Hyponatremia: evaluating the correction factor for hyperglycemia

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.

The effect of ionic redistributions on the microwave dielectric response of cytosol water upon glucose uptake

The sensitivity of cytosol water's microwave dielectric (MD) response to D-glucose uptake in Red Blood Cells (RBCs) allows the detailed study of cellular mechanisms as a function of controlled exposures to glucose and other related analytes like electrolytes. However, the underlying mechanism behind the sensitivity to glucose exposure remains a topic of debate. In this research, we utilize MDS within the frequency range of 0.5-40 GHz to explore how ionic redistributions within the cell impact the microwave dielectric characteristics associated with D-glucose uptake in RBC suspensions. Specifically, we compare glucose uptake in RBCs exposed to the physiological concentration of Ca2+ vs. Ca-free conditions. We also investigate the potential involvement of Na+/K+ redistribution in glucose-mediated dielectric response by studying RBCs treated with a specific Na+/K+ pump inhibitor, ouabain. We present some insights into the MD response of cytosol water when exposed to Ca2+ in the absence of D-glucose. The findings from this study confirm that ion-induced alterations in bound/bulk water balance do not affect the MD response of cytosol water during glucose uptake.

Positive association between sodium-to-chloride ratio and in-hospital mortality of acute heart failure

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.

Hyponatremia, hypernatremia and impairment of functional, psychological and sexual domains

OBJECTIVE

To determine the influence of serum sodium on physical, psychologic and sexual function.

METHODS

This is a cross-sectional survey on 3340 community-dwelling men aged 40-79 years from a prospective cohort study in eight European countries, the European Male Ageing Study (EMAS). Participants filled-out the Short Form-36 (SF-36), the Physical Activity Scale for the Elderly (PASE), and the EMAS sexual function questionnaire. For all the analyses, serum sodium corrected for glycaemia ([Na+]G) was used.

RESULTS

The relationship between [Na+]G and SF-36 physical function score (F = 3.99; p = 0.01), SF-36 mental health score (F = 7.69; p < 0.001), and PASE score (F = 14.95; p < 0.001) were best described by a quadratic equation, with worse scores for [Na+]G in either the lowest or the highest ends of the range. After dividing the sample into [Na+]G < 136 mmol/L (n = 81), 136-147 mmol/L (n = 3223) and > 147 mmol/L (n = 36), linear regression analyses with linear spline functions adjusted for confounders did not confirm these relationships. Similarly, erectile dysfunction and [Na+]G, were in a quadratic relationship (F = 9.00; p < 0.001). After adjusting for confounders, the linear regression with spline functions denoted a significantly worsened erectile function for increases in serum [Na+]G > 147 mmol/L (B = 0.15 [0.04;0.26], p < 0.01) but no relationship with [Na+]G < 136 mmol/L. Likewise, the relationship of [Na+]G with concerns about sexual dysfunction was confirmed only for men with serum [Na+]G > 147 mmol/L.

CONCLUSIONS

This is the first study supporting an association between [Na+]G and sexual function. A worsening of erection and concerns about sexual function were observed for the highest values of [Na+]G, independently of other relevant factors.

Incidence and Characteristics of the Hyperosmolar Hyperglycemic State: A Danish Cohort Study

OBJECTIVE

The hyperosmolar hyperglycemic state (HHS) is a rare and life-threatening complication of diabetes. We aimed to estimate the incidence of HHS and describe the clinical and biomarker profiles of patients with HHS, including subgroups with acidosis and acute kidney injury.

RESEARCH DESIGN AND METHODS

This nationwide, descriptive cohort study used Danish registry data during years 2016-2018 to identify acutely admitted patients fulfilling the hyperglycemia and hyperosmolarity criteria of HHS (glucose ≥33 mmol/L and osmolarity [2 × sodium + glucose] ≥320 mmol/L).

RESULTS

We identified 634 patients (median age, 69 years (first quartile; third quartile: 58; 79) who met the criteria of HHS among 4.80 million inhabitants aged ≥18 years. The incidence rates were 16.5 and 3.9 per 10,000 person-years among people with known type 1 (n = 24,196) and type 2 (n = 251,357) diabetes, respectively. Thirty-two percent of patients with HHS were not previously diagnosed with diabetes. Patients were categorized as pure HHS (n = 394) and combined HHS and diabetic ketoacidosis (HHS-DKA; n = 240). The in-hospital mortality rate for pure HHS was 17% and 9% for HHS-DKA.

CONCLUSIONS

The incidence of HHS was higher among patients with type 1 diabetes compared with type 2 diabetes. HHS is a spectrum of hyperglycemic crises and can be divided in pure HHS and HHS-DKA. In one-third of patients, HHS was the debut of their diabetes diagnosis.

[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.

A retrospective cohort study on the clinical outcomes of patients admitted to intensive care units with dysnatremia

With evolving patient characteristics and patterns of ICU utilization, the impact of dysnatremias on patient outcomes and healthcare costs in the present era have not been well studied. Patients ≥ 18 years admitted to the ICUs in public hospitals in Hong Kong between January 2010 and June 2022 and had at least one serum sodium measurement obtained within 24 h prior to or following ICU admission were stratified into normonatremic (135-145 mmol/L), hyponatremic (< 135 mmol/L) and hypernatremic (> 145 mmol/L) groups. A total of 162,026 patients were included-9098 (5.6%), 40,533 (25.0%) and 112,395 (69.4%) patients were hypernatremic, hyponatremic and normonatremic at the time of ICU admission, respectively. The odds of patients with hypernatremia and hyponatremia dying in the ICU were 27% and 14% higher (aOR 1.27, 95% CI 1.19-1.36 and aOR 1.14, 95% CI 1.08-1.19, respectively; P < 0.001 for both), and 52% and 21% higher for dying in the hospital (aOR 1.52, 95% CI 1.43-1.62 and aOR 1.21, 95% CI 1.17-1.26, respectively; P < 0.001 for both] compared with those with normonatremia. Patients with dysnatremia also had longer ICU length of stay (LOS), hospital LOS, and higher healthcare costs than the normonatremic group. Dysnatremias at ICU admission were associated with increased ICU and in-hospital mortality and overall healthcare burden.

What is the aetiology of dysnatraemia in COVID-19 and how is this related to outcomes in patients admitted during earlier and later COVID-19 waves? A multicentre, retrospective observational study in 11 Dutch hospitals

OBJECTIVES

To evaluate the relationship among dysnatraemia at hospital presentation and duration of admission, risk of intensive care unit (ICU) admission and all-cause mortality and to assess the underlying pathophysiological mechanism of hyponatraemia in patients with COVID-19. Our hypothesis is that both hyponatraemia and hypernatraemia at presentation are associated with adverse outcomes.

DESIGN

Observational study.

SETTING

Secondary care; 11 Dutch hospitals (2 university and 9 general hospitals).

PARTICIPANTS

An analysis was performed within the retrospective multicentre cohort study COVIDPredict. 7811 patients were included (60% men, 40% women) between 24 February 2020 and 9 August 2022. Patients who were ≥18 years with PCR-confirmed COVID-19 or CT with COVID-19 reporting and data system score≥4 and alternative diagnosis were included. Patients were excluded when serum sodium levels at presentation were not registered in the database or when they had been transferred from another participating hospital.

OUTCOME MEASURES

We studied demographics, medical history, symptoms and outcomes. Patients were stratified according to serum sodium concentration and urinary sodium excretion.

RESULTS

Hyponatraemia was present in 2677 (34.2%) patients and hypernatraemia in 126 (1.6%) patients. Patients with hyponatraemia presented more frequently with diarrhoea, lower blood pressure and tachycardia. Hyponatraemia was, despite a higher risk for ICU admission (OR 1.27 (1.11-1.46; p<0.001)), not associated with mortality or the risk for intubation. Patients with hypernatraemia had higher mortality rates (OR 2.25 (1.49-3.41; p<0.001)) and were at risk for ICU admission (OR 2.89 (1.83-4.58)) and intubation (OR 2.95 (1.83-4.74)).

CONCLUSIONS

Hypernatraemia at presentation was associated with adverse outcomes in patients with COVID-19. Hypovolaemic hyponatraemia was found to be the most common aetiology of hyponatraemia. Hyponatraemia of unknown aetiology was associated with a higher risk for ICU admission and intubation and longer duration of admission.

Outcomes of Hospital-Acquired Hypernatremia

BACKGROUND

Hospital-acquired hypernatremia is highly prevalent, overlooked, and associated with unfavorable consequences. There are limited studies examining the outcomes and discharge dispositions of various levels of hospital-acquired hypernatremia in patients with or without CKD.

METHODS

We conducted an observational retrospective cohort study, and we analyzed the data of 1,728,141 patients extracted from the Cerner Health Facts database (January 1, 2000, to June 30, 2018). In this report, we investigated the association between hospital-acquired hypernatremia (serum sodium [Na] levels >145 mEq/L) and in-hospital mortality or discharge dispositions with kidney function status at admission using adjusted multinomial regression models.

RESULTS

Of all hospitalized patients, 6% developed hypernatremia after hospital admission. The incidence of in-hospital mortality was 12% and 1% in patients with hypernatremia and normonatremia, respectively. The risk of all outcomes was significantly greater for serum Na >145 mEq/L compared with the reference interval (serum Na, 135-145 mEq/L). In patients with hypernatremia, odds ratios (95% confidence interval) for in-hospital mortality, discharge to hospice, and discharge to nursing facilities were 14.04 (13.71 to 14.38), 4.35 (4.14 to 4.57), and 3.88 (3.82 to 3.94), respectively ( P < 0.001, for all). Patients with eGFR (Chronic Kidney Disease Epidemiology Collaboration) 60-89 ml/min per 1.73 m 2 and normonatremia had the lowest odds ratio for in-hospital mortality (1.60 [1.52 to 1.70]).

CONCLUSIONS

Hospital-acquired hypernatremia is associated with in-hospital mortality and discharge to hospice or to nursing facilities in all stages of CKD.

Diabetic Ketoacidosis

This article reviews the most current literature on diabetic ketoacidosis, including how to make the diagnosis and management. It discusses euglycemic diabetic ketoacidosis and the risk factors for this rare but dangerous disease process. Pertinent pearls and pitfalls encountered by the emergency physician when managing these patients are included. Because these patients often stay in the emergency department for prolonged periods, recommendations on transitioning to subcutaneous insulin are included, along with dosing recommendations. Finally, the article reviews how to disposition patients with diabetic ketoacidosis and examines important factors that lead to a successful discharge home.

Disorders of Sodium

Sodium imbalances are a common occurrence in the emergency department. Although recognition and diagnosis are relatively straightforward, discovering the cause and management should be approached systematically. The most important history items to ascertain is if the patient has symptoms and how long this imbalance has taken to develop. Treatment rapidity depends on severity of symptoms with the most rapid treatment occurring in only the severely symptomatic. Overcorrection has dire consequences and must be approached in a careful and systematic fashion in order to prevent these devastating consequences.

Evidence-based hyponatremia management in liver disease

Hyponatremia is primarily a water balance disorder associated with high morbidity and mortality. The pathophysiological mechanisms behind hyponatremia are multifactorial, and diagnosing and treating this disorder remains challenging. In this review, the classification, pathogenesis, and step-by-step management approaches for hyponatremia in patients with liver disease are described based on recent evidence. We summarize the five sequential steps of the traditional diagnostic approach: 1) confirm true hypotonic hyponatremia, 2) assess the severity of hyponatremia symptoms, 3) measure urine osmolality, 4) classify hyponatremia based on the urine sodium concentration and extracellular fluid status, and 5) rule out any coexisting endocrine disorder and renal failure. Distinct treatment strategies for hyponatremia in liver disease should be applied according to the symptoms, duration, and etiology of disease. Symptomatic hyponatremia requires immediate correction with 3% saline. Asymptomatic chronic hyponatremia in liver disease is prevalent and treatment plans should be individualized based on diagnosis. Treatment options for correcting hyponatremia in advanced liver disease may include water restriction; hypokalemia correction; and administration of vasopressin antagonists, albumin, and 3% saline. Safety concerns for patients with liver disease include a higher risk of osmotic demyelination syndrome.

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.

The prevalence and outcomes of hyponatremia in children with COVID-19 and multisystem inflammatory syndrome in children (MIS-C)

Introduction

To assess the prevalence of hyponatremia among pediatric patients with coronavirus disease 2019 (COVID-19) and Multisystem Inflammatory Syndrome in Children (MIS-C) and determine if pediatric hyponatremia was associated with an increased length of stay, higher rates of mechanical ventilation, and/or elevated inflammatory markers on admission as compared to eunatremic patients.

Methods

Electronic health records were retrospectively analyzed for 168 children less than 18 years old with COVID-19 or MIS-C who were admitted to pediatric units within the Northwell Health system. The primary exposure was hyponatremic status (serum sodium <135 mEq/L) and the primary outcomes were length of stay, mechanical ventilation usage and increased inflammatory markers.

Results

Of the 168 children in the study cohort, 95 (56%) were admitted for COVID-19 and 73 (43.5%) for MIS-C. Overall, 60 (35.7%) patients presented with hyponatremia on admission. Patients with hyponatremia had higher rates of intensive care unit admission when compared to eunatremic patients (32/60 [53.3%] vs. 39/108 [36.1%], p = 0.030). In regression models, hyponatremia was not significantly associated with increased length of stay or mechanical ventilation rates. After adjustment for relevant confounders, hyponatremia remained associated with an increased square root CRP (β = 1.79: 95% CI: 0.22-3.36) and lower albumin levels (β = -0.22: 95% CI: -0.42--0.01).

Conclusion

Hyponatremia is common in pediatric COVID-19 and MIS-C. Hyponatremia was associated with a lower albumin and higher square root CRP levels. This may suggest an association of inflammation with lower serum sodium levels.

High Osmol Gap Hyponatremia Caused by Icodextrin: A Case Series Report

Recently, hyperosmolar hyponatremia following excessive off-label use of two exchanges of 2 L icodextrin daily during peritoneal dialysis (PD) was reported. We encountered a cluster of 3 cases of PD patients who developed hyperosmolar hyponatremia during on-label use of icodextrin. This appeared to be due to absorption of icodextrin since after stopping icodextrin, the serum sodium level and osmol gap returned to normal, while a rechallenge again resulted in hyperosmolar hyponatremia. We excluded higher than usual concentrations of specific fractions of dextrins in fresh icodextrin dialysis fluid (lot numbers of used batches were checked by manufacturer). We speculate that in our patients, either an exaggerated degradation of polysaccharide chains by α-amylase activity in dialysate, lymph, and interstitium and/or rapid hydrolysis of the absorbed larger degradation products in the circulation may have contributed to the hyperosmolality observed, with the concentration of oligosaccharides exceeding the capacity of intracellular enzymes (in particular maltase) to metabolize these products to glucose. Both hyponatremia and hyperosmolality are risk factors for poor outcomes in PD patients. Less conventional PD prescriptions such as off-label use of two exchanges of 2 L icodextrin might raise the risk of this threatening side effect. This brief report is intended to create awareness of a rare complication of on-label icodextrin use in a subset of PD patients and/or PD prescriptions.

Diabetic Ketoacidosis in Children and Adolescents; Diagnostic and Therapeutic Pitfalls

Diabetic ketoacidosis (DKA) represents an acute, severe complication of relative insulin deficiency and a common presentation of Type 1 Diabetes Mellitus (T1DM) primarily and, occasionally, Type 2 Diabetes Mellitus (T2DM) in children and adolescents. It is characterized by the biochemical triad of hyperglycaemia, ketonaemia and/or ketonuria, and acidaemia. Clinical symptoms include dehydration, tachypnoea, gastrointestinal symptoms, and reduced level of consciousness, precipitated by a variably long period of polyuria, polydipsia, and weight loss. The present review aims to summarize potential pitfalls in the diagnosis and management of DKA. A literature review was conducted using the Pubmed/Medline and Scopus databases including articles published from 2000 onwards. Diagnostic challenges include differentiating between T1DM and T2DM, between DKA and hyperosmolar hyperglycaemic state (HHS), and between DKA and alternative diagnoses presenting with overlapping symptoms, such as pneumonia, asthma exacerbation, urinary tract infection, gastroenteritis, acute abdomen, and central nervous system infection. The mainstays of DKA management include careful fluid resuscitation, timely intravenous insulin administration, restoration of shifting electrolyte disorders and addressing underlying precipitating factors. However, evidence suggests that optimal treatment remains a therapeutic challenge. Accurate and rapid diagnosis, prompt intervention, and meticulous monitoring are of major importance to break the vicious cycle of life-threatening events and prevent severe complications during this potentially fatal medical emergency.

Inappropriate therapy of euvolemic hyponatremia, the most frequent type of hyponatremia in SARS-CoV-2 infection, is associated with increased mortality in COVID-19 patients

Introduction

Admission hyponatremia, frequent in patients hospitalized for COVID-19, has been associated with increased mortality. However, although euvolemic hyponatremia secondary to the Syndrome of Inappropriate Antidiuresis (SIAD) is the single most common cause of hyponatremia in community-acquired pneumonia (CAP), a thorough and rigorous assessment of the volemia of hyponatremic COVID-19 subjects has yet to be described. We sought to identify factors contributing to mortality and hospital length-of-stay (LOS) in hospitalized COVID-19 patients admitted with hyponatremia, taking volemia into account.

Method

Retrospective study of 247 patients admitted with COVID-19 to a tertiary hospital in Madrid, Spain from March 1st through March 30th, 2020, with a glycemia-corrected serum sodium level (SNa) < 135 mmol/L. Variables were collected at admission, at 2nd-3rd day of hospitalization, and ensuing days when hyponatremia persisted. Admission volemia (based on both physical and analytical parameters), therapy, and its adequacy as a function of volemia, were determined.

Results

Age: 68 years [56-81]; 39.9% were female. Median admission SNa was 133 mmol/L [131- 134]. Hyponatremia was mild (SNa 131-134 mmol/L) in 188/247 (76%). Volemia was available in 208/247 patients; 57.2% were euvolemic and the rest (42.8%) hypovolemic. Hyponatremia was left untreated in 154/247 (62.3%) patients. Admission therapy was not concordant with volemia in 43/84 (51.2%). In fact, the majority of treated euvolemic patients received incorrect therapy with isotonic saline (37/41, 90.2%), whereas hypovolemics did not (p=0.001). The latter showed higher mortality rates than those receiving adequate or no therapy (36.7% vs. 19% respectively, p=0.023). The administration of isotonic saline to euvolemic hyponatremic subjects was independently associated with an elevation of in-hospital mortality (Odds Ratio: 3.877, 95%; Confidence Interval: 1.25-12.03).

Conclusion

Hyponatremia in COVID-19 is predominantly euvolemic. Isotonic saline infusion therapy in euvolemic hyponatremic COVID-19 patients can lead to an increased mortality rate. Thus, an exhaustive and precise volemic assessment of the hyponatremic patient with CAP, particularly when due to COVID-19, is mandatory before instauration of therapy, even when hyponatremia is mild.

Impact of serum sodium concentrations, and effect modifiers on mortality in the Irish Health System

BACKGROUND

Abnormalities of serum sodium are associated with increased mortality risk in hospitalised patients, but it is unclear whether, and to what extent other factors influence this relationship. We investigated the impact of dysnatraemia on total and cause-specific mortality in the Irish health system while exploring the concurrent impact of age, kidney function and designated clinical work-based settings.

METHODS

A retrospective cohort study of 32,666 participants was conducted using data from the National Kidney Disease Surveillance System. Hyponatraemia was defined as < 135 mmol/L and hypernatraemia as > 145 mmol/L with normal range 135-145 mmol/L. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR's) and 95% Confidence Intervals (CIs) while penalised spline models further examined patterns of risk.

RESULTS

There were 5,114 deaths (15.7%) over a median follow up of 5.5 years. Dysnatraemia was present in 8.5% of patients overall. In multivariable analysis, both baseline and time-dependent serum sodium concentrations exhibited a U-shaped association with mortality. Hyponatremia was significantly associated with increased risk for cardiovascular [HR 1.38 (1.18-1.61)], malignant [HR: 2.49 (2.23-2.78)] and non-cardiovascular/non-malignant causes of death [1.36 (1.17-1.58)], while hypernatremia was significantly associated with cardiovascular [HR: 2.16 (1.58-2.96)] and non-cardiovascular/ non-malignant deaths respectively [HR: 3.60 (2.87-4.52)]. The sodium-mortality relationship was significantly influenced by age, level of kidney function and the clinical setting at baseline (P < 0.001). For hyponatraemia, relative mortality risks were significantly higher for younger patients (interaction term P < 0.001), for patients with better kidney function, and for patients attending general practice [HR 2.70 (2.15-3.36)] than other clinical settings. For hypernatraemia, age and kidney function remained significant effect modifiers, with patients attending outpatient departments experiencing the greatest risk [HR 9.84 (4.88-18.62)] than patients who attended other clinical locations. Optimal serum sodium thresholds for mortality varied by level of kidney function with a flattening of mortality curve observed for patients with poorer kidney function.

CONCLUSION

Serum sodium concentrations outside the standard normal range adversly impact mortality and are associated with specific causes of death. The thresholds at which these risks appear to vary by age, level of kidney function, and are modified in specific clinical settings within the health system.

Concurrent bacterial liver abscess and mild encephalitis/encephalopathy with reversible splenial lesion in a patient with poorly controlled type 2 diabetes

A 34-year-old man with poorly controlled type 2 diabetes was admitted to our hospital because of fever, headache, vomiting, and impaired consciousness. His hemoglobin A1c level was as high as 11.0%. Abdominal computed tomography revealed a bacterial liver abscess, while head magnetic resonance imaging simultaneously showed a high-signal lesion on diffusion-weighted imaging and a low-signal lesion on the apparent diffusion coefficient map of the splenium of the corpus callosum. No significant findings were detected in the cerebrospinal fluid. The latter findings led to a diagnosis of mild encephalitis/encephalopathy with reversible splenial lesions. His impaired consciousness resolved on Day 5 after treatment with ceftriaxone and metronidazole infusion and intensive insulin therapy; magnetic resonance imaging on Day 20 showed that the lesion in the splenium of the corpus callosum had disappeared. We propose that when a person with poorly controlled diabetes develops a bacterial infection and presents with impaired consciousness and headache, clinicians should consider the complications of mild encephalitis/encephalopathy with reversible splenial lesion.

Use of the osmolal gap in diagnosing mixed physiology hyponatremia in a child with B-cell acute lymphoblastic leukemia

Hyponatremia is common among children undergoing treatment for hematologic malignancies and may be attributed to multiple underlying causes. In cases of hyponatremia due to mixed physiology, the osmolal gap, can identify pseudohyponatremia that may be masked by other causes.

Consensus document on the management of hyponatraemia of the Acqua Group of the Spanish Society of Endocrinology and Nutrition

INTRODUCTION

Hyponatremia is the most prevalent electrolyte disorder in the outpatient and inpatient settings. Despite this frequency, hyponatremia, including severe hyponatremia, is frequently underestimated and inadequately treated, thus highlighting the need to produce consensus documents and clinical practice guidelines geared towards improving the diagnostic and therapeutic approach to it in a structured fashion.

MATERIAL AND METHODS

Members of the Acqua Group of the Spanish Society of Endocrinology and Nutrition (SEEN) met using a networking methodology over a period of 20 months (between October 2019 and August 2021) with the aim of discussing and developing an updated guideline for the management of hyponatraemia. A literature search of the available scientific evidence for each section presented in this document was performed.

RESULTS

A document with 8 sections was produced, which sets out to provide updated guidance on the most clinically relevant questions in the management of hyponatraemia. The management of severe hyponatraemia is based on the i.v. administration of a 3% hypertonic solution. For the management of chronic euvolemic hyponatraemia, algorithms for the initiation of treatment with the two pharmacological therapeutic options currently available in Spain are presented: urea and tolvaptan.

CONCLUSIONS

This document sets out to simplify the approach to and the treatment of hyponatraemia, making it easier to learn and thus improve the clinical approach to hyponatremia.

Clinical Approach to Euvolemic Hyponatremia

Euvolemic hyponatremia is frequently encountered in hospitalized patients and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause in most patients. SIADH diagnosis is confirmed by decreased serum osmolality, inappropriately elevated urine osmolality (>100 mosmol/L), and elevated urine sodium (Na) levels. Patients should be screened for thiazide use and adrenal or thyroid dysfunction should be ruled out before making a diagnosis of SIADH. Clinical mimics of SIADH like cerebral salt wasting and reset osmostat should be considered in some patients. The distinction between acute (<48 hours) versus chronic (>48 hours or without baseline labs) hyponatremia and clinical symptomatology are important to initiate proper therapy. Acute hyponatremia is a medical emergency and osmotic demyelination syndrome (ODS) occurs commonly when rapidly correcting any chronic hyponatremia. Hypertonic (3%) saline should be used in patients with significant neurologic symptoms and maximal correction of serum Na level should be limited to <8 mEq over 24 hours to prevent the ODS. Simultaneous administration of parenteral desmopressin is one of the best ways to prevent overly rapid Na correction in high-risk patients. Free water restriction combined with increased solute intake (e.g., urea) is the most effective therapy to treat patients with SIADH. 0.9% saline acts as a hypertonic solution in patients with hyponatremia and should be avoided in the treatment of SIADH due to rapid fluctuations in serum Na levels. Dual effects of 0.9% saline resulting in rapid correction of serum Na during infusion (inducing ODS) and post-infusion worsening of serum Na levels are described in the article with clinical examples.

Impact of Dapagliflozin Treatment on Serum Sodium Concentrations in Acute Heart Failure

INTRODUCTION

The dynamics of serum sodium are important in acute heart failure (AHF), and hyponatremia is associated with a poor prognosis. The effect of sodium-glucose cotransporter type 2 inhibitors (SGLT2i) on serum sodium concentrations in AHF is unknown.

METHODS

In a single-centre, controlled, randomized study, patients were prescribed dapagliflozin in addition to standard treatment during the first 24 h of hospitalization versus standard treatments. The pre-specified outcome was an absolute change in plasma sodium concentrations between randomization (first 24 h after admission) and discharge. The secondary outcomes were an absolute change in serum sodium concentrations within 48 h of randomization and the persistence of hyponatremia.

RESULTS

The sample comprised 285 patients (53% males; average age 73.26 ± 13 years); 140 of these were randomized to the dapagliflozin group. The average ejection fraction was 46 ± 14%; 155 patients (54%) had ischaemic heart failure; and 35% had diabetes mellitus. Median N-terminal pro b-type natriuretic peptide was 4,225 [2,120; 9,105] pg/mL. The average estimated glomerular filtration rate was 53.9 ± 17.2 mL/min. Hospital mortality was 6.7%. At randomization, serum sodium concentrations were 139.8 ± 4.32 mmol/L in the dapagliflozin group versus 140.85 ± 4.04 mmol/L in the control group; p = 0.048. 48 h later, there was an increase in serum sodium in the dapagliflozin group (2 [-2; 4] mmol/L), as compared to the control group (-1 [-3.75; 2]); p < 0.001. This was accompanied by equilibration of the sodium levels between the groups (141.08 ± 4.08 mmol/L in the dapagliflozin group vs. 140.05 ± 4.82 mmol/L in the control group; p = 0.096). At the time of discharge, there was no difference in serum sodium concentrations (140.98 ± 4.77 mmol/L vs. 139.86 ± 4.45 mmol/L; p = 0.082). The increase in serum sodium concentrations during the period of observation [randomization; discharge] was small but statistically significant in the dapagliflozin group (1 [-3; 3.75] mmol/L vs. -2 [-4.5; 2] mmol/L; p = 0.015). Of 36 patients (21 in the dapagliflozin group and 15 in the control group) with baseline hyponatraemia, this persisted in 6 (16.6%) in the dapagliflozin group and in 11 (73.3%) in the control group (p = 0.008).

CONCLUSION

The use of dapagliflozin in AHF is associated with a tendency to the increase in serum sodium concentrations and lesser persistence of hyponatremia. This effect occurred within the first 48 h and persisted until discharge. The impact of dapagliflozin on serum sodium was more pronounced in patients with hyponatremia at randomization.

Evaluation and management of hypernatremia in adults: clinical perspectives

Hypernatremia is an occasionally encountered electrolyte disorder, which may lead to fatal consequences under improper management. Hypernatremia is a disorder of the homeostatic status regarding body water and sodium contents. This imbalance is the basis for the diagnostic approach to hypernatremia. We summarize the eight diagnostic steps of the traditional approach and introduce new biomarkers: exclude pseudohypernatremia, confirm glucose-corrected sodium concentrations, determine the extracellular volume status, measure urine sodium levels, measure urine volume and osmolality, check ongoing urinary electrolyte free water clearance, determine arginine vasopressin/copeptin levels, and assess other electrolyte disorders. Moreover, we suggest six steps to manage hypernatremia by replacing water deficits, ongoing water losses, and insensible water losses: identify underlying causes, distinguish between acute and chronic hypernatremia, determine the amount and rate of water administration, select the type of replacement solution, adjust the treatment schedule, and consider additional therapy for diabetes insipidus. Physicians may apply some of these steps to all patients with hypernatremia, and can also adapt the regimens for specific causes or situations.

Baseline electrolyte disorders predict disease severity and mortality in patients with COVID-19

Distinguishing critical laboratory biomarkers for disease severity at the time of hospital presentation is important for early identification of patients who are most likely to have poor outcomes and effective use of health resources. This study aimed to evaluate whether electrolyte imbalances on hospital admission predict severe disease and mortality in patients with coronavirus disease 2019 (COVID-19). We retrospectively collected data on the blood electrolyte concentrations of 286 COVID-19 patients at admission. The correlations between electrolyte imbalances, inflammation, and thrombosis markers in COVID-19 patients were also evaluated. We assessed the predictive performance of baseline blood electrolyte concentrations for severe disease and death using receiver operating characteristic curve analysis and multivariate logistic regression methods. Abnormalities in serum sodium, calcium, and potassium levels at admission were found at 20.6%, 14%, and 4.2%, respectively in this study. In the receiver operating characteristic curve analyses, hypocalcemia and hyponatremia effectively predicted disease progression to hospitalization (area under the curve 0.82, P < .001 and 0.81, P < .001, respectively) and 30-day mortality (area under the curve 0.85, P < .001 and 0.91, P < .001, respectively). In the multivariate logistic regression analysis, baseline hypocalcemia was identified as an independent risk factor associated with the risk of hospitalization (β = 2.019, P = .01; odds ratio: 7.53). Baseline hypocalcemia and hyponatremia effectively predicted disease progression toward hospitalization and 30-day mortality in patients with COVID-19. Clinicians should closely follow up or reevaluate COVID-19 patients with baseline electrolyte disorders.

Differential diagnosis of hyponatremia and hypernatremia

Dysnatremias are among the most common mineral imbalances encountered in clinical practice. Both hyponatremia and hypernatremia are associated with increased morbiditidy and mortality and represent negative prognostic factors regardless of their cause. Serum osmolality, extracellular fluid volume and sodium urine concentration are important parameters for evaluation the cause and differential diagnosis. The rate of onset of ionic disorder and severity of clinical symptoms are essential. While acute disorders with symptoms are treated immediately, in chronic disorders, thorough diagnostic evaluation and a careful approach to their correction are necessary. Especially with rapid substitution of chronic hyponatremia, there is a risk of osmotic demyelination syndrome. Therefore, a slow correction of the serum sodium level with frequent mineralogram checks is required.

The Evolution of Hypovolemic and Euvolemic Hyponatremia Coincides with an Inflammatory Status in Patients with COVID-19: An Observational Cohort Study

We evaluated the hospital evolution of hyponatremia and inflammation markers in patients with coronavirus disease 2019 (COVID-19). The hospital evolutions of a cohort of adult patients with COVID-19 pneumonia and hyponatremia were retrospectively analyzed. Data of the admission day, 2nd–3rd and 7th–10th day of hospitalization, and of the discharge day were collected. Comparative and multivariate analyzes were developed, and Hazzard ratio (HR) with 95% confidence intervals (95% CI) were calculated. Of the 172 hospitalized patients with COVID-19, 49 of them (28.5%) had hyponatremia, which were analyzed. A total of 32/49 (65.3%) patients were male, and 22/49 (44.9%) euvolemic. Mean age: 69.9 ± 14.7 years. All patients had high inflammatory markers at admission. Of the total patients with hyponatremia at admission, only 26.2% remained hyponatremic at the 7th–10th day of hospitalization. Improvement in serum sodium (SNa) coincided with improvement in inflammatory markers during hospitalization, in both euvolemic and hypovolemic hyponatremic patients. A higher serum creatinine at admission was independently associated with mortality (HR: 12.23, 95% CI: 2 to 25.6) in hyponatremic COVID-19 patients. In conclusion, both hypovolemic and euvolemic hyponatremia in COVID-19 patients occurred in an inflammation status, and improved as inflammation decreased.

Korean Society of Nephrology 2022 recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Korean Society of Nephrology 2022 Recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

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.

Approach to the Patient: Hyponatremia and the Syndrome of Inappropriate Antidiuresis (SIAD)

Hyponatremia is the most common electrolyte disturbance seen in clinical practice, affecting up to 30% of acute hospital admissions, and is associated with significant adverse clinical outcomes. Acute or severe symptomatic hyponatremia carries a high risk of neurological morbidity and mortality. In contrast, chronic hyponatremia is associated with significant morbidity including increased risk of falls, osteoporosis, fractures, gait instability, and cognitive decline; prolonged hospital admissions; and etiology-specific increase in mortality. In this Approach to the Patient, we review and compare the current recommendations, guidelines, and literature for diagnosis and treatment options for both acute and chronic hyponatremia, illustrated by 2 case studies. Particular focus is concentrated on the diagnosis and management of the syndrome of inappropriate antidiuresis. An understanding of the pathophysiology of hyponatremia, along with a synthesis of the duration of hyponatremia, biochemical severity, symptomatology, and blood volume status, forms the structure to guide the appropriate and timely management of hyponatremia. We present 2 illustrative cases that represent common presentations with hyponatremia and discuss the approach to management of these and other causes of hyponatremia.

The impact of the correction of hyponatremia during hospital admission on the prognosis of SARS-CoV-2 infection

Background

SARS-CoV-2 infection is frequently associated with hyponatremia (plasma sodium <135 mmol/L), being associated with a worse prognosis. The incidence of hyponatremia is estimated to be 20-37% according to the series, but there are no data on the prognosis after correction of hyponatremia. Therefore, our objectives were: to analyse the incidence and severity of hyponatremia at hospital admission, and to determine the association of this hyponatremia with the prognosis of COVID-19.

Methods

Observational and retrospective cohort study. Patients who were admitted with a diagnosis of COVID-19 infection and hyponatremia, in the period March-May 2020, were included. We recorded epidemiological, demographic, clinical, biochemical, and radiological variables of SARS-CoV-2 infection and hyponatremia at the time of diagnosis and during hospitalization. The clinical follow-up ranged from admission to death or discharge.

Results

91 patients (21.8%) of the 414 admitted for SARS-CoV-2 infection presented hyponatremia (81.32% mild hyponatremia, 9.89% moderate and 8.79% severe). The absence of correction of hyponatremia 72-96 h after hospital admission was associated with higher mortality in patients with COVID-19 (Odds Ratio 0.165; 95% confidence interval: 0.018-0.686; p = 0.011). 19 patients (20.9%) died. An increase in mortality was observed in patients with severe hyponatremia compared with moderate and mild hyponatremia during hospital admission (37.5% versus 11.1% versus 8.1%, p = 0.041).

Conclusion

We conclude that persistence of hyponatremia at 72-96 h of hospital admission was associated with higher mortality in patients with SARS-Cov-2.

Changes in Serum Creatinine Levels Can Help Distinguish Hypovolemic from Euvolemic Hyponatremia

Background and Objectives: Differentiating between hypovolemic (HH) and euvolemic hyponatremia (EH) is crucial for correct diagnosis and therapy, but can be a challenge. We aim to ascertain whether changes in serum creatinine (SC) can be helpful in distinguishing HH from EH. Materials and Methods: Retrospective analysis of patients followed in a monographic hyponatremia outpatient clinic of a tertiary hospital during 1 January 2014−30 November 2019. SC changes during HH and EH from eunatremia were studied. The diagnostic accuracy of the SC change from eunatremia to hyponatremia (∆SC) was analyzed. Results: A total of 122 hyponatremic patients, median age 79 years (70−85), 46.7% women. In total, 70/122 patients had EH, 52/122 HH. During hyponatremia, median SC levels increased in the HH group: +0.18 mg/dL [0.09−0.39, p < 0.001], but decreased in the EH group: −0.07 mg/dL (−0.15−0.02, p < 0.001), as compared to SC in eunatremia. HH subjects presented a higher rate of a positive ∆SC than EH (90.4% vs. 25.7%, p < 0.001). EH subjects presented a higher rate of a negative/null ∆SC than HH (74.3% vs. 9.6%, p < 0.001). ROC curve analysis found an AUC of 0.908 (95%CI: 0.853 to 0.962, p < 0.001) for ∆SC%. A ∆SC% ≥ 10% had an OR of 29.0 (95%CI: 10.3 to 81.7, p < 0.001) for HH. A ∆SC% ≤ 3% had an OR of 68.3 (95%CI: 13.0 to 262.2, p < 0.001) for EH. Conclusions: The assessment of SC changes from eunatremia to hyponatremia can be useful in distinguishing between HH and EH.

The association of hyponatremia and clinical outcomes in patients with acute myocardial infarction: a cross-sectional study

INTRODUCTION

Hyponatremia is a common electrolyte abnormality that has been associated with poor outcomes in several conditions including acute myocardial infarction (AMI). However, those studies were performed in the era before percutaneous coronary intervention (PCI), focused mostly on ST-elevation myocardial infarction (STEMI), and sodium levels up to 72 h of admission. The purpose of this study was to identify the association between hyponatremia and clinical outcomes in patients with acute myocardial infarction.

METHODS

We performed a retrospective analysis of patients with a diagnosis of non-ST-elevation myocardial infarction (NSTEMI) and STEMI presenting at our institution from March 2021 to September 2021. Our independent variables were sodium levels on the day of admission and up to 7 days later. Dependent variables were in-hospital mortality, 30-day mortality, length of hospital stay, intensive care admission, new heart failure diagnosis, and ejection fraction.

RESULTS

50.2% of patients had hyponatremia up to 7 days of admission. Intensive care admission was higher in patients with hyponatremia up to7 days (69.7% vs 54.3%, P 0.019, OR 1.9), they had worse 30-day mortality (12.7% vs to 2.2%, P 0.004, OR 6.5), in hospital mortality (9.9% vs 1.1%, P 0.006, OR 9.9), and new heart failure diagnosis (31.5% vs 17.9%, P < 0.043, OR 2.1). Hyponatremia on admission was associated with in-hopital mortality (16.3% vs 3.8%, P 0.004, OR 4.9), 30-day mortality (18.4% vs 5.9%, P 0.017, OR 3.5).

CONCLUSIONS

This study suggests that hyponatremia on admission and at any point during the first seven days of hospitalization are associated with in-hospital and 30-day mortality.

Tonicity Matters, Especially in Complex Hyponatremia Resulting from Pseudo-, Trans-locational, and True Hypotonic Hyponatremia: An Educational Case Report

Serum tonicity is defined by the serum concentrations of sodium (sNa) and glucose, which can promote free water movement across intra/extracellular compartments. Rapid changes in serum tonicity can cause brain damage. We herein report an educational case of a patient with hyponatremia (sNa: 112 mEq/L) concomitant with acute alcoholic pancreatitis. The cause of hyponatremia was considered complex. Pseudo- and trans-locational natremia was secondary to hyperglycemia (721 mg/dL) and hypertriglyceridemia (1,768 mg/dL), respectively, and true hypotonic hyponatremia. Regarding sNa correction, rapid correction was suspected. However, this was safely managed by monitoring tonicity (not sNa or osmolarity), thereby avoiding brain damage.

Tolvaptan versus fluid restriction in acutely hospitalised patients with moderate-profound hyponatraemia (TVFR-HypoNa): design and implementation of an open-label randomised trial

Background

Current hyponatraemia guidelines are divided on the use of tolvaptan in hospitalised patients with moderate to severe hyponatraemia, due to an uncertain risk-benefit ratio. We will conduct a randomised trial to test the hypothesis that early use of tolvaptan improves the rate of serum sodium correction and clinical outcomes compared with current standard first-line therapy, restriction of fluid intake, without increasing the risk of serum sodium overcorrection.

Methods

We will enrol hospitalised patients with euvolaemic or hypervolaemic hyponatraemia and serum sodium of 115–130 mmol/L at Austin Health, a tertiary care centre in Melbourne, Australia. Participants will be randomised 1:1 to receive either tolvaptan (initial dose 7.5 mg) or fluid restriction (initial limit 1000 ml per 24 h), with titration of therapy based on serum sodium response according to a pre-determined protocol over a 72-h intervention period.

The primary endpoint will be the between-group change in serum sodium over time, from study day 1 to day 4. Secondary endpoints include serum sodium increment in the first 24 and 48 h, proportion of participants with normalised serum sodium, length of hospital stay, requirement for serum sodium re-lowering with intravenous dextrose or desmopressin, cognitive and functional measures (Confusion Assessment Method Short form, Timed Up and Go test, hyponatraemia symptom questionnaire), 30-day readmission rate, treatment satisfaction score and serum sodium 30 days after discharge. The trial will be overseen by an independent Data Safety Monitoring Board. Serum sodium will be monitored every 6–12 h throughout the study period, with pre-specified thresholds for commencing intravenous 5% dextrose if serum sodium rise targets are exceeded.

Discussion

We seek to inform future international guidelines with high-quality data regarding the utility and safety of tolvaptan compared to standard therapy fluid restriction in patients with moderate-severe hyponatraemia in hospital. If tolvaptan use in this patient group is endorsed by our findings, we will have established an evidence-based framework for tolvaptan initiation and monitoring to guide its use.

Trial registration

Australia and New Zealand Clinical Trials Registry ACTRN12619001683123. Registered on December 2 2019

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06237-5.

Hypernatremia in Hospitalized Patients: A Large Population-Based Study

Background

Hypernatremia is a frequently encountered electrolyte disorder in hospitalized patients. Controversies still exist over the relationship between hypernatremia and its outcomes in hospitalized patients. This study examines the relationship of hypernatremia to outcomes among hospitalized patients and the extent to which this relationship varies by kidney function and age.

Methods

We conducted an observational study to investigate the association between hypernatremia, eGFR, and age at hospital admission and in-hospital mortality, and discharge dispositions. We analyzed the data of 1.9 million patients extracted from the Cerner Health Facts databases (2000-2018). Adjusted multinomial regression models were used to estimate the relationship of hypernatremia to outcomes of hospitalized patients.

Results

Of all hospitalized patients, 3% had serum sodium (Na) >145 mEq/L at hospital admission. Incidence of in-hospital mortality was 12% and 2% in hyper- and normonatremic patients, respectively. The risk of all outcomes increased significantly for Na >155 mEq/L compared with the reference interval of Na=135-145 mEq/L. Odds ratios (95% confidence intervals) for in-hospital mortality and discharge to a hospice or nursing facility were 34.41 (30.59-38.71), 21.14 (17.53-25.5), and 12.21 (10.95-13.61), respectively (all P<0.001). In adjusted models, we found that the association between Na and disposition was modified by eGFR (P<0.001) and by age (P<0.001). Sensitivity analyses were performed using the eGFR equation without race as a covariate, and the inferences did not substantially change. In all hypernatremic groups, patients aged 76-89 and ≥90 had higher odds of in-hospital mortality compared with younger patients (all P<0.001).

Conclusions

Hypernatremia was significantly associated with in-hospital mortality and discharge to a hospice or nursing facility. The risk of in-hospital mortality and other outcomes was highest among those with Na >155 mEq/L. This work demonstrates that hypernatremia is an important factor related to discharge disposition and supports the need to study whether protocolized treatment of hypernatremia improves outcomes.

Efficacy and safety of rapid intermittent bolus compared with slow continuous infusion in patients with severe hypernatremia (SALSA II trial): a study protocol for a randomized controlled trial

Background

Methods

Conclusion

Aetiological diagnosis of hyponatraemia in non-critical patients on total parenteral nutrition: A prospective multicentre study

BACKGROUND

In patients receiving total parenteral nutrition (TPN), the frequency of hyponatraemia is high. However, the causes of hyponatraemia in TPN have not been elucidated, although diagnosis is required for appropriate therapy. The aim of this study is to describe the aetiology of hyponatraemia in non-critical hospitalised patients receiving TPN.

METHODS

Prospective multicentre study in 19 Spanish hospitals. Non-critically hyponatraemic patients receiving TPN and presenting hyponatraemia over a 9-month period were studied. Data collected included sex, age, previous comorbidities, and serum sodium levels (SNa) before and following TPN initiation. Parameters for study of hyponatraemia were also included: clinical volaemia, the presence of pain, nausea, gastrointestinal losses, diuretic use, oedema, renal function, plasma and urine osmolality, urinary electrolytes, cortisolaemia, and thyroid stimulating hormone.

RESULTS

162 patients were included, 53.7% males, age 66.4 (SD13.8) years. Volume status was evaluated in 142 (88%): 21 (14.8%) were hypovolaemic, 96 (67.6%) euvolaemic and 25 (17.6%) hypervolaemic. In 111/142 patients the analytical assessment of hyponatraemia was completed. Hypovolaemic hyponatraemia was secondary to GI losses in 10/111 (9%), and to diuretics in 3/111 (2.7%). Euvolaemic hyponatraemia was due to Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH) in 47/111 (42.4%), and to physiological stimuli of Arginine Vasopressin (AVP) secretion in 28/111 (25.2%). Hypervolaemic hyponatraemia was induced by heart failure in 19/111 (17.1%), cirrhosis of the liver in 4/111 (3.6%).

CONCLUSIONS

SIADH was the most frequent cause of hyponatraemia in patients receiving TPN. The second most frequent cause was physiological stimuli of AVP secretion induced by pain/nausea.

Risk factors for overcorrection of severe hyponatremia: a post hoc analysis of the SALSA trial

Background

Hyponatremia overcorrection can result in irreversible neurologic impairment such as osmotic demyelination syndrome. Few prospective studies have identified patients undergoing hypertonic saline treatment with a high risk of hyponatremia overcorrection.

Methods

We conducted a post hoc analysis of a multicenter, prospective randomized controlled study, the SALSA trial, in 178 patients aged above 18 years with symptomatic hyponatremia (mean age, 73.1 years; mean serum sodium level, 118.2 mEq/L). Overcorrection was defined as an increase in serum sodium levels by >12 or 18 mEq/L within 24 or 48 hours, respectively.

Results

Among the 178 patients, 37 experienced hyponatremia overcorrection (20.8%), which was independently associated with initial serum sodium level (≤110, 110–115, 115–120, and 120–125 mEq/L with 7, 4, 2, and 0 points, respectively), chronic alcoholism (7 points), severe symptoms of hyponatremia (3 points), and initial potassium level (<3.0 mEq/L, 3 points). The NASK (hypoNatremia, Alcoholism, Severe symptoms, and hypoKalemia) score was derived from four risk factors for hyponatremia overcorrection and was significantly associated with overcorrection (odds ratio, 1.41; 95% confidence interval, 1.24–1.61; p < 0.01) with good discrimination (area under the receiver-operating characteristic [AUROC] curve, 0.76; 95% CI, 0.66–0.85; p < 0.01). The AUROC curve of the NASK score was statistically better compared with those of each risk factor.

Conclusion

In treating patients with symptomatic hyponatremia, individuals with high hyponatremia overcorrection risks were predictable using a novel risk score summarizing baseline information.

Clinical manifestations and associated factors in acquired hypoaldosteronism in endocrinological practice

INTRODUCTION

Hypoaldosteronism can be congenital or acquired, isolated or part of primary adrenal insufficiency, and caused by an aldosterone deficit, resistance, or a combination of both. Reduced mineralocorticoid action can induce a decrease in urine K+ and H+ excretion and an increase in urine Na+ excretion, leading to hyperkalemia, and/or hyponatremia, often combined with metabolic acidosis. We aimed to characterize the clinical manifestations of hypoaldosteronism, and their associated factors.

METHODS

Retrospective analysis of 112 episodes of hypoaldosteronism diagnosed in 86 adult patients from 2012-2019 by the Endocrinology and Nutrition Department of a tertiary hospital. The frequency of hyperkalemia, hypovolemic hyponatremia (HH) and metabolic acidosis (MA), and their associated factors were evaluated.

RESULTS

Patients had a median age of 77 [65 - 84], 55.4% were male. 94.6% cases showed hyperkalemia, 54.5% HH, and 60.3% MA. The mean serum K+ of all cases was 5.4 ± 0.5 mmol/L, Na+: 132.1 ± 6.3 mmol/L, HCO3: 22.6 ± 3.3 mmol/L. Hypoaldosteronism was isolated in the majority of cases: only 6/112 (5%) had primary adrenal insufficiency. Hypovolemia was associated with hyponatremia and a more florid clinical presentation. HH was associated with a combined presence of aldosterone-lowering and mineralocorticoid resistance factors. MA was associated with the presence of mineralocorticoid resistance factors.

CONCLUSIONS

Hypoaldosteronism in adult endocrinological clinical practice is primarily isolated, and acquired. It predisposes not only to the development of hyperkalemia and MA, but also to that of HH. Hypoaldosteronism must be considered in the differential diagnosis of HH with urinary sodium wasting.

The association between normal serum sodium levels and bone turnover in patients with type 2 diabetes

BACKGROUND

Sodium is a critically important component of bones, and hyponatremia has firmly been established as a risk factor associated with the incidence of fragility fractures. However, researches have also revealed that lower serum sodium are linked to reductions in muscle mass and a higher risk of cardiovascular disease even when these levels are within the normal range. Accordingly, this study was developed to examine the relationships between normal serum sodium concentrations and bone turnover in patients with type 2 diabetes (T2D).

METHODS

Patients with T2D were enrolled in the present study from January 2021 to April 2022. All patients underwent analyses of serum sodium levels, oral glucose tolerance testing (OGTT), bone turnover markers (BTMs), and dual-energy X-ray absorptiometry (DXA) scanning. BTMs included bone formation markers osteocalcin (OC) and N-terminal propeptide of type-I procollagen (PINP), and bone resorption marker C-terminal telopeptide (CTx). Patients were stratified into three subgroups based on the tertiles of their serum sodium concentrations.

RESULTS

In total, 372 patients with T2D and sodium levels in the normal range were enrolled in this study. Serum OC and PINP levels were increased from subgroup with the low sodium tertile to that with the high sodium tertile (p for trend < 0.05), whereas CTx level was comparable among the subgroups. A positive correlation was detected between serum sodium levels and both lnOC (r = 0.210, p < 0.001) and lnPINP (r = 0.196, p < 0.001), with these relationships remaining significant even following adjustment for age, sex, body mass index (BMI), and HbA1c. Only after adjusting for these four factors a positive correlation was detected between serum sodium levels and CTx levels (r = 0.108, p < 0.05). Linear regression analyses revealed that following adjustment for potential covariates, serum sodium level was and positively significantly associated with lnOC level (β = 0.134, t = 2.281, p < 0.05) and PINP level (β = 0.179, t = 3.023, p < 0.01).

CONCLUSION

These results highlight a significant association between low-normal serum sodium levels and low bone turnover.

Association between metabolic parameters and risks of anemia and electrolyte disturbances among stages 3-5 chronic kidney disease patients in Taiwan

Background

Anemia and electrolyte disturbances are adverse outcomes of chronic kidney disease (CKD). This study explored the association between metabolic parameters with anemia and electrolyte and mineral disorders among CKD patients in Taiwan.

Methods

This cross-sectional study with a total of 2176 CKD stages 3–5 patients were collected from the Department of Nephrology at Shuang Ho Hospital, Taipei Medical University through the “Chronic Kidney Disease Common Care Network” database from December 2008 to April 2019. A multivariable-adjusted logistic regression expressed as odd ratios (OR) was performed to assess the association of metabolic parameters with anemia and electrolyte and mineral disorders.

Results

Elevated diastolic blood pressure, fasting blood glucose, and glycated hemoglobin A1c (HbA1c) were associated with presence of anemia. Similarly, elevated fasting blood glucose and HbA1c were associated with hyponatremia (OR = 1.59 and 1.58, P for both < 0.01) and hypercalcemia (OR = 1.38 and 1.33, P for both < 0.05). There was no significant association in serum lipid levels with presence of anemia. However, total triglycerides, total cholesterol and low-density lipoprotein-cholesterol were only associated with presence of hypercalcemia (OR = 1.43, 1.95 and 3.08, respectively, P for all < 0.05).

Conclusions

Elevated diastolic blood pressure, fasting blood glucose, HbA1c and blood lipids are associated with anemia or electrolyte and mineral disorders in CKD patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02590-w.