Diagnosis and Management of Hyponatremia: A Review

Hyponatremia with an Osmolar Gap, Pseudohyponatremia or Hyper-Osmolar Hyponatremia?

Pseudohyponatremia is frequently misunderstood and often mistaken for other types of hyponatremia. In this study, we present a case of pseudohyponatremia resulting from hypertriglyceridemia. We provide an in-depth analysis of the pathophysiological mechanisms involved, comparing them with those of other hyponatremic disorders, and outline the diagnostic approach used to identify this atypical form of hyponatremia. Recognizing and accurately diagnosing non-hypo-osmolar hyponatremia is paramount, as these conditions are treated differently than other forms of hyponatremia.

Adolescent Girls With Type 1 Diabetes Develop Changes in Bone Prior to Evidence of Clinical Neuropathy

CONTEXT

Neuropathy and fracture are prevalent complications of type 1 diabetes (T1D). Although correlated in the clinical literature, it remains unknown whether neuropathy contributes to the initiation of bone loss at the earliest stages of disease.

METHODS

We performed a single-center, cross-sectional study to quantify parameters of nerve and bone health in adolescent girls with T1D (n = 21) and associated controls (n = 12). Groups were well matched for age, height, strength, and physical activity.

RESULTS

By high-resolution peripheral quantitative computed tomograpy, participants with T1D had lower trabecular bone volume fraction at the distal radius (-14.6%, P-adj = .095) and the tibia (-12.8%, P-adj = .017) and decreased trabecular thickness (-8.3% radius, P-adj = .007; -7.5% tibia, P-adj = .034) after adjustment for body size. In the tibia only, cortical bone mineral density was increased by 8.6% (P-adj = .024) and porosity was decreased by 52.9% with T1D (P-adj = .012). There were no significant differences in bone density by dual-energy x-ray absorptiometry. Participants with T1D also had lower circulating levels of osteocalcin (-30%, P = .057), and type I collagen cross-linked C-telopeptide (-36%, P = .035), suggesting low bone formation and turnover in T1D. Based on the Michigan Neuropathy Screening Instrument, 9.5% of those with T1D had clinical evidence of diabetic peripheral neuropathy. However, consideration of neuropathy status failed to explain the widespread T1D-associated changes in bone.

CONCLUSION

Our study defines early deficits in trabecular bone microarchitecture, decreased cortical porosity in the tibia, and suppression of biomarkers of bone turnover in adolescent girls with T1D, prior to the onset of symptomatic peripheral neuropathy. These findings inform our understanding of the rapid progression of skeletal disease in young girls with T1D and suggests that early detection and management strategies may help to prevent fracture and related comorbidities later in life.

[Tolvaptan versus fluid restriction in the treatment of hyponatremia due to inappropriate antidiuretic hormone secretion: efficacy and safety analysis in a cohort study]

Introduction

Background and objectives: hyponatremia is a common in older and hospitalized patients, often caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This study compares the efficacy and safety of tolvaptan versus fluid restriction in patients with hyponatremia and SIADH. Materials and methods: an observational cohort study was conducted with 186 patients with hyponatremia (Na+ < 135 mmol/L) due to SIADH, treated at the Hospital Universitario de Pontevedra between 2015 and 2022. Of these, 86 were treated with tolvaptan (mean dose of 7.5 mg) and 100 with fluid restriction (1 liter of fluids per day). The primary endpoint was the normalization of sodium levels (Na ≥ 135 mmol/L). Results: tolvaptan was more effective than fluid restriction in correcting hyponatremia, increasing plasma sodium from 125.09 to 135.69 mmol/L in 4 days, compared to an increase from 126.44 to 130.5 mmol/L in 8 days with fluid restriction (p < 0.001). Mortality at 60 days was lower in the tolvaptan group (12.8 % vs. 32.8 %, p < 0.003). However, tolvaptan showed higher risks of sodium overcorrection (10.46 %) and polyuria (5.81 %), while fluid restriction was associated with greater dehydration, headache, and cramps. Conclusion: tolvaptan corrects hyponatremia more quickly and effectively than fluid restriction, although with a higher risk of overcorrection and polyuria, and is associated with lower 60-day mortality.

[Effectiveness of the administration of a dietary supplement (oral urea) for the treatment of hyponatremia in SIADH]

Introduction

Background and objectives: the most common cause of hyponatraemia in hospital settings is the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This study compares the efficacy and safety of urea versus fluid restriction in the treatment of hyponatraemia caused by SIADH. Material and methods: an observational cohort study was conducted with 212 patients suffering from hyponatremia (Na+ < 135 mmol/L) due to SIADH at the Complejo Hospitalario Universitario de Pontevedra between January 2015 and May 2022. Of these, 112 patients received urea (15 g/day) and 100 were treated with fluid restriction (1 liter/day). The primary objective was to normalize sodium levels (Na ≥ 135 mmol/L). Results: urea was significantly more effective than fluid restriction. Sodium levels increased from 126.35 to 133.9 mmol/L with urea, compared to an increase from 126.44 to 130.5 mmol/L with fluid restriction (p < 0.001). Sodium normalization was achieved in an average of 6 days with urea, compared to 8 days with fluid restriction (p = 0.04). At discharge, 59.8 % of patients treated with urea reached normal sodium levels, compared to 42 % in the fluid restriction group (p = 0.007). The 60-day mortality rate was lower in the urea group (16.1 %) compared to the fluid restriction group (32.8 %) (p < 0.007). Conclusion: urea is more effective than fluid restriction in normalizing sodium levels, with a better safety profile and lower 60-day mortality.

Role of hyponatremia and antihypertensives in falls

OBJECTIVE

Falls in older adults represent a significant public health concern. Specific drug categories represent a significant risk factor for falls, yet there is a paucity of awareness regarding this issue. The use of diuretics in the treatment of hypertension has been associated with an increased risk of complications related to electrolyte imbalance. The objective of this study was to evaluate the role of hyponatremia and antihypertensives in patients who have experienced a fall.

METHODS

The study included a total of 322 patients who had been admitted to the hospital with a diagnosis of fall-related injuries. At the time of hospital admission, the following data were recorded: age, gender, presence of disease, medications, presence of fracture, and laboratory values. Two groups, with and without hyponatremia, were compared. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The mean age of the participants was 73.28 years (±14.26), and 60.2 % were female. The use of antihypertensive drugs such as hydrochlorothiazide (HCT) (p=.037), angiotensin-converting enzyme inhibitor (ACE) (p=.045), beta-blocker (p=.041) and ACE+HCT (p=.046) was significantly higher in the group with Na≤135 mEq/L than in the group with Na≥136 mEq/L. Logistic regression analysis showed that hyponatremia was 2.2 times and female gender was 1.9 times more effective in the occurrence of fracture, furosemide use was 2.2 times, and SSRI use was 1.8 times more effective in the development of hyponatremia.

CONCLUSIONS

Careful use of antihypertensives that cause hyponatremia in older adults will be effective in preventing falls and their complications.

From Brew to Bronchoscopy: A Case of Hyponatremia That Was Anything but Basic

We present the case of a 53-year-old female with a history of chronic alcohol use, hypertension, chronic obstructive pulmonary disease (COPD), and significant smoking history, who presented with severe hyponatremia. Initial laboratory studies revealed a sodium level of 115 mEq/L. The patient reported chronic vomiting, poor oral intake, and heavy alcohol consumption. Her hyponatremia was initially attributed to multiple factors, including alcohol-related dehydration, beer potomania, and potential medication-induced syndrome of inappropriate antidiuretic hormone (SIADH) secretion. However, further evaluation with chest computed tomography (CT) revealed extensive mediastinal lymphadenopathy. Bronchoscopy with fine-needle aspiration confirmed a diagnosis of small cell lung cancer (SCLC). This case highlights the importance of a comprehensive evaluation for hyponatremia, particularly in patients with malignancy risk factors, to avoid overlooking severe underlying conditions such as cancer.

Small cell carcinoma of the cervix with syndrome of inappropriate antidiuretic hormone secretion following chemotherapy: A case report and literature review

Objective

This report aims to present a rare case of severe hyponatremia induced by syndrome of inappropriate antidiuretic hormone secretion (SIADH) following chemotherapy in a patient with small cell carcinoma of the cervix (SCCC). It also reviews the existing literature on this rare phenomenon.

Case

A 45-year-old female with SCCC developed acute symptomatic hyponatremia (sodium level 110 mmol/L) three days following cisplatin-based chemotherapy. SIADH was diagnosed, and the patient required intubation and admission to the intensive care unit due to severe agitation and confusion. Despite initial correction of sodium levels, the patient developed recurrent hyponatremia after subsequent chemotherapy cycles that was refractive to first line agents. She required the use of Tolvaptan, a vasopressin type 2 receptor antagonist, for the management of hyponatremia.

Conclusions

This case highlights the rare occurrence of severe SIADH in a patient with SCCC, underscoring the complexity of managing electrolyte disturbances in the context of both paraneoplastic syndromes and chemotherapeutic side effect. The severity of our patient's presentation calls attention to the importance of early recognition of SIADH in the differential diagnosis of oncology patients with altered mental status and confusion. Post chemotherapy sodium surveillance could lead to improved patient outcomes, as well as monitoring for signs and symptoms of hyponatremia.

Endocrine paraneoplastic syndromes in lung cancer: A call for clinical vigilance (Review)

Endocrine paraneoplastic syndromes (PNS) are uncommon but clinically impactful manifestations associated with malignancies, particularly lung cancer, most notably small-cell lung cancer. These syndromes arise from ectopic hormone production by malignant cells, causing systemic effects that are independent of direct tumor invasion or metastasis. Their presentation often precedes or signals recurrence of the primary cancer, underscoring the importance of early recognition and targeted intervention. Common endocrine PNS in lung cancer include syndrome of inappropriate antidiuretic hormone secretion, hypercalcemia, Cushing syndrome, carcinoid syndrome, and other hormonal imbalances such as non-islet cell tumor hypoglycemia, gynecomastia and acromegaly. The pathophysiology of these conditions involves ectopic secretion of bioactive substances such as hormones and cytokines, leading to diverse clinical manifestations. Accurate diagnosis necessitates a combination of biochemical assessments, imaging modalities, and histopathological evaluations to differentiate paraneoplastic processes from primary endocrine disorders. Management strategies emphasize treating the underlying malignancy, often through chemotherapy, radiotherapy, or surgical intervention, alongside symptomatic therapies tailored to the specific endocrine abnormality. Multidisciplinary care is critical for optimizing outcomes and enhancing patients' quality of life. The current review highlights the need for heightened clinical vigilance and a systematic approach to diagnosing and managing endocrine PNS in lung cancer. By fostering early detection and comprehensive management, clinicians can significantly improve prognostic outcomes for affected individuals.

Urea to Treat Hyponatremia Due to Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Systematic Review and Meta-Analysis

RATIONALE & OBJECTIVE

The use of urea to treat hyponatremia related to the syndrome of inappropriate antidiuretic hormone secretion (SIADH) has not been universally adopted due to questions about effectiveness, safety, and tolerability. This systematic review and meta-analysis of observational studies addresses these questions.

STUDY DESIGN

This PRISMA-guided study examined published research across 4 electronic databases.

STUDY POPULATIONS

Patients with SIADH-related hyponatremia.

SELECTION CRITERIA

Clinical trials and observational studies reporting at least 1 outcome related to serum sodium concentration, symptom resolution, or adverse effects after oral or nasogastric urea administration.

DATA EXTRACTION

Data extraction was performed independently by 2 reviewers using a standardized form recording study characteristics, participant demographics, intervention details, and treatment outcomes.

ANALYTICAL APPROACH

A meta-analysis was conducted using the restricted maximum likelihood method for the random effects model to assess the effect of urea treatment on serum sodium and serum urea compared with other treatment modalities. Subgroup analyses were conducted based on treatment duration and SIADH severity.

RESULTS

Urea treatment significantly increased serum sodium (mean difference [MD], 9.08 [95% CI, 7.64-10.52], P<0.01) and urea (MD, 31.66 [95% CI, 16.05-47.26], P<0.01) in patients with SIADH, albeit with significantly high heterogeneity. Subgroup analysis based on the treatment duration showed a significant rise in the serum sodium level after 24 hours and 2, 5, 7, and 14 days, as well as after 1 year of treatment. Greater increases in serum sodium levels after treatment with urea occurred in patients with severe (<120 mEq/L) (MD, 18.04 [95% CI, 13.68-22.39]) than with moderate (120-129 mEq/L) (MD, 7.86 [95% CI, 6.78-8.94]) or mild (130-135 mEq/L) (MD, 8.00 [95% CI, 7.31-8.69]) SIADH-induced hyponatremia. Urea treatment was comparable to fluid restriction (MD, 0.81 [95% CI, -0.93 to 2.55], P = 0.4) and vaptans (MD, -1.96 [95% CI, -4.59 to 0.66], P=0.1) but superior to no treatment (MD, 7.99 [95% CI, 6.25-9.72], P<0.01). Urea was associated with minor adverse events, with poor palatability being the most common.

LIMITATIONS

As no randomized controlled trials investigating urea as a treatment for hyponatremia were identified for inclusion, these analyses were based on observational studies.

CONCLUSIONS

Urea is safe and effective for managing SIADH-induced hyponatremia. These finding suggest that urea may be a useful treatment modality in resource-limited settings or when other treatments are contraindicated or poorly tolerated.

TRIAL REGISTRATION

Registered at PROSPERO with study number CRD42024511685.

The role of the clinical laboratory in diagnosing hyponatremia disorders

In clinical medicine, hyponatremia is highly prevalent and frequently misdiagnosed, leading to substantial mismanagement and iatrogenic morbidity. Its differential diagnosis includes numerous diseases with diverse etiologies, making accurate assessment challenging. Despite extensive literature and guidelines on hyponatremia, most patients do not receive adequate evaluation due to the limitations of diagnostic algorithms, which rely on low-value clinical signs and are unable to identify concurrent conditions. In this review, we examine the range of laboratory tests available for hyponatremia assessment. Understanding renal mechanisms of solute and water exchange (e.g., fractional excretion) is essential for selecting appropriate tests and interpreting their diagnostic value. Additionally, detailed electrolyte and acid-base assessments remain critical for establishing a definitive diagnosis. We comprehensively discuss the selection of laboratory tests for specific differential diagnoses of hyponatremia. Importantly, in cases of acute hyponatremia, rapid correction should take precedence over a complete diagnostic workup. Ultimately, a thorough understanding of laboratory evaluation is crucial for accurately diagnosing hyponatremia. This paper critically reviews the available literature and explores relevant diseases in the context of associated laboratory parameters.

Associations of serum sodium, potassium and chloride levels with the all-cause and cardiovascular diseases mortality among patients with depression

BACKGROUND

Electrolyte disturbances are relatively common in patients with depression, but they are often overlooked, and the relationship between electrolyte changes and adverse outcomes in depression is not yet clear. This study aims to explore the impact of serum electrolyte levels on the all-cause and cardiovascular disease (CVD) mortality rates in patients with depression.

METHODS

This prospective cohort study included 3127 patients with depression who participated in the National Health and Nutrition Examination Survey (NHANES) from 2005 through 2018. Depression was assessed using the Patient Health Questionnaire (PHQ-9), with a PHQ-9 score ≥10 defined as depression. The data were analyzed from April 1 to July 30, 2024. Multivariable Cox proportional hazards regression model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) between serum sodium, potassium, and chloride levels and the CVD risk and all-cause mortality in patients with depression. Three multivariable models were constructed. We further stratified the analysis by age, gender, hypertension, smoking, alcohol consumption, diabetes, and drinking status. Interaction significance was estimated using P-values for the product terms between serum sodium, potassium, chloride, and stratification factors.

RESULTS

This cohort study included data from 2946 participants in the analysis (mean [SD] age, 50.13 [16.48] years; 1116 men [37.88]); During a median (IQR) follow-up of 7.2 (3.6-10.5) years, 398 deaths were recorded, of which 117 were attributed to CVD.After multivariable adjustment, compared with participants in the first quartile of serum sodium levels, the HRs of CVD mortality were 0.90(95% CI, 0.53-1.53) in the fourth quartile (p for trend = 0.484). The HRs of all-cause mortality were 0.73(95% CI, 0.55-0.99) for the fourth quartile (p for trend = 0.003). A nonlinear association was observed between serum sodium levels and all-cause mortality in patients with depression (p for overall = 0.003, p for nonlinear = 0.047). Compared with participants in the first quartile of serum potassium levels, the HRs of CVD mortality were and 1.58(95% CI, 0.98-2.54) in the fourth quartile (p for trend = 0.050), the HRs of all-cause mortality were 1.52(95% CI, 1.16-1.99) for the fourth quartile (p for trend <0.001). A nonlinear association was observed between serum potassium levels and all-cause (p for overall<0.001, p for nonlinear = 0.005) and CVD (p for nonlinear = 0.003) mortality in patients with depression. Compared with participants in the first quartile of serum chlorine levels, the HRs of CVD mortality were 0.84(95% CI, 0.49-1.46) in the fourth quartile(p for trend = 0.284). The HRs of all-cause mortality were 0.70(95% CI, 0.51-0.95) for the fourth quartile(p for trend <0.001). A nonlinear association was observed between serum chlorine levels and all-cause (p for nonlinear<0.001) and CVD (p for nonlinear<0.001) mortality in patients with depression.

CONCLUSION AND CORRELATIONS

This cohort study found that in patients with depression, higher sodium is significantly correlated with lower all-cause mortality, higher potassium is significantly correlated with higher all-cause and CVD mortality, and higher chloride is significantly correlated with lower all-cause and CVD mortality.

Rapid Microfluidic Ion-Exchange Optode System for Point-of-Care Determination of Sodium Concentration in Serum

A microfluidic system for detecting sodium ions (Na+) has been developed, incorporating a micro finger-pump chip and a micro-spectrometer platform to measure Na+ concentration in human serum. A small volume (10 μL) of serum sample is introduced into the microchip and reacted with a preloaded reagent mixture through a two-step finger-pump actuation process. The resulting purple complex is directed into the detection area of the chip and analyzed using the micro-spectrometer at wavelengths of 555 and 666 nm. The Na+ concentration is then inversely derived from the measured A555/A666 absorbance ratio using self-written software installed on a Raspberry Pi. The entire detection process is completed in just 3 min, offering a significant advantage in meeting clinical needs compared to the traditional reporting turnaround time of several hours in medical institutions. The experimental results indicate a linear relationship between the measured absorbance ratio and Na+ concentration within the range of 1-200 mM, with a correlation coefficient of R2 = 0.9989. Additionally, the detection results from 60 serum samples collected from chronic kidney disease (CKD) patients showed a strong agreement with those obtained using the conventional indirect ion-selective electrode (ISE) method, achieving a correlation coefficient of R2 = 0.9885 and an average recovery rate of 99.4%. In summary, the proposed system provides a practical, affordable, and rapid alternative to conventional Na+ detection methods, making it highly promising for point-of-care (POC) testing applications.

Safety assessment of selinexor: a real-world pharmacovigilance study

BACKGROUND

Selinexor is approved for the treatment of relapsed or refractory multiple myeloma. However, a comprehensive understanding of adverse events associated with selinexor is lacking.

METHODS

Clinical trials of selinexor in patients with multiple myeloma were reviewed. We investigated selinexor-related adverse events through data of the US Food and Drug Administration Adverse Event Reporting System (FAERS). The disproportionality analysis was conducted. Four algorithms were employed to evaluate the signals of adverse events. The adverse effects of selinexor combined with dexamethasone were compared with bortezomib and dexamethasone. Sensitivity analysis was performed to exclude consumer-reported adverse events. The onset of adverse reactions were calculated.

RESULTS

A total of 1,698 reports related with selinexor from FAERS were identified. 6 significant system organ class and 42 significant preferred terms (PTs) were found. Unexpected significant adverse events including mania, acute kidney injury, orthostatic hypotension, and embolisms were identified. 14 PTs reported significant signals in treatment of selinexor combined dexamethasone compared with traditional treatment of bortezomib and dexamethasone. 45.2% of adverse events occurred within the first month of starting selinexor.

CONCLUSIONS

Comprehensive analyses of selinexor related adverse events are helpful for clinical detection of adverse events and timely intervention, advancing selinexor's therapeutic progress in future treatment.

Comparative study of the effectiveness of tolvaptan versus urea in patients with hyponatremia caused by SIADH

BACKGROUND AND OBJECTIVES

Hyponatraemia is common in elderly and hospitalised patients, often caused by the syndrome of inappropriate antidiuretic hormone secretion (SIADH). This study evaluates the efficacy and safety of tolvaptan and urea in patients with hyponatraemia and SIADH.

MATERIALS AND METHODS

An observational cohort study was conducted on 198 patients with SIADH and hyponatraemia (Na+ <135 mmol/L) at the Complejo Hospitalario Universitario de Pontevedra from January 2015 to May 2022. Of these, 86 were treated with tolvaptan (average dose of 7.5 mg) and 112 with urea (average dose of 15 g). The primary outcome was the normalization of sodium levels (Na ≥ 135 mmol/L).

RESULTS

The tolvaptan group showed higher sodium concentrations at the end of therapy compared to the urea group (ME = 136, IQR = 135-137 vs. ME = 134, IQR = 132-137; p < 0.001). The time to normalise sodium was shorter with tolvaptan (4 ± 3.4 days) compared to urea (6 ± 3.6 days; p = 0.03). A higher percentage of patients achieved sodium normalization with tolvaptan (83.72% vs. 59.82%; p = 0.005). Tolvaptan had more adverse effects, such as dry mouth, thirst, and sodium overcorrection, while urea caused dysgeusia, abdominal pain, and diarrhea. There were no significant differences in mortality between the groups.

CONCLUSIONS

Tolvaptan was more effective and quicker than urea in normalising sodium levels, though it showed a higher percentage of adverse effects, which did not require discontinuation of the drug.

A Snake Toxin Derivative for Treatment of Hyponatremia and Polycystic Kidney Diseases

Key Points

MQ232, a disulfide-bond reticulated peptide derived from a natural snake toxin, was optimized as a new aquaretic drug candidate. MQ232 showed very low acute and chronic toxicity in rat and a biodistribution in mice strongly in favor of the kidney organs. MQ232 induced a sole aquaretic effect and demonstrated high in vivo activities on hyponatremia and polycystic kidney disease models.

Background

Vaptans were developed at the end of the previous century as vasopressin type 2 receptor antagonists. Tolvaptan is the most prescribed vaptan for hyponatremia and autosomal dominant polycystic kidney disease (ADPKD). However, its use is not as widespread as it should be due to price issues, a narrow therapeutic window, and some side effects. With the aim of discovering new efficient and safer vasopressin type 2 receptor antagonists, we screened animal venoms and identified several peptide toxins. Among them, mambaquaretin 1 (MQ1) displayed unique biological properties in that regard that it was the starting point for the development of a potential drug candidate.

Methods

Human T-cell assays and bioinformatics were used to mitigate MQ1 immunogenicity risk. MQ232 biodistribution in mice was performed by positron emission tomography. Pharmacodynamics, pharmacokinetics, and acute and chronic toxicity tests were performed on control rats. A rat experimental model of desmopressin-induced hyponatremia, ex vivo mice model of kidney cysts, and mice orthologous model of ADPKD were used to validate MQ232 efficacy in these pathologies.

Results

Three mutations were introduced in MQ1 to mitigate its immunogenicity risk. A fourth gain-of-function mutation was added to generate MQ232. MQ232's safety was demonstrated by a first toxic dose as high as 3000 nmol/kg and a strong kidney organ selectivity by positron emission tomography imaging, while showing almost no interaction with the liver. MQ232's efficacy was first demonstrated with an effective dose of 3 nmol/kg in a hyponatremic model and then in polycystic kidney models, on which MQ232 significantly reduced cyst growth.

Conclusions

We demonstrated, using diverse translational techniques and minimizing animal use, MQ232's safety and efficacy in several rodent models of hyponatremia and ADPKD.

Syndrome of Inappropriate Antidiuretic Hormone (SIADH) in Chronic Respiratory Diseases: A Comprehensive Review

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a complex and often underdiagnosed disorder characterized by impaired water homeostasis, leading to hyponatremia and associated complications. This comprehensive review explores the intersection of SIADH with chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), pulmonary tuberculosis, cystic fibrosis, and interstitial lung disease. The review looks at current evidence on pathophysiology, diagnostic challenges, and treatment approaches, highlighting the need for specialized management strategies to improve patient outcomes. Through an analysis of clinical and observational studies, this review highlights the significant impact of SIADH on morbidity and mortality among patients with respiratory diseases. It illustrates the necessity for further research to refine diagnostic and therapeutic modalities.

Cerebrospinal fluid-induced stable and reproducible SERS sensing for various meningitis discrimination assisted with machine learning

Cerebrospinal fluid (CSF)-based pathogen or biochemical testing is the standard approach for clinical diagnosis of various meningitis. However, misdiagnosis and missed diagnosis always occur due to the shortages of unusual clinical manifestations and time-consuming shortcomings, low sensitivity, and poor specificity. Here, for the first time, we propose a simple and reliable CSF-induced SERS platform assisted with machine learning (ML) for the diagnosis and identification of various meningitis. Stable and reproducible SERS spectra are obtained within 30 s by simply mixing the colloidal silver nanoparticles (Ag NPs) with CSF sample, and the relative standard deviation of signal intensity is achieved as low as 2.1%. In contrast to conventional salt agglomeration agent-induced irreversible aggregation for achieving Raman enhancement, a homogeneous and dispersed colloidal solution is observed within 1 h for the mixture of Ag NPs/CSF (containing 110-140 mM chloride), contributing to excellent SERS stability and reproducibility. In addition, the interaction processes and potential enhancement mechanisms of different Ag colloids-based SERS detection induced by CSF sample or conventional NaCl agglomeration agents are studied in detail through in-situ UV-vis absorption spectra, SERS analysis, SEM and optical imaging. Finally, an ML-assisted meningitis classification model is established based on the spectral feature fusion of characteristic peaks and baseline. By using an optimized KNN algorithm, the classification accuracy of autoimmune encephalitis, novel cryptococcal meningitis, viral meningitis, or tuberculous meningitis could be reached 99%, while an accuracy value of 68.74% is achieved for baseline-corrected spectral data. The CSF-induced SERS detection has the potential to provide a new type of liquid biopsy approach in the fields of diagnosis and early detection of various cerebral ailments.

Pre-treatment of hyponatremia as a biomarker for poor immune prognosis in advanced or metastatic gastric cancer: A retrospective case analysis

Hyponatremia, a prevalent electrolyte imbalance among tumor patients, has often been overlooked regarding its prognostic significance for immunotherapy. In this study, we delved into the prognostic ramifications of hyponatremia in advanced gastric cancer (AGC) patients undergoing immunotherapy. Enrolling AGC patients diagnosed between December 2014 and May 2021, we extracted pertinent data from electronic medical records, with a median follow-up of 35.8 months. Kaplan-Meier curves illuminated patients' progression-free survival (PFS) and overall survival (OS), while survival disparities were tested using the Mantel-Haenszel log rank test. COX and logistic regressions were employed to scrutinize the correlation between serum sodium levels and prognosis in 268 AGC patients, both at baseline and during treatment. Notably, patients with hyponatremia exhibited shorter PFS (4.7 vs 2.1 months, p = .001*) and OS (12.5 vs 3.9 months, p < .001*). Serum sodium emerged as an independent prognostic factor for both PFS (HR = 1.773; 95% CI 1.067-2.945; p = .001*) and OS (HR = 1.773; 95% CI 1.067-2.945; p = .003*). Subgroup analysis revealed that AGC patients with hyponatremia derived no benefit from immunotherapy in terms of PFS and OS. Strikingly, a decrease in serum sodium during immunotherapy was associated with early relapse and mortality. Based on these findings, we hypothesize that hyponatremia portends poor prognostic outcomes in AGC patients treated with immunotherapy and may serve as a valuable prognostic biomarker. However, further large-scale prospective studies are warranted to validate these observations.

A Review of the Risk Factors and Approaches to Prevention of Post-Reperfusion Syndrome During Liver Transplantation

Post-reperfusion syndrome (PRS) is a severe and highly lethal syndrome that occurs after declamping the portal vein forceps during liver transplantation. It is marked by severe hemodynamic disturbances manifested by decreased mean arterial pressure, increased heart rate and elevated pulmonary artery pressure. The complex pathogenesis of PRS remains understudied. It is generally believed to be related to the large amount of acidic, cold blood that enters the circulation after release of the portal clamp. This blood is rich in oxygen-free radicals and metabolic toxins, which not only aggravate the ischemia-reperfusion injury of the liver but also further attack the systemic organs indiscriminately. Considering the range of possible adverse prognoses including acute kidney injury, delirium and graft nonfunction, it is imperative that clinicians increase their awareness and prevention of PRS. The aim of this article is to review the current risk factors, pathophysiological mechanisms and prevention strategies for PRS.

Syndrome of inappropriate antidiuresis/hyponatremia in COVID-19

Hyponatremia is the most frequent electrolyte alteration among hospitalized patients and it has been reported in 20-40% of patients with SARS-CoV-2 (COVID-19) infection. Multiple causes of hyponatremia have been hypothesized in these patients. The syndrome of inappropriate antidiuresis (SIAD) has been considered one of the main reasons leading to hyponatremia in this condition. SIAD can be secondary to cytokines release, in particular IL-6. Positive pressure ventilation can be another cause of hyponatremia due to SIAD. Other possible etiologies of hyponatremia in COVID-19 patients can be related to secondary hypocortisolism, nausea, vomiting, heart and kidney damage. Similar to many other clinical conditions, there is strong evidence that hyponatremia is associated with a worse prognosis also in patients with COVID-19 infection. In particular, hyponatremia has been identified as an independent risk of ICU transfer, need of non-invasive ventilation and death. Hyponatremia in COVID-19 patients is in principle acute and symptomatic and should be treated as such, according to the published guidelines. Therefore, patients should be initially treated with i.v. hypertonic saline (3% NaCl) infusion and serum [Na+] should be frequently monitored, in order to remain within a safe rate of correction. There is evidence showing that serum [Na+] correction is associated with a better outcome in different pathologies, including COVID-19 infection.

Clinical Significance of Hyponatremia in Tuberculous Meningitis: A Prospective Cohort in Indonesia

Background

Hyponatremia is common in tuberculous meningitis (TBM), but its impact on disease severity and outcomes is unclear.

Methods

In a cohort of 864 adult patients with TBM in Indonesia, we assessed the prevalence and prognostic significance of hyponatremia, classified as moderate (120-130 mEq/L) or severe (<120 mEq/L). Patients received standard antituberculous therapy and corticosteroids and were followed for 1-year mortality.

Results

Hyponatremia occured in 86.8% of patients, with 26% classified as severe. Severe hyponatremia associated with male, younger age, a lower Glasgow Coma Scale (GCS), and markers of more severe disease (P < .05). One-year mortality was 46.5% and associated with older age, HIV infection, lower GCS, markers of neurologic severity, fever, and thrombocytosis. Severe hyponatremia predicted mortality in univariate analysis showed no impact in HIV-positive patients.

Conclusions

Hyponatremia reflects disease severity in TBM but does not independently predict mortality, suggesting limited benefit from agressive correction.

Comparative Safety and Effectiveness of Urea and Tolvaptan for the Management of Hyponatremia

Background: The optimal management of euvolemic and hypervolemic hyponatremia remains controversial. The effectiveness of the vasopressin receptor antagonist tolvaptan on serum sodium normalization has been well described in the literature, although the associated risk of serum sodium overcorrection limits its use. Urea has been proposed as an alternative treatment option due to its milder serum sodium raising effects and adverse event profile. Objective: This study aimed to compare urea and tolvaptan for their serum sodium raising effects and potential for overcorrection. Methods: In a multicenter retrospective review, 46 hospitalized patients who received either urea or tolvaptan for the management of hyponatremia were evaluated for the rate of serum sodium normalization and overcorrection. Results: Mean serum sodium concentrations at baseline were 125.91 mEq/L and 123.83 mEq/L for patients treated with urea and tolvaptan, respectively. After 12 hours, tolvaptan was associated with a significantly higher rate of serum sodium increase compared with urea (5.05 mEq/L vs 1.10 mEq/L; P = .001). However, no statistically significant differences were observed in the mean change in serum sodium concentrations at 24 hours, 48 hours, or with the proportion of patients who reached a serum sodium concentration of 135 mEq/L. Overcorrection rates were significantly higher with tolvaptan compared with urea at 43% and 9%, respectively. Conclusion: The results of this study suggest that urea has a comparable effectiveness profile to tolvaptan for the management of hyponatremia with a significantly reduced risk of overcorrection.

Diagnostic validity and solute-corrected prevalence for hyponatremia and hypernatremia among 1 813 356 admissions

Background and hypothesis

We aimed to evaluate the diagnostic validity of the International Classification of Diseases, 10th Revision (ICD-10) codes for hyponatremia and hypernatremia, using a database containing laboratory data. We also aimed to clarify whether corrections for blood glucose, triglyceride, and total protein may affect the prevalence and the diagnostic validity.

Methods

We retrospectively identified admissions with laboratory values using a Japanese hospital-based database. We calculated the sensitivity, specificity, and positive/negative predictive values of recorded ICD-10-based diagnoses of hyponatremia (E87.1) and hypernatremia (E87.2), using serum sodium measurements during hospitalization (<135 and >145 mmol/l, respectively) as the reference standard. We also performed analyses with corrections of sodium concentrations for blood glucose, triglyceride, and total protein.

Results

We identified 1 813 356 hospitalizations, including 419 470 hyponatremic and 132 563 hypernatremic cases based on laboratory measurements, and 18 378 hyponatremic and 2950 hypernatremic cases based on ICD-10 codes. The sensitivity, specificity, positive predictive value, and negative predictive value of the ICD-10 codes were 4.1%, 99.9%, 92.5%, and 77.6%, respectively, for hyponatremia and 2.2%, >99.9%, 96.5%, and 92.8%, respectively, for hypernatremia. Corrections for blood glucose, triglyceride, and total protein did not largely alter diagnostic values, although prevalence changed especially after corrections for blood glucose and total protein.

Conclusions

The ICD-10 diagnostic codes showed low sensitivity, high specificity, and high positive predictive value for identifying hyponatremia and hypernatremia. Corrections for glucose or total protein did not affect diagnostic values but would be necessary for accurate prevalence calculation.

Psychological Assessment and Intervention at the Boston Marathon

The Boston Marathon is a highly regarded event in the running world, not just for its prestige and challenging course, but also for its implementation of a psychology team to support runners. The 2013 Boston Marathon bombings underscored the essential role that mental health support plays at this event, prompting the development and expansion of its innovative care model. This review critically outlines, evaluates, and analyzes the approach and effectiveness of the psychological care model provided to runners on race day as part of the Boston Marathon medical team, including the standard of care, how it functions, and best practices for other marathons. The implications for this review contribute to the increasing trend of providing psychological care in marathon and other athletic settings, and to provide a framework for standardizing assessment and intervention procedures for both elite and novice runners.

Hyponatremia due to preserved non-osmotic arginine vasopressin secretion in adipsic diabetes insipidus: a case report with review of literature

Adipsic diabetes insipidus (ADI) is characterized by central diabetes insipidus and an impaired thirst response to hyperosmolality, leading to hypernatremia. Hyponatremia observed in patients with ADI has been considered a complication of desmopressin therapy. Herein, we present a case of impaired thirst sensation and arginine vasopressin (AVP) secretion without desmopressin therapy, in which hyponatremia developed due to preserved non-osmotic AVP secretion. A 53-year-old woman with hypopituitarism, receiving hydrocortisone and levothyroxine, experienced hyponatremia three times over 5 months without desmopressin treatment. The first hyponatremic episode (120 mEq/L) was complicated by a urinary tract infection with a plasma AVP level of 33.8 pg/mL. Subsequent hyponatremia episodes occurred after administration of antipsychotic (124 mEq/L) and spontaneously (125 mEq/L) with unsuppressed plasma AVP levels (1.3 and 1.8 pg/mL, respectively). Hypertonic saline infusion did not affect AVP or copeptin levels. Regulating water intake using a sliding scale based on body weight prevented the recurrence of hyponatremia without the use of desmopressin. Except during infection, plasma AVP levels (1.3 ± 0.4 pg/mL) were not significantly correlated with serum sodium levels (rs = -0.04, p = 0.85). In conclusion, we present a unique case of impaired thirst sensation and AVP secretion in which hyponatremia developed without desmopressin therapy. Preserved non-osmotic AVP secretion, possibly stimulated by glucocorticoid deficiency, may contribute to the development of hyponatremia in patients with ADI.

Shisandra Decoction Alleviates Parkinson's Disease Symptoms in a Mouse Model Through PI3K/AKT/mTOR Signalling Pathway

Purpose

The present study aimed to characterize neuroprotective effects of Schisandra Decoction (Sch D) treatment in a mouse model of Parkinson's disease (PD), and to explore underlying mechanisms focused on the mammalian target of rapamycin (mTOR) signaling pathway.

Materials and Methods

50 male C57 BL/6 mice were randomly assigned to either control (n = 10) or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model (n = 40) groups. PD mice were further divided into four groups of ten mice each: MPTP group, LY294002 group, Sch D group, and LY2940002 + Sch D group. Mice from each group were assessed in pole climbing, rotary rod and open field tests. Brain Tyrosine hydroxylase (TH) protein was observed using immunohistochemistry. mRNA levels of PTEN, PI3K and LC3 in brain tissue were measured using RT-PCR. Protein levels of PTEN, PI3K, Akt, p-Akt, mTOR, p-mTOR, p70s6K, p62, LC3II / I, α-synuclein (α-syn), TH in brain tissue were assessed by Western blotting (WB).

Results

In behavioral tests, PD mice treated with Sch D showed reduced pole climbing time, longer rotarod duration, and greater distance traveled. In terms of neuroprotection, PD mice in the Sch D group exhibited higher levels of TH protein and enhanced α-syn clearance. Regarding autophagy, compared to the control group, mice in the MPTP group had elevated PTEN protein expression, which inhibited PI3K, p-AKT/AKT, and p-mTOR/mTOR protein levels, decreased LC3II/I protein expression, and increased P62 protein expression. Treatment with Sch D reversed these effects.

Conclusion

Sch D reduces α-syn aggregation in the brains of MPTP-induced PD model mice, exerts neuroprotective effects, and improves motor function. Additionally, Sch D inhibits autophagy through the PI3K/AKT/mTOR pathway. The neuroprotective effect of Sch D may involve the suppression of abnormal autophagy and its antioxidant properties, which indirectly reduces α-syn accumulation. Future studies should assess the impact of Sch D on oxidative stress markers to evaluate its antioxidant effects.

Suspected paraneoplastic syndrome of inappropriate antidiuretic hormone secretion associated with a gastric adenocarcinoma in a dog

This report describes a suspected case of paraneoplastic syndrome of inappropriate antidiuretic hormone (SIADH) in a 5-year-old male entire Australian Kelpie associated with a gastric adenocarcinoma. The dog had a history of chronic vomiting and presented with hyponatraemia, hypokalaemia, hypochloraemia and increased urinary sodium. Computed tomography identified the presence of a gastric tumour and histopathology confirmed a pyloric gastric adenocarcinoma. Removal of the tumour via a Billroth I procedure resulted in rapid resolution of electrolyte derangements. The dog was still alive six months postoperatively with no recurrence of either SIADH or tumour at the time of publication.

Unveiling the Patterns of Water Diuresis in Profound Hyponatremia Management in Intensive Care Unit Settings

Key Points

Water diuresis presents a conundrum during the treatment of profound hyponatremia, but its clinical characteristics remain unclear. This study revealed that water diuresis mostly manifests within 24 hours of treatment, preceded by changes in urinary characteristics. Careful urine monitoring in the early stages of hyponatremia treatment could facilitate the early detection of water diuresis.

Background

Hyponatremia treatment guidelines recommend avoiding excessive increases in serum sodium concentration (s[Na]) to prevent osmotic demyelination syndrome. Although an unexpected rise in s[Na] has been attributed to water diuresis during the treatment of hyponatremia, clinical courses of water diuresis are unclear. We conducted this study to investigate the clinical characteristics of water diuresis during profound hyponatremia management.

Methods

In this retrospective observational study, we examined patients with profound hyponatremia (s[Na] ≤120 mEq/L) admitted to the intensive care unit of a Japanese hospital. The manifestation of water diuresis was defined as a urine volume (UV) ≥2 ml/kg per hour and a urinary sodium plus potassium concentration (u[Na+K]) ≤50 mEq/L. We analyzed changes in UV and u[Na+K] over time for patients experiencing water diuresis. This analysis employed a mixed-effects model with spline terms for time, and the results are graphically presented.

Results

Among 47 eligible patients, 30 (64%) met the criteria for water diuresis. The etiologies of hyponatremia were drug-related hyponatremia (n =10; 33%), primary polydipsia (n =8; 27%), hypovolemic hyponatremia (n =7; 23%), syndrome of inappropriate antidiuresis (n =7; 23%), and acute heart failure (n =1; 3%). Among patients with water diuresis, 27 (90%) experienced the manifestation of water diuresis within 24 hours after the start of correction. The increased UV and decreased u[Na+K] levels began several hours before the peak manifestation of water diuresis. Within 6 hours after the manifestation of water diuresis, 29 patients (97%) received electrolyte-free infusions and 14 (47%) received desmopressin. One patient (3%) with water diuresis experienced overcorrection.

Conclusions

Water diuresis is common during the treatment for profound hyponatremia and typically occurs within the first 24 hours, preceded by changes in urinary characteristics. Early detection and prompt response to water diuresis through urine monitoring during the early periods of hyponatremia treatment may be effective for managing water diuresis.

Hyponatraemia-treatment standard 2024

Hyponatraemia is the most common electrolyte disorder in hospital patients associated with increased morbidity, mortality, hospital stay and financial burden. The speed of a correction with 3% sodium chloride as a 100- to 150-ml intravenous bolus or continuous infusion depends on the severity and persistence of the symptoms and needs frequent biochemical monitoring. The rapid intermittent administration of hypertonic saline is preferred for treatment of symptomatic hyponatraemia. In asymptomatic mild hyponatraemia, an adequate solute intake with an initial fluid restriction (FR) of 500 ml/day adjusted according to the serum sodium (sNa) levels is preferred. Almost half of the syndrome of inappropriate antidiuretic hormone (SIADH) patients do not respond to FR as first-line therapy. At present, urea and tolvaptan are considered the most effective second-line therapies in SIADH. However, the evidence for guidance on the choice of second-line therapy of hypotonic hyponatraemia is lacking. Oral urea is considered to be a very effective and safe treatment. Mild and asymptomatic hyponatraemia is treated with adequate solute intake (salt and protein) and initial FR with adjustments based on sNa levels. Specific treatment with vaptans may be considered in either euvolaemic or hypervolaemic patients with high ADH activity. In order to ensure optimal patient outcome, close monitoring and readiness for administration of either hypotonic fluids or desmopressin may be crucial in the decision-making process for specific treatment and eventual overcorrection consequences. According to the guidelines, gradual correction and clinical evaluation is preferable over rapid normalization of sNa towards the laboratory reference ranges.

Prevalence and prognostic role of hypochloremia in patients with acute heart failure in Ethiopia: A single-center retrospective analysis

BACKGROUND

In patients with heart failure (HF), multiple electrolyte disorders are common, and recent studies have shown that chloride disorders play a significant role in the prognosis of HF. Data about the prevalence and prognostic role of hypochloremia in patients with acute HF (AHF) are scarce in African nations, including Ethiopia. Hence, this study aimed to assess the prevalence, associated factors, and prognostic role of hypochloremia in patients with AHF in Ethiopia.

METHODS

This was a single-center retrospective analysis of AHF patients, aged ≥15 years, with chloride determination upon admission to the medical wards and medical ICU of Yekatit 12 Hospital Medical College, Addis Ababa, Ethiopia, from July 1, 2022, to July 1, 2023. Statistical Package for Social Sciences, version 26, was used to enter and analyze the data. Descriptive analysis was used to summarize clinical profiles, laboratory data, and outcomes of AHF patients stratified by the presence and absence of hypochloremia. Logistic regression analysis was used to determine the factors associated with hypochloremia and to assess the association of hypochloremia and other factors with in-hospital mortality in patients with AHF. A two-tailed P value <0.05 was regarded as statistically significant.

RESULTS

A total of 267 AHF patients who had chloride determination on admission were included in this study; the mean age was 56.7 years (standard deviation: 18.6), and the gender-based distribution of the patients was nearly equal. The prevalence of hypochloremia was 36.7%. Diastolic blood pressure <60 mm Hg [adjusted odds ratio (AOR) = 3.63, 95% confidence interval (CI), 1.04, 12.72] and hyponatremia (AOR = 29.20, 95% CI, 13.21, 64.56) were significantly associated with hypochloremia. The in-hospital mortality rate was higher in AHF patients with hypochloremia (16.3%) compared to those without hypochloremia (4.7%). The odds of in-hospital mortality among AHF patients with hypochloremia were 2.8 times higher compared to patients without hypochloremia (AOR = 2.82, 95% CI: 1.08, 7.04) after adjusting for ICU admission, systolic blood pressure < 120 mm Hg and diastolic blood pressure < 60 mm Hg.

CONCLUSIONS

This study revealed a high prevalence of hypochloremia among patients with AHF. Low diastolic blood pressure and hyponatremia were significantly associated with the development of hypochloremia. Most importantly, AHF patients with hypochloremia had a higher in-hospital mortality rate compared to those without hypochloremia. Hence, hypochloremia on admission should be considered a potential prognostic factor in patients with AHF, and further research with a larger sample size is needed to support the findings of this study.

Impact of Hyponatremia on COVID-19-Related Outcomes: A Retrospective Analysis

BACKGROUND

Sodium disturbances are observed in one-third of patients with COVID-19 and result from multifaceted mechanisms. Notably, hyponatremia is associated with disease progression and mortality.

AIM

We aimed to analyze the impact of hyponatremia on COVID-19 outcomes and its correlation with clinical and laboratory parameters during the first wave.

METHODS

We evaluated the sodium levels of 558 patients with COVID-19 between 21 March 2020, and 31 July 2020, at a single center. We performed linear regression analyses to explore the correlation of sodium levels with COVID-19-related outcomes, demographic data, signs and symptoms, and laboratory parameters. Next, we conducted Pearson correlation analyses. A p-value < 0.05 was considered significant.

RESULTS

Hyponatremia was found in 35.3% of hospitalized patients with COVID-19. This was associated with the need for intensive care transfer (B = -1.210, p = 0.009) and invasive mechanical ventilation (B = -1.063, p = 0.032). Hyponatremia was frequently found in oncologic patients (p = 0.002) and solid organ transplant recipients (p < 0.001). Sodium was positively associated with diastolic blood pressure (p = 0.041) and productive cough (p = 0.022) and negatively associated with dry cough (p = 0.032), anorexia (p = 0.004), and nausea/vomiting (p = 0.007). Regarding the correlation of sodium levels with other laboratory parameters, we observed a positive correlation with hematocrit (p = 0.011), lymphocytes (p = 0.010), pCO2 (p < 0.0001), bicarbonate (p = 0.0001), and base excess (p = 0.008) and a negative correlation with the neutrophil-to-lymphocyte ratio (p = 0.009), the platelet-to-lymphocyte ratio (p = 0.033), and arterial blood glucose (p = 0.016).

CONCLUSIONS

Hyponatremia is a risk factor for adverse outcomes in COVID-19 patients. It is associated with demographic data and clinical and laboratory parameters. Therefore, hyponatremia is an important tool for risk stratification in COVID-19 patients.

Pituitary Disorders

In this article, we will review common pituitary disorders. There are 6 hormones secreted by the anterior pituitary gland: thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, growth hormone, and prolactin. The posterior pituitary gland stores and releases the hormones made in the hypothalamus, oxytocin and antidiuretic hormone, based on the body's needs. This article will discuss the role of these hormones, conditions and symptoms that occur with elevated or reduced hormone levels, as well as the evaluation and treatment of these pituitary disorders.

Prevalence of hyponatremia among medically hospitalized patients and associated outcomes: a retrospective cohort study

BACKGROUND

Hyponatremia is a common electrolyte disturbance among hospitalized patients and is linked to increased mortality as well as poor outcomes.

OBJECTIVES

Study the prevalence of hyponatremia among medically admitted patients and the outcomes associated with hyponatremia.

DESIGN

Retrospective cohort.

SETTING

Medical ward at tertiary hospital setting.

PATIENTS AND METHODS

The study included adult (≥18 years) hospitalized patients in general medical wards. Three readings of serum sodium level were taken (initial sodium level, nadir during admission, and before discharge).

SAMPLE SIZE AND BASIS

The sample size of 350 was determined based on a presumed 35% incidence of hyponatremia among hospitalized patients, with a 5% error margin.

MAIN OUTCOME MEASURES

The prevalence of hyponatremia among medically hospitalized patients and association with health outcomes including length of hospital stay, inpatient mortality, 90-days readmission and 1-year mortality.

RESULTS

In this study, 736 patients met the inclusion criteria. Of these, 377 (51.2%) had hyponatremia on admission, increasing to 562 (76.35%) during hospitalization. Mild hyponatremia was observed in 49.6% (n=365), moderate in 13.6% (n=100), and severe in 13.2% (n=97). Severe hyponatremia patients were significantly older (P<.01), predominantly female (P=.014), and had lower serum magnesium and albumin levels (P<.01). Hypertension, ischemic heart disease, heart failure, and diabetes were more prevalent in severe hyponatremia cases (P<.01, P<.01, P=.045, P<.01, respectively). Hospital stays were significantly shorter for patients with normal sodium levels (P<.01). Patients with severe hyponatremia had a shorter time for first hospital readmission (HR=0.80, P<.01 [95% CI; 0.69-0.94]).

CONCLUSION

Hyponatremia was prevalent among medically hospitalized patients and more common among old patients, women, and patients with comorbidities. Hyponatremia was associated with increased length of stay in hospital and increased risk of 90-day re-admission.

LIMITATIONS

Single-centre design and retrospective nature.

Hyponatremia Is Associated with Mortality in Acute Pancreatitis Patients

BACKGROUND

Disorders of serum sodium are common among general patients and are associated with poor outcomes. The prognostic value of serum sodium disorders in patients with acute pancreatitis (AP) has not been studied. We conducted this retrospective study to explore the association between serum sodium levels and the outcomes of patients with AP.

MATERIALS AND METHODS

Patients with AP from the Medical Information Mart for Intensive Care III (MIMIC-III) were screened for this study. The laboratory variables, including serum sodium levels, were obtained by analyzing the first blood sample on the first day after admission. Univariate logistic regression was performed to discover potential factors for mortality of AP. The unadjusted and adjusted association between serum sodium level and mortality of AP was shown by the restricted cubic spline (RCS). The categorical cutoff for the detrimental effect of serum sodium level on the prognosis of AP was also confirmed by stepwise logistic regression after adjusting for con-founding effects of significant factors in the univariate logistic regression.

RESULTS

A total of 869 patients with AP in the MIMIC-III were included with a mortality of 13.1%. Unadjusted logistic regression showed that age (p < 0.001), simplified acute physiological score (SAPS) (p < 0.001), systolic blood pressure (p < 0.001), diastolic blood pressure (p < 0.001), hemoglobin (p = 0.040), serum creatinine (p = 0.046), and serum phosphorus (p < 0.001) were significantly associated with the mortality of AP. The RCS showed that the serum sodium level was negatively and linearly associated with mortality of AP after adjusting for confounding effects of significant factors in the univariate logistic regression. Serum sodium < 133 mmol/L, which indicated hyponatremia, was significantly correlated with a higher mortality risk than serum sodium ≥ 133 mmol/L (p = 0.013).

CONCLUSIONS

Hyponatremia is widely developed among patients with AP and correlates with a higher mortality risk of AP. Physicians should pay more attention to managing patients with AP with hyponatremia.

Acute Urinary Retention and Severe Hyponatremia in a Patient With a Large Intramural Uterine Fibroid

Acute urinary retention (AUR) is defined as the inability to pass urine voluntarily. It is more common in males, with a male-to-female incidence ratio of 13:1. In males, benign prostatic hyperplasia is the most common cause of AUR, especially in men aged above 60, whereas in females, pelvic anatomy distortion secondary to pelvic organ prolapse and pelvic masses causes most cases of AUR. Prompt diagnosis and management are the keys to avoiding complications secondary to AUR, such as pain and acute kidney injury. Less commonly, it can cause acute hyponatremia, as was seen in our patient. Hyponatremia is generally asymptomatic, but if acute and/or severe, it can cause mental status changes, seizures, and coma. Such patients need closer monitoring of their mental status and sodium level to avoid overcorrection. Here we present a unique case report of a patient with asymptomatic large uterine fibroid presented with abdominal distention who was found to have acute urinary retention with associated asymptomatic severe hyponatremia, managed conservatively.

Effects of donors' and recipients' preoperative serum sodium on the prognosis of liver transplantation

Dysnatremia is common in donors and recipients of liver transplantation (LT). However, the influence of dysnatremia on LT prognosis remains controversial. This study aimed to investigate effects of donors' and recipients' serum sodium on LT prognosis. We retrospectively reviewed 248 recipients who underwent orthotopic LT at our center between January 2016 and December 2018. Donors and recipients perioperative and 3-year postoperative clinical data were included. Delta serum sodium was defined as the donors' serum sodium minus the paired recipients' serum sodium. Donors with serum sodium > 145 mmol/L had significantly higher preoperative blood urea nitrogen (BUN) (P < 0.01) and creatinine (Cr) (P < 0.01) than others. Preoperative total bilirubin (TBIL) (P < 0.01), direct bilirubin (DBIL) (P < 0.01), BUN (P < 0.01), Cr (P < 0.01) were significantly higher in the hyponatremia group of recipients than the other groups, but both of donors' and recipients' serum sodium had no effect on the LT prognosis. In the delta serum sodium < 0 mmol/L group, TBIL (P < 0.01) and DBIL (P < 0.01) were significantly higher in postoperative 1 week than the other groups, but delta serum sodium had no effect on the postoperative survival rates. Dysnatremia in donors and recipients of LT have no effect on postoperative survival rates, hepatic and renal function, but recipients with higher serum sodium than donors have significantly higher TBIL and DBIL at 1 week postoperatively.

Intensive Care Management of Severe Hyponatraemia-An Observational Study

Background and Subject: Hyponatraemia is a common electrolyte disorder. For patients with severe hyponatraemia, intensive care unit (ICU) admission may be required. This will enable close monitoring and allow safe management of sodium levels effectively. While severe hyponatraemia may be associated with significant symptoms, rapid overcorrection of hyponatraemia can lead to complications. We aimed to describe the management and outcomes of severe hyponatraemia in our ICU and identify risk factors for overcorrection. Materials and Methods: This was a retrospective single-centre cohort that included consecutive adults admitted to the ICU with serum sodium < 120 mmol/L between 1 January 2017 and 8 March 2023. Anonymised data were collected from electronic records. We included 181 patients (median age 67 years, 51% male). Results: Median admission serum sodium was 113 mmol/L (IQR: 108-117), with an average rate of improvement over the first 48 h of 10 mmol/L/day (IQR: 5-15 mmol/L). A total of 62 patients (34%) met the criteria for overcorrection at 48 h, and they were younger, presented with severe symptoms (seizures/arrythmias), and had lower admission sodium concentration. They were more likely to be treated with hypertonic saline infusions. Lower admission sodium was an independent risk factor for overcorrection within 48 h, whereas the presence of liver cirrhosis and fluid restriction was associated with normal correction. No difference was identified between the normal and overcorrected cohorts for ICU/hospital length of stay or mortality. Conclusions: In some patients with severe hyponatraemia, overcorrection is inevitable to avoid symptoms such as seizures and arrhythmias, and consequently, we highlight the key factors associated with overcorrection. Overall, we identified that overcorrection was common and concordant with the current literature.

Impact of electrolyte abnormalities and adverse outcomes in persons with eating disorders: A systematic review protocol

BACKGROUND

Electrolytes (sodium, potassium, calcium, magnesium, chloride, phosphate) are required in specific amounts for proper functioning of the human body. Although the body has different organ systems, such as the kidneys, that regulate electrolyte levels in the blood, electrolyte abnormalities occur frequently in people with eating disorders. The objective of this review will be to examine the association between electrolyte imbalances and adverse outcomes in people with eating disorders.

METHODS

A systematic review of studies on eating and electrolyte disorders shall be conducted. Electronic searches shall be done in the Ovid MEDLINE, EMBASE, and PsycINFO databases. Selected studies shall include randomized control trials (RCTs), non-randomized controlled trials, and cross-sectional studies published in English or French. Quality appraisal of studies and a narrative synthesis of extracted data shall be conducted.

DISCUSSION

This review will synthesize existing evidence on electrolyte abnormalities in people with eating disorders. It will identify the type of electrolyte imbalances, their impact, and outcomes in people with eating disorders. We anticipate that information that will be useful to policy makers and clinicians in designing better policies to prevent eating disorders and or manage people with eating disorders shall be elucidated in this study.

DISSEMINATION

The final manuscript will be submitted for publication in a journal.

REVIEW REGISTRATION

This protocol has been registered with the International Prospective Register of Systematic Reviews (PROSPERO); registration number CRD42023477497.

Strategies for the Management of Cardiorenal Syndrome in the Acute Hospital Setting

Cardiorenal syndrome (CRS) is a life-threatening disorder that involves a complex interplay between the two organs. Managing this multifaceted syndrome is challenging in the hospital and requires a multidisciplinary approach to tackle the many manifestations and complications. There is no universally accepted algorithm to treat patients, and therapeutic options vary from one patient to another. The mainstays of therapy involve the stabilization of hemodynamics, decongestion using diuretics or renal replacement therapy, improvement of cardiac output with inotropes, and goal-directed medical treatment with renin–angiotensin–aldosterone system inhibitors, beta-blockers, and other medications. Mechanical circulatory support is another viable option in the armamentarium of agents that improve symptoms in select patients.

Unmeasured Osmoles: The Hidden Solutes Obscuring a Hyponatremia Evaluation

Hyponatremia is defined as serum sodium less than 135 mEq/L and is principally a result of water excess relative to total body sodium content. The evaluation of hyponatremia is incomplete without a careful assessment of the patient's volume status, history, and acquisition of both serum and urine osmolality and sodium studies. Many of these studies can be affected by various clinical factors, and these nuances should be considered while interpreting the results. This is because these results guide the etiologic diagnosis of hyponatremia and consequently its management. In this report, we describe a 50-year-old male being evaluated for hyponatremia found to have unusual serum/urine osmolality studies but ultimately found to have an unmeasured serum osmole (ethanol) interfering with the interpretation of these results. Clinical scenarios that interfere with serum and urine studies commonly obtained in a hyponatremia evaluation are reviewed and an equation to correct for ethanol's osmotic contribution is described.

Urea transporter UT-A1 as a novel drug target for hyponatremia

Hyponatremia is the most common disorder of electrolyte imbalances. It is necessary to develop new type of diuretics to treat hyponatremia without losing electrolytes. Urea transporters (UT) play an important role in the urine concentrating process and have been proved as a novel diuretic target. In this study, rat and mouse syndromes of inappropriate antidiuretic hormone secretion (SIADH) models were constructed and analyzed to determine if UTs are a promising drug target for treating hyponatremia. Experimental results showed that 100 mg/kg UT inhibitor 25a significantly increased serum osmolality (from 249.83 ± 5.95 to 294.33 ± 3.90 mOsm/kg) and serum sodium (from 114 ± 2.07 to 136.67 ± 3.82 mmol/L) respectively in hyponatremia rats by diuresis. Serum chemical examination showed that 25a neither caused another electrolyte imbalance nor influenced the lipid metabolism. Using UT-A1 and UT-B knockout mouse SIADH model, it was found that serum osmolality and serum sodium were lowered much less in UT-A1 knockout mice than in UT-B knockout mice, which suggest UT-A1 is a better therapeutic target than UT-B to treat hyponatremia. This study provides a proof of concept that UT-A1 is a diuretic target for SIADH-induced hyponatremia and UT-A1 inhibitors might be developed into new diuretics to treat hyponatremia.

Electrolytes, Zinc and Vitamin D3 in COVID-19 Patients with Cardiovascular Complications

INTRODUCTION

COVID-19 is strongly linked to cardiovascular disease, with direct myocardial injury and systemic inflammation as common mechanisms. Pre-existing or infection-induced cardiovascular disease worsens the outcomes for COVID-19 patients.

MATERIALS AND METHODS

To estimate the serum electrolytes (Na+, K+, Ca++, Zn) and vitamin D3, the study depended on ichroma ii device for Vitamin D3 and Chemistry Analyzer for electrolytes in patient samples.

RESULTS

A study was conducted on 192 individuals diagnosed with COVID-19, including 35 critical cases, 53 severe cases, 54 moderate cases, and 50 individuals in a control group. The age group with the highest prevalence of infection was between 50‒69 years, while the lowest prevalence was observed in those under 30 years. The study found significant decreases in calcium, potassium, sodium, zinc, and vitamin D3 levels among COVID-19 patients compared to the control group. Zinc and vitamin D3 levels showed a significant correlation with sex, with males experiencing a decline in zinc levels and females having lower vitamin D3 levels. The concentration of calcium, sodium, and zinc showed a negative correlation with age, with older patients having the lowest levels. COVID-19 patients with chronic cardiac issues and high blood pressure exhibited the lowest levels of these markers. The severity of the disease also had a detrimental impact on electrolyte levels, zinc, and vitamin D3, with critical cases showing the lowest levels. The complications such as heart failure were associated with lower levels of potassium, sodium, and zinc.

CONCLUSION

In conclusion, the study revealed significant associations between COVID-19 and decreased electrolyte levels, zinc, and vitamin D3. Sex and age were found to be correlated with these markers. Patients with chronic cardiac issues and high blood pressure exhibited the lowest levels of these markers. The severity of the disease was also linked to lower electrolyte levels, zinc, and vitamin D3. Complications such as heart failure were associated with decreased levels of potassium, sodium, and zinc.

2024 AAHA Fluid Therapy Guidelines for Dogs and Cats

Fluids are drugs used in veterinary patients capable of producing beneficial therapeutic or inadvertent harmful effects within the body's intravascular, interstitial, and intracellular fluid spaces. The individualized design of a fluid therapy plan requires careful patient assessment and targeted selection of proper fluid types, administration routes, and rates, along with adjustments during therapy tailored specifically as per the individual patient's fluid requirement and therapeutic response. Personalized fluid prescriptions and vigilant patient monitoring help avoid patient morbidity from body fluid deficiencies, fluid excess, and electrolyte derangements and support better patient outcomes. These guidelines provide an overview of fluid dynamics within the fluid spaces of the body, describe various types of fluids and their uses, and outline recommendations for fluid administration for resuscitation, rehydration, and maintenance purposes. The guidelines also outline approaches to fluid therapy for anesthetized patients and reiterate the recommendations of reduced fluid rates in this population of patients. Additionally, the guidelines include practical fluid therapy strategies for patients with various common disorders. The goal of these guidelines is to help veterinary professionals safely and effectively prescribe and administer fluid therapy for canine and feline patients.

Short-Term Outcomes of Patients With Hyponatremia Presenting to the Emergency Department: An Observational Study

BACKGROUND

Hyponatremia is the predominant electrolyte imbalance disorder in the emergency department. It can manifest with a diverse array of symptoms, ranging from non-specific and moderate to severe and even life-threatening. There is a scarcity of literature addressing the clinical characteristics and prognosis of patients with hyponatremia presenting to the emergency department in the western part of Rajasthan. The objective of this study was to investigate the impact of hyponatremia on the outcomes of patients presenting to the emergency department.

METHODS

In this prospective, cross-sectional, observational study, 200 patients aged more than 18 years who presented to the emergency department with serum sodium < 135 mEq/l were included. The triage of patients was determined by their primary complaints. The primary outcome was to study the clinical profile of patients with hyponatremia presenting to the emergency department. The secondary outcomes were to examine the etiology, i.e., hypovolemic, euvolemic, or hypervolemic, and the outcome of patients on the 7th day (patient admitted to the ward or intensive care unit) and the 28th day (discharged or death) with hyponatremia presenting to the emergency department. The clinical status of the patients was noted by telephonic follow-up in case they were not admitted for this period.

RESULTS

Out of 200 patients, 66 (33%) had hypovolemic, 96 (48%) had euvolemic, and 38 (19%) had hypervolemic hyponatremia. We observed that seizures (84.2%), confusion (56%), and coma (77.7%) were the most common clinical features of patients with severe hyponatremia in the emergency, which was statistically significant than mild and moderate hyponatremia (p = 0.03, 0.023, and 0.029, respectively). On the 7th day of hospitalization, out of 181 (90.5%) admissions in the ward, 116 (64.08%) had severe hyponatremia, and out of 19 (9.5%) ICU admissions, 13 (68.4%) had severe hyponatremia. Death was seen in five (2.5%) patients, one (20%) in moderate and four (80%) in severe hyponatremia cases.

CONCLUSION

Most cases of hyponatremia in this study were euvolemic. Most patients experienced severe hyponatremia, and seizures, confusion, and coma were the most prevalent symptoms. These disorders must be recognized early to properly diagnose and treat hyponatremia and prevent its morbidity and death.

Hyponatremia in the emergency department: an overview of diagnostic and therapeutic approach

INTRODUCTION

Hyponatremia, defined as a serum sodium concentration <135 mmol/l, is a frequent electrolyte disorder in patients presenting to an emergency department (ED). In this context, appropriate diagnostic and therapeutic management is rarely performed and challenging due to complex pathophysiologic mechanisms and a variety of underlying diseases.

OBJECTIVE

To implement a feasible pathway of central diagnostic and therapeutic steps in the setting of an ED.

METHODS

We conducted a narrative review of the literature, considering current practice guidelines on diagnosis and treatment of hyponatremia. Underlying pathophysiologic mechanisms and management of adverse treatment effects are outlined. We also report four cases observed in our ED.

RESULTS

Symptoms associated with hyponatremia may appear unspecific and range from mild cognitive deficits to seizures and coma. The severity of hyponatremia-induced neurological manifestation and the risk of poor outcome is mainly driven by the rapidity of serum sodium decrease. Therefore, emergency treatment of hyponatremia should be guided by symptom severity and the assumed onset of hyponatremia development, distinguishing acute (<48 hours) versus chronic hyponatremia (>48 hours).

CONCLUSIONS

Especially in moderately or severely symptomatic patients presenting to an ED, the application of a standard management approach appears to be critical to improve overall outcome. Furthermore, an adequate work-up in the ED enables further diagnostic and therapeutic evaluation during hospitalization.

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

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

Thiazide-associated hyponatremia in arterial hypertension patients: A nationwide population-based cohort study

OBJECTIVE

Thiazides are the first-line treatment for hypertension, however, they have been associated with hospitalizations for thiazide-associated hyponatremia (TAH). The aim of this study was to evaluate the risk of TAH and other drug-associated hyponatremia in a Korean population.

METHODS

The study used big data from the National Health Insurance Sharing Service of 1,943,345 adults treated for hypertension from January 2014 to December 2016. The participants were divided into two groups based on the use of thiazides. Cox proportional hazard models were used to identify independent risk factors for the occurrence of hyponatremia.

RESULTS

The study found that hyponatremia-related hospitalizations were significantly higher in the thiazide group than the control group (2.19% vs. 1.45%). The risk increased further with concurrent use of other diuretics or desmopressin, and thiazide+spironolactone+desmopressin and hospitalization risk further increased (4.0 and 6.9 times). Multivariate analysis showed that hyponatremia occurrence increased with age, diabetes mellitus, depression, and thiazide use (hazard ratio = 1.436, p < 0.001). The thiazide group had better 6-year overall survival than the control group but had more fractures and hyponatremia.

CONCLUSIONS

Thiazide use is associated with an increased risk of hyponatremia and related complications. However, the mortality rate decreased in those who received thiazides, suggesting that thiazide use itself is not harmful and may help decrease complications and improve prognosis with proper, cautious use in high-risk patients.

The feasibility of emergency department observation units in the management of mild to moderate hyponatremia

OBJECTIVE

To describe the feasibility of managing hyponatremia patients under outpatient observation status in an academic medical center, and compare outcomes based on the use of an emergency department observation unit (EDOU).

METHODS

This is a retrospective cohort study of emergency department hyponatremic patients managed in four hospitals within a large urban academic medical center over 27 months. All patients had an admit-to-observation order, ICD-10 codes for hyponatremia, and mild (130-135 mmol/L) to moderate (121-129 mmol/L) hyponatremia. Observation settings were divided into two groups: EDOU and Non-Observation Unit (NOU) inpatient beds. Severe hyponatremia (≤120 mmol/L) was excluded. Primary clinical outcomes were inpatient admit rate, length of stay (LOS), total direct cost, the rate of adverse events and 30-day recidivism.

RESULTS

188 patients were managed as an observation patient, with 64 managed in an EDOU setting (age 74.0 yr, 70.3% female) and 124 managed in a NOU setting (age 71.5 yr, 64.5% female). Patient subgroups were similar in terms of presenting complaints, comorbidities, and medication histories. Initial and final sodium levels were similar between settings: EDOU (125.1 to 132.6 mmol/L) vs NOU (123.5 to 132.0 mmol/L). However, outcomes differed by setting for observation to inpatient admit rate (EDOU 28.1% vs NOU 37.9%, adjusted effect 0.70), overall length of stay (EDOU 19.2 h vs NOU 31.9 h; adjusted effect -10.5 h and total direct cost ($1230 vs $1531; adjusted effect -$167). EDOU sodium correction rates were faster (EDOU 0.44 mmol/L/h vs 0.24 mmol/L/h; adjusted effect 0.15 mmol/L/h) and 30-day recidivism rate was similar (EDOU 13% vs NOU 15%). There were no index visit deaths or intensive care unit admissions.

CONCLUSION

Management of selected hyponatremia patients under observation status is feasible, with the EDOU setting demonstrating lower admit rates, shorter length of stay, and lower total direct costs with similar clinical outcomes.

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.