Exertional hyponatremia among active component members of the U.S. Armed Forces, 2008-2023.

Exertional hyponatremia, or exercise-associated hyponatremia, occurs within 24 hours after physical activity due to a serum, plasma, or blood sodium concentration (Na+) below the normal reference range of 135 mEq/L. If not detected early and managed properly, hyponatremia can be fatal. From 2008 to 2023, 1,812 cases of exertional hyponatremia were diagnosed among U.S. active component service members (ACSMs), with an overall incidence rate of 8.3 cases per 100,000 person-years (p-yrs). In 2023 there were 153 cases of exertional hyponatremia diagnosed among ACSMs, resulting in a crude incidence rate of 11.7 per 100,000 p-yrs. Female service members, those older than 40, non-Hispanic Black service members, Marine Corps members, recruits, those in combat-specific occupations, and ACSMs stationed in the Northeast U.S. region had higher incidence rates of exertional hyponatremia diagnoses than their respective counterparts. During the surveillance period, annual rates of incident exertional hyponatremia diagnoses peaked in 2010 (12.8 per 100,000 p-yrs) and then decreased to a low of 5.3 cases per 100,000 p-yrs in 2013. Thereafter the incidence rate fluctuated but has increased from 6.2 per 100,000 p-yrs in 2017 to its second-highest level in 2023. Service members and their supervisors should be aware of the dangers of excessive fluid consumption and prescribed limits for consumption during prolonged physical activity including field training exercises, personal fitness training, or recreational activities, particularly in hot, humid weather.

Precision medicine: "Point of Care Ultrasound" (PoCUS) in the diagnostic approach to the patient with hyponatremia.

Hyponatremia is a multifactorial disorder defined as a decrease in plasma sodium concentration. Its differential diagnosis requires an adequate evaluation of the extracellular volume (ECV). However, ECV determination, simply based on the clinical history, vital signs, physical examination, and laboratory findings can leads to misdiagnosis and inappropriate treatment. The use of Point-of-Care Ultrasound (POCUS), through the combination of Lung Ultrasound (LUS), Venous Excess UltraSound (VExUS) and Focused Cardiac Ultrasound (FoCUS), allows a much more accurate holistic assessment of the patient's ECV status in combination with the other parameters.

Study of Serum Electrolytes (Sodium and Potassium) Abnormalities in Acute Stroke.

Stroke is the common cause of death and disability worldwide, as well as in Bangladesh. Serum electrolytes abnormalities or dyselectrolytaemia is one of the major acute complications of stroke. Dyselectrolytaemia or serum electrolytes (sodium and potassium) abnormalities are more common in patients with acute stroke that can be easily measured. The study was planned to find out the serum electrolytes (sodium and potassium) abnormalities in acute stroke patients. This cross-sectional study was conducted in the Department of Neurology and Medicine, Mymensingh Medical College and Hospital from January 2019 to June 2020. Total 84 purposively selected patients with acute strokes were evaluated following informed written consent. Diagnosis was confirmed by neuroimaging of brain. Moreover, serum electrolytes level was measured for each patient. Data were collected by interviews, clinical examinations & laboratory investigations of the patients using a case record form and analysis was carried out by the help of SPSS 25.0. Mean age of the patients with acute strokes were 57.65±15.79 years. About two thirds (60.7%) of the patients were male and the remaining (39.3%) were female. Sodium imbalances were observed in 32.2% and potassium imbalances in 25.0% cases. About 66.7% haemorrhagic strokes patients and 42.2% ischaemic strokes patients had dyselectrolytaemia (p<0.05). More than twenty eight percent (28.6%) of all stroke patients had hyponatraemia, which was more common (35.9%) among haemorrhagic strokes patients (p<0.05). Of all stroke patients 21.4% had hypokalaemia, which was more common (28.2%) in haemorrhagic strokes patients (p<0.05). This study reveals that, serum electrolytes (sodium and potassium) abnormalities are more common in haemorrhagic than ischaemic strokes, which is mainly hyponatraemia and hypokalaemia.

Frequency of Hyponatremia in Adults with Acute Bacterial Meningitis.

Bacterial meningitis is a life-threatening disease. Bacterial meningitis patients are prone to develop acute hyponatremia. In the central nervous system infection hyponatremia could be due to the Syndrome of Inappropriate Anti Diuretic Hormone secretion. The frequency of hyponatremia in adults with acute bacterial meningitis patients was seen in this study. This cross-sectional study was conducted in the Internal Medicine Department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh from February 2016 to July 2016. A total of 50 patients were enrolled in this study by purposive sampling. Among 50 acute bacterial meningitis patients, 33 (66%) were diagnosed as hyponatremic state. The mean serum sodium level of 33 hyponatremic bacterial meningitis cases was 130.66±2.95 mmol/L. Most of the cases (78.79%) were mild hyponatremic state (130 mmol/L-135 mmol/L) whereas 18.18% were revealed as moderate hyponatremia (125 mmol/L-129 mmol/L). Only 3.03% of cases were presented as severe cases (≤124 mmol/L). The result revealed that a large number of patients with acute bacterial meningitis were suffering from hyponatremia and in the majority of cases were mildly hyponatremic.

Hyponatremia in the Context of Liver Disease.

Hyponatremia is common in patients with liver disease and is associated with increased mortality, morbidity, and a reduced quality of life. In liver transplantation, the inclusion of hyponatremia in organ allocation scores has reduced waitlist mortality. Portal hypertension and the resulting lowering of the effective arterial blood volume are important pathogenetic factors, but in most patients with liver disease, hyponatremia is multifactorial. Treatment requires a multifaceted approach that tries to reduce electrolyte-free water intake, restore urinary dilution, and increase nonelectrolyte solute excretion. Albumin therapy for hyponatremia is a peculiarity of advanced liver disease. Its use appears to be increasing, while the vaptans are currently only given in selected cases. Osmotic demyelination is a special concern in patients with liver disease. Serial checks of serum sodium concentrations and urine volume monitoring are mandatory.

Examining the significance of arginine vasopressin release to elucidate the often multifactorial etiology of hypotonic hyponatremia: A novel criterion.

Clinical hyponatremia guidelines, protocols and flowcharts are a convenient means for clinicians to quickly establish an etiological diagnosis for hyponatremia, and facilitate its often complex analysis. Unfortunately, they often erroneously attribute multifactorial hyponatremia to a single cause, which is potentially dangerous. In this manuscript, a novel criterion is proposed to quickly determine the physiological relevance of non-osmotic arginine vasopressin (AVP) release, and to add nuance to hyponatremia analysis. While analyzing hypotonic hyponatremia, it is imperative to not only verify whether or not a certain degree of inappropriate AVP release is present, but also to ascertain whether it-in itself-could sufficiently explain the observed hyponatremia, as these two are not always synonymous. Using well-known concepts from renal physiology to combine the electrolyte-free water balance and solute-free water balance, a novel physiological criterion is derived mathematically to easily distinguish three common hyponatremia scenarios, and to further elucidate the underlying etiology. The derived criterion can hopefully facilitate the clinician's and physiologist's interpretation of plasma and urine parameters in a patient presenting with hyponatremia, and warn against the important clinical pitfall of attributing hyponatremia too readily to a single cause.

A retrospective study: exploring preoperative hyponatremia in elderly patients with hip fractures.

BACKGROUND: This research aims to examine the frequency, age-related distribution, and intensity of preoperative hyponatremia among elderly individuals with hip fractures. This study aims to provide valuable insights into the diagnosis of preoperative hyponatremia in this patient population. METHODS: This research involved the analysis of clinical data obtained from 419 elderly individuals with hip fractures (referred to as the fracture group) and 166 elderly individuals undergoing routine health examinations (designated as the control group). A comprehensive comparison was conducted, examining baseline characteristics such as age, gender, and comorbidities between these two groups. We further investigated variations in the incidence rate of hyponatremia, age distribution, and the severity of hyponatremia. Additionally, a subgroup analysis compared patients with femoral neck fractures to those with intertrochanteric femur fractures, specifically examining the incidence rate and severity of hyponatremia in these distinct fracture types. RESULTS: The incidence of cerebrovascular disease was found to be higher in the fracture group as compared to the control group in our research. Nevertheless, no significant differences in general health and other comorbidities were observed between the two groups. Notably, the fracture group exhibited a greater preoperative prevalence of hyponatremia, with its severity increasing with age. Furthermore, among elderly patients with intertrochanteric femur fractures, the incidence of preoperative hyponatremia was not only higher but also more severe when compared to those with femoral neck fractures. CONCLUSION: Elderly individuals experiencing hip fractures exhibit a notable prevalence of preoperative hyponatremia, predominantly mild to moderate, with an escalating occurrence linked to advancing age. This phenomenon is especially conspicuous among patients with intertrochanteric fractures, warranting dedicated clinical scrutiny. The administration of sodium supplementation is advisable for the geriatric demographic as deemed necessary. Addressing hyponatremia becomes crucial, as it may play a role in the etiology of hip fractures in the elderly, and rectifying this electrolyte imbalance could potentially serve as a preventive measure against such fractures.

Safety and efficacy of proactive versus reactive administration of desmopressin in severe symptomatic hyponatremia: a randomized controlled trial.

This randomized controlled trial aimed to evaluate the safety and efficacy of proactive versus reactive desmopressin (DDAVP) strategies in treating severe symptomatic hyponatremia. Conducted from June 20, 2022, to February 20, 2023, it involved 49 patients with serum sodium levels below 125 mmol/L. Patients were assigned to either the proactive group, receiving DDAVP immediately upon diagnosis, or the reactive group, receiving DDAVP only if the serum sodium level tended to be overcorrected. The primary outcome was the incidence of overcorrection. The study revealed no significant difference in the overcorrection incidence between the proactive (16.7%) and reactive (28%) groups (p = 0.54). The change in serum sodium levels at 1, 6, 12, and 24 h were not different, however, at 48 h, the proactive group exhibited a higher but still safe change in serum sodium levels compared to the reactive group (10.3 ± 3.6 mmol/L vs. 7.7 ± 3.6 mmol/L, p = 0.013). Other parameters including time to symptom improvement, total intravenous fluid administered, DDAVP dose, urine volume, hospital stay duration, osmotic demyelination syndrome incidence, and 28-day mortality did not significantly differ between the groups. In conclusion, our findings suggest that there was no significant disparity in overcorrection rates between proactive and reactive DDAVP strategies for treating severe symptomatic hyponatremia. However, further large-scale studies are warranted to validate these results.

Serum sodium level fluctuations following the resection of childhood-onset craniopharyngioma.

BACKGROUND: Craniopharyngiomas are low-grade malignancies (WHO I) in the sellar region. Most cases of childhood-onset craniopharyngioma are adamantinomatous craniopharyngioma, and neurosurgery is the treatment of choice. Affected patients have postoperative complications, including water and electrolyte disturbances, because these malignancies develop near the hypothalamus and pituitary gland. Determining postoperative serum sodium fluctuation patterns in these patients can reduce postoperative mortality and improve prognosis. OBJECTIVE: To measure changes in serum sodium levels in pediatric patients who underwent craniopharyngioma surgery and identify influencing factors. METHODS: This retrospective study measured the serum sodium levels of 202 patients aged 0-18 years who underwent craniopharyngioma resection in Beijing Tiantan Hospital and Beijing Children's Hospital and identified predictors of severe hyponatremia and hypernatremia. RESULTS: The mean age of the cohort was 8.35 ± 4.35 years. The prevalence of hypernatremia, hyponatremia, and their severe forms (serum Na+  > 150 mmol/L and serum Na+  < 130 mmol/L) within 14 days after surgery was 66.3%, 72.8%, 37.1%, and 40.6%, respectively. The mean postoperative serum sodium level showed a triphasic pattern, characterized by two peaks separated by a nadir. Sodium levels peaked on days 2 (143.6 ± 7.6 mmol/L) and 14 (143.2 ± 6.7 mmol/L) and reached their lowest on day 6 (135.5 ± 7.5 mmol/L). A total of 31 (15.3%) patients met the diagnostic threshold for hyponatremia and hypernatremia of the triphase response, whereas 116 (57.4%) patients presented this pattern, regardless of met the diagnostic criteria or not. The prevalence of severe hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach. CONCLUSIONS: Serum sodium levels after craniopharyngioma resection in children showed a triphasic pattern in most cases. The risk of postoperative hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach.

Evaluation and Management of Hyponatremia in Heart Failure.

PURPOSE OF REVIEW: To provide a contemporary overview of the pathophysiology, evaluation, and treatment of hyponatremia in heart failure (HF). RECENT FINDINGS: Potassium and magnesium losses due to poor nutritional intake and treatment with diuretics cause an intracellular sodium shift in HF that may contribute to hyponatremia. Impaired renal blood flow leading to a lower glomerular filtration rate and increased proximal tubular reabsorption lead to an impaired tubular flux through diluting distal segments of the nephron, compromising electrolyte-free water excretion. Hyponatremia in HF is typically a condition of impaired water excretion by the kidneys on a background of potassium and magnesium depletion. While those cations can and should be easily repleted, further treatment should mainly focus on improving the underlying HF and hemodynamics, while addressing congestion. For decongestive treatment, proximally acting diuretics such as sodium-glucose co-transporter-2 inhibitors, acetazolamide, and loop diuretics are the preferred options.

[Consensus recommendations on the diagnosis and treatment of hyponatremia from the Austrian Society for Nephrology 2024]. / Konsensusempfehlungen zur Diagnose und Therapie der Hyponatriämie der Österreichischen Gesellschaft für Nephrologie 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.

[Features of water-electrolyte balance in persons of the older age group].

Age-related changes have a great influence on the regulation of water and electrolyte homeostasis in the body, which is regulated by a complex interaction of environmental factors, drinking behavior, the secretion of a number of hormones and hormone-like substances, as well as the innervation and functional state of the kidneys. It is well known that the changes that are part of physiological aging underlie fluid and electrolyte imbalances, exacerbated by the presence of age-related diseases, medications, or a number of external factors such as malnutrition, fluid intake, and the presence of dementia. This review considers literature data on the effect of normal aging on the development of pathology of the water-sodium balance, including dehydration of senile patients, hyponatremia, hypernatremia, changes in the secretion of antidiuretic hormone and the activity of elements of the renin-angiotensin-aldosterone system.

[SIADH treatment: beyond fluid restriction]. / Traitement du SIADH : au-delà de la restriction hydrique.

Treatment of chronic hyponatremia due to secretion of anti-diuretic hormone (SIADH) is often more complicated than it seems. Although initial treatment with fluid restriction is well established, it has limitations and is often insufficient. These limitations can be overcome by different second-line treatments. In this article, we address the limits of fluid restriction and propose pragmatic management based on the urinary spot.

La prise en charge de l'hyponatrémie chronique due au syndrome de sécrétion inappropriée d'hormone antidiurétique (SIADH) s'avère souvent plus compliquée qu'il n'y paraît. Même si le traitement initial par restriction hydrique est bien établi, celui-ci présente des limitations et est souvent insuffisant. Ces limitations peuvent être surmontées par différents traitements de seconde ligne. Dans cet article, nous explorons les limites de la restriction hydrique et proposons une prise en charge pragmatique basée sur le spot urinaire.

Preoperative Serum Copeptin Can Predict Delayed Hyponatremia after Pituitary Surgery in the Absence of Arginine Vasopressin Deficiency.

BACKGRUOUND: Delayed postoperative hyponatremia (DPH) is the most common cause of readmission after pituitary surgery. In this study, we aimed to evaluate the cutoff values of serum copeptin and determine the optimal timing for copeptin measurement for the prediction of the occurrence of DPH in patients who undergo endoscopic transsphenoidal approach (eTSA) surgery and tumor resection. METHODS: This was a prospective observational study of 73 patients who underwent eTSA surgery for pituitary or stalk lesions. Copeptin levels were measured before surgery, 1 hour after extubation, and on postoperative days 1, 2, 7, and 90. RESULTS: Among 73 patients, 23 patients (31.5%) developed DPH. The baseline ratio of copeptin to serum sodium level showed the highest predictive performance (area under the curve [AUROC], 0.699), and its optimal cutoff to maximize Youden's index was 2.5×10-11, with a sensitivity of 91.3% and negative predictive value of 92.0%. No significant predictors were identified for patients with transient arginine vasopressin (AVP) deficiency. However, for patients without transient AVP deficiency, the copeptin-to-urine osmolarity ratio at baseline demonstrated the highest predictive performance (AUROC, 0.725). An optimal cutoff of 6.5×10-12 maximized Youden's index, with a sensitivity of 92.9% and a negative predictive value of 94.1%. CONCLUSION: The occurrence of DPH can be predicted using baseline copeptin and its ratio with serum sodium or urine osmolarity only in patients without transient AVP deficiency after pituitary surgery.

Updates in hyponatremia and hypernatremia.

PURPOSE OF REVIEW: Hyponatremia and hypernatremia are commonly encountered electrolyte abnormalities that require timely and careful intervention, as they can be associated with significant morbidity and mortality. RECENT FINDINGS: This review article addresses the etiology, presentation, diagnosis, and management of both hyponatremia and hypernatremia, emphasizing the latest advancements and emerging trends in pediatric care. SUMMARY: A methodical approach is needed to accurately assess and treat hyponatremia and hypernatremia. Both conditions continue to rely on serum and urine testing, however newer tests such as copeptin and stimulated testing may hold promise to further refine testing in the future.

Edelman Gamblegrams: a tool to teach and learn disorders of water/plasma tonicity homeostasis.

This article introduces an innovative teaching and learning tool called "Edelman Gamblegrams" that aims to help medical learners better understand disorders related to water/plasma tonicity homeostasis, i.e., hyponatremia and hypernatremia. Gamblegrams, named after physician James L. Gamble, are bar diagrams displaying the relative abundance of extracellular anions and cations and are commonly used in the analysis of acid-base disorders. The Edelman equation represents the physiological variables that determine plasma sodium concentration, namely, total body sodium mass, total body potassium mass, and total body water volume. Edelman Gamblegrams inspired by traditional Gamblegrams but using the components of the Edelman equation, visually demonstrate how sodium, potassium, and water contribute to plasma sodium concentration under normal and pathological conditions. Scenarios that lead to hypotonic hyponatremia and hypernatremia in Edelman Gamblegrams are also discussed. Furthermore, examples of how these visual aids can enhance understanding of the pathogenesis of dysnatremias are also presented. Overall, the use of Edelman Gamblegrams has the potential to improve comprehension and retention of concepts related to water/plasma tonicity homeostasis.NEW & NOTEWORTHY This article introduces a new teaching tool called "Edelman Gamblegrams," modeled after the conventional Gamblegrams used in acid-base disorder analysis and using the independent physiological variables that determine the plasma sodium concentration (Edelman equation), that aims to help medical learners understand disorders related to water/plasma tonicity homeostasis.

Sodium and Its Impact on Outcome After Aneurysmal Subarachnoid Hemorrhage in Patients With and Without Delayed Cerebral Ischemia.

OBJECTIVES: To perform a detailed examination of sodium levels, hyponatremia and sodium fluctuations, and their association with delayed cerebral ischemia (DCI) and poor outcome after aneurysmal subarachnoid hemorrhage (aSAH). DESIGN: An observational cohort study from a prospective SAH Registry. SETTING: Tertiary referral center focused on SAH treatment in the Amsterdam metropolitan area. PATIENTS: A total of 964 adult patients with confirmed aSAH were included between 2011 and 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 277 (29%) developed DCI. Hyponatremia occurred significantly more often in DCI patients compared with no-DCI patients (77% vs. 48%). Sodium levels, hyponatremia, hypernatremia, and sodium fluctuations did not predict DCI. However, higher sodium levels were significantly associated with poor outcome in DCI patients (DCI onset -7, DCI +0, +1, +2, +4, +5, +8, +9 d), and in no-DCI patients (postbleed day 6-10 and 12-14). Also, hypernatremia and greater sodium fluctuations were significantly associated with poor outcome in both DCI and no-DCI patients. CONCLUSIONS: Sodium levels, hyponatremia, and sodium fluctuations were not associated with the occurrence of DCI. However, higher sodium levels, hypernatremia, and greater sodium fluctuations were associated with poor outcome after aSAH irrespective of the presence of DCI. Therefore, sodium levels, even with mild changes in levels, warrant close attention.