Hyponatremia in neurosurgical patients: clinical guidelines development

Predictive value of hyponatremia for short-term mortality in supratentorial spontaneous intracerebral hemorrhage: a single center study

Background

Hyponatremia is a common electrolyte disturbance in patients with neurological disease; however, its predictive role for outcome in patients with supratentorial spontaneous intracerebral hemorrhage (sICH) is controversial. This study aims to explore the association between hyponatremia within 7 days after bleeding and 90-day mortality in patients with supratentorial sICH.

Methods

A retrospective analysis was conducted at our institution. Patients with sICH meeting the inclusion criteria were enrolled in this study. Multivariate regression analyses were performed to determine the predictive value of hyponatremia (serum sodium <135 mmol/L) for 90-day mortality and functional outcome. Subgroup analysis was performed based on the degree and duration of hyponatremia and therapeutic strategies. The Spearman correlation test was performed to explore the relationship between hyponatremia severity and duration with variables in a multivariate regression model. Kaplan-Meier curve was depicted to reveal the relationship between hyponatremia and mortality. The receiver operating characteristic (ROC) curve was plotted to show the diagnostic effect of the minimum concentration of serum sodium (sodiummin) on 90-day mortality.

Results

A total of 960 patients were enrolled, 19.6% (188) of whom were patients with hyponatremia and 26.0% (250) had 90-day mortality. The incidence of hyponatremia was roughly 2.5 times in non-survivors compared with survivors (34.8% vs. 14.2%). Multivariate regression analysis revealed that hyponatremia was the independent predictor of 90-day mortality (OR 2.763, 95%CI 1.836-4.157) and adverse outcome (OR 3.579, 95%CI 2.332-6.780). Subgroup analysis indicated an increased trend in mortality risk with both duration (more or less than 48 h) and severity of hyponatremia (mild, moderate, and severe) and confirmed the predictive value of hyponatremia for mortality in patients undergoing surgical intervention (external ventricular drainage, craniotomy, and decompressive craniectomy; all p < 0.05). The Spearman correlation test indicated no moderate or strong relationship between hyponatremia severity and duration with other variables in the multivariate model (all |rs| < 0.4). The ROC curve suggested the moderate diagnostic performance of sodiummin for mortality in both general patients and subgroups of therapeutic method patients (AUC from 0.6475 to 0.7384).

Conclusion

Hyponatremia occurring in the first 7 days after bleeding is an independent predictor of 90-day morality and adverse outcome. Rigorous electrolyte scrutiny in patients treated surgically is required.

Association between preoperative serum sodium and postoperative 30-day mortality in adult patients with tumor craniotomy

BACKGROUND

Limited data exist regarding preoperative serum sodium (Na) and 30-day mortality in adult patients with tumor craniotomy. Therefore, this study investigates their relationship.

METHODS

A secondary retrospective analysis was performed using data from the ACS NSQIP database (2012-2015). The principal exposure was preoperative Na. The outcome measure was 30-day postoperative mortality. Binary logistic regression modeling was conducted to explore the link between them, and a generalized additive model and smooth curve fitting were applied to evaluate the potential association and its explicit curve shape. We also conducted sensitivity analyses and subgroup analyses.

RESULTS

A total of 17,844 patients (47.59% male) were included in our analysis. The mean preoperative Na was 138.63 ± 3.23 mmol/L. The 30-day mortality was 2.54% (455/17,844). After adjusting for covariates, we found that preoperative Na was negative associated with 30-day mortality. (OR = 0.967, 95% CI:0.941, 0.994). For patients with Na ≤ 140, each increase Na was related to a 7.1% decreased 30-day mortality (OR = 0.929, 95% CI:0.898, 0.961); for cases with Na > 140, each increased Na unit was related to a 8.8% increase 30-day mortality (OR = 1.088, 95% CI:1.019, 1.162). The sensitivity analysis and subgroup analysis indicated that the results were robust.

CONCLUSIONS

This study shows a positive and nonlinear association between preoperative Na and postoperative 30-day mortality in adult patients with tumor craniotomy. Appropriate preoperative Na management and maintenance of serum Na near the inflection point (140) may reduce 30-day mortality.

Cerebral Salt Wasting Syndrome Following Right Occipital Craniotomy in a Patient With Metastatic Lung Adenocarcinoma

Cerebral salt wasting syndrome (CSW) is characterized by excessive natriuresis leading to hyponatremia and hypovolemia. It is commonly encountered among patients who have undergone brain trauma or subarachnoid hemorrhage. The occurrence of CSW after neurosurgical procedures has been frequently reported in the pediatric age group; however, it is a rare phenomenon in adults. We describe the case of a 59-year-old female who developed symptoms of polyuria and polydipsia after a right occipital craniotomy.

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland

BACKGROUND

Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH.

METHODS

We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (<135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration >10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression.

RESULTS

175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was >3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I-III, modified Fisher 2-4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia.

CONCLUSIONS

In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care.

Profound hyponatremia and dehydration: A case of cisplatin induced renal salt wasting syndrome

Cisplatin is a well-known chemotherapeutic agent that can be associated with hyponatremia. It is known to be associated with a multitude of renal disorders including acute kidney injury with reduced glomerular filtration, Fanconi syndrome, and renal tubular acidosis, nephrogenic diabetes insipidus and renal salt wasting syndrome. We report a case of an elderly male presenting with significant recurrent hyponatremia, and prerenal azotemia. With recent exposure to cisplatin along with significant hypovolemia and urinary loss of sodium, he was diagnosed to have cisplatin induced renal salt wasting syndrome.

Predictors of in-hospital mortality in stroke patients

In-hospital mortality is a good indicator to assess the efficacy of stroke care. Identifying the predictors of in-hospital mortality is important to advance the stroke outcome and plan the future strategies of stroke management. This was a prospective cohort study conducted at a tertiary referral center in Sri Lanka to identify the possible predictors of in-hospital mortality. The study included 246 confirmed stroke patients. The diagnosis of stroke was established on the clinical history, examination and neuroimaging. The differentiation of stroke in to haemorrhagic type and ischaemic type was based on the results of computed tomography. In all patients, demographic data, comorbidities, clinical signs (pulse rate, respiratory rate, systolic blood pressure, diastolic blood pressure, on admission Glasgow Coma Scale (GCS) score) and imaging findings were recorded. All patients were followed up throughout their hospital course and the in-hospital mortality was recorded. In hospital mortality was defined as the deaths which occurred due to stroke after 24 hours of hospital admission. The incidence of in-hospital mortality was 11.7% (95% confidence interval: 8-16.4). The mean day of in-hospital deaths to occur was 5.9 days (SD ± 3.8 Min 2 Max 20). According to multivariate logistic regression analysis on admission GCS score (Odds Ratio (OR)-0.71) and haemorrhagic stroke type (OR-5.12) predict the in-hospital mortality. The area under the curve of receiver operating curve drawn for the on admission GCS score was 0.78 with a sensitivity of 96.31% and specificity of 41.38% for a patient presented with the GCS score of <10. On admission GCS and haemorrhagic stroke are independent predictors of in-hospital mortality. Thus, a special attention should be given to the patients with low GCS score and haemorrhagic strokes for reducing rates of in-hospital mortality.

Investigation and management of serum sodium after subarachnoid haemorrhage (SaSH): a survey of practice in the United Kingdom and Republic of Ireland

BACKGROUND

Hyponatraemia is a common complication of aneurysmal subarachnoid haemorrhage (SAH). We aimed to determine current neurosurgical practice for the identification, investigation and management of hyponatraemia after SAH.

METHODS

An online questionnaire was completed by UK and Irish neurosurgical trainees and consultant collaborators in the Sodium after Subarachnoid Haemorrhage (SaSH) audit.

RESULTS

Between August 2019 and June 2020, 43 responses were received from 31 of 32 UK and Ireland adult neurosurgical units (NSUs). All units reported routine measurement of serum sodium either daily or every other day. Most NSUs reported routine investigation of hyponatraemia after SAH with paired serum and urinary osmolalities (94%), urinary sodium (84%), daily fluid balance (84%), but few measured glucose (19%), morning cortisol (13%), or performed a short Synacthen test (3%). Management of hyponatraemia was variable, with units reporting use of oral sodium supplementation (77%), fluid restriction (58%), hypertonic saline (55%), and fludrocortisone (19%).

CONCLUSIONS

Reported assessment of serum sodium after SAH was consistent between units, whereas management of hyponatraemia varied. This may reflect the lack of a specific evidence-base to inform practice.

Coexisting Cerebral Salt Wasting Syndrome and Central Diabetes Insipidus in a Patient with Posterior Cerebrovascular Infarction: A Case Report

<b><i>Background:</i></b> Disorders of sodium balance are common in critically ill neurologic patients. However, the coexisting of cerebral salt wasting syndrome (CSW) and central diabetes insipidus (CDI) in such patients is rare. Early recognition of such conditions is challenging, thus making the prognosis ominous. <b><i>Case Presentation:</i></b> A 50-year-old male patient presented with acute posterior cerebrovascular infarction complicated by several attacks of disturbed sodium homeostasis. The first attack manifested as hypernatremia (up to 161 mmol/L) and polyuria with high urine sodium (188 mmol/L) could only be explained by CSW on top of CDI. Especially the patient was not receiving any hyperosmolar or sodium-containing fluids. Serum sodium was corrected by desmopressin acetate. Later, the patient developed 2 attacks of hyponatremia (down to 119 mmol/L) diagnosed as CSW that was treated with fludrocortisone. Finally, he developed hypernatremia (up to 165 mmol/L) diagnosed as CDI and was treated with desmopressin acetate. <b><i>Conclusion:</i></b> Sodium hemostasis disorders require full consideration of serum electrolytes, intravascular volume state, and urine electrolytes in view of the clinical condition. Early diagnosis and administration of the proper treatment are the cornerstones of successful management.

Diagnosis and Treatment of Unruptured Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage

Unruptured intracranial aneurysms (UIAs) are commonly acquired vascular lesions that form an outpouching of the arterial wall due to wall thinning. The prevalence of UIAs in the general population is 3.2%. In contrast, an intracranial aneurysm may be manifested after rupture with classic presentation of a thunderclap headache suggesting aneurysmal subarachnoid hemorrhage (SAH). Previous consensus suggests that although small intracranial aneurysms (<7 mm) are less susceptible to rupture, aneurysms larger than 7 mm should be treated on a case-by-case basis with consideration of additional risk factors of aneurysmal growth and rupture. However, this distinction is outdated. The PHASES score, which comprises data pooled from several prospective studies, provides precise estimates by considering not only the aneurysm size but also other variables, such as the aneurysm location. The International Study of Unruptured Intracranial Aneurysms is the largest observational study on the natural history of UIAs, providing the foundation to the current guidelines for the management of UIAs. Although SAH accounts for only 3% of all stroke subtypes, it is associated with considerable burden of morbidity and mortality. The initial management is focused on stabilizing the patient in the intensive care unit with close hemodynamic and serial neurologic monitoring with endovascular or open surgical aneurysm treatment to prevent rebleeding. Since the results of the International Subarachnoid Aneurysm Trial, treatment of aneurysmal SAH has shifted from surgical clipping to endovascular coiling, which demonstrated higher odds of survival free of disability at 1 year after SAH. Nonetheless, aneurysmal SAH remains a public health hazard and is associated with high rates of disability and death.

Acute hyponatremia after aneurysmal subarachnoid hemorrhage: Frequency, treatment, and outcome

We retrospectively examined the course of serum sodium levels in 180 patients with acute aneurysmal subarachnoid hemorrhage (SAH) who had been admitted to the anesthesiologic-neurosurgical intensive care unit of the University Medical Center Regensburg, Germany, between January 2014 and December 2018. Each patient file was analyzed regarding the frequency and intensity of hyponatremic episodes and the administered medication. At admission to the intensive care unit (ICU), 18patients had shown initial hyponatremia (<135 mmol/L) and 4 patients hypernatremia (greater than145 mmol/L). 88(48.9%) of the 158 patients with normal serum sodium levels developed at least one hyponatremic episode during ICU treatment. The number of hyponatremic episodes was similar between patients with higher-grade and lower-grade aneurysmal SAH (P = 0.848). At the end of ICU treatment, outcome did not differ between patients with and without hyponatremia (40/88, 45.5% vs. 38/70, 54.3%, P = 0.270). At 6 months after SAH, however, good outcome (Glasgow outcome scale, GOS 4-5) was more frequently observed in patients with hyponatremia (26/88, 29.5% vs. 32/70, 45.7%, P = 0.036). Medication with sodium chloride, fludrocortisone, or tolvaptan was initiated in 75.4% patients with mild hyponatremia (130-134 mmol/L) and in 92.9% with moderate hyponatremia (125-129 mmol/L). At 6 months after SAH, patients treated with tolvaptan had a lower rate of poor outcome than patients who had not received tolvaptan (1/14, 7.1% vs. 25/74, 33.8%, P = 0.045). In patients with acute aneurysmal SAH and hyponatremic episodes, consequent treatment of hyponatremia prevented impaired outcome. Because administration of tolvaptan rapidly normalized serum sodium levels, this therapy seems to be a promising treatment approach.

An overview of pharmacotherapy for cerebral vasospasm and delayed cerebral ischemia after subarachnoid hemorrhage

Introduction: Survival from aneurysmal subarachnoid hemorrhage has increased in the past few decades. However, functional outcome after subarachnoid hemorrhage is still suboptimal. Delayed cerebral ischemia (DCI) is one of the major causes of morbidity.Areas covered: Mechanisms underlying vasospasm and DCI after aneurysmal subarachnoid hemorrhage and pharmacological treatment are summarized in this review.Expert opinion: Oral nimodine, an L-type dihydropyridine calcium channel blocker, is the only FDA-approved drug for the prevention and treatment of neurological deficits after aneurysmal subarachnoid hemorrhage. Fasudil, a potent Rho-kinase inhibitor, has also been shown to improve the clinical outcome and has been approved in some countries for use in patients with aneurysmal subarachnoid hemorrhage. Although other drugs, including nicardipine, cilostazol, statins, clazosentan, magnesium and heparin, have been expected to have beneficial effects on DCI, there has been no convincing evidence supporting the routine use of those drugs in patients with aneurysmal subarachnoid hemorrhage in clinical practice. Further elucidation of the mechanisms underlying DCI and the development of effective therapeutic strategies for DCI, including combination therapy, are necessary to further improve the functional outcome and mortality after subarachnoid hemorrhage.

Evaluation of Desmopressin in Critically Ill Patients with Hyponatremia Requiring 3% Hypertonic Saline

BACKGROUND

Desmopressin (DDAVP) is often used for hyponatremia management but has been associated with increases in hospital length of stay and duration of hypertonic saline use. The purpose of this study was to evaluate hyponatremia management strategies and their effect on sodium correction in critically ill patients requiring 3% hypertonic saline (3HS).

METHODS

This retrospective, single-center study included critically ill patients with hyponatremia (serum sodium ≤ 125 mEq/L) receiving 3HS from May 31 2015, to May 31 2019. Patients were divided into those who received 3HS for hyponatremia management (HTS) and those who received proactive or reactive DDAVP in addition to 3HS (D-HTS). Patients in either group could receive rescue DDAVP. The primary outcome was the percentage of patients achieving goal sodium correction of 5-10 mEq/L 24 h after 3HS initiation.

RESULTS

Goal sodium correction was achieved in 52.5% of patients in HTS compared to 65.6% of patients in D-HTS (p = 0.21). Patients in HTS had a shorter duration of 3HS infusion (p = 0.0022) with no difference in ICU length of stay, free water intake, urine output, or serum sodium increases 12 and 24 h after receiving 3HS. Overcorrection during any 24- or 48 h period was not statistically different between groups.

CONCLUSION

Patients in HTS and D-HTS had similar rates of achieving goal sodium correction at 24 h. A proactive or reactive DDAVP strategy led to an increase in 3HS duration and total amount with no significant difference in rates of overcorrection. Prospective, randomized studies assessing standardized strategies for hyponatremia management and DDAVP administration are warranted.

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.

The Outcome of Aneurysm Clipping in Septuagenarians - A Retrospective Analysis in a Basic Neurovascular Unit

Introduction

The management of aneurysmal subarachnoid hemorrhage (SAH) in the elderly is challenging. Clipping as the definitive treatment is less well tolerated by the elderly population. The outcome is anticipated to be more glimmer in poor grade SAH and in a setup which lacks modern neurovascular gadgets. We present our experience of surgical clipping in elderly patients in such a basic neurovascular unit.

Materials and Methods

A retrospective analysis of hospital records of elderly patients between 70 and 79 of age who underwent surgical clipping of intracranial aneurysms between 2015 and 2017 was done. The patients' characteristics, comorbidities, aneurysm characteristics, intraoperative complications, and postoperative complications were studied to determine the factors influencing an unfavorable outcome. All information was entered into a database (Microsoft Excel) and analyzed using SPSS trial version 16. Outcomes were grouped into a favorable outomce which included Glasgow Outcome Scale scores of 4 and 5, whereas an unfavorable outcome which included Glasgow Outcome Scale scores of 1, 2, and 3.

Results

There were 21 patients with aneurysms located either in the anterior or posterior circulation or both. All underwent standard craniotomy and clipping pertaining to that particular type of aneurysm. A favorable outcome was achieved in 48% of the patients and 52% had an unfavorable outcome. The duration of surgery, number of days on ventilator, and presence of hydrocephalus were the factors found to be statistically significantly associated with unfavorable outcomes.

Conclusion

A team approach consisting of a neuroanaesthetist, neurosurgeons, and critical care personnel can have a huge impact on the postoperative outcome.

Prognostic Significance of Hyponatremia in Acute Stroke: A Systematic Review and Meta-Analysis

<b><i>Objective:</i></b> Hyponatremia is a common electrolyte disorder in patients with stroke, which leads to various fatal complications. We performed a systematic review and meta-analysis to investigate the outcomes of acute stroke patients with hyponatremia. <b><i>Methods:</i></b> We searched MEDLINE, EMBASE, and the Cochrane Library databases for relevant literature in English published up to March 2020. Two review authors independently screened and selected the studies by assessing the eligibility and validity based on the inclusion criteria. Mortality at 90 days was set as the primary end point, and in-hospital mortality and length of hospital stay were set as the secondary end points. We conducted the data synthesis and analyzed the outcomes by calculating the odds ratio (OR) and mean difference. <b><i>Results:</i></b> Of 835 studies, 15 studies met the inclusion criteria (<i>n</i> = 10,745). The prevalence rate of stroke patients with hyponatremia was 7.0–59.2%. They had significantly higher 90-day mortality (OR, 1.73; 95% confidence interval (CI), 1.24–2.42) and longer length of hospital stay (mean difference, 10.68 days; 95% CI, 7.14–14.22) than patients without hyponatremia. Patients with hyponatremia had a higher tendency of in-hospital mortality than those without hyponatremia (OR, 1.61; 95% CI, 0.97–2.69). <b><i>Conclusions:</i></b> The development of hyponatremia in the clinical course of stroke is associated with higher short-term mortality and a longer hospital stay. Although the causal relationship is unclear, hyponatremia could be a significant predictor of poor outcomes after stroke.

Incidence of hyponatremia in patients given levetiracetam vs. phenytoin for early posttraumatic seizure prophylaxis

BACKGROUND

Levetiracetam and phenytoin are comparable for acute posttraumatic seizure(PTS) prophylaxis. Levetiracetam-induced hyponatremia has been reported in non-trauma patients. We studied hyponatremia in posttraumatic intracranial hemorrhage(ICH) patients receiving either drug.

METHODS

Retrospective review of patients with ICH receiving PTS prophylaxis was performed. Patients were categorized by degree of sodium nadir: normal, mild, moderate, or severe, and analyzed by levetiracetam versus phenytoin. Patients were matched 2:1 regarding age and injury severity score(ISS). Incidence and treatment for hyponatremia was examined.

RESULTS

1735 ICH patients received PTS prophylaxis over an 8-year period. After exclusions and matching, there were 282 phenytoin and 564 levetiracetam patients. Age, ISS and initial sodium were comparable between the matched cohorts. There was no clinically significant difference in the rate or degree of hyponatremia. Treatment was more common in levetiracetam patients.

DISCUSSION

There was a small but clinically insignificant difference in the incidence of hyponatremia in traumatic ICH patients receiving levetiracetam vs. phenytoin for PTS prophylaxis. There was an increased rate of intervention for hyponatremia in the levetiracetam group, possibly due to a coincidental preventive paradigm shift.

Long-Term Outcomes of Elderly Patients with Poor-Grade Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE

Long-term outcomes after surgical treatment and intensive care have not been investigated in elderly patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to analyze 12-month outcomes and prognostic factors of patients with poor-grade aSAH who were at least age 70 years.

METHODS

We performed a single-center, retrospective study including poor-grade (World Federation of Neurological Societies [WFNS] grades IV and V) aSAH patients who were at least age 70 years, were admitted to our stroke center, and received aneurysmal treatment between April 2012 and September 2018. The clinical outcomes were evaluated at months 3 and 12. Univariate/multivariate analyses were performed to identify the independent prognostic factors of good neurologic outcomes (modified Rankin Scale score 0-3). These factors included sex, age, WFNS grade, Fisher group, delayed cerebral ischemia, aneurysm treatment, aneurysm size, aneurysm location, and blood examination data in the 14 days post subarachnoid hemorrhage.

RESULTS

The proportion of patients with good outcomes (modified Rankin Scale score 0-3) was increased at 12 months compared with that at 3 months. No intracerebral hemorrhage was a significant predictor of good neurologic outcomes at 3 months (P = 0.03). The absence of delayed cerebral ischemia and small fluctuations in the average absolute daily difference from normal sodium levels were significant predictors of good neurologic outcomes at months 3 and 12 (P = 0.04 and P = 0.03, respectively).

CONCLUSIONS

The absence of delayed cerebral ischemia and small fluctuations in the average absolute daily difference from the normal sodium levels were independently associated with good neurologic outcomes at 12 months in elderly patients. Intracerebral hemorrhage did not appear to affect long-term outcomes. These findings suggest that elderly patients with severe subarachnoid hemorrhage should not be excluded from receiving surgical treatment on the basis of their age alone.

Compromised regulation of the rat brain parenchymal arterioles in vasopressin-associated acute hyponatremia

OBJECTIVE

In this study, we examined the effect of acute hyponatremia associated with vasopressin (AVP) on the responses of the isolated rat's MCAs and PAs to acidosis, nitric oxide donor (SNAP) and to endothelium-dependent vasodilator ATP.

METHODS

The studies were performed on isolated, perfused and pressurized MCAs and PAs in control conditions and during AVP-associated hyponatremia. Hyponatremia was induced in vitro by lowering Na⁺ concentration from 144 to 121 mmol/L in intra- and extravascular fluid in the presence of AVP.

RESULTS

Parenchymal arterioles showed greater response to an increase in H⁺ and K⁺ ions concentration and to ATP in comparison with MCAs in control normonatremic conditions. Both PAs and MCAs constricted in response to acute hyponatremia associated with AVP. Interestingly, disordered regulation of vascular tone was observed in PAs but not in MCAs. The abnormalities in the regulation comprised a significant reduction of PA response to acidosis and the absence of the response to the administration of SNAP or ATP.

CONCLUSIONS

Arginine vasopressin-associated hyponatremia leads to constriction and dysregulation of PAs which may impair neurovascular coupling.

Assessment of Acute Kidney Injury in Neurologically Injured Patients Receiving Hypertonic Sodium Chloride: Does Chloride Load Matter?

Background: Increasing evidence suggests that large-volume infusions of 0.9% sodium chloride (NaCl) for resuscitation are associated with hyperchloremic metabolic acidosis, renal vasoconstriction, and increased risk of acute kidney injury (AKI). Patients with neurological injury may require hypertonic NaCl for therapeutic hypernatremia, treatment of cerebral salt wasting, hyponatremia, or elevated intracranial pressure. Consequently, this increased exposure to chloride may result in an increased risk for development of AKI. Objective: The primary aim of this study was to describe the risk for development of AKI in neurologically injured patients receiving large volumes of intravenous hypertonic NaCl. Methods: This single-center, retrospective study looked at neurologically injured patients who received hypertonic NaCl and sodium acetate. Data were collected to assess renal function, hyperchloremia, and acidemia. Receiver operating characteristic (ROC) curve analysis was used to determine the predictive association between the amount of daily and overall chloride exposure and development of AKI. Results: A total of 301 patients were screened, and of those, 142 were included. Of the 142 patients included, 13% developed AKI, and 38% developed hyperchloremia. Additionally, 32% of patients were switched from NaCl to sodium acetate after an average of 3.4 ± 1.5 days of NaCl therapy. The ROC curve demonstrated that if patients received greater than 2055 mEq of chloride over 7 days, they were more likely to develop AKI (sensitivity 72%, specificity 70%; P = 0.002; area under the curve = 0.7). Conclusion and Relevance: Neurologically injured patients receiving hypertonic sodium therapy with a high chloride load are at risk of developing hyperchloremia and AKI.

Inappropriate Antidiuretic Hormone Secretion and Cerebral Salt-Wasting Syndromes in Neurological Patients

The differential diagnosis of syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral salt-wasting syndrome (CSWS) in patients with neurological disorders has been a perplexing clinical controversy. The purpose of this review is to summarize the characteristics and risk factors of patients with different types of neurological disorders complicated by hyponatremia (HN) and review various methods to distinguish SIADH from CSWS. Common neurological disorders with high rates of HN include subarachnoid hemorrhage (SAH), traumatic brain injuries, stroke, cerebral tumors, central nervous system (CNS) infections, and Guillain-Barré syndrome (GBS), which have their own characteristics. Extracellular volume (ECV) status of patients is a key point to differentiate SIADH and CSWS, and a comprehensive assessment of relevant ECV indicators may be useful in differentiating these two syndromes. Besides, instead of monitoring the urinary sodium excretion, more attention should be paid to the total mass balance, including Na⁺, K⁺, Cl^-, and extracellular fluid. Furthermore, the dynamic detection of fractional excretions (FE) of urate before and after correction of HN and a short-term infusion of isotonic saline solution may be useful in identifying the etiology of HN. As for brain natriuretic peptide (BNP) or N-terminal prohormone of BNP (NT-proBNP), more prospective studies and strong evidence are needed to determine whether there is a pertinent and clear difference between SIADH and CSWS.

Significance of fluctuations in serum sodium levels following aneurysmal subarachnoid hemorrhage: an exploratory analysis

OBJECTIVE

Fluctuations in patient serum sodium levels are common after aneurysmal subarachnoid hemorrhage (aSAH), but their effect on patient outcome is not well described in the literature. The goal of this work was to better characterize the relationship between fluctuations in serum sodium levels, outcome, and the development of delayed cerebral ischemia (DCI) after aSAH.

METHODS

The authors performed a post hoc analysis of data from the Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage (CONSCIOUS-1) trial. Patients had their serum sodium values recorded daily for 14 days post-aSAH. Average and average absolute daily differences in sodium levels were calculated for each patient based on 3 reference points: admission sodium levels, a normal sodium level (defined as 140 mmol/L), and the previous day’s sodium level. These variables were also calculated for the classic “vasospasm window” (days 3–12) post-aSAH. A stepwise logistic regression model, locally weighted scatterplot smoothing curves, and receiver operator characteristic curve analysis were used to evaluate the relationship between alterations in serum sodium levels and clinical outcome or the development of DCI after aSAH. Poor outcome was defined as a modified Rankin Scale (mRS) score of > 2 at 3 months.

RESULTS

The average daily difference in sodium values from baseline (p < 0.001), average daily difference from a normal sodium level (p < 0.001), average absolute daily difference from a normal sodium level (p = 0.015), and average absolute daily difference from the previous day’s sodium level (p = 0.017) were significant predictors of poor outcome in a stepwise multivariate regression model. There was a trend toward significance for average absolute daily difference from admission sodium levels during the vasospasm window as an independent predictor of DCI (p = 0.052). There was no difference in the predictive capacity for DCI when sodium fluctuations from post-aSAH days 1–14 were compared with those from the classic vasospasm window (days 3–12).

CONCLUSIONS

Fluctuations in serum sodium levels may play a role in clinical outcome and the development of DCI after aSAH. The timing of these fluctuations appears to have no significant effect on the development of DCI.

Association of Hyponatremia and Risk of Short- and Long-Term Mortality in Patients with Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Hyponatremia is the most common electrolyte disorder in the clinic practice and it is closely related to the prognosis of various diseases. Studies reported that hyponatremia increased the risk of stroke mortality while yielded inconsistent findings during the follow-up period. Thus, a systematic review and meta-analysis to assess the relationship between hyponatremia and the short-term (within 90 days) and long-term (more than 1 year) prognosis of stroke patients was conducted.

METHODS

A computerized systematic literature search was performed before November of 2018 for relevant articles evaluating the relationship between hyponatremia and all-cause mortality risk in stroke patients. Pooled relative risk (RR) and hazard risk (HR) with 95% confidence interval (CI) were calculated using DerSimonian-Laird random-effects model. Subgroup analyses were performed according to the follow-up period, types of stroke, different controls, sample size, and sampling time.

RESULTS

A total of 12 studies with 21,973 patients were identified. Compared to the nonhyponatremia patients, hyponatremia was associated with a higher risk of all-cause mortality in short-term (RR 1.61, 95% CI 1.33-1.96; HR 1.78 95% CI 1.19-2.75) and long-term follow-up (RR 1.77, 95% CI 1.27-2.47; HR 2.23,95% CI 1.30-3.82). Subgroups analysis showed the similar results in most subgroups.

CONCLUSIONS

This meta-analysis concludes that hyponatremia has a significant prognostic value for short- and long-term prognosis to stroke patients.

Be aware of the effects of glucocorticoids on SIADH: A case report

RATIONALE

Hyponatremia is one of the most common electrolyte disorders in clinic. Due to the complicated etiology and the nonspecific clinical manifestations, the diagnosis of hyponatremia is a complicated process. A variety of clinical disorders can cause inappropriately increased antidiuretic hormone (ADH) secretion, leading to inappropriate water retention and consequent hyponatremia. The most common cause of hyponatremia in hospital inpatients is syndrome of inappropriate antidiuretic (SIADH). The action of glucocorticoid against pituitary posterior lobe can reduce the secretion of ADH. However, the effect of hormone on diuretic hormone during treatment has been less reported.

PATIENT CONCERNS AND DIAGNOSIS

The patient in this case report was misdiagnosed as anterior pituitary hypofunction because of the long-term glucocorticoid therapy was effective in this patient, and the patient was finally diagnosed as SIADH after reassessment. The patient is a 76-year-old male with long-term symptomatic hyponatremia after traumatic brain injury (TBI). The patient has been consistently diagnosed as anterior pituitary hypofunction. Based on the diagnosis, glucocorticoid replacement therapy was administered. The serum sodium of the patient gradually increased to normal level after hydrocortisone intravenous injection but dropped again after switch to hydrocortisone oral administration. Through examination and analysis of the patient status during the five-time hospitalization, syndrome of inappropriate antidiuretic hormone (SIADH) was considered.

INTERVENTIONS

Water intake limitation and oral furosemide and antisterone were administered after glucocorticoid therapy was stopped.

OUTCOME

The serum sodium level of the patient gradually increased and maintained within normal range based on his clinical follow-up.

LESSONS

For hyponatremia with effective glucocorticoid treatment, SIADH should still be excluded.

Successful Use of Fludrocortisone in a Child with Refractory Cerebral Salt Wasting Syndrome: A Case Report and Review of Literature

Hyponatremia post-neurosurgical intervention can be dangerous and potentially life-threatening. Two of its most common causes are cerebral salt wasting (CSW) and syndrome of inappropriate anti-diuretic hormone release (SIADH). CSW is proposed to be secondary not only to the elevated levels of circulating atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) but inhibition of steroidogenesis in the zona glomerulosa of the adrenal cortex, thus resulting in mineralocorticoid deficiency. We present a two-year-old male who had developed acute hyponatremia secondary to CSW on post-operative day two after a sub-total resection of a low-grade juvenile pilocytic astrocytoma (WHO grade I). Fludrocortisone was successfully used to manage the refractory hyponatremia and alleviated the need to use very large amounts of oral sodium supplementation.

Hyponatremia is a potential predictor of progression in radiation-induced brain necrosis: a retrospective study

Background

To investigate the prognostic value of hyponatremia, defined as serum sodium level < 135 mEq/L, in radiation-induced brain necrosis (RN) patients.

Methods

We performed a retrospective analysis of the RN patients (The patients included in our study had a history of primary cancers including nasopharyngeal carcinoma/glioma/oral cancer and received radiotherapy previously and then were diagnosed with RN) treated in Sun yat-sen Memorial Hospital from January 2013 to August 2015. Patients without cranial magnetic resonance imaging (MRI) scan and serum sodium data were excluded. Progression was identified when the increase of edema area ≥ 25% on the MRI taken in six months comparing with those taken at the baseline. Factors that might associate with prognosis of RN were collected. Multivariable logistic regression analyses were used to identify potential predictors.

Results

We total included 135 patients, 32 (23.7%) of them with hyponatremia and 36 (26.7%) with RN progression. Percentage of progression was roughly three fold in hyponatremia patients compared with nonhyponatremia patients (53.1% versus 18.4%), translating into a 5-fold increased odds ratio (P <  0.001). Multivariable analyses identified hyponatremia as a potential predictor of progression (OR, 4.82; 95% CI [1.94–11.94]; P = 0.001).

Conclusions

Hyponatremia was identified as a potential predictor for the progression of patients with RN. Hyponatremia management in patients with RN should be paid much more concern in clinical practice.

Development of severe hyponatremia due to cerebrospinal fluid leakage following meningomyelocele surgery in a newborn

Cerebrospinal fluid leakage following meningomyelocele surgery is a frequent complication in the wound-healing period and is associated with wound dehiscence. CSF loss can cause severe hyponatremia, especially in the newborn and early infancy periods when dietary sodium content is relatively low. Hyponatremia in the newborn period can result in adverse neurodevelopmental outcomes. In addition, hyponatremia's cerebral effects can increase complications in neurosurgery patients. The authors present the case of a newborn in whom CSF leakage from the operative site and severe hyponatremia developed following meningomyelocele surgery. To the best of their knowledge, severe hyponatremia caused by CSF leakage after meningomyelocele surgery has not been previously reported in the literature.

From renal salt wasting to SIADH

Hyponatraemia is common following major head injury and is associated with significant morbidity and mortality. A 20-year-old man presented with reduced consciousness after head trauma and was found to have a fractured skull base with bilateral frontal contusions. On day 3 of his admission, he developed hyponatraemia with raised urine sodium and osmolality, despite receiving dexamethasone and intravenous fluid therapy. His hyponatraemia worsened after the treatment with fluid restriction and oral salt. He was in negative fluid balance suggesting possible renal salt wasting. A trial of isotonic normal saline resulted in a further fall in serum sodium level. He was subsequently treated for suspected syndrome of inappropriate ADH with a hypertonic (3%) saline infusion. His sodium level and neurological status improved. This case report illustrates the confounding factors that commonly affect clinical decision-making when treating patients with hyponatraemia following head injury. The guidelines for diagnosis and management are discussed.

Prevention and Treatment of Hyponatremia in Patients with Subarachnoid Hemorrhage: A Systematic Review

BACKGROUND

Current guidelines for the management of hyponatremia in patients with subarachnoid hemorrhage (SAH) are not based on a systematic assessment of the literature. We evaluated published studies on the efficacy and safety of current preventative and treatment strategies for hyponatremia in patients with SAH.

METHODS

We searched the Cochrane Central Register of Controlled Trials, Embase, MEDLINE, and PubMed for relevant studies. Primary outcomes of interest included neurologic functional outcomes, symptomatic vasospasm, and others. Secondary outcomes included measures of sodium and volume status.

RESULTS

We included 5 out of 117 identified studies: 1 before-and-after observational trial (using fludrocortisone) and 4 randomized controlled trials (2 using fludrocortisone; 2 using hydrocortisone). All 5 trials had a high risk of bias in at least 1 domain. We could not perform a meta-analysis of functional outcomes; however, individual studies did not demonstrate statistically significant differences. Mineralocorticoid use did not statistically significantly reduce the incidence of symptomatic vasospasm (relative risk, 0.60; 95% confidence interval, 0.35-1.03; I² = 0%). The studies did not report other primary outcomes. In the 4 RCTs, mineralocorticoid use reduced natriuresis and volume contraction.

CONCLUSIONS

Current evidence does not demonstrate a benefit of preventative treatment with mineralocorticoids in clinically important outcomes, although a difference cannot be ruled out due to imprecision. Larger well-designed trials are needed to establish the impact of mineralocorticoids and fluid and sodium supplementation strategies on clinically relevant outcomes in the prevention and treatment of hyponatremia in patients with SAH.

Transient Diabetes Insipidus After Discontinuation of Vasopressin in Neurological Intensive Care Unit Patients: Case Series and Literature Review

BACKGROUND

Arginine vasopressin (AVP) is a common second-line or third-line vasopressor used in critically ill neurosurgical patients. Neurosurgical indications include hyperdynamic therapy for vasospasm, maintenance of cerebral perfusion pressure in patients with intracranial hypertension, and prevention of hypotension in patients with sepsis.

CASE DESCRIPTION

A series of 6 neurosurgical patients receiving AVP infusions developed severe but transient diabetes insipidus (tDI) after cessation of AVP. To our knowledge, no previous reports of this phenomenon in neurosurgical patients have been published. We reviewed the clinical histories, intensive care unit treatment, medication administration records, and laboratory values of these patients, and we found recurrent elevated serum sodium and urine output and decreased urine specific gravity after discontinuation of AVP. Resolution of tDI occurred upon resumption of AVP or administration of desmopressin. Elevated serum sodium levels were often severe, resulting in worsened clinical outcomes. When AVP was resumed, tDI typically recurred if AVP was again tapered and discontinued. Routine administration of desmopressin was useful in controlling sodium levels until the tDI resolved.

CONCLUSIONS

Recognition of this phenomenon has caused us to change our clinical management of neurosurgical patients receiving AVP. We hypothesize that tDI is caused by downregulation of the V2 receptor mass in the renal distal convoluted tubule and collecting duct cells. When AVP is discontinued, patients develop nephrogenic tDI secondary to decreased V2 receptor binding, which explains why desmopressin is effective in correcting tDI. Future research includes a large prospective study to determine risk factors for tDI, its incidence, and its pathophysiology.

Comparison of hyponatremia and SIADH frequency in patients with tick borne encephalitis and meningitis of other origin

AIM

The aim of the study was the evaluation of frequency and origin of hyponatremia in tick borne encephalitis (TBE) in comparison to non-TBE viral meningitis and bacterial meningitis.

METHODS

A total of 124 patients aged 18-80 years, with TBE were included to the study. The mild form of TBE was diagnosed in 59 patients, while the severe form was diagnosed in 65 patients. The first control group (VMG) consisted of 72 patients with viral meningitis, but excluded TBE. The second control group (BMG) consisted of 16 patients diagnosed with bacterial meningitis.

RESULTS

Hyponatremia was diagnosed in 55 (44.4%) patients with TBE. In 12 (9.7%) patients (mean age 56.6 ± 19.9 years; 9 men, 3 women) syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was diagnosed. In VMG hyponatremia was diagnosed in 7 (9.7%) patients. In the age group <35 years and in the age group of 50-64 years the frequency of hyponatremia and SIADH was higher in TBE than in VMG (p < 0.05). In BMG hyponatremia was diagnosed in 6 (37.5%) patients. No statistically significant differences in frequency of hyponatremia between BMG and TBE groups were observed.

CONCLUSIONS

(1) Hyponatremia is a common disorder in TBE and is more frequent than in other viral types of meningitis, especially in young patients (< 35 years). (2) The most common cause of hyponatremia in TBE patients is dehydration and fluid supplementation should be a treatment of choice. (3) Overall, 16.9% of the patients with the severe form of TBE develop SIADH syndrome and they required treatment based on fluid restriction and hypertonic saline infusion.

A review in the treatment of oncologic emergencies

AIM

Oncologic emergencies are often categorized as a group of metabolic abnormalities associated with the diagnosis of cancer or the initiation of chemotherapy for treatment. These syndromes often arise in the acute setting, demanding an accurate knowledge of the associated condition and current treatment. In this review, we evaluate five oncologic emergencies: tumor lysis syndrome, hypercalcemia, hyponatremia, spinal cord compression, and disseminated intravascular coagulation.

SUMMARY

Oncologic emergencies are often diverse in etiology and are often associated with the initiation of chemotherapy. Tumor lysis syndrome presents as severe electrolyte abnormalities that need to be addressed urgently, sometimes prior to initiation of chemotherapy. Hypercalcemia of malignancy is treated with aggressive rehydration, furosemide, and intravenous bisphosphonates. If a patient with cancer presents with normovolemic hyponatremia, syndrome of inappropriate antidiuretic hormone should be suspected. Malignant spinal cord compression happens when cancer cells grow in, or near to, the spine and press on the spinal cord and nerves. This causes swelling and a reduction in the blood supply to the spinal cord and nerve roots. Disseminated intravascular coagulation is characterized by systemic activation of blood coagulation, which results in generation and deposition of fibrin, leading to microvascular thrombi in various organs and contributing to multiple organ dysfunction syndrome.

CONCLUSION

Knowledge of oncology emergencies is critical to the understanding of these emergent syndromes in oncology patients. Each of these disease states requires careful evaluation of the patient's symptoms, monitoring parameters for conditions and supportive care measures and interventions.

Impact of Hyponatremia on Morbidity, Mortality, and Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

BACKGROUND

Hyponatremia is a common metabolic disturbance after aneurysmal subarachnoid hemorrhage (SAH), and it may worsen outcomes. This review aims to characterize the effect of hyponatremia on morbidity and mortality after SAH.

OBJECTIVES

We sought to determine the prevalence of hyponatremia after SAH, including in subgroups, as well as its effect on mortality and certain outcome measures, including degree of disability and duration of hospitalization.

METHODS

A search of terms "hyponatremia" and "subarachnoid hemorrhage" was performed on PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE. Studies were included if they reported prevalence of hyponatremia and if they discussed outcomes such as mortality, duration of stay, functional outcomes (e.g., Glasgow Outcomes Scale), or incidence of complications in patients with aneurysmal SAH. Two independent researchers assessed the titles and abstracts and reviewed articles for inclusion.

RESULTS

Thirteen studies met inclusion criteria. The prevalence of at least mild hyponatremia was 859 of 2387 (36%) of patients. Hyponatremia was associated with vasospasm and duration of hospitalization, but it did not influence mortality.

CONCLUSION

Hyponatremia is common after SAH, and there is evidence that it is associated with certain poorer outcomes. Larger, prospective studies are needed to assess these findings and provide further evidence.

Cerebral Vasospasm: A Review

Cerebral vasospasm is a prolonged but reversible narrowing of cerebral arteries beginning days after subarachnoid hemorrhage. Progression to cerebral ischemia is tied mostly to vasospasm severity, and its pathogenesis lies in artery encasement by blood clot, although the complex interactions between hematoma and surrounding structures are not fully understood. The delayed onset of vasospasm provides a potential opportunity for its prevention. It is disappointing that recent randomized, controlled trials did not demonstrate that the endothelin antagonist clazosentan, the cholesterol-lowering agent simvastatin, and the vasodilator magnesium sulfate improve patient outcome. Minimizing ischemia by avoiding inadequate blood volume and pressure, administering the calcium antagonist nimodipine, and intervention with balloon angioplasty, when necessary, constitutes current best management. Over the past two decades, our ability to manage vasospasm has led to a significant decline in patient morbidity and mortality from vasospasm, yet it still remains an important determinant of outcome after aneurysm rupture.

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.