunatremic patients, while five SIADH patients died from complications.

Conclusions

SIADH had higher plasma NT-proBNP levels and poorer prognosis compared to eunatremic neurological patients. NT-proBNP serves as a biomarker of disease severity while not extracellular volume (ECV) status in critically ill neurological patients.

The Prognostic Role of Lactate Concentrations after Aneurysmal Subarachnoid Hemorrhage

Blood lactate concentrations are often used to assess global tissue perfusion in critically ill patients; however, there are scarce data on lactate concentrations after subarachnoid hemorrhage (SAH). We aimed to assess the prognostic role of serial blood lactate measurements on hospital mortality and neurological outcomes at 3 months after SAH. We reviewed all SAH patients admitted to the intensive care unit from 2007 to 2019 and recorded the highest daily arterial lactate concentration for the first 6 days. Patients with no lactate concentration were excluded. Hyperlactatemia was defined as a blood lactate concentration >2.0 mmol/L. A total of 456 patients were included: 158 (35%) patients died in hospital and 209 (46%) had an unfavorable outcome (UO) at 3 months. The median highest lactate concentration was 2.7 (1.8–3.9) mmol/L. Non-survivors and patients with UO had significantly higher lactate concentrations compared to other patients. Hyperlactatemia increased the chance of dying (OR 4.19 (95% CI 2.38–7.39)) and of having UO in 3 months (OR 4.16 (95% CI 2.52–6.88)) after adjusting for confounding factors. Therefore, initial blood lactate concentrations have prognostic implications in patients with SAH; their role in conjunction with other prognostic indicators should be evaluated in prospective studies.

N-Terminal Pro-Brain Natriuretic Peptide Concentrations After Hypertensive Intracerebral Hemorrhage: Relationship With Hematoma Size, Hyponatremia, and Intracranial Pressure

Introduction:

The role of N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with hypertensive intracerebral hemorrhage (HICH) is poorly understood. This study aimed to investigate the secretion pattern of NT-proBNP in patients with HICH and to assess its relationship with hematoma size, hyponatremia, and intracranial pressure (ICP).

Methods:

This prospective study enrolled 147 isolated patients with HICH. Blood samples were obtained from each patient, and values of serum NT-proBNP, hematoma size, blood sodium, and ICP were collected for each patient.

Results:

The peak-to-mean concentration of NT-proBNP was 666.8 ± 355.1 pg/mL observed on day 4. The NT-proBNP levels in patients with hematoma volume >30 mL were significantly higher than those in patients with hematoma volume <30 mL ( P < .05). In patients with severe HICH, the mean concentration of NT-proBNP was statistically higher than that in patients with mild–moderate HICH ( P < .05), and the mean level of NT-proBNP in hyponatremia group was significantly higher than that in normonatremic group ( P < .05). In addition, the linear regression analysis indicated that serum NT-proBNP concentrations were positively correlated with ICP ( r = .703, P < .05) but negatively with blood sodium levels only in patients with severe HICH ( r = −.704, P < .05). The serum NT-proBNP levels on day 4 after admission were positively correlated with hematoma size ( r = .702, P < .05).

Conclusion:

The NT-proBNP concentrations were elevated progressively and markedly at least in the first 4 days after HICH and reached a peak level on the fourth day. The NT-proBNP levels on day 4 were positively correlated with hematoma size. There was a notable positive correlation between plasma NT-proBNP levels and ICP in patients with severe HICH. Furthermore, only in patients with severe HICH, the plasma NT-proBNP levels presented a significant correlation with hyponatremia, which did not occur in patients with mild–moderate HICH.

Diagnosis and Treatment of Cerebral Salt Wasting Syndrome With Cryptococcal Meningitis in HIV Patient

Hyponatremia is one of the most common electrolyte imbalances in HIV patients. The differential diagnosis may include hypovolemic hyponatremia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and adrenal insufficiency. Here, we describe a case of hyponatremia secondary to cerebral salt wasting syndrome (CSWS) in an HIV patient with cryptococcal meningitis. A 52-year-old man with a history of diabetes and HIV was admitted for headache and found to have cryptococcal meningitis. He was also found to have asymptomatic hyponatremia. He had signs of hypovolemia, such as orthostatic hypotension, dry mucosa, decreased skin turgor, hemoconcentration, contraction alkalosis, and high BUN/Cr ratio. The laboratory findings revealed sodium of 125 mmol/L, potassium of 5.5 mmol/L, urine osmolality of 522 mOsm/kg, urine sodium of 162 mmol/L, and urine chloride of 162 mmol/L. We started normal saline for hypovolemia, each 1 L prior and after amphotericin therapy. However, hypovolemia did not improve significantly despite IV fluid. Cosyntropin stimulation test was negative, and renin level was 0.25 ng·mL·h, with the aldosterone level of <1 ng/dL, the serum brain natriuretic peptide of 15 pg/mL, and serum uric acid of 2.8 mg/dL. The diagnosis of CSWS was suspected, fludrocortisone was tried, and hypovolemia and hyponatremia improved. Cryptococcal meningitis in HIV patients can present with CSWS, and the distinction between CSWS and SIADH is important because the treatment for CSWS is different than that of SIADH. Both share a similar clinical picture except that CSWS presents with constant hypovolemia despite volume replacement. Salt tablets, normal saline, or fludrocortisone can be used for treatment.

Mid-regional pro-adrenomedullin (MR-proADM), a marker of positive fluid balance in critically ill patients: results of the ENVOL study

Background

The optimal control of blood volume without fluid overload is a main challenge in the daily care of intensive care unit (ICU) patients. Accordingly this study focused on the identification of biomarkers to help characterize fluid overload status.

Methods

Sixty-seven patients were studied from ICU admission to day 7 (D₇). Blood and urine samples were taken daily and sodium and water balance strictly calculated resulting in a total cumulative assessment of ∆Na⁺ and ∆H₂O. Furthermore, plasmatic biomarkers (cortisol, epinephrine, norepinephrine, renin, angiotensin II, aldosterone, pro-endothelin, copeptine, atrial natriuretic peptide, erythropoietin, mid-regional pro-adrenomedullin (MR-proADM)) and Sequential Organ Failure Assessment (SOFA) scores were measured at D₂, D₅ and D₇. Blood volumes were measured with ⁵¹Cr fixed on red blood cells at D₂ and D₇.

Results

The ∆Na⁺ or ∆H₂O were increased in all patients but never related to blood volumes at D₂ nor D₇. Total blood volumes were at normal values with constantly low red blood cell volumes and normal or decreased plasmatic volume. Weight, plasmatic proteins, and hemoglobin were weakly related to ∆Na⁺ or ∆H₂O. Amongst all tested biomarkers, only MR-proADM was related to sodium and fluid overload. This biomarker was also a predictor of SOFA scores.

Conclusions

Plasmatic concentration in MR-proADM seems to be a good surrogate for evaluation of ∆Na⁺ or ∆H₂O and predicts sodium and extracellular fluid overload.

Trial registration

ClinicalTrials.gov: NCT01858675 in May 13, 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1540-x) contains supplementary material, which is available to authorized users.

Role of PiCCO monitoring for the integrated management of neurogenic pulmonary edema following traumatic brain injury: A case report and literature review

Neurogenic pulmonary edema (NPE) is occasionally observed in patients with traumatic brain injury (TBI); however, this condition is often underappreciated. NPE is frequently misdiagnosed due to its atypical clinical performance, thus delaying appropriate treatment. A comprehensive management protocol of NPE in patients with TBI has yet to be established. The current study reported the case of a 67-year-old man with severe TBI who was transferred to our intensive care unit (ICU). On day 7 after hospitalization, the patient suddenly suffered tachypnea, tachycardia, systemic hypertension and hypoxemia during lumbar cistern drainage. Intravenous diuretics, tranquilizer and glucocorticoid were administered due to suspected left heart failure attack. Chest radiography examination supported the diagnosis of pulmonary edema; however, hypotension and hypovolemia were subsequently observed. Pulse index continuous cardiac output (PiCCO) hemodynamic monitoring and bedside echocardiography were performed, which excluded the diagnosis of cardiac pulmonary edema, and thus the diagnosis of NPE was confirmed. Goal-directed therapy by dynamic PiCCO monitoring was then implemented. In addition, levosimendan, an inotropic agent, was introduced to improve cardiac output. The patient had complete recovered from pulmonary edema and regained consciousness on day 11 of hospitalization. The current case demonstrated that PiCCO monitoring may serve a central role in the integrated management of NPE in patients with TBI. Levosimendan may be a potential medicine in treating cardiac dysfunction, along with its benefit from improving neurological function in NPE patients.

Hyponatremia in Neurotrauma: The Role of Vasopressin

Hyponatremia is frequent in patients suffering from traumatic brain injury, subarachnoid hemorrhage, or following intracranial procedures, with approximately 20% having a decreased serum sodium concentration to <125 mmol/L. The pathophysiology of hyponatremia in neurotrauma is not completely understood, but in large part is explained by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). The abnormal water and/or sodium handling creates an osmotic gradient promoting the shift of water into brain cells, thereby worsening cerebral edema and precipitating neurological deterioration. Unless hyponatremia is corrected promptly and effectively, morbidity and mortality increases through seizures, elevations in intracranial pressure, and/or herniation. The excess mortality in patients with severe hyponatremia (<125 mmol/L) extends beyond the time frame of hospital admission, with a reported mortality of 20% in hospital and 45% within 6 months of follow-up. Current options for the management of hyponatremia include fluid restriction, hypertonic saline, mineralocorticoids, and osmotic diuretics. However, the recent development of vasopressin receptor antagonists provides a more physiological tool for the management of excess water retention and consequent hyponatremia, such as occurs in SIADH. This review summarizes the existing literature on the pathophysiology, clinical features, and management of hyponatremia in the setting of neurotrauma.

Polyuria and cerebral vasospasm after aneurysmal subarachnoid hemorrhage

Background

Natriuresis with polyuria is common after aneurysmal subarachnoid hemorrhage (aSAH). Previous studies have shown an increased risk of symptomatic cerebral vasospasm or delayed cerebral ischemia (DCI) in patients with hyponatremia and/or the cerebral salt wasting syndrome (CSW). However, natriuresis may occur in the absence of hyponatremia or hypovolemia and it is not known whether the increase in DCI in patients with CSW is secondary to a concomitant hypovolemia or because the physiology that predisposes to natriuretic peptide release also predisposes to cerebral vasospasm. Therefore, we investigated whether polyuria per se was associated with vasospasm and whether a temporal relationship existed.

Methods

A retrospective review of patients with aSAH was performed. Exclusion criteria were admission more than 48 h after aneurysmal rupture, death within 5 days, and the development of diabetes insipidus or acute renal failure. Polyuria was defined as >6 liters of urine in a 24 h period. Vasospasm was defined as a mean velocity > 120 m/s on Transcranial Doppler Ultrasonography (TCDs) or by evidence of vasospasm on computerized tomography (CT) or catheter angiography. Multivariable logistic regression was performed to assess the relationship between polyuria and vasospasm.

Results

95 patients were included in the study. 51 had cerebral vasospasm and 63 met the definition of polyuria. Patients with polyuria were significantly more likely to have vasospasm (OR 4.301, 95 % CI 1.378–13.419) in multivariate analysis. Polyuria was more common in younger patients (52 vs 68, p <.001) but did not impact mortality after controlling for age and disease severity. The timing of the development of polyuria was clustered around the diagnosis of vasospasm and patients with polyuria developed vasospasm faster than those without polyuria.

Conclusions

Polyuria is common after aSAH and is significantly associated with cerebral vasospasm. The development of polyuria may be temporally related to the development of vasospasm. An increase in urine volume may be a useful clinical predictor of patients at risk for vasospasm.

Diagnosis and Management of Hyponatremia in Patients with Aneurysmal Subarachnoid Hemorrhage

Hyponatremia is the most common, clinically-significant electrolyte abnormality seen in patients with aneurysmal subarachnoid hemorrhage. Controversy continues to exist regarding both the cause and treatment of hyponatremia in this patient population. Lack of timely diagnosis and/or providing inadequate or inappropriate treatment can increase the risk of morbidity and mortality. We review recent literature on hyponatremia in subarachnoid hemorrhage and present currently recommended protocols for diagnosis and management.

Monitoring biomarkers of cellular injury and death in acute brain injury

BACKGROUND

Molecular biomarkers have revolutionalized diagnosis and treatment of many diseases, such as troponin use in myocardial infarction. Urgent need for high-fidelity biomarkers in neurocritical care has resulted in numerous studies reporting potential candidate biomarkers.

METHODS

We performed an electronic literature search and systematic review of English language articles on cellular/molecular biomarkers associated with outcome and with disease-specific secondary complications in adult patients with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), traumatic brain injury (TBI), and post-cardiac arrest hypoxic ischemic encephalopathic injuries (HIE).

RESULTS

A total of 135 articles were included. Though a wide variety of potential biomarkers have been identified, only neuron-specific enolase has been validated in large cohorts and shows 100% specificity for poor outcome prediction in HIE patients not treated with therapeutic hypothermia. There are many promising candidate blood and CSF biomarkers in SAH, AIS, ICH, and TBI, but none yet meets criteria for routine clinical use.

CONCLUSION

Current studies vary significantly in patient selection, biosample collection/processing, and biomarker measurement protocols, thereby limiting the generalizability of overall results. Future large prospective studies with standardized treatment, biosample collection, and biomarker measurement and validation protocols are necessary to identify high-fidelity biomarkers in neurocritical care.

Neurosurgical Hyponatremia

Hyponatremia is a frequent electrolyte imbalance in hospital inpatients. Acute onset hyponatremia is particularly common in patients who have undergone any type of brain insult, including traumatic brain injury, subarachnoid hemorrhage and brain tumors, and is a frequent complication of intracranial procedures. Acute hyponatremia is more clinically dangerous than chronic hyponatremia, as it creates an osmotic gradient between the brain and the plasma, which promotes the movement of water from the plasma into brain cells, causing cerebral edema and neurological compromise. Unless acute hyponatremia is corrected promptly and effectively, cerebral edema may manifest through impaired consciousness level, seizures, elevated intracranial pressure, and, potentially, death due to cerebral herniation. The pathophysiology of hyponatremia in neurotrauma is multifactorial, but most cases appear to be due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Classical treatment of SIADH with fluid restriction is frequently ineffective, and in some circumstances, such as following subarachnoid hemorrhage, contraindicated. However, the recently developed vasopressin receptor antagonist class of drugs provides a very useful tool in the management of neurosurgical SIADH. In this review, we summarize the existing literature on the clinical features, causes, and management of hyponatremia in the neurosurgical patient.

Impact of clipping versus coiling on postoperative hemodynamics and pulmonary edema after subarachnoid hemorrhage

Volume management is critical for assessment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). This multicenter prospective cohort study compared the impact of surgical clipping versus endovascular coiling on postoperative hemodynamics and pulmonary edema in patients with SAH. Hemodynamic parameters were measured for 14 days using a transpulmonary thermodilution system. The study included 202 patients, including 160 who underwent clipping and 42 who underwent coiling. There were no differences in global ejection fraction (GEF), cardiac index, systemic vascular resistance index, or global end-diastolic volume index between the clipping and coiling groups in the early period. However, extravascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI) were significantly higher in the clipping group in the vasospasm period. Postoperative C-reactive protein (CRP) level was higher in the clipping group and was significantly correlated with postoperative brain natriuretic peptide level. Multivariate analysis found that PVPI and GEF were independently associated with high EVLWI in the early period, suggesting cardiogenic edema, and that CRP and PVPI, but not GEF, were independently associated with high EVLWI in the vasospasm period, suggesting noncardiogenic edema. In conclusion, clipping affects postoperative CRP level and may thereby increase noncardiogenic pulmonary edema in the vasospasm period. His trial is registered with University Hospital Medical Information Network UMIN000003794.

Predictors of increased cumulative serum levels of the N-terminal prohormone of brain natriuretic peptide 4 days after acute spontaneous subarachnoid hemorrhage

Object

The rupture of an intracranial aneurysm is followed by increased intracranial pressure and decreased cerebral blood flow. A major systemic stress reaction follows, presumably to restore cerebral blood flow. However, this reaction can also cause adverse effects, including myocardial abnormalities, which are common and can be serious, and increased levels of natriuretic peptides, especially brain natriuretic peptide (BNP). The association of BNP with fluid and salt balance, vasospasm, brain ischemia, and cardiac injury has been studied but almost exclusively regarding events after admission. Brain natriuretic peptide has also been measured at various time points and analyzed in different ways statistically. The authors approached BNP measurement in a new way; they used the calculated area under the curve (AUC) for the first 4 days to quantitatively measure the BNP load during the first critical part of the disease state. Their rationale was a suspicion that early BNP load is a marker of the severity of the ictus and will influence the subsequent course of the disease by disturbing the fluid and salt balance.

Methods

The study included 156 patients with acute spontaneous subarachnoid hemorrhage (SAH). Mean patient age was 59.8 ± 11.2 years, and 105 (67%) of the patients were female. An aneurysm was found in 138 patients. A total of 82 aneurysms were treated by endovascular coiling, 50 were treated by surgery, and 6 were untreated. At the time of admission, serum samples were collected for troponin-I analysis and for the N-terminal prohormone of BNP (NT-proBNP); daily thereafter, samples were collected for the NT-proBNP analysis. The cumulative BNP load was calculated as the AUC for NT-proBNP during the first 4 days. The following variables were studied in terms of their influence on the AUC for NT-proBNP: sex, age, World Federation of Neurosurgical Societies grade of SAH, Fisher grade, angiographic result, treatment of aneurysm, clinical neurological deterioration, verified infections, vasospasm treatment, and 6-month outcome.

Results

The AUC for NT-proBNP was larger when variables indicated a more severe SAH. These variables were higher Fisher and World Federation of Neurosurgical Societies grades, high levels of troponin-I at admission, an aneurysm, neurological deficits, and infections. The AUC for NT-proBNP was also larger among women, older patients, and patients with poor outcomes. Linear regression showed that the best predicting model for large AUC for NT-proBNP was the combination of the following: female sex, high levels of troponin-I, an aneurysm, neurological deficits, and advanced age.

Conclusions

The cumulative BNP load during the first days after SAH can be predicted by variables describing the severity of the disease already known at the time of admission. This information can be used to identify patients at risk for an adverse course of the disease.

Hyponatremia following mild/moderate subarachnoid hemorrhage is due to SIAD and glucocorticoid deficiency and not cerebral salt wasting

CONTEXT

Hyponatremia is common after acute subarachnoid hemorrhage (SAH) but the etiology is unclear and there is a paucity of prospective data in the field. The cause of hyponatremia is variously attributed to the syndrome of inappropriate antidiuresis (SIAD), acute glucocorticoid insufficiency, and the cerebral salt wasting syndrome (CSWS).

OBJECTIVE

The objective was to prospectively determine the etiology of hyponatremia after SAH using sequential clinical examination and biochemical measurement of plasma cortisol, arginine vasopressin (AVP), and brain natriuretic peptide (BNP).

DESIGN

This was a prospective cohort study.

SETTING

The setting was the National Neurosurgery Centre in a tertiary referral centre in Dublin, Ireland.

PATIENTS

One hundred patients with acute nontraumatic aneurysmal SAH were recruited on presentation.

INTERVENTIONS

Clinical examination and basic biochemical evaluation were performed daily. Plasma cortisol at 0900 hours, AVP, and BNP concentrations were measured on days 1, 2, 3, 4, 6, 8, 10, and 12 following SAH. Those with 0900 hours plasma cortisol<300 nmol/L were empirically treated with iv hydrocortisone.

MAIN OUTCOME MEASURES

Plasma sodium concentration was recorded daily along with a variety of clinical and biochemical criteria. The cause of hyponatremia was determined clinically. Later measurement of plasma AVP and BNP concentrations enabled a firm biochemical diagnosis of the cause of hyponatremia to be made.

RESULTS

Forty-nine of 100 developed hyponatremia<135 mmol/L, including 14/100<130 mmol/L. The cause of hyponatremia, and determined by both clinical examination and biochemical hormone measurement, was SIAD in 36/49 (71.4%), acute glucocorticoid insufficiency in 4/49 (8.2%), incorrect iv fluids in 5/49 (10.2%), and hypovolemia in 5/49 (10.2%). There were no cases of CSWS.

CONCLUSIONS

The most common cause of hyponatremia after acute nontraumatic aneurysmal SAH is SIAD. Acute glucocorticoid insufficiency accounts for a small but significant number of cases. We found no cases of CSWS.

Hormonal dysfunction in neurocritical patients

PURPOSE OF REVIEW

Acute brain injury results in widespread systemic endocrine dysfunction and affects how we care for patients. We review the existing literature on incidence, type and duration of endocrine dysfunction with special focus on the pituitary dependent function.

RECENT FINDINGS

Acute studies document widespread alterations of the hypothalamic-pituitary-adrenal axis, disruption of the anterior hypothalamus related hormones, and alteration of regulation of sodium and fluid balance. Diagnostic testing and therapeutic intervention are outlined in this review. Relative adrenal insufficiency and cerebral salt wasting are the two main forms of endocrine dysfunction in neurocritical care patients.

SUMMARY

Surveillance for endocrine dysfunction and early treatment with hormonal replacement may be life-saving in neurologic critically ill patients.

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.