Hyponatremia and the Brain

Syndrome of Inappropriate Antidiuresis

Syndrome of inappropriate antidiuresis (SIAD)-the most frequent cause of hypotonic hyponatremia-is mediated by nonosmotic release of arginine vasopressin, which promotes water retention by activating renal vasopressin type 2 (V2) receptors. There are numerous causes of SIAD, including malignancy, pulmonary and central nervous system diseases, and medications. Rare activating mutations of the V2 receptor can also cause SIAD. Determination of the etiology of SIAD is important because removal of the stimulus for inappropriate arginine vasopressin secretion offers the most effective therapy. Treatment of SIAD is guided by symptoms and their severity, as well as the level of plasma sodium. In the absence of severe symptoms, which require urgent intervention, many clinicians focus on fluid restriction as a first-line treatment. Second-line therapeutic options include loop diuretics and salt tablets, urea, and V2 receptor antagonists.

A review of the interplay between Takotsubo cardiomyopathy and adrenal insufficiency: Catecholamine surge and glucocorticoid deficiency

BACKGROUND

Takotsubo Cardiomyopathy (TCM) is a transient heart condition often precipitated by stress and characterized by atypical ventricular ballooning. The interplay between TCM and Adrenal Insufficiency (AI), particularly the influence of catecholamine excess and glucocorticoid deficiency on TCM's pathogenesis in individuals with AI, warrants comprehensive exploration for a better understanding of TCM pathophysiology and establishment of potential therapeutic strategies.

METHODS

We conducted an extensive literature search via PubMed and Google Scholar, targeting reports on AI, heart failure, and cardiomyopathy, supplemented by forward and backward citation tracing. We analyzed 46 cases from 45 reports, assessing the clinical presentation and outcomes in the context of AI categorization.

RESULTS

In patients with AI, a glucocorticoid deficit appears to exacerbate the myocardial vulnerability to catecholamine toxicity, precipitating TCM. Most conditions were reversible; however, three pre-1990 cases resulted in irreversible outcomes.

CONCLUSIONS

The investigation into the AI and TCM intersection highlights the pathogenic significance of catecholamines in the absence of glucocorticoids. The data consolidates the hypothesis that glucocorticoid scarcity exacerbates the cardiac susceptibility to catecholaminergic toxicity, potentially triggering TCM. The study affirms glucocorticoids' cardioprotective roles and elucidates how catecholamine surges contribute to TCM pathogenesis, suggesting strategic clinical management adjustments for AI patients to reduce TCM incidence.

A better understanding of basic science may help our management of LUTS/LUTD in older persons with nocturnal polyuria and nocturia: ICI-RS 2024

AIMS

To discuss the role of autocrine/paracrine signaling of urothelial arginine vasopressin (AVP) on mammalian bladder capacities and micturition thresholds, impact of distension on water/urea reabsorption from the bladder, review of the literature to better characterize the central/peripheral effects of AVP, desmopressin (dAVP) toxicity, and urine biomarkers of nocturia.

METHODS

This review summarizes discussions during an International Consultation on Incontinence-Research Society 2024 think tank with respect to the role of urothelial AVP in aged individuals with nocturnal polyuria, impact of solute and water reabsorption by the bladder on uninterrupted sleep, central effects of AVP, pharmacological basis of dAVP toxicity, and biomarkers in nocturia/lower urinary tract dysfunction (LUTD) with neurological diseases.

RESULTS

Consensus recognized AVP function and pathways in the central nervous system (CNS), pre-proAVP localized using immunohistochemistry in bladder sections from adult/aged noncancerous human punch biopsies and rodent bladder sections is likely to accelerate the systemic uptake of water and urea from the bladder of anesthetized mice instilled with 3H-water and 14C-urea. Mechanisms for charged and uncharged solutes and water transport across the bladder, mechanism of dAVP toxicity, and utility of urine biomarkers in those with neurological diseases/nocturia were determined from literature reviews.

CONCLUSION

Pre-proAVP is present in human/rodent bladders and may be involved in water reabsorption from bladder that prevents the sensation of fullness for uninterrupted sleep in healthy adults. The mechanism of action of AVP in the CNS was discussed, as was electrolyte/water transport across the bladder, the basis for dAVP toxicity, and feasibility of urine biomarkers to identify nocturia/LUTD with neurological diseases.

The Intersections of COVID-19, HIV, and Race/Ethnicity: Machine Learning Methods to Identify and Model Risk Factors for Severe COVID-19 in a Large U.S. National Dataset

We investigate risk factors for severe COVID-19 in persons living with HIV (PWH), including among racialized PWH, using the U.S. population-sampled National COVID Cohort Collaborative (N3C) data released from January 1, 2020 to October 10, 2022. We defined severe COVID-19 as hospitalized with invasive mechanical ventilation, extracorporeal membrane oxygenation, discharge to hospice or death. We used machine learning methods to identify highly ranked, uncorrelated factors predicting severe COVID-19, and used multivariable logistic regression models to assess the associations of these variables with severe COVID-19 in several models, including race-stratified models. There were 3 241 627 individuals with incident COVID-19 cases and 81 549 (2.5%) with severe COVID-19, of which 17 445 incident COVID-19 and 1 020 (5.8%) severe cases were among PWH. The top highly ranked factors of severe COVID-19 were age, congestive heart failure (CHF), dementia, renal disease, sodium concentration, smoking status, and sex. Among PWH, age and sodium concentration were important predictors of COVID-19 severity, and the effect of sodium concentration was more pronounced in Hispanics (aOR 4.11 compared to aOR range: 1.47-1.88 for Black, White, and Other non-Hispanics). Dementia, CHF, and renal disease was associated with higher odds of severe COVID-19 among Black, Hispanic, and Other non-Hispanics PWH, respectively. Our findings suggest that the impact of factors, especially clinical comorbidities, predictive of severe COVID-19 among PWH varies by racialized groups, highlighting a need to account for race and comorbidity burden when assessing the risk of PWH developing severe COVID-19.

Development of predictive model for the neurological deterioration among mild traumatic brain injury patients using machine learning algorithms

BACKGROUND

Mild traumatic brain injury (mTBI) comprises a majority of traumatic brain injury (TBI) cases. While some mTBI would suffer neurological deterioration (ND) and therefore have poorer prognosis. This study was designed to develop the predictive model for the ND among mTBI using machine learning algorithms.

METHODS

mTBI patients recorded in the Medical Information Mart for Intensive Care-III were selected for the study. The ND was defined as a drop of Glasgow Coma Scale ≥ 2 within the first 7 day after admission. Eight machine learning algorithms were trained and validated with 5-fold cross validation including extreme gradient boosting, logistic regression, light gradient boosting machine, random forest, adaptive boosting, decision tree, complement naïve Bayes, and support vector machine. The value of eight machine learning algorithms was compared by the area under the receiver operating characteristic curve (AUC).

RESULTS

361 mTBI patients suffered the ND with the incidence of 30.7%. The ND group had higher 30-day mortality (p = 0.001). In the training cohort of mTBI patients, the random forest performed the best on predicting the ND with the AUC of 1.000. The XGBoost and AdaBoost had an AUC of 0.827 and 0.815, respectively. The logistic regression performed the best on predicting the ND in the validation cohort with the AUC of 0.741. The XGBoost, random forest and AdaBoost had an AUC of 0.729, 0.735, 0.736 in the validation cohort, respectively. After adjusting confounding effects, the multivariate logistic regression found only two independent risk factors for the ND including Sequential Organ Failure Assessment (SOFA) (p < 0.001) and hypertension (p = 0.001). The logistic regression predictive model composed of SOFA and hypertension had an AUC of 0.741.

CONCLUSIONS

SOFA score and complicated hypertension are two independent risk factors for the neurological deterioration among mTBI patients. The logistic regression predictive model incorporating SOFA and hypertension is helpful to identify mTBI patients with the high risk of ND.

Chronic Hyponatremia and Brain Structure and Function Before and After Treatment

RATIONALE & OBJECTIVE

Hyponatremia is the most common electrolyte disorder and is associated with significant morbidity and mortality. This study investigated neurocognitive impairment, brain volume, and alterations in magnetic resonance imaging (MRI)-based measures of cerebral function in patients before and after treatment for hyponatremia.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Patients with presumed chronic hyponatremia without signs of hypo- or hypervolemia treated in the emergency department of a German tertiary-care hospital.

EXPOSURE

Hyponatremia (ie, plasma sodium concentration [Na+]<125mmol/L) before and after treatment leading to [Na+]>130mmol/L.

OUTCOMES

Standardized neuropsychological testing (Mini-Mental State Examination, DemTect, Trail Making Test A/B, Beck Depression Inventory, Timed Up and Go) and resting-state MRI were performed before and after treatment of hyponatremia to assess total brain and white and gray matter volumes as well as neuronal activity and its synchronization.

ANALYTICAL APPROACH

Changes in outcomes after treatment for hyponatremia assessed using bootstrapped confidence intervals and Cohen d statistic. Associations between parameters were assessed using correlation analyses.

RESULTS

During a 3.7-year period, 26 patients were enrolled. Complete data were available for 21 patients. Mean [Na+]s were 118.4mmol/L before treatment and 135.5mmol/L after treatment. Most measures of cognition improved significantly. Comparison of MRI studies showed a decrease in brain tissue volumes, neuronal activity, and synchronization across all gray matter after normalization of [Na+]. Volume effects were particularly prominent in the hippocampus. During hyponatremia, synchronization of neuronal activity was negatively correlated with [Na+] (r=-0.836; 95% CI, -0.979 to-0.446) and cognitive function (Mini-Mental State Examination, r=-0.523; 95% CI, -0.805 to-0.069; DemTect, r=-0.744; 95% CI, -0.951 to-0.385; and Trail Making Test A, r=0.692; 95% CI, 0.255-0.922).

LIMITATIONS

Small sample size, insufficient quality of several MRI scans as a result of motion artifact.

CONCLUSIONS

Resolution of hyponatremia was associated with improved cognition and reductions in brain volumes and neuronal activity. Impaired cognition during hyponatremia is closely linked to increased neuronal activity rather than to tissue volumes. Furthermore, the hippocampus appears to be particularly susceptible to hyponatremia, exhibiting pronounced changes in tissue volume.

PLAIN-LANGUAGE SUMMARY

Hyponatremia is a common clinical problem, and patients often present with neurologic symptoms that are at least partially reversible. This study used neuropsychological testing and magnetic resonance imaging to examine patients during and after correction of hyponatremia. Treatment led to an improvement in patients' cognition as well as a decrease in their brain volumes, spontaneous neuronal activity, and synchronized neuronal activity between remote brain regions. Volume effects were particularly prominent in the hippocampus, an area of the brain that is important for the modulation of memory. During hyponatremia, patients with the lowest sodium concentrations had the highest levels of synchronized neuronal activity and the poorest cognitive test results.

Case report: Acute severe hyponatremia-induced seizures in a newborn: a community-acquired case and literature review

Severe neonatal hyponatremia represents a critical electrolyte imbalance with potentially severe neurological outcomes, a condition rarely documented in community-acquired, full-term newborns. This report underscores a unique case of a 23-day-old, previously healthy, full-term male neonate experiencing severe hyponatremia that precipitated seizures, underscoring the urgency of prompt recognition and intervention. The neonate presented with symptoms including vomiting, groaning, chills, fixed staring, and limb tremors. Critical findings upon admission encompassed hypothermia, hypotension, tachycardia, and tachypnea accompanied by significant weight loss. The clinical presentation was marked by dehydration, lethargy, weak crying, a fixed gaze, irregular breathing, and coarse lung sounds, yet a distended abdomen, hypertonic limb movements, and recurrent seizures were observed. Immediate interventions included establishing IV access, rewarming, mechanical ventilation, seizure management, volume expansion, dopamine for circulatory support, and initiation of empirical antibiotics. Diagnostic evaluations revealed a sodium ion concentration of 105.9 mmol/L, while amplitude-integrated electroencephalography (aEEG) detected pronounced seizure activity characterized by a lack of sleep-wake rhythmicity, noticeable elevation in both the lower and upper amplitude margins, and a sustained decrease in the lower margin voltage dropping below 5 μV, presenting as sharp or serrated waveforms. The management strategy entailed rapid electrolyte normalization using hypertonic saline and sodium bicarbonate, anticonvulsant therapy, and comprehensive supportive care, with continuous aEEG monitoring until the cessation of seizures. Remarkably, by the third day, the neonate's condition had stabilized, allowing for discharge in good health 10 days post-admission. At a 16-month follow-up, the child exhibited no adverse neurological outcomes and demonstrated favorable growth and development. Our extensive review on the etiology, clinical manifestations, aEEG monitoring, characteristics of seizures induced by severe neonatal hyponatremia, treatment approaches, and the prognosis for seizures triggered by severe hyponatremia aims to deepen the understanding and enhance clinical management of this complex condition. It stresses the importance of early detection, accurate diagnosis, and customized treatment protocols to improve outcomes for affected neonates. Additionally, this review accentuates the indispensable role of aEEG monitoring in managing neonates at elevated risk for seizures. Yet, the safety and efficacy of swiftly administering hypertonic saline for correcting severe hyponatremia-induced seizures necessitate further investigation through medical research.

Hyponatremia as a predictor of cognitive deterioration in hospitalized post-stroke patients

PURPOSE

Evidence is scarce regarding the association between hyponatremia and alterations in cognitive function among hospitalized older patients. We aimed to investigate the associations between hyponatremia and the baseline cognitive status, as well as the improvement in cognitive function, in hospitalized post-stroke patients.

METHODS

This retrospective cohort study included consecutive hospitalized post-stroke patients. Serum sodium concentrations were extracted from medical records based on blood tests performed within 24 h of admission, with hyponatremia defined as a serum sodium concentration < 135 mEq/L. The main outcomes included admission and discharge scores for cognitive levels, assessed through the cognitive domain of the Functional Independence Measure (FIM-cognition), as well as the score changes observed during the hospitalization period. Multivariate linear regression analyses were used to determine the association between hyponatremia and outcomes of interest, adjusted for potential confounders.

RESULTS

Data from 955 patients (mean age 73.2 years; 53.6 % men) were included in the analysis. The median baseline blood sodium level was 139 [137, 141], and 84 patients (8.8 %) exhibited hyponatremia. After full adjustment for confounders, the baseline hyponatremia was significantly and negatively associated with FIM-cognition values at admission (β = -0.009, p = 0.016), discharge (β = -0.038, p = 0.043), and the gain during hospital stay (β = -0.040, p = 0.011).

CONCLUSION

Baseline hyponatremia has demonstrated a correlation with decline in cognitive level over the course of rehabilitation in individuals after stroke. Assessing hyponatremia at the outset proves to be a pivotal prognostic indicator.

Physiologic responses of Cownose Rays following freshwater dips for treatment of capsalid monogeneans

OBJECTIVE

Two Cownose Rays Rhinoptera bonasus were presented for management of a severe capsalid monogenean infection Benedeniella posterocolpa in a mixed species habitat at an aquarium.

METHODS

A series of freshwater (FW) dips were elected to mitigate parasite resistance to praziquantel due to the endemic monogenean population in the system. A pretreatment blood sample was opportunistically obtained, and subsequent samples were processed due to development of clinical signs.

RESULT

While the first FW dip was tolerated well and did not induce abnormal behavior, the second led to one individual presenting with tachypnea, pallor, and lethargy. Marked hematological abnormalities requiring medical intervention occurred in both individuals after the second dip. After treatment with elasmobranch Ringer's fluid therapy, sodium bicarbonate, prednisolone acetate, and vitamin E/selenium in the more severely affected ray, and elasmobranch Ringer's alone in the second ray, hematologic derangements and symptoms resolved. Hemoconcentration, hyperproteinemia, hyperlactatemia, and hyperglycemia were attributed to a stress response. A selective loss of urea after exposure to FW resulted in decreased plasma osmolality.

CONCLUSION

Given the severity of the stress response and associated complications observed, hyposalinity treatments should be utilized with caution in this species. If this therapy is employed, the clinician is advised to be prepared to administer supportive care coinciding with the FW dip if necessary.

Pre-thrombolysis serum sodium concentration is associated with post-thrombolysis symptomatic intracranial hemorrhage in ischemic stroke patients

Background and aim

Symptomatic intracranial hemorrhage (sICH) was the most serious complication associated with alteplase intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients. However, the relationship between serum sodium levels and post-thrombolysis symptomatic intracranial hemorrhage has not been investigated. Therefore, the aim of this study was to investigate the relationship between pre-thrombolysis serum sodium levels and sICH after IVT, as well as to explore the optimal pre-thrombolysis serum sodium levels for lowering the risk of sICH following IVT.

Methods

From July 1, 2017 to April 30, 2023, out-of-hospital AIS patients who received IVT in the emergency department were enrolled in this study. Serum sodium levels were measured at admission prior to IVT, and National Institutes of Health Stroke Scale scores were continuously assessed during and after thrombolysis. Routine follow-up neuroimaging was performed between 22 to 36 h after IVT. Initially, three logistic regression models and restricted cubic splines (RCS) were established to investigate the relationship between serum sodium levels and post-thrombolysis sICH. Furthermore, to evaluate the predictive value of serum sodium for post-thrombolysis sICH, we compared area under the receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) before and after incorporating serum sodium into traditional models. Finally, subgroup analysis was conducted to explore interactions between serum sodium levels and other variables.

Results

A total of 784 AIS patients who underwent IVT were enrolled, among whom 47 (6.0%) experienced sICH. The median serum sodium concentration for all patients was 139.10 [interquartile ranges (IQR): 137.40-141.00] mmol/L. Patients who developed sICH had lower serum sodium levels than those without sICH [138.20(IQR:136.00-140.20) vs. 139.20(IQR:137.40-141.00), p = 0.031]. Logistic regression analysis (model 3) revealed a 14% reduction in the risk of post-thrombolysis sICH for every 1 mmol/L increase in serum sodium levels after adjusting for confounding variables (p < 0.001). The risk of post-thrombolysis sICH was minimized within the serum sodium range of 139.1-140.9 mmol/L compared to serum sodium concentration below 137.0 mmol/L [odds ratio (OR) = 0.33, 95% confidence interval (CI): 0.13-0.81] in model3. Furthermore, there was a significant trend of decreasing risk for sICH as serum sodium concentrations increased across the four quartiles (P for trend = 0.036). The RCS analysis indicated a statistically significant reduction in the risk of sICH as serum sodium levels increased when the concentration was below 139.1 mmol/L. Incorporating serum sodium into traditional models improved their predictive performance, resulting in higher AUROC and NRI values. Subgroup analysis suggested that early infarct signs (EIS) appeared to moderate the relationship between serum sodium and sICH (p < 0.05).

Conclusion

Lower serum sodium levels were identified as independent risk factors for post-thrombolysis sICH. Maintaining pre-thrombolysis serum sodium concentrations above 139.1 mmol/L may help reduce the risk of post-thrombolysis sICH.

Acute Kidney Injury and Electrolyte Imbalances Caused by Dapagliflozin Short-Term Use

Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor (SGLT2i), has shown demonstrated benefits for renal and cardiovascular outcomes in large clinical trials. However, short-term concerns regarding its impact on renal function and electrolyte balance exist. This study aimed to evaluate the short-term effects of dapagliflozin on renal function and electrolyte balance in patients newly prescribed the medication. A retrospective analysis of 246 patients who initiated dapagliflozin therapy was conducted. Serum creatinine, sodium, and potassium levels were measured at baseline (before dapagliflozin) and 5-8 days after initiation (endpoint). A Wilcoxon signed-rank test, Pearson's chi-square test, and Fischer's exact test were used for the data analysis. Glycemia and sodium levels were significantly higher at the baseline compared to the endpoint (p < 0.001). Conversely, creatinine and potassium levels were significantly higher at the endpoint than at the baseline (p < 0.001). The prevalence of hyponatremia and hyperkalemia were increased at the endpoint (17.5% vs. 10.2% and 16.7% vs. 8.9%, respectively). Although not statistically significant, a trend towards increased hyponatremia with the co-administration of furosemide was observed (p = 0.089). No significant association was found between potassium-sparing medications (p > 0.05) and hyperkalemia, except for angiotensin receptor blockers (p = 0.017). The combination of dapagliflozin and furosemide significantly increased the risk of acute kidney injury (AKI) at the endpoint (p = 0.006). Age, gender, and chronic kidney disease status did not significantly influence the occurrence of AKI, hyponatremia, or hyperkalemia (p > 0.05). These findings emphasize the importance of the close monitoring of renal function and electrolyte balance, particularly in the early stages of dapagliflozin therapy, especially in patients receiving diuretics or renin-angiotensin-aldosterone system inhibitors.

Association between serum sodium and 28-day mortality in sepsis patients: A secondary data analysis from three large critical illness cohorts

OBJECTIVE

The present study was designed to explore the association between serum sodium and mortality in patients with sepsis by using a large sample, multicenter MIMIC-IV database.

METHODS

We extracted the data of 34 925 sepsis patients from the retrospective cohort mimicIV database. After adjusting the confounders, we explored the independent effects of serum sodium on 28-day mortality.

RESULTS

A nonlinear relationship existed between serum sodium and 28-day mortality, of which a negative association was found between serum sodium and 28-day mortality (odds ratio: 0.95, 95% CI: 0.94, 0.96, p = 0.0001) when serum sodium was in 102 mmol/L to 138 mmol/L, but a positive correlation appeared when sodium climbed to the range of 140-179 mmol/L (odds ratio: 1.04, 95% CI: 1.03-1.06, p = 0.0001).

CONCLUSIONS

Both lower and higher serum sodium levels are associated with an increased risk of death in sepsis patients.

Fluid management in children with volume depletion

Volume depletion is a common condition and a frequent cause of hospitalization in children. Proper assessment of the patient includes a detailed history and a thorough physical examination. Biochemical tests may be useful in selected cases. Understanding the pathophysiology of fluid balance is necessary for appropriate management. A clinical dehydration scale assessing more physical findings may help to determine dehydration severity. Most dehydrated children can be treated orally; however, intravenous therapy may be indicated in patients with severe volume depletion, in those who have failed oral therapy, or in children with altered consciousness or significant metabolic abnormalities. Proper management consists of restoring circulatory volume and electrolyte balance. In this paper, we review clinical aspects, diagnosis, and management of children with volume depletion.

A pragmatic, open-label, randomized controlled trial of Plasma-Lyte-148 versus standard intravenous fluids in children receiving kidney transplants (PLUTO)

Acute electrolyte and acid-base imbalance is experienced by many children following kidney transplant. This is partly because doctors give very large volumes of artificial fluids to keep the new kidney working. When severe, fluid imbalance can lead to seizures, cerebral edema and death. In this pragmatic, open-label, randomized controlled trial, we randomly assigned (1:1) pediatric kidney transplant recipients to Plasma-Lyte-148 or standard of care perioperative intravenous fluids (predominantly 0.45% sodium chloride and 0.9% sodium chloride solutions). We then compared clinically significant electrolyte and acid-base abnormalities in the first 72 hours post-transplant. The primary outcome, acute hyponatremia, was experienced by 53% of 68 participants in the Plasma-Lyte-148 group and 58% of 69 participants in the standard fluids group (odds ratio 0·77 (0·34 - 1·75)). Five of 16 secondary outcomes differed with Plasma-Lyte-148: hypernatremia was significantly more frequent (odds ratio 3·5 (1·1 - 10·8)), significantly fewer changes to fluid prescriptions were made (rate ratio 0·52 (0·40-0·67)), and significantly fewer participants experienced hyperchloremia (odds ratio 0·17 (0·07 - 0·40)), acidosis (odds ratio 0·09 (0·04 - 0·22)) and hypomagnesemia (odds ratio 0·21 (0·08 - 0·50)). No other secondary outcomes differed between groups. Serious adverse events were reported in 9% of participants randomized to Plasma-Lyte-148 and 7% of participants randomized to standard fluids. Thus, perioperative Plasma-Lyte-148 did not change the proportion of children who experienced acute hyponatremia compared to standard fluids. However fewer fluid prescription changes were made with Plasma-Lyte-148, while hyperchloremia and acidosis were less common.

[Consensus recommendations on the diagnosis and treatment of hyponatremia from the Austrian Society for Nephrology 2024]

Hyponatremia is a disorder of water homeostasis. Water balance is maintained by the collaboration of renal function and cerebral structures, which regulate thirst mechanisms and secretion of the antidiuretic hormone. Measurement of serum-osmolality, urine osmolality and urine-sodium concentration help to diagnose the different reasons for hyponatremia. Hyponatremia induces cerebral edema and might lead to severe neurological symptoms, which need acute therapy. Also, mild forms of hyponatremia should be treated causally, or at least symptomatically. An inadequate fast increase of the serum sodium level should be avoided, because it raises the risk of cerebral osmotic demyelination. Basic pathophysiological knowledge is necessary to identify the different reasons for hyponatremia which need different therapeutic procedures.

Electrolyte Imbalance and Neurologic Injury

Neurologic injury continues to be a debilitating worldwide disease with high morbidity and mortality. The systemic sequelae of a neural insult often lead to prolonged hospital stays and challenging nutritional demands that contribute to poorer prognoses. Clinical management of a given condition should prioritize preserving the homeostatic parameters disrupted by inflammatory response cascades following the primary insult. This focused review examines the reciprocal relationship between electrolyte disturbance and neurologic injury. A prolonged electrolyte imbalance can significantly impact morbidity and mortality in neurologic injuries. A detailed overview of the major electrolytes and their physiologic, iatrogenic, and therapeutic implications are included. The pathophysiology of how dysnatremias, dyskalemias, dyscalcemias, and dysmagnesemias occur and the symptoms they can induce are described. The manifestations in relation to traumatic brain injury, status epilepticus, and acute ischemic stroke are addressed. Each type of injury and the strength of its association with a disruption in either sodium, potassium, calcium, or magnesium is examined. The value of supplementation and replacement is highlighted with an emphasis on the importance of early recognition in this patient population. This review also looks at the current challenges associated with correcting imbalances in the setting of different injuries, including the relevant indications and precautions for some of the available therapeutic interventions. Based on the findings of this review, there may be a need for more distinct clinical guidelines on managing different electrolyte imbalances depending on the specified neurologic injury. Additional research and statistical data on individual associations between insult and imbalance are needed to support this potential future call for context-based protocols.

Osmotic demyelination as a complication of hyponatremia correction: a systematic review

BACKGROUND

Rapid correction of hyponatremia, especially when severe and chronic, can result in osmotic demyelination. The latest guideline for diagnosis and treatment of hyponatremia (2014) recommends a correction limit of 10 mEq/L/day. Our aim was to summarize published cases of osmotic demyelination to assess the adequacy of this recommendation.

METHOD

Systematic review of case reports of osmotic demyelination. We included cases confirmed by imaging or pathology exam, in people over 18 years of age, published between 1997 and 2019, in English or Portuguese.

RESULTS

We evaluated 96 cases of osmotic demyelination, 58.3% female, with a mean age of 48.2 ± 12.9 years. Median admission serum sodium was 105 mEq/L and > 90% of patients had severe hyponatremia (<120 mEq/L). Reports of gastrointestinal tract disorders (38.5%), alcoholism (31.3%) and use of diuretics (27%) were common. Correction of hyponatremia was performed mainly with isotonic (46.9%) or hypertonic (33.7%) saline solution. Correction of associated hypokalemia occurred in 18.8%. In 66.6% of cases there was correction of natremia above 10 mEq/L on the first day of hospitalization; the rate was not reported in 22.9% and in only 10.4% was it less than 10 mEq/L/day.

CONCLUSION

The development of osmotic demyelination was predominant in women under 50 years of age, with severe hyponatremia and rapid correction. In 10.4% of cases, there was demyelination even with correction <10 mEq/L/day. These data reinforce the need for conservative targets for high-risk patients, such as 4-6 mEq/L/day, not exceeding the limit of 8 mEq/L/day.

Pharmacodynamics Research on Danggui-Shaoyao-San through Body Fluid Indexes of Spleen Deficiency-water Dampness Rats using Bio-impedance Technology

BACKGROUND

Spleen deficiency-water dampness symptom is closely related to body fluid-mediated organism metabolism and circulation. However, previous clinical evaluation of spleen deficiency-water dampness model was based only on body weight, D-xylose excretion rate, serum gastrin content, etc. Therefore, we established a large sample of normal rats and model rats experiment to verify the scientific nature of bio-impedance measuring body fluid indexes for evaluation of the modeling state. Pharmacodynamics research on Danggui-Shaoyao- San (DSS) was conducted through body fluid index changes of rats using bio-impedance technology.

METHODS

A spleen deficiency-water dampness symptom rat model was established through an inappropriate diet combined with excess fatigue. Experimental rats were divided into a normal control group, a model control group, a positive drug control group (hydrochlorothiazide), a blood-activating group, a water-disinhibiting group, and a DSS group. Total Body Water/Body Weight (TBW%), extracellular fluid/total body water content (ECF%), intracellular fluid/total body water content (ICF%), extracellular fluid/intracellular fluid (ECF/ICF), fat mass/body weight (FM%), fat-free mass/body weight (FFM%), and fat mass/fat-free mass (FM/FFM) of 150 rats were detected by a Bio-Imp Vet Body analyzer.

RESULTS

The TBW% of the model control group increased significantly, and the FM/FFM was significantly reduced compared with the normal group (P < 0.05) (P < 0.01), showing symptoms of spleen deficiency and diarrhea; the TBW% of the blood-activating group, and the waterdisinhibiting group decreased significantly, and the FM/FFM increased significantly (P < 0.05) (P < 0.01). The TBW% and FM/FFM in the water-disinhibiting group had returned to nearnormal values compared with the model control group. The blood-activating and waterdisinhibiting split prescriptions in DSS are both effective in treating spleen deficiency-water dampness rats. Comparatively, the fluid-regulating effect of split prescriptions in DSS was even stronger than that of DSS as shown in the present study.

CONCLUSIONS

These findings suggest that using bio-impedance technology to measure body fluid indexes can pave a road for further exploring the molecular mechanism of the reason why the blood-activating and disinhibit-water split prescriptions in DSS are both effective in treating spleen deficiency-water dampness rats.

Review of adverse events associated with COVID-19 vaccines, highlighting their frequencies and reported cases

This review examines the immunological and autoimmune adverse events associated with COVID-19 vaccines, highlighting their frequencies, reported cases, and associations with specific vaccine classes. The concept of vaccine-induced immune thrombotic thrombocytopenia is crucial in addressing vaccine skepticism. Understanding this concept helps healthcare professionals identify and manage potential adverse events after vaccination. Despite their rarity, immunological and autoimmune adverse events cause concern and anxiety among the public. To maintain public trust in vaccination programs, healthcare professionals and public health agencies must actively monitor and address these adverse events, promptly disclose suspicious incidents, take measures to mitigate dangers, and inform the public with transparency and accurate information. Continuing research and surveillance are essential for understanding the underlying mechanisms of these adverse events and developing strategies to minimize their occurrence.

Associations of Hyponatremia with Cognition Function and All-Cause Mortality: Post Hoc Analysis of the Systolic BP Intervention Trial

Key Points

Incident hyponatremia is associated with probable dementia. Incident hyponatremia does not seem to be associated with mild cognitive impairment or death.

Background

Acute neurologic effects of severe hyponatremia are well-known. However, the long-term association of hyponatremia with cognitive impairment is unclear.

Methods

In this post hoc analysis of the Systolic Blood Pressure Intervention Trial, we examined whether incident hyponatremia is a risk factor of mild cognitive impairment (MCI) or probable dementia (PD). In those with baseline serum sodium level ≥130 mmol/L, we defined incident hyponatremia in the first 6 months as a Systolic Blood Pressure Intervention Trial safety alert for serum sodium level <130 mmol/L from randomization to the 6-month visit. In multivariate Cox regression models adjusted for baseline cognitive function and other variables, we related incident hyponatremia in the first 6 months with subsequent MCI or PD in 8540 participants with cognitive outcomes data and with all-cause mortality (ACM) in 9135 participants with mortality data.

Results

Incident hyponatremia in the first 6 months was noted in 116 participants (1.4%). Older age, female sex, non-Black race, lower body mass index, and randomization to intensive systolic BP control were associated with incident hyponatremia. Compared with those without hyponatremia, those with incident hyponatremia had higher risk of PD (2.1 versus 0.9 events/100 person-years; hazard ratio [HR], 3.08; 95% confidence interval [CI], 1.48 to 6.41) but not MCI (3.1 versus 3.6 events/100 person-years; HR, 0.95; 95% CI, 0.54 to 1.68) and the composite of MCI/PD (5.0 versus 4.2 events/100 person-years; HR, 1.28; 95% CI, 0.82 to 2.0). There were no significant differences in ACM (HR, 1.84; 95% CI, 0.90 to 3.73).

Conclusions

Biologic plausibility for the association of incident hyponatremia with PD but not MCI or death is unclear. The association of incident hyponatremia with PD could reflect a chance finding or noncausal biologic association or causal relationship.

Syndrome of Inappropriate Antidiuresis: From Pathophysiology to Management

Hyponatremia is the most common electrolyte disorder, affecting more than 15% of patients in the hospital. Syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of hypotonic hyponatremia, mediated by nonosmotic release of arginine vasopressin (AVP, previously known as antidiuretic hormone), which acts on the renal V2 receptors to promote water retention. There are a variety of underlying causes of SIAD, including malignancy, pulmonary pathology, and central nervous system pathology. In clinical practice, the etiology of hyponatremia is frequently multifactorial and the management approach may need to evolve during treatment of a single episode. It is therefore important to regularly reassess clinical status and biochemistry, while remaining alert to potential underlying etiological factors that may become more apparent during the course of treatment. In the absence of severe symptoms requiring urgent intervention, fluid restriction (FR) is widely endorsed as the first-line treatment for SIAD in current guidelines, but there is considerable controversy regarding second-line therapy in instances where FR is unsuccessful, which occurs in around half of cases. We review the epidemiology, pathophysiology, and differential diagnosis of SIAD, and summarize recent evidence for therapeutic options beyond FR, with a focus on tolvaptan, urea, and sodium-glucose cotransporter 2 inhibitors.

Frequency of Hyponatremia and Its Impact on Prognosis in Ischemic Stroke

Background Hyponatremia, often encountered in hospitalized patients, is associated with adverse outcomes in ischemic stroke patients. In this study, we investigated the frequency of hyponatremia and its impact on prognosis and clinical outcomes in ischemic stroke patients from a tertiary care hospital. Methodology A total of 289 patients admitted to the hospital with ischemic stroke from September 2022 to February 2023 were considered in this cross-sectional study. Serum sodium level was measured on admission, and hyponatremia was defined as sodium less than 135 mmol/L. The primary outcome of the study was assessed by the National Institutes of Health Stroke Scale (NIHSS) score on admission and discharge and inpatient mortality. Data were analyzed using SPSS version 20 (IBM Corp., Armonk, NY, USA), and multivariate logistic regressions were conducted using variables identified as having a relationship with hyponatremia. Results Our study shows that among 289 patients with ischemic stroke, the mean age was 61 ± 8.53 years. Hyponatremia was observed in 101 (35%) patients, and all baseline characteristics and risk factors for stroke were similar between patients with and without hyponatremia. The patients with hyponatremia had higher NIHSS scores on admission (p = 0.041) and at discharge (p = 0.039). In the resultant multivariate analysis, hyponatremia was an independent predictor of mortality rates during the hospital stay. The cumulative incidence rates of in-hospital mortality for hyponatremia and normal sodium level were 16.8% and 10.1%, respectively. Conclusions Hyponatremia is prevalent in ischemic stroke and is independently associated with in-hospital mortality and worse NIHSS scores at admission and discharge.

[Dysnatremia]

Changes in serum sodium concentrations are frequently encountered by anesthesiologists, are complex and are often inadequately treated. Feared consequences include neurological complications, such as cerebral hemorrhage, cerebral edema and coma. Dysnatremia is always accompanied disturbances in the water balance. Accordingly, these are routinely classified based on the tonicity; however, in the daily routine and especially in the acute setting, the volume status and extracellular volume are often difficult to assess. Severe symptomatic hyponatremia with impending cerebral edema is treated by administration of hypertonic saline solution. If the rise in serum sodium is too rapid, there is a risk of central pontine myelinolysis. In a second step, the cause of the hyponatremia can be investigated and the appropriate treatment can be initiated. In the case of hypernatremia, the etiology of the disorder must be clarified before treatment. The goal is to compensate for the water deficiency by correcting the cause, specific volume therapy and, if necessary, drug support. A slow and controlled compensation must be closely monitored in order to avoid neurological complications. An algorithm has been developed that provides an overview of the dysnatremias, aids with making the diagnosis and gives recommendations for treatment measures in the clinical routine.

Overcorrection and undercorrection with fixed dosing of bolus hypertonic saline for symptomatic hyponatremia

OBJECTIVE

Current guidelines recommend treating symptomatic hyponatremia with rapid bolus-wise infusion of fixed volumes of hypertonic saline regardless of body weight. We hypothesize that this approach is associated with overcorrection and undercorrection in patients with low and high body weight.

DESIGN

Single-center, retrospective cohort study.

METHODS

Data were collected on patients treated with ≥1 bolus 100 or 150 mL 3% NaCl for symptomatic hyponatremia between 2017 and 2021. Outcomes were overcorrection (plasma sodium rise > 10 mmol/L/24 h, > 18 mmol/L/48 h, or relowering therapy) and undercorrection (plasma sodium rise < 5 mmol/L/24 h). Low body weight and high body weight were defined according to the lowest (≤60 kg) and highest (≥80 kg) quartiles.

RESULTS

Hypertonic saline was administered to 180 patients and caused plasma sodium to rise from 120 mmol/L to 126.4 mmol/L (24 h) and 130.4 mmol/L (48 h). Overcorrection occurred in 32 patients (18%) and was independently associated with lower body weight, weight ≤ 60 kg, lower baseline plasma sodium, volume depletion, hypokalemia, and less boluses. In patients without rapidly reversible causes of hyponatremia, overcorrection still occurred more often in patients ≤ 60 kg. Undercorrection occurred in 52 patients (29%) and was not associated with body weight or weight ≥ 80 kg but was associated with weight ≥ 100 kg and lean body weight in patients with obesity.

CONCLUSION

Our real-world data suggest that fixed dosing of bolus hypertonic saline may expose patients with low and high body weight to more overcorrection and undercorrection, respectively. Prospective studies are needed to develop and validate individualized dosing models.

Pontine and bilateral cerebellar lesion in osmotic demyelination syndrome associated with uncontrolled type II diabetes mellitus: a case report

Osmotic demyelination syndrome (ODS) as a result of the hyperosmolar hyperglycemic state is rare and can present with variable neurological manifestation due to lysis of myelin sheath.

Case presentation

A 44-year diabetic male presented with complaints of sudden onset, progressive bilateral weakness in lower limbs, and slurring of speech for the past 1.5 months. Cerebellar examination showed a bilaterally impaired finger nose test, dysdiadochokinesia, impaired heel shin test, and an impaired tandem gait. MRI brain (T2 and fluid-attenuated inversion recovery sequences) showed high signal intensity in the central pons and bilateral cerebellum. With a diagnosis of ODS with poorly controlled diabetes, he was treated with insulin, metformin, and supportive measures following which his symptoms subsided gradually.

Clinical discussion

A rapid correction of hyponatremia is considered the most common cause of ODS. Variations in plasma glucose levels, a rare cause of ODS, can cause an abrupt osmolality change causing pontine and extrapontine myelinolysis. Prevention of rapid correction of hyponatremia and rapid changes in plasma osmolality in vulnerable patients is the mainstay of treatment.

Conclusions

Clinical features, imaging studies, and monitoring of serum osmolality, serum glucose, and electrolytes aid in diagnosis and favorable outcomes for the patient.

Adaptation of the Brain to Hyponatremia and Its Clinical Implications

Hyponatremia is the most common electrolyte disorder, occurring in up to 25% of hospitalized patients. Hypo-osmotic hyponatremia when severe and left untreated invariably results in cell swelling, which can lead to fatal consequences, especially in the central nervous system. The brain is particularly vulnerable to the consequences of decreased extracellular osmolarity; because of being encased in the rigid skull, it cannot withstand persistent swelling. Moreover, serum sodium is the major determinant of extracellular ionic balance, which in turn governs crucial brain functions such as the excitability of neurons. For these reasons, the human brain has developed specific ways to adapt to hyponatremia and prevent brain edema. On the other hand, it is well known that rapid correction of chronic and severe hyponatremia can lead to brain demyelination, a condition known as osmotic demyelination syndrome. In this paper, we will discuss the mechanisms of brain adaptation to acute and chronic hyponatremia and the neurological symptoms of these conditions as well as the pathophysiology and prevention of osmotic demyelination syndrome.

Severe hyponatraemia with cerebral oedema after Pfizer BNT162b2 mRNA vaccination against COVID-19

Background

Severe hyponatraemia can lead to serious neurological complications including coma, seizure and death. Hyponatraemia and the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) has been previously described in cases of COVID-19, however there have been few reports post vaccination. We describe a case of severe hyponatraemia post second Pfizer BNT162b2 mRNA vaccination against COVID-19.

Case presentation

A 48-year-old previously well woman presented to the emergency department with severe headaches and confusion one day after she received her second Pfizer COVID-19 vaccination. She reported no more than 2.5 L fluid intake. Vital signs were normal. Laboratory investigation revealed serum sodium 113 mmol/L, potassium 3.4 mmol/L, urea 3.5 mmol/L and serum osmolality 266 mmol/kg. TSH, random cortisol and C-reactive protein levels were normal. She was found to be in urinary retention and developed marked polyuria post in dwelling catheter insertion. Following this she underwent spontaneous and rapid correction of serum sodium without intervention. Retrospective analysis showed an inappropriately high copeptin of 4.4 pmol/L.

Conclusions

It is important to be cautioned and aware of hyponatraemia as an immediate side effect of COVID-19 vaccination. The exact mechanism is unknown and further research is required to understand the acute endocrine effects which may arise in response to COVID-19 vaccination.

Case report: Recovery and sequential imaging of a patient with osmotic demyelination syndrome

A 4-year-old neutered-male Australian Shepherd was presented to an emergency and referral hospital for an acute onset of neurologic signs and abnormal mentation. Seven days prior, the patient had been diagnosed with hypoadrenocorticism and was treated accordingly at another hospital. Based on recent clinical history, the neurologic signs were consistent with thalamic and brainstem deficits and suspected to be caused by osmotic demyelination syndrome secondary to rapid correction of hyponatremia. A brain MRI confirmed lesions consistent with osmotic demyelination syndrome. The patient's clinical signs initially worsened, and he required intensive nursing care with multimodal sedation, close monitoring of electrolytes and tailored fluid therapy. The patient recovered and was discharged on day seven of hospitalization. Four and a half months later, re-evaluation of the patient showed complete resolution of the neurological deficits with a now unremarkable neurological exam, and follow-up MRI revealed still present, yet improved bilateral thalamic lesions. This is the first known veterinary case report of sequential brain imaging of a dog that has recovered from osmotic demyelination syndrome. In humans, patients can have evidence of near to full clinical recovery, yet imaging findings may still be abnormal several months after recovery. This report details similar imaging findings in a canine with improved clinical signs, despite persistent lesions on brain MRI. Prognosis of canines with osmotic demyelination syndrome may be better than previously perceived, despite the severity of clinical signs and brain lesions apparent on MRI.

Rapid correction of severe hyponatremia and control of subsequent overcorrection in operative hysteroscopy intravascular absorption syndrome: A case report

RATIONALE

Operative hysteroscopy intravascular absorption syndrome (OHIAS) results from systemic absorption of hypotonic solution during hysteroscopy, which may induce severe hyponatremia within hours. Depending on the serum sodium (Na+) level, this can be life-threatening and requires prompt and careful remedial treatment.

PATIENT CONCERNS AND DIAGNOSES

A 53-year-old woman underwent hysteroscopic myomectomy for submucosal leiomyoma. Approximately 3 hours postoperatively, the serum Na+ level decreased to 82 mM/L, accompanied by pulmonary edema and lactic acidosis. The patient was strongly suspicious of OHIAS.

INTERVENTIONS AND OUTCOMES

A rapid correction was made using 3% NaCl to prevent brain edema as an initial response. After the serum Na+ level reached 120 mM/L, gradual correction was performed considering osmotic demyelination syndrome, and desmopressin was administered to prevent overcorrection caused by excessive water diuresis. Serum Na+ level normalized in 4 days and the patient recovered without any specific sequelae.

LESSONS

The detection of OHIAS may be delayed under general anesthesia, and prior vigilance is important if the operation time is prolonged. In severe hyponatremia with an apparently rapid onset, such as OHIAS, a two-step correction process may be safe and useful: rapid correction followed by more gradual correction.

The diagnosis and management of acute hyponatraemia in critical care

Nurses working in critical care, consisting of the intensive care and high dependency units, will encounter a broad range of diseases and conditions. Therefore, a comprehensive knowledge and understanding of common presentations is required, especially for advanced clinical practitioners (ACPs). One of the most common electrolyte disturbances seen within these areas is hyponatraemia, affecting around 40% of patients in critical care and 30% of inpatients. It is important that ACPs working in this area are aware of the symptoms and recommended diagnosis and management.

Identification of risk factors associated with hyponatremia in psychiatric patients: a case-control study

Background and aims

Prompt recognition and optimal management of hyponatremia helps the physician devise a better treatment plan to prevent future complications in patients. Hence this study aims to identify the risk factors associated with hyponatremia in psychiatric patients.

Methods

A case-control study was conducted among psychiatric inpatients in a tertiary care teaching hospital. Patients admitted from January 2013 to December 2017 were identified using ICD-10 code F01-F99. Patients with serum sodium levels < 135 mmol/L were considered to have hyponatremia and between 135-145 mmol/L as controls. Factors associated with hyponatremia were identified by multiple logistic regression, and the odds ratio (OR) was calculated.

Results

Based on the inclusion and exclusion criteria, 264 cases of hyponatremia and 253 matching controls were included in the study. The mean age of patients with hyponatremia was 56.4 ± 16.8 years compared to 39.6 ± 13.9 years in controls, and 65.7% of them were males. Seizure disorder (OR = 3.14, p = 0.047), bipolar disorder (OR = 6.03, p = 0.001), depression (OR = 4.78, p = 0.0005), use of quetiapine (OR = 2.11, p = 0.007) and insulin (OR = 3.53, p = 0.038) were independent risk factors associated with development of hyponatremia.

Conclusions

The chances of developing hyponatremia are increased in psychiatric patients with a seizure disorder, bipolar disorder, depression and using quetiapine or insulin. And they should be monitored carefully.

Hiponatremili hastalarda serum nöron spesifik enolaz düzeyleri ile beyin hasarı arasındaki ilişki

Amaç: Bu çalışmada hiponatremili hastalarda serum nöron spesifik enolazın santral sinir sistemi hasarını öngörmesi ve klinik gidiş üzerindeki etkilerini araştırmayı amaçladık. Gereç ve Yöntem: Bu prospektif çalışmada, serum sodyum seviyeleri 135 mEq/L'nin altında olan 75 yetişkin hasta değerlendirildi. Hastalar serum nöron spesifik enolaz düzeylerine göre gruplandırıldı (grup 1 ≤ 17.0 ng/mL ve grup 2 > 17.0 ng/mL). Gruplar demografik ve laboratuvar verilerine göre karşılaştırıldı. Bulgular: Grup 2 hastalarında hipertansiyon, kalp yetmezliği ve bilinç kaybı insidansı anlamlı olarak daha yüksekti. Yüksek nöron spesifik enolaz seviyeleri, daha düşük serum sodyum seviyeleri ile ilişkiliydi. Ortalama sodyum seviyeleri grup 1 ve 2'de sırasıyla 129.5 ± 4.3 mEq/L ve 126 ± 4.5 mEq/L idi. Grup 2'deki hastalardan (n = 45), bilinç kaybı olan (düşük Glasgow Koma Skalası skorları) (GKS

Treatment of hyponatremia in children with acute bacterial meningitis

Purpose

Few studies have evaluated hyponatremia management in children with bacterial meningitis (BM). Thus, we aimed to describe variations in clinical practice, the effectiveness of sodium management, and adverse outcomes in children with BM and hyponatremia.

Methods

This retrospective cross-sectional study conducted at a tertiary institution analyzed participants' demographic, clinical, and sodium-altering treatment data. The sodium trigger for treatment was defined as pretreatment sodium level, with response and overcorrection defined as increments of ≥5 and &gt;10 mmol/L after 24 h, respectively.

Results

This study enrolled 364 children with BM (age: &lt;16 years; 215 boys). Hyponatremia occurred in 62.1% of patients, among whom 25.7% received sodium-altering therapies; 91.4% of those individuals had moderate/severe hyponatremia. Monotherapy was the most common initial hyponatremia treatment. After 24 h of treatment initiation, 82.4% of the patients responded. Logistic regression analyses revealed that ΔNa24 &lt;5 mmol/L [odds ratio (OR) 15.52, 95% CI 1.71–141.06, p = 0.015] and minimum Glasgow Coma Scale (GCS) score ≤ 8 (OR 11.09, 95% CI 1.16–105.73, p = 0.036) predicted dysnatremia at 48 h after treatment initiation. Although rare, persistent moderate/severe hyponatremia or hypernatremia at 48 h after treatment initiation was associated with a high mortality rate (57.1%).

Conclusion

This study found that most cases of hyponatremia responded well to various treatments. It is important to identify and institute appropriate treatment early for moderate or severe hyponatremia or hypernatremia in children with BM. This study was limited by its non-randomized nature.

Hyponatremia in the emergency department

Hyponatremia, defined as a serum sodium <135 mmol/L, is frequently encountered in patients presenting to the emergency department. Symptoms are often unspecific and include a recent history of falls, weakness and vertigo. Common causes of hyponatremia include diuretics, heart failure as well as Syndrome of Inappropriate Antidiuresis (SIAD) and correct diagnosis can be challenging. Emergency treatment of hyponatremia should be guided by presence of symptoms and focus on distinguishing between acute and chronic hyponatremia.

Whole-brain metabolic pattern analysis in patients with anti-LGI1 encephalitis

BACKGROUND AND PURPOSE

Faciobrachial dystonic seizures (FBDS) and hyponatraemia are the distinct clinical features of autoimmune encephalitis (AE) caused by antibodies against leucine-rich glioma-inactivated 1 (LGI1). The pathophysiological pattern and neural mechanisms underlying these symptoms remain largely unexplored.

METHODS

We included 30 patients with anti-LGI1 AE and 30 controls from a retrospective observational cohort. Whole-brain metabolic pattern analysis was performed to assess the pathological network of anti-LGI1 AE, as well as the symptomatic networks of FBDS. Logistic regression was applied to explore independent predictors of FBDS. Finally, we applied multiple regression model to investigate the hyponatraemia-associated brain network and its effect on serum sodium levels.

RESULTS

The pathological network of anti-LGI1 AE involved a hypermetabolism in cerebellum, subcortical structures, and Rolandic area, as well as a hypometabolism in the medial prefrontal cortex. The symptomatic network of FBDS shown a hypometabolism in cerebellum and Rolandic area (P_FDR < 0.05). Hypometabolism in the cerebellum was an independent predictor of FBDS (P < 0.001). Hyponatraemia-associated network highlighted a negative effect on caudate nucleus, frontal and temporal white matter. Serum sodium level had the negative trend with metabolism of hypothalamus (Pearson's R = -0.180, P = 0.342) but the mediation was not detected (path c' = -7.238, 95% CI = -30.947 to 16.472).

CONCLUSIONS

Our results provide insights into the whole-brain metabolic patterns of patients with anti-LGI1 AE, including the symptomatic network FBDS and the hyponatraemia-associated brain network, which is conducive to understanding the neural mechanisms and evaluating disease progress of anti-LGI1 AE.

[Hyponatraemia in elderly patient - significance, clarification and therapy]

In the general population, the prevalence of mild, usually asymptomatic hyponatremia ranges from 1,7-7,7 %. With increasing age, it rises to 11,6 % in > 75-year-olds. The prevalence is much higher in nursing home residents and hospital patients. Hyponatremia thus represents the most common electrolyte disturbance in the elderly. Despite the existing evidence on the acute as well as chronic effects of hyponatremia, too little attention is paid to it in clinical practice. An algorithm has proven to be useful for the diagnosis of hyponatremia, which enables the cause to be identified in a few simple steps and at the same time leads to the correct therapeutic steps. The goal must be a serum sodium within the normal range. This is the only way to improve the prognosis and functionality of elderly patients. For SIADH, we have a potent substance available in tolvaptan. In order to be able to recognize the danger of overcorrection in time, the adjustment should take place in the inpatient setting.

Multicentre randomised controlled trial: protocol for Plasma-Lyte Usage and Assessment of Kidney Transplant Outcomes in Children (PLUTO)

INTRODUCTION

Acute electrolyte and acid-base imbalance is experienced by many children following kidney transplantation. When severe, this can lead to complications including seizures, cerebral oedema and death. Relatively large volumes of intravenous fluid are administered to children perioperatively in order to establish perfusion to the donor kidney, the majority of which are from living and deceased adult donors. Hypotonic intravenous fluid is commonly used in the post-transplant period due to clinicians' concerns about the sodium, chloride and potassium content of isotonic alternatives when administered in large volumes.Plasma-Lyte 148 is an isotonic, balanced intravenous fluid that contains sodium, chloride, potassium and magnesium with concentrations equivalent to those of plasma. There is a physiological basis to expect that Plasma-Lyte 148 will reduce the incidence of clinically significant electrolyte and acid-base abnormalities in children following kidney transplantation compared with current practice.The aim of the Plasma-Lyte Usage and Assessment of Kidney Transplant Outcomes in Children (PLUTO) trial was to determine whether the incidence of clinically significantly abnormal plasma electrolyte levels in paediatric kidney transplant recipients will be different with the use of Plasma-Lyte 148 compared with intravenous fluid currently administered.

METHODS AND ANALYSIS

PLUTO is a pragmatic, open-label, randomised controlled trial comparing Plasma-Lyte 148 to current care in paediatric kidney transplant recipients, conducted in nine UK paediatric kidney transplant centres.A total of 144 children receiving kidney transplants will be randomised to receive either Plasma-Lyte 148 (the intervention) intraoperatively and postoperatively, or current fluid. Apart from intravenous fluid composition, all participants will receive standard clinical transplant care.The primary outcome measure is acute hyponatraemia in the first 72 hours post-transplant, defined as laboratory plasma sodium concentration of <135 mmol/L. Secondary outcomes include symptoms of acute hyponatraemia, other electrolyte and acid-base imbalances and transplant kidney function.The primary outcome will be analysed using a logistic regression model adjusting for donor type (living vs deceased donor), patient weight (<20 kg vs ≥20 kg pretransplant) and transplant centre as a random effect.

ETHICS AND DISSEMINATION

The trial received Health Research Authority approval on 20 January 2020. Findings will be presented to academic groups via national and international conferences and peer-reviewed journals. The patient and public involvement group will play an important part in disseminating the study findings to the public domain.

TRIAL REGISTRATION NUMBERS

2019-003025-22 and 16586164.

Impact of Sodium Levels on Functional Outcomes in Patients With Stroke - A Swiss Stroke Registry Analysis

CONTEXT

Correction of hyponatremia might represent an additional treatment for improving stroke patients' clinical outcomes.

OBJECTIVE

Admission hyponatremia is associated with worse clinical outcome in stroke patients, but whether normalization of hyponatremia improves outcome is unknown. We investigated whether normalization of hyponatremia affects patients' disability, mortality, and stroke recurrence within 3 months; length of hospitalization; and discharge destination.

DESIGN

This was a registry-based analysis of data collected between January 2016 and December 2018. We linked data from Swiss Stroke Registry (SSR) with electronic patients' records for extracting sodium values.

SETTING

We analyzed data of hospitalized patients treated at University Hospital of Basel.

PATIENTS

Stroke patients whose data and informed consent were available.

MAIN OUTCOME MEASURE

Modified Rankin Scale (mRS) score at 3 months. The tested hypothesis was formulated after SSR data collection but before linkage with electronic patients' records.

RESULTS

Of 1995 patients, 144 (7.2%) had hyponatremia on admission; 102 (70.8%) reached normonatremia, and 42 (29.2%) remained hyponatremic at discharge. An increase of initial sodium was associated with better functional outcome at 3 months (odds ratio [OR] 0.94; 95% CI, 0.90-0.99, for a shift to higher mRS per 1 mmol/L sodium increase). Compared with normonatremic patients, patients who remained hyponatremic at discharge had a worse functional outcome at 3 months (odds ratio 2.46; 95% CI, 1.20-5.03, for a shift to higher mRS). No effect was found on mortality, recurrence, or length of hospitalization.

CONCLUSIONS

In hospitalized acute stroke patients, persistent hyponatremia is associated with worse functional outcome. Whether active correction of hyponatremia improves outcome remains to be determined in prospective studies.

Management of SIADH-related hyponatremia due to psychotropic medications - An expert consensus from the Association of Medicine and Psychiatry

OBJECTIVE

Hyponatremia is the most common electrolyte imbalance encountered in clinical practice and is associated with negative healthcare outcomes and cost. SIADH is thought to account for one third of all hyponatremia cases and is typically an insidious process. Psychotropic medications are commonly implicated in the etiology of drug induced SIADH. There is limited guidance for clinicians on management of psychotropic-induced SIADH.

METHODS

After an extensive review of the existing literature, clinical-educators from the Association of Medicine and Psychiatry developed expert consensus recommendations for management of psychotropic-induced SIADH. A risk score was proposed based on risk factors for SIADH to guide clinical decision-making.

RESULTS

SSRIs, SNRIs, antipsychotics, carbamazepine, and oxcarbazepine have moderate to high level of evidence demonstrating their association with SIADH. Evaluation for an avoidance of medications that cause hyponatremia is particularly important. Substitution with medication that is less likely to cause SIADH should be considered when appropriate. We propose an algorithmic approach to monitoring hyponatremia with SIADH and corresponding treatment depending on symptom severity.

CONCLUSIONS

The proposed algorithm can help clinicians in determining whether psychotropic medication should be stopped, reduced or substituted where SIADH is suspected with recommendations for sodium (Na+) monitoring. These recommendations preserve a role for clinical judgment in the management of hyponatremia with consideration of the risks and benefits, which may be particularly relevant for complex patients that present with medical and psychiatric comorbidities. Further studies are needed to determine whether baseline and serial Na+ monitoring reduces morbidity and mortality.

Compositional Features and Nutritional Value of Pig Brain: Potential and Challenges as a Sustainable Source of Nutrients

The goal of this study was to establish the nutritional value and compositional properties of the brains of crossbred pigs (Landrace-Large white-Duroc (LLD)), in order to realize the zero-waste concept and increase the use of by-products in the sustainable meat industry. Fat (9.25% fresh weight (fw)) and protein (7.25% fw) were the principal dry matters of pig brain, followed by carbohydrate and ash. Phospholipid and cholesterol had a 3:1 ratio. Pig brain had a red tone (L* = 63.88, a* = 5.60, and b* = 15.43) and a high iron content (66 mg/kg) due to a total heme protein concentration of 1.31 g/100 g fw. The most prevalent macro-element was phosphorus (14 g/kg), followed by potassium, sodium, calcium, and magnesium. Zinc, copper, and manganese were among the other trace elements discovered. The most prevalent nitrogenous constituents were alkali-soluble protein, followed by water-soluble protein, stromal protein, salt-soluble protein, and non-protein nitrogen. Essential amino acids were abundant in pig brain (44% of total amino acids), particularly leucine (28.57 mg/g protein), threonine, valine, and lysine. The total lipid, neutral, and polar lipid fractions of the pig brain had different fatty acid compositions. The largest amount was observed in saturated fatty acids (SFA), followed by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Stearic acid and palmitic acid were the most common SFA. Oleic acid was the most prevalent MUFA, while docosahexaenoic acid was the most common PUFA. Thus, the pig brain can be used in food formulations as a source of nutrients.

Lead, mercury, and selenium alter physiological functions in wild caimans (Caiman crocodilus)

Environmental contaminants affect ecosystems worldwide and have deleterious effects on biota. Non-essential mercury (Hg) and lead (Pb) concentrations are well documented in some taxa and are described to cause multiple detrimental effects on human and wildlife. Additionally, essential selenium (Se) is known to be toxic at high concentrations but, at lower concentrations, Se can protect organisms against Hg toxicity. Crocodilians are known to bioaccumulate contaminants. However, the effects of these contaminants on physiological processes remain poorly studied. In the present study, we quantified Hg, Pb and Se concentrations in spectacled caimans (Caiman crocodilus) and investigated the effects of these contaminants on several physiological processes linked to osmoregulatory, hepatic, endocrine and renal functions measured through blood parameters in 23 individuals. Mercury was related to disruption of osmoregulation (sodium levels), hepatic function (alkaline phosphatase levels) and endocrine processes (corticosterone levels). Lead was related to disruption of hepatic functions (glucose and alanine aminotransferase levels). Selenium was not related to any parameters, but the Se:Hg molar ratio was positively related to the Na⁺ and corticosterone concentrations, suggesting a potential protective effect against Hg toxicity. Overall, our results suggest that Hg and Pb alter physiological mechanisms in wild caimans and highlight the need to thoroughly investigate the consequences of trace element contamination in crocodilians.

A critical review of the neurovascular nature of migraine and the main mechanisms of action of prophylactic antimigraine medications

INTRODUCTION

Migraine involves neurovascular, functional, and anatomical alterations. Migraineurs experience an intense unilateral and pulsatile headache frequently accompanied with vomiting, nausea, photophobia, etc. Although there is no ideal preventive medication, frequency in migraine days may be partially decreased by some prophylactics, including antihypertensives, antidepressants, antiepileptics, and CGRPergic inhibitors. However, the mechanisms of action involved in antimigraine prophylaxis remain elusive.

AREAS COVERED

This review recaps some of the main neurovascular phenomena related to migraine and currently available preventive medications. Moreover, it discusses the major mechanisms of action of the recommended prophylactic medications.

EXPERT OPINION

In the last three years, migraine prophylaxis has evolved from nonspecific to specific antimigraine treatments. Overall, nonspecific treatments  mainly involve neural actions, whereas specific pharmacotherapy (represented by CGRP receptor antagonists and CGRPergic monoclonal antibodies) is predominantly mediated by neurovascular mechanisms that may include, among others: (i) reduction in the cortical spreading depression (CSD)-associated events; (ii) inhibition of pain sensitization; (iii) blockade of neurogenic inflammation; and/or (iv) increase in cranial vascular tone. Accordingly, the novel antimigraine prophylaxis promises to be more effective, devoid of significant adverse effects (unlike nonspecific treatments), and more beneficial for the quality of life of migraineurs.

Acute and Chronic Hyponatremia

Hyponatremia is the most common electrolyte disorder in clinical practice. Catastrophic complications can occur from severe acute hyponatremia and from inappropriate management of acute and chronic hyponatremia. It is essential to define the hypotonic state associated with hyponatremia in order to plan therapy. Understanding cerebral defense mechanisms to hyponatremia are key factors to its manifestations and classification and subsequently to its management. Hypotonic hyponatremia is differentiated on the basis of urine osmolality, urine electrolytes and volume status and its treatment is decided based on chronicity and the presence or absence of central nervous (CNS) symptoms. Proper knowledge of sodium and water homeostasis is essential in individualizing therapeutic plans and avoid iatrogenic complications while managing this disorder.

Central pontine myelinolysis and the osmotic demyelination syndromes: an open and shut case?

Central pontine myelinolysis and extrapontine myelinolysis are collectively called the osmotic demyelination syndromes. Despite being described in 1959, there are several aspects of the disorder that remain an enigma. Animal models and neuroimaging techniques have allowed us to understand the condition better. From being a universally fatal disorder that was diagnosed post mortem, increased awareness, neuroimaging techniques and supportive care have enabled us to make the diagnosis ante-mortem. This has also led to a significant drop in associated mortality. The aim of this review is to highlight the clinical spectrum, neuroimaging findings, and recent developments.

Hyponatremia and extrapontine myelinolysis in a patient with COVID-19: A case report

Until we have strong evidence to the contrary, symptomatic hyponatremia should be treated with extra caution in COVID-19 co-infection patients as the latter could be another risk factor for the development of extrapontine myelinolysis.

Troubleshooting a Nonresponder: Guidance for the Strength and Conditioning Coach

Ideally an athlete would continue to improve performance indefinitely over time, however improvement slows as the athlete approaches their genetic limits. Measuring performance is complex—performance may be temporarily depressed following aggressive training for multiple reasons, physiological and psychosocial. This reality may be vexing to the strength and conditioning coach, who, as a service provider, must answer to sport coaches about an athlete’s progress. Recently an evaluation mechanism for strength and conditioning coaches was proposed, in part to help coaches establish their effectiveness within the organization. Without formal guidance and realistic expectations, if an athlete is not bigger, leaner, stronger, etc. as a result of training within a specified timeframe, blame is often placed upon the strength and conditioning coach. The purpose of this article is to explore possible causes of what may be perceived as athlete non-responses to training and to provide guidance for the coach on how to handle those issues within their domain. A process of investigation is recommended, along with resources to assist coaches as they consider a broad range of issues, including enhancing existing testing methods, improving athlete behaviors, and adjusting processes designed to bring about performance improvement.

Prolonged Altered Mental Status in a Diabetic Hemodialysis Patient

Osmotic demyelination syndrome (ODS) is a demyelinating disorder of the central nervous system. It usually occurs with rapid correction of severe chronic hyponatremia. ODS is rarely seen as a complication of hyperglycemia. Herein, we report a rare presentation of ODS secondary to hyperosmolar hyperglycemic state. A 28-year-old female with type 1 diabetes, hypertension, seizure disorder, and end-stage renal disease on hemodialysis was brought from a shelter with two days of unresponsiveness and developed ODS after hyperosmolar hyperglycemic state in long-standing uncontrolled diabetes with normal serum electrolyte levels.

Increased mortality risk associated with serum sodium variations and borderline hypo- and hypernatremia in hospitalized adults

Background

This study aimed to evaluate short-term and long-term mortalities in a cohort of unselected hospitalized patients with serum sodium concentration ([Na⁺]) variations within and outside of reference range.

Methods

All adult patients admitted to the Mayo Clinic, Rochester, MN, USA from January 2011 to December 2013 (n = 147358) were retrospectively screened. Unique patients admitted during the study period were examined. The main exposure was serum [Na⁺] variation. Outcome measures were hospital and 1-year all-cause mortalities.

Results

A total of 60944 patients, mean age 63 ± 17 years, were studied. On admission, 17% (n = 10066) and 1.4% (n = 852) had hypo- and hypernatremia, respectively. During the hospital stay, 11044 and 4128 developed hypo- and hypernatremia, respectively, accounting for 52.3 and 82.9% of the total hypo- and hypernatremic patients. Serum [Na⁺] variations of ≥6 mEq/L occurred in 40.6% (n = 24 740) of the 60 944 patients and were significantly associated with hospital and 1-year mortalities after adjusting potential confounders (including demographics, comorbidities, estimated glomerular filtration rate, admission serum [Na⁺], number of [Na⁺] measurements and length of hospital stay). Adjusted odds ratios for hospital and 1-year mortalities increased with increasing [Na⁺] variations in a dose-dependent manner, from 1.47 to 5.48 (all 95% confidence intervals >1.0). Moreover, in fully adjusted models, [Na⁺] variations (≥6 mEq/L) within the reference range (135–145 mEq/L) or borderline hypo- or hypernatremia (133–137 and 143–147 mEq/L, respectively) compared with 138–142 mEq/L were associated with increased hospital and 1-year mortalities.

Conclusion

In hospitalized adults, [Na⁺] fluctuation (≥6 mEq/L) irrespective of admission [Na⁺] and borderline hypo- or hypernatremia are independent predictors of progressively increasing short- and long-term mortality burdens.