Association between hyponatremia, inflammation, and mortality in patients undergoing peritoneal dialysis: A nationwide observations

INTRODUCTION

Hyponatremia is the most common electrolyte disorder often present in peritoneal dialysis (PD) patients. The aim of this retrospective study was to investigate the effect of hyponatremia on mortality in patients undergoing PD.

METHODS

The health records of adult individuals with an inserted PD catheter identified via the centralized national e-health database were used.

RESULTS

The mean age of the 846 patients included in the study was 52.48 years (±14.6). The mean sodium level was 136.51 mEq/L. Sodium levels <137 mEq/L were associated with higher death risk independent of comorbidities. There was a 0.821 times less reduction in mortality for each mEq /L increase in serum sodium.

CONCLUSION

Our study provides evidence that monitoring and adjusting serum sodium levels is crucial in managing PD patients with hyponatremia, as low serum sodium level was found to be a significant and independent predictor of mortality.

Frequency of Hyponatremia in Adults with Acute Bacterial Meningitis

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

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

BACKGROUND

This research aims to examine the frequency, age-related distribution, and intensity of preoperative hyponatremia among elderly individuals with hip fractures. This study aims to provide valuable insights into the diagnosis of preoperative hyponatremia in this patient population.

METHODS

This research involved the analysis of clinical data obtained from 419 elderly individuals with hip fractures (referred to as the fracture group) and 166 elderly individuals undergoing routine health examinations (designated as the control group). A comprehensive comparison was conducted, examining baseline characteristics such as age, gender, and comorbidities between these two groups. We further investigated variations in the incidence rate of hyponatremia, age distribution, and the severity of hyponatremia. Additionally, a subgroup analysis compared patients with femoral neck fractures to those with intertrochanteric femur fractures, specifically examining the incidence rate and severity of hyponatremia in these distinct fracture types.

RESULTS

The incidence of cerebrovascular disease was found to be higher in the fracture group as compared to the control group in our research. Nevertheless, no significant differences in general health and other comorbidities were observed between the two groups. Notably, the fracture group exhibited a greater preoperative prevalence of hyponatremia, with its severity increasing with age. Furthermore, among elderly patients with intertrochanteric femur fractures, the incidence of preoperative hyponatremia was not only higher but also more severe when compared to those with femoral neck fractures.

CONCLUSION

Elderly individuals experiencing hip fractures exhibit a notable prevalence of preoperative hyponatremia, predominantly mild to moderate, with an escalating occurrence linked to advancing age. This phenomenon is especially conspicuous among patients with intertrochanteric fractures, warranting dedicated clinical scrutiny. The administration of sodium supplementation is advisable for the geriatric demographic as deemed necessary. Addressing hyponatremia becomes crucial, as it may play a role in the etiology of hip fractures in the elderly, and rectifying this electrolyte imbalance could potentially serve as a preventive measure against such fractures.

Effect of mild hyponatremia on in-hospital falls of elderly hospitalized patients: A retrospective, cohort study

OBJECTIVES

This study investigated the association between hyponatremia and falls in elderly hospitalized patients, focusing on mild hyponatremia as a potential risk factor.

MATERIALS AND METHODS

A retrospective analysis of 16,952 patients admitted to Kochi Medical School Hospital from 2012 to 2021 was performed. Serum sodium levels were categorized, and falls during a 30-day observation period were recorded. A Cox proportional hazards model and a machine learning model were used to estimate risk and explore interactions.

RESULTS

Mild hyponatremia (130-134 mEq/L) was identified as an independent risk factor for falls (hazard ratio: 1.42, 95 % confidence interval 1.16-1.74), especially in patients with higher activities of daily living. The fall prediction model showed an area under the curve (AUC) of 0.780 (95 % confidence interval 0.751-0.806).

CONCLUSION

A significant association between mild hyponatremia and falls in elderly hospitalized patients was found. The findings highlight the need for targeted fall prevention and further research into the underlying mechanisms. Mild hyponatremia may serve as a clinical marker for fall risk, especially in patients with independent activities of daily living.

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

BACKGROUND

Craniopharyngiomas are low-grade malignancies (WHO I) in the sellar region. Most cases of childhood-onset craniopharyngioma are adamantinomatous craniopharyngioma, and neurosurgery is the treatment of choice. Affected patients have postoperative complications, including water and electrolyte disturbances, because these malignancies develop near the hypothalamus and pituitary gland. Determining postoperative serum sodium fluctuation patterns in these patients can reduce postoperative mortality and improve prognosis.

OBJECTIVE

To measure changes in serum sodium levels in pediatric patients who underwent craniopharyngioma surgery and identify influencing factors.

METHODS

This retrospective study measured the serum sodium levels of 202 patients aged 0-18 years who underwent craniopharyngioma resection in Beijing Tiantan Hospital and Beijing Children's Hospital and identified predictors of severe hyponatremia and hypernatremia.

RESULTS

The mean age of the cohort was 8.35 ± 4.35 years. The prevalence of hypernatremia, hyponatremia, and their severe forms (serum Na+  > 150 mmol/L and serum Na+  < 130 mmol/L) within 14 days after surgery was 66.3%, 72.8%, 37.1%, and 40.6%, respectively. The mean postoperative serum sodium level showed a triphasic pattern, characterized by two peaks separated by a nadir. Sodium levels peaked on days 2 (143.6 ± 7.6 mmol/L) and 14 (143.2 ± 6.7 mmol/L) and reached their lowest on day 6 (135.5 ± 7.5 mmol/L). A total of 31 (15.3%) patients met the diagnostic threshold for hyponatremia and hypernatremia of the triphase response, whereas 116 (57.4%) patients presented this pattern, regardless of met the diagnostic criteria or not. The prevalence of severe hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach.

CONCLUSIONS

Serum sodium levels after craniopharyngioma resection in children showed a triphasic pattern in most cases. The risk of postoperative hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach.

Establishment and representativeness of the Stockholm Sodium Cohort: A laboratorial and pharmacoepidemiologic database covering 1.6 million individuals in the Stockholm County

OBJECTIVE

Hyponatremia is associated with considerable morbidity and mortality, but causal links have been difficult to establish. Here, we describe the establishment and representativeness of the Stockholm Sodium Cohort (SSC), designed to study etiologies and outcomes of hyponatremia.

STUDY DESIGN AND SETTING

All residents of Stockholm County undertaking at least one serum sodium test between 2005-2018 were included in the SSC. Individual-level test results from over 100 laboratory parameters relevant to hyponatremia were collected and linked to data on demographics, socioeconomic status, healthcare contacts, diagnoses and dispensed prescription medications using national registers.

RESULTS

A total of 1,632,249 individuals, corresponding to 64% of the population of Stockholm County, were included in the SSC. Coverage increased with advancing age, ranging from 32% in children and adolescents (≤18 years) to 97% among the oldest (≥80 years). The coverage of SSC included the vast majority of patients in Stockholm County diagnosed with diabetes mellitus (93%), myocardial infarction (98%), ischemic stroke (97%), cancer (85%), pneumonias requiring inpatient care (95%) and deaths (88%).

CONCLUSION

SSC is the first cohort specifically designed to investigate sodium levels in a large, population-based setting. It includes a wide range of administrative health data and laboratory analyses. The coverage is high, particularly among elderly and individuals with comorbidities. Consequently, the cohort has a large potential for exploration of various aspects of hyponatremia.

The risk of antidepressant-induced hyponatremia: A meta-analysis of antidepressant classes and compounds

BACKGROUND

Hyponatremia (hypoNa) is a potentially serious adverse event of antidepressant treatment. Previous research suggests the risk of drug-induced hyponatremia differs between antidepressants. This meta-analysis sought to determine the risk of antidepressant-induced hypoNa, stratified by different compounds and classes.

METHODS

A PRISMA-compliant systematic search of Web of Science and PubMed databases was performed from inception until Jan 5, 2023, for original studies reporting incidences or risks of hypoNa in adults using antidepressants. We modelled random-effects meta-analyses to compute overall event rates and odds ratios of any and clinically relevant hypoNa for each compound and class, and ran head-to-head comparisons based on hypoNa event rates. We conducted subgroup analyses for geriatric populations and sodium cut-off value. The study is registered with PROSPERO, CRD42021269801.

RESULTS

We included 39 studies (n = 8,175,111). Exposure to antidepressants was associated with significantly increased odds of hypoNa (k = 7 studies, OR = 3.160 (95%CI 1.911-5.225)). The highest event rates were found for SNRIs (7.44%), SSRIs (5.59%), and TCAs (2.66%); the lowest for mirtazapine (1.02%) and trazodone (0.89%). Compared to SSRIs, SNRIs were significantly more likely (k = 10, OR = 1.292 (1.120 - 1.491), p < 0.001) and mirtazapine significantly less likely (k = 9, OR = 0.607 (0.385 - 0.957), p = 0.032) to be associated with hypoNa.

CONCLUSION

Our meta-analysis demonstrated that, while no antidepressant can be considered completely risk-free, for hypoNa-prone patients mirtazapine should be considered the treatment of choice and SNRIs should be prescribed more cautiously than SSRIs and TCAs.

Eslicarbazepine-induced hyponatremia: A retrospective single-center real clinical practice study

Hyponatremia is a typical side effect of antiseizure drugs from the dibenzazepine family. The study investigated the prevalence of hyponatremia in patients with epilepsy who were treated with eslicarbazepine. We aimed to determine the prevalence of hyponatremia, reveal the factors leading to the discontinuation of treatment, and identify possible risk factors for the development of hyponatremia including the dose dependency. The medical records of 164 patients with epilepsy taking eslicarbazepine in our center were analyzed. The overall prevalence of hyponatremia was 30.5%. The prevalence of mild hyponatremia, seen in 14%-20% of patients, was not dose dependent. The prevalence of moderate and severe hyponatremia was significantly dose dependent. The severity of hyponatremia was significantly dose dependent. Severe hyponatremia was found in 6.1% of patients. Hyponatremia was asymptomatic in the majority of cases, and in 48% did not require any management. Hyponatremia was the reason for discontinuation in 6.2% of patients. The major risk factor for developing hyponatremia was older age. The study shows that eslicarbazepine-induced hyponatremia is usually mild and asymptomatic. It usually does not require any management and seldom leads to treatment discontinuation. Hyponatremia is dose dependent. Another major risk for developing hyponatremia (besides dose) is older age.

Incidence of postoperative hyponatremia after endoscopic endonasal pituitary transposition for skull base pathologies

PURPOSE

Pituitary transposition is a novel surgical approach to access the retroinfundibular space and interpeduncular cistern. Few studies have evaluated post-surgical outcomes, including incidence of hyponatremia, following pituitary transposition.

METHODS

This is a retrospective study including 72 patients who underwent endoscopic endonasal surgery involving pituitary transposition for non-pituitary derived tumors over a decade at the University of Pittsburgh Medical Center. Anterior pituitary deficiencies and replacement therapy, tumor pathology and pre-operative serum sodium (Na) were recorded. Na was assessed at postoperative day 1, 3, 5, 7, and 10. Anatomical/surgical parameters included sellar height, sellar access angle to approach the tumor, and cranial extension of the tumor above the sellar floor (B) compared to the height of the gland (A) (B/A). T-test (normally distributed variables) and Wilcoxon rank-sum test (not-normally distributed) were applied for mean comparison. Logistic regression analyzed correlations between anatomical/surgical parameters and postoperative hyponatremia.

RESULTS

55.6% of patients developed post-operative transient hyponatremia. Two patients (5%) developed severe hyponatremia (sodium level < 120 mmol/L). Eleven (15.3%) patients required desmopressin replacement immediately post-operatively, and 2 other patients needed desmopressin after discharge and after sodium nadir developed. Hyponatremia was inversely associated with sellar access angle (p = 0.02) and the tumor cranial extension above the sellar floor showing a trend towards significance (p = 0.09).

CONCLUSION

More than half of patients who had pituitary transposition developed transient hyponatremia. Hyponatremia was more common in those with narrower sellar access angle and smaller cranial extension of the tumor above the sellar floor. Anatomical/surgical parameters may allow risk-stratification for post-operative hyponatremia following pituitary transposition.

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

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

Hyponatremia after COVID-19 is frequent in the first year and increases re-admissions

Hyponatremia on admission has been related to worse outcomes in patients with COVID-19 infection. However, little is known about the frequency and the associated risk factors of hyponatremia after COVID-19 discharge. We performed an observational 24-month follow-up study of patients admitted during the first COVID-19 wave. Kaplan-Meier curves and Cox proportional hazard models were used to assess the main variables in predicting hyponatremia on follow-up (HYPO-FU). A total of 161 out of 683 (24.4%) developed HYPO-FU. The group with HYPO-FU comprised of more men [(62.3%) vs. (49.2%); p < 0.01], older [65.6 ± 18.2 vs. 60.3 ± 17.0; p < 0.01] and more frequently re-admitted [(16.2%) vs. (3.8%); p < 0.01). The rate of HYPO-FU was higher in the first year 23.6 per 100 individuals per year. After Cox regression analysis, the independent risk factors of HYPO-FU were diabetes [OR 2.12, IC 95% (1.48-3.04)], hypertension [OR 2.18, IC 95% (1.53-3.12)], heart failure [OR 3.34, IC 95% (1.72-6.48)] and invasive ventilation support requirement [OR: 2.38, IC 95% (1.63-3.50)]. To conclude, HYPO-FU was frequent in the first year after COVID-19 infection, and the risk was higher in older men with comorbidities, increasing rehospitalisation. Further studies aimed at evaluating the beneficial effects of correcting hyponatremia in these patients are warranted.

Cumulative Incidence of Thiazide-Induced Hyponatremia : A Population-Based Cohort Study

BACKGROUND

According to drug labels, the frequency of thiazide-induced hyponatremia is unknown or uncommon to very rare (that is, <1 in 10 000 to <1 in 100), but the exact burden remains unclear.

OBJECTIVE

To estimate the increase in the cumulative incidence of hyponatremia using thiazide diuretics compared with nonthiazide antihypertensive drugs in routine clinical practice.

DESIGN

Population and register-based cohort study using target trial emulation.

SETTING

Denmark, 1 January 2014 to 31 October 2018.

PARTICIPANTS

Two target trials were emulated among persons aged 40 years or older who had no recent prescription for any antihypertensive drug, had no previous hyponatremia, and were eligible for the studied antihypertensive treatments. The first target trial emulation compared new use of bendroflumethiazide (BFZ) versus a calcium-channel blocker (CCB). The second target trial emulation compared new use of hydrochlorothiazide plus a renin-angiotensin system inhibitor (HCTZ-RASi; that is, combination pill) versus a RASi alone.

MEASUREMENTS

Two-year cumulative incidences of sodium levels less than 130 mmol/L using stabilized inverse probability of treatment-weighted survival curves.

RESULTS

The study compared 37 786 new users of BFZ with 44 963 of a CCB and 11 943 new users of HCTZ-RASi with 85 784 of a RASi. The 2-year cumulative incidences of hyponatremia were 3.83% for BFZ and 3.51% for HCTZ-RASi. The risk differences were 1.35% (95% CI, 1.04% to 1.66%) between BFZ and CCB and 1.38% (CI, 1.01% to 1.75%) between HCTZ-RASi and RASi; risk differences were higher with older age and higher comorbidity burden. The respective hazard ratios were 3.56 (CI, 2.76 to 4.60) and 4.25 (CI, 3.23 to 5.59) during the first 30 days since treatment initiation and 1.26 (CI, 1.09 to 1.46) and 1.29 (CI, 1.05 to 1.58) after 1 year.

LIMITATION

The study assumed that filled prescriptions equaled drug use, and residual confounding is likely.

CONCLUSION

Treatment initiation with thiazide diuretics suggests a more substantial excess risk for hyponatremia, particularly during the first months of treatment, than indicated by drug labeling.

PRIMARY FUNDING SOURCE

Independent Research Fund Denmark.

Thiazide-associated hyponatremia increases the risk of major adverse cardiovascular events among elderly Taiwanese patients

BACKGROUND

Thiazide-associated hyponatremia (TAH) has been supposed to increase the risk of major adverse cardiovascular events (MACE) in the elderly. Therefore, this study aimed to evaluate the association of TAH with the risk of MACE in elderly Taiwanese patients.

METHODS

Data from the longitudinal generation tracking database (LGTD 2010) of the Health and Welfare Data Science Center (HWDC) were retrospectively assessed. The TAH study group was defined as using > 30 cumulative daily defined doses (CDDDs) thiazide diuretics within one year before diagnosis of hyponatremia. The control group (1:3 propensity score matching) had no diagnosis of hyponatremia but had used > 30 CDDDs thiazide diuretics within one year. Data on MACE were extracted using International Classification of Diseases codes. Outcomes were assessed using a multivariable Cox proportional hazard model and Kaplan-Meier analysis.

RESULTS

A total of 1155 and 3465 individuals were enrolled in the TAH and the control groups, respectively. The rates of MACE (11.1% vs. 7.3%) and death (22.8% vs.12.2%) were significantly higher in the TAH group than the control group. In the TAH group, the adjusted HRs were 1.29 (CI 1.01 ‒ 1.65) for MACE, 1.39 (CI 1.19 ‒ 1.63) for all-cause death, and 1.61 (CI 0.90 ‒ 2.92) for stroke.

CONCLUSION

TAH in patients above 65-years-old is associated with a 29% higher risk of MACE, 39% higher risk of all-cause death, and 61% higher risk of stroke. This work suggests that thiazides prescription in elderly patients should be more careful. However, further research is required to confirm our findings.

Prevalence of hyponatremia and associated factors in patients with chronic kidney disease: the Fukuoka Kidney Disease Registry (FKR) study

BACKGROUND

Hyponatremia is a common and important electrolyte disorder. However, the prevalence and factors associated with hyponatremia in patients with chronic kidney disease (CKD) are unknown.

METHODS

We studied the factors associated with hyponatremia (< 135 mEq/L) in CKD patients registered in the Fukuoka Kidney Disease Registry (FKR) study using a logistic regression model variable selected using the variable reduction method.

RESULTS

We analyzed the baseline characteristics of 4367 participants with CKD (age, 64 ± 16 years; male, 56.1%). Hyponatremia was detected in 2.0% of the patients at baseline, and multivariate logistic analysis showed that the independent factors for hyponatremia were body mass index (odds ratio [OR] 0.91; 95% confidence interval [CI] 0.85-0.97), prescription of benzodiazepine (OR 2.31; 95% CI 1.39-3.86), blood hemoglobin level (OR 0.76; 95% CI 0.65-0.88), and serum C-reactive protein level (OR 1.27; 95% CI 1.04-1.54).

CONCLUSION

The cross-sectional analysis using baseline data from the FKR study revealed independent factors associated with hyponatremia in patients with decreased kidney function. Longitudinal analyses of the FKR cohort are needed to evaluate the effects of these factors on the prognosis of hyponatremia in patients with CKD.

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.

Serum sodium improvement: change in Comprehensive Geriatric Assessment parameters in geriatric patients with hyponatremia

BACKGROUND

Hyponatremia presents with symptoms considered age-associated in the elderly. We assess the change in Comprehensive Geriatric Assessment (CGA) parameters after hyponatremia improvement in hospitalized geriatric patients.

METHODS

We took 100 hyponatremic and same number of eunatremic geriatric patients (> 60 years) who were comorbidity, presenting-complaints, and age-matched. Four CGA parameters were utilized, the new Hindi Mental State Examination (HMSE), Barthel's index of activities of daily living (ADL), Timed up and go Test (TUG), and handgrip strength by hand dynamometer (HG). We analyzed these at admission and discharge, and their relationship with change in sodium levels.

RESULTS

Average age was 68.1 ± 5.8 years, with males constituting 75%. The CGA parameters demonstrated worse values amongst the hyponatremia than the normonatremia group. Severe hyponatremia group showed worse CGA scores in comparison with moderate and mild. With improvement in sodium level, the improvements in ADL, TUG, and HMSE scores were greater in the hyponatremia group (8.8 ± 10.1, 2.2 ± 2.5, and 1.7 ± 2.3 respectively) in comparison to the normonatremia reference group (4.7 ± 9.0, 1 ± 2.0, and 0.7 ± 1.3 respectively, P < 0.05).

CONCLUSION

Our study is the first utilizing HMSE to assess change in cognitive ability with improvement in serum sodium levels in the Indian elderly. Hyponatremic patients show worse baseline CGA parameters, and hyponatremia severity correlates with worse motor and cognitive function. Improvement in the serum sodium level improves the CGA parameters. Correction of hyponatremia in the geriatric age group significantly impacts life quality.

Higher versus lower sodium intake for preterm infants

BACKGROUND

Infants born preterm are at increased risk of early hypernatraemia (above-normal blood sodium levels) and late hyponatraemia (below-normal blood sodium levels). There are concerns that imbalances of sodium intake may impact neonatal morbidities, growth and developmental outcomes.

OBJECTIVES

To determine the effects of higher versus lower sodium supplementation in preterm infants.

SEARCH METHODS

We searched CENTRAL in February 2023; and MEDLINE, Embase and trials registries in March and April 2022. We checked reference lists of included studies and systematic reviews where subject matter related to the intervention or population examined in this review. We compared early (< 7 days following birth), late (≥ 7 days following birth), and early and late sodium supplementation, separately.

SELECTION CRITERIA

We included randomised, quasi-randomised or cluster-randomised controlled trials that compared nutritional supplementation that included higher versus lower sodium supplementation in parenteral or enteral intake, or both. Eligible participants were preterm infants born before 37 weeks' gestational age or with a birth weight less than 2500 grams, or both. We excluded studies that had prespecified differential water intakes between groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and risk of bias, and extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included nine studies in total. However, we were unable to extract data from one study (20 infants); some studies contributed to more than one comparison. Eight studies (241 infants) were available for quantitative meta-analysis. Four studies (103 infants) compared early higher versus lower sodium intake, and four studies (138 infants) compared late higher versus lower sodium intake. Two studies (103 infants) compared intermediate sodium supplementation (≥ 3 mmol/kg/day to < 5 mmol/kg/day) versus no supplementation, and two studies (52 infants) compared higher sodium supplementation (≥ 5 mmol/kg/day) versus no supplementation. We assessed only two studies (63 infants) as low risk of bias. Early (less than seven days following birth) higher versus lower sodium intake Early higher versus lower sodium intake may not affect mortality (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.38 to 2.72; I2 = 0%; 3 studies, 83 infants; low-certainty evidence). Neurodevelopmental follow-up was not reported. Early higher versus lower sodium intake may lead to a similar incidence of hyponatraemia < 130 mmol/L (RR 0.68, 95% CI 0.40 to 1.13; I2 = 0%; 3 studies, 83 infants; low-certainty evidence) but an increased incidence of hypernatraemia ≥ 150 mmol/L (RR 1.62, 95% CI 1.00 to 2.65; I2 = 0%; 4 studies, 103 infants; risk difference (RD) 0.17, 95% CI 0.01 to 0.34; number needed to treat for an additional harmful outcome 6, 95% CI 3 to 100; low-certainty evidence). Postnatal growth failure was not reported. The evidence is uncertain for an effect on necrotising enterocolitis (RR 4.60, 95% CI 0.23 to 90.84; 1 study, 46 infants; very low-certainty evidence). Chronic lung disease at 36 weeks was not reported. Late (seven days or more following birth) higher versus lower sodium intake Late higher versus lower sodium intake may not affect mortality (RR 0.13, 95% CI 0.01 to 2.20; 1 study, 49 infants; very low-certainty evidence). Neurodevelopmental follow-up was not reported. Late higher versus lower sodium intake may reduce the incidence of hyponatraemia < 130 mmol/L (RR 0.13, 95% CI 0.03 to 0.50; I2 = 0%; 2 studies, 69 infants; RD -0.42, 95% CI -0.59 to -0.24; number needed to treat for an additional beneficial outcome 2, 95% CI 2 to 4; low-certainty evidence). The evidence is uncertain for an effect on hypernatraemia ≥ 150 mmol/L (RR 7.88, 95% CI 0.43 to 144.81; I2 = 0%; 2 studies, 69 infants; very low-certainty evidence). A single small study reported that later higher versus lower sodium intake may reduce the incidence of postnatal growth failure (RR 0.25, 95% CI 0.09 to 0.69; 1 study; 29 infants; low-certainty evidence). The evidence is uncertain for an effect on necrotising enterocolitis (RR 0.07, 95% CI 0.00 to 1.25; 1 study, 49 infants; very low-certainty evidence) and chronic lung disease (RR 2.03, 95% CI 0.80 to 5.20; 1 study, 49 infants; very low-certainty evidence). Early and late (day 1 to 28 after birth) higher versus lower sodium intake for preterm infants Early and late higher versus lower sodium intake may not have an effect on hypernatraemia ≥ 150 mmol/L (RR 2.50, 95% CI 0.63 to 10.00; 1 study, 20 infants; very low-certainty evidence). No other outcomes were reported.

AUTHORS' CONCLUSIONS

Early (< 7 days following birth) higher sodium supplementation may result in an increased incidence of hypernatraemia and may result in a similar incidence of hyponatraemia compared to lower supplementation. We are uncertain if there are any effects on mortality or neonatal morbidity. Growth and longer-term development outcomes were largely unreported in trials of early sodium supplementation. Late (≥ 7 days following birth) higher sodium supplementation may reduce the incidence of hyponatraemia. We are uncertain if late higher intake affects the incidence of hypernatraemia compared to lower supplementation. Late higher sodium intake may reduce postnatal growth failure. We are uncertain if late higher sodium intake affects mortality, other neonatal morbidities or longer-term development. We are uncertain if early and late higher versus lower sodium supplementation affects outcomes.

Incidence of Hyponatremia Among Critically Ill Patients With and Without COVID-19 Infection at a Community Teaching Hospital

Background: Various studies have demonstrated the incidence of hyponatremia in patients with Coronavirus Disease 2019 (COVID-19); however, to our knowledge, no study has assessed the difference in the incidence of hyponatremia in patients with and without COVID-19. Purpose: To compare the incidence of hyponatremia in patients requiring intensive care unit (ICU) admission with and without COVID-19 infection. Methods: This was a single-center, retrospective cohort study of patients with a diagnosis of pneumonia from February 2019 to January 2020, or a diagnosis of COVID-19 from June 2020 to May 2021. Included patients were matched on age and sex. The primary outcome was the incidence of hyponatremia within 72 h of admission. Secondary endpoints collected included severity of hyponatremia, symptomatic hyponatremia, and lowest serum sodium. Results: There were 99 and 104 patients included in pneumonia and COVID-19 arms, respectively. Twenty-nine patients in the pneumonia group and 56 patients in the COVID-19 group had a sodium level <134 mEq/L (29% vs 56%, RR 1.84, P < .01). The mean lowest serum sodium within 72 h of admission was 136.9 mEq/L in the pneumonia group and 134.5 mEq/L in the COVID-19 group (P < .01). Other notable findings included days of mechanical ventilation (3 days vs 8 days, respectively; P < .01), downgrade from the ICU (74.8% vs 59.6%, P = .02), ICU length of stay (4 days vs 10 days, P < .01), hospital length of stay (6 days vs 14 days, P < .01), and mortality (16.2% vs 39.4%, P < .01). Conclusion: Among critically ill patients with COVID-19, the risk of hyponatremia was significantly greater than the risk in critically ill patients with pneumonia.

An enigma of hypothyroidism and hyponatremia coexistence: a nationwide population-based retrospective study

INTRODUCTION

Hypothyroidism is a rare and possible cause of hyponatremia. However, the clinical epidemiology and risk of mortality (ROM) when they coexist still remain elusive.

OBJECTIVES

We assessed the epidemiology and ROM among index patients with coexisting hypothyroidism and hyponatremia via a national population database.

PATIENTS AND METHODS

This retrospective cohort study utilized Taiwan's National Health Insurance program database. Distributions of definite sociodemographic factors were analyzed. The annual incidence among the overall group and sex-subgroups was investigated. In addition, potential factors influencing the ROM were also evaluated.

RESULTS

Of 4,549,226 patients from 1998 to 2015, a total of 3,140 index patients with concurrent hypothyroidism and hyponatremia were analyzed. The incidence rate increased tenfold from 1998 to 2015; average annual incidence rate was 174. Among the total participants, 57.1% were women; mean age was 72.6 ± 14.7 years and 88.8% were aged > 55 years. Although average length of stay (LOS) was 13.1 ± 15.4 days, the mortality group had significantly longer LOS than that in the survival group (12.9 days vs 22.2 days). Old age, catastrophic illness, cardiac dysrhythmia, and low hospital hierarchy were independent predictors of hospital mortality. The optimal LOS cutoff value for ROM prediction was 16 days. Index patients with LOS > 16 days increased ROM by 2.3-fold.

CONCLUSIONS

Coexistent hypothyroidism and hyponatremia is rare, although the incidence increased gradually. Factors influencing the ROM, such as old age, underlying catastrophic status, cardiac dysrhythmia, hospital hierarchy, and LOS should be considered in clinical care.

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.

Hyponatraemia and changes in natraemia during hospitalization for acute heart failure and associations with in-hospital and long-term outcomes - from the ESC-HFA EORP Heart Failure Long-Term Registry

AIMS

To comprehensively assess hyponatraemia in acute heart failure (AHF) regarding prevalence, associations, hospital course, and post-discharge outcomes.

METHODS AND RESULTS

Of 8298 patients in the European Society of Cardiology Heart Failure Long-Term Registry hospitalized for AHF with any ejection fraction, 20% presented with hyponatraemia (serum sodium <135 mmol/L). Independent predictors included lower systolic blood pressure, estimated glomerular filtration rate (eGFR) and haemoglobin, along with diabetes, hepatic disease, use of thiazide diuretics, mineralocorticoid receptor antagonists, digoxin, higher doses of loop diuretics, and non-use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and beta-blockers. In-hospital death occurred in 3.3%. The prevalence of hyponatraemia and in-hospital mortality with different combinations were: 9% hyponatraemia both at admission and discharge (hyponatraemia Yes/Yes, in-hospital mortality 6.9%), 11% Yes/No (in-hospital mortality 4.9%), 8% No/Yes (in-hospital mortality 4.7%), and 72% No/No (in-hospital mortality 2.4%). Correction of hyponatraemia was associated with improvement in eGFR. In-hospital development of hyponatraemia was associated with greater diuretic use and worsening eGFR but also more effective decongestion. Among hospital survivors, 12-month mortality was 19% and adjusted hazard ratios (95% confidence intervals) were for hyponatraemia Yes/Yes 1.60 (1.35-1.89), Yes/No 1.35 (1.14-1.59), and No/Yes 1.18 (0.96-1.45). For death or heart failure hospitalization they were 1.38 (1.21-1.58), 1.17 (1.02-1.33), and 1.09 (0.93-1.27), respectively.

CONCLUSION

Among patients with AHF, 20% had hyponatraemia at admission, which was associated with more advanced heart failure and normalized in half of patients during hospitalization. Admission hyponatraemia (possibly dilutional), especially if it did not resolve, was associated with worse in-hospital and post-discharge outcomes. Hyponatraemia developing during hospitalization (possibly depletional) was associated with lower risk.

Risk of Hyponatremia after Tramadol/Acetaminophen Single-Pill Combination Therapy: A Real-World Study Based on the OMOP-CDM Database

BACKGROUND AND OBJECTIVE

Tramadol has been reported to cause hyponatremia but the evidence is conflicting. The risk of hyponatremia resulting from combination oral tramadol/acetaminophen (TA) therapy is thus unknown. This study examined whether, compared with acetaminophen (AA), TA use is associated with an increased risk of hyponatremia.

METHODS

Hospital data compatible with the Observational Medical Outcomes Partnership-Common Data Model (OMOP-CDM; version 5.3) for 30,999 patients taking TA or AA from 2011 through 2020 were analyzed. New-onset hyponatremia was defined as a serum sodium level < 135 mEq/L within 10 days after drug initiation. The incidence rate ratio was calculated based on crude and 1:1 propensity-score-matched models. Subgroup analyses compared patients taking TA extended-release (TA-ER) and TA immediate-release (TA-IR) formulations.

RESULTS

Among the 30,999 patients, 12,122 (39.1%) were aged > 65 years and 16,654 (53.7%) were male. Hyponatremia within 10 days developed in 1613 (8.4%) of the 19,149 patients in the TA group; the incidence rate was higher than in the AA group (4.2%; 493 out of 11,850 cases). In the propensity-score-matched model, the incidence rate of hyponatremia in the TA group was 6.8 per 1000 person-days (PD), which was 1.57-fold (1.31, 1.89) higher than that in the AA group (4.3 per 1000 PD). In both the crude and propensity-score-matched models, the incidence rate of hyponatremia was significantly higher in the TA-ER than TA-IR subgroup.

CONCLUSION

In this real-world study, hyponatremia was more frequently observed in the TA than AA group, and in the TA-ER than TA-IR subgroup. Therefore, it is imperative to prescribe tramadol cautiously and closely monitor electrolyte levels.

Plasma sodium concentration in older patients as an indicator of severity in emergencies: Results from the Emergency Department and Elder Needs-16 study

OBJECTIVES

To study baseline factors associated with hypo- and hypernatremia in older patients attended in emergency departments (EDs) and explore the association between these dysnatremias and indicators of severity in an emergency.

MATERIAL AND METHODS

We included patients attended in 52 Spanish hospital EDs aged 65 years or older during a designated week. All included patients had to have a plasma sodium concentration on record. Patients were distributed in 3 groups according to sodium levels: normal, 135-145 mmol/L; hyponatremia, 135 mmol/L; or hypernatremia > 145 mmol/L. We analyzed associations between sodium concentration and 24 variables (sociodemographic information, measures of comorbidity and baseline functional status, and ongoing treatment for hypo- or hypernatremia). Indicators of the severity in emergencies were need for hospitalization, in-hospital mortality, prolonged ED stay (> 12 hours) in discharged patients, and prolonged hospital stay (> 7 days) in admitted patients. We used restricted cubic spline curves to analyze the associations between sodium concentration and severity indicators, using 140 mmol/L as the reference.

RESULTS

A total of 13 368 patients were included. Hyponatremia was diagnosed in 13.5% and hypernatremia in 2.9%. Hyponatremia was associated with age ($ 80 years), hypertension, diabetes mellitus, an active neoplasm, chronic liver disease, dementia, chemotherapy, and needing help to walk. Hypernatremia was associated with needing help to walk and dementia. The percentages of cases with severity indicators were as follows: hospital admission, 40.8%; in-hospital mortality, 4.3%; prolonged ED stay, 15.9%; and prolonged hospital stay, 49.8%. Odds ratios revealed associations between lower sodium concentration cut points in patients with hyponatremia and increasing need for hospitalization (130 mmol/L, 2.24 [IC 95%, 2.00-2.52]; 120 mmol/L, 4.13 [3.08-5.56]; and 110 mmol/L, 7.61 [4.53-12.8]); risk for in-hospital death (130 mmol/L, 3.07 [2.40-3.92]; 120 mmol/L, 6.34 [4.22- 9.53]; and 110 mmol/L, 13.1 [6.53-26.3]); and risk for prolonged ED stay (130 mmol/L, 1.59 [1.30-1.95]; 120 mmol/L, 2.77 [1.69-4.56]; and 110 mmol/L, 4.83 [2.03-11.5]). Higher sodium levels in patients with hypernatremia were associated with increasing need for hospitalization (150 mmol/L, 1.94 [1.61-2.34]; 160 mmol/L, 4.45 [2.88-6.87]; 170 mmol/L, 10.2 [5.1-20.3]; and 180 mmol/L, 23.3 [9.03-60.3]); risk for in-hospital death (150 mmol/L, 2.77 [2.16-3.55]; 160 mmol/L, 6.33 [4.11-9.75]; 170 mmol/L, 14.5 [7.45-28.1]; and 180 mmol/L, 33.1 [13.3-82.3]); and risk for prolonged ED stay (150 mmol/L, 2.03 [1.48-2.79]; 160 mmol/L, 4.23 [2.03-8.84]; 170 mmol/L, 8.83 [2.74-28.4]; and 180 mmol/L, 18.4 [3.69-91.7]). We found no association between either type of dysnatremia and prolonged hospital stay.

CONCLUSION

Measurement of sodium plasma concentration in older patients in the ED can identify hypo- and hypernatremia, which are associated with higher risk for hospitalization, death, and prolonged ED stays regardless of the condition that gave rise to the dysnatremia.

Fluid Restriction Reduces Delayed Hyponatremia and Hospital Readmissions After Transsphenoidal Surgery

CONTEXT

Postoperative hyponatremia leads to prolonged hospital length of stay and readmission within 30 days.

OBJECTIVE

To assess 3 strategies for reducing rates of postoperative hyponatremia and analyze risk factors for hyponatremia.

DESIGN

Two retrospective analyses and 1 prospective study.

SETTING

Tertiary referral hospital.

PATIENTS

Patients undergoing transsphenoidal surgery for pituitary adenomas and other sellar and parasellar pathologies.

INTERVENTION(S)

Phase 1: no intervention. Phase 2: postoperative day (POD) 7 sodium testing and patient education. Phase 3: fluid restriction to 1 L/day on discharge in addition to phase 2 interventions.

MAIN OUTCOME MEASURES

Rates of early and delayed hyponatremia and readmissions. Secondary outcomes were risk factors for hyponatremia and readmission costs.

RESULTS

In phase 1, 296 patients underwent transsphenoidal surgery. Twenty percent developed early and 28% delayed hyponatremia. Thirty-eight percent underwent POD 7 sodium testing. Readmission rates were 15% overall and 4.3% for hyponatremia. In phase 2 (n = 316), 22% developed early and 25% delayed hyponatremia. Eighty-nine percent complied with POD 7 sodium testing. Readmissions were unchanged although severity of hyponatremia was reduced by 60%. In phase 3 (n = 110), delayed hyponatremia was reduced 2-fold [12.7%, relative risk (RR) = 0.52] and readmissions 3-fold [4.6%, RR = 0.30 (0.12-0.73)]; readmissions for hyponatremia were markedly reduced. Hyponatremia readmission increased costs by 30%.

CONCLUSIONS

Restricting fluid to 1 L/day on discharge decreases rates of delayed hyponatremia and readmissions by 50%. Standardized patient education and POD 7 sodium testing decreases severity of hyponatremia but does not impact readmission rates. These protocols should be considered standard practice for patients undergoing transsphenoidal surgery.

Postoperative free water administration is associated with dysnatremia after congenital heart disease surgery in infants

Dysnatremia after congenital heart disease (CHD) surgery is common. European guidelines on intraoperative fluid therapy in children recommend isotonic solutions to avoid hyponatremia, but prolonged cardiopulmonary bypass and administration of high sodium-containing solutions (i.e., blood products and sodium bicarbonate) are associated with postoperative hypernatremia. The aim of the study was to describe fluid composition prior to and during the development of postoperative dysnatremia. A retrospective observational, single-center study including infants undergoing CHD surgery. Demographics and clinical characteristics were registered. Highest and lowest plasma sodium values were recorded and associations with perioperative fluid administration, blood products, crystalloids, and colloids were explored in relation to three perioperative periods. Postoperative dysnatremia occurred in nearly 50% of infants within 48 h after surgery. Hypernatremia was mainly associated with administration of blood products (median [IQR]: 50.5 [28.4-95.5] vs. 34.5 [18.5-61.1] mL/kg; p = 0.001), and lower free water load (1.6 [1.1-2.2] mL/kg/h; p = 0.01). Hyponatremia was associated with a higher free water load (2.3 [1.7-3.3] vs. 1.8 [1.4-2.5] mL/kg/h; p = 0.001) and positive fluid balance. On postoperative day 1, hyponatremia was associated with higher volumes of free water (2.0 [1.5-2.8] vs. 1.3 [1.1-1.8] mL/kg/h; p < 0.001) and human albumin, despite a larger diuresis and more negative daily fluid balance. Postoperative hyponatremia occurred in 30% of infants despite restrictive volumes of hypotonic maintenance fluid, whereas hypernatremia was mainly associated with blood product transfusion. Individualized fluid therapy, with continuous reassessment to reduce the occurrence of postoperative dysnatremia is mandatory in pediatric cardiac surgery. Prospective studies to evaluate fluid therapy in pediatric cardiac surgery patients are warranted.

Osmotic demyelination syndrome: novel risk factors and proposed pathophysiology

BACKGROUND

Osmotic demyelination syndrome (ODS) is non-inflammatory demyelination in response to an osmotic challenge. It can be pontine or extrapontine in presentation.

AIMS

To retrospectively review cases involving ODS and define the spectrum of causes, risk factors, clinical and radiological presentations, and functional outcomes.

RESULTS

The study utilised data from 15 patients with a mean age of 53.6 years. Malnutrition (9; 60%) and chronic alcoholism (10; 66.7%) were the most common associated disorders. Two (13.3%) patients had severe hyponatraemia (<120 mmol/L). The average highest single-day change was 5.1 mmol/L. Radiologically, 14 (93.3%) had pontine and 6 (40%) had extra-pontine lesions. Hypokalaemia (14; 93.3%) and hypophosphataemia (9; 60%) were commonly associated. Common clinical manifestations include altered consciousness/encephalopathy (9; 60%), dysphagia (4; 26.7%) and limb weakness (4; 26.7%). At 3 months, two (14.3%) had died and six (40%) were functionally independent (modified Rankin scale 0-2).

CONCLUSION

We found that ODS occurred despite appropriate correction rates of hyponatraemia. Factors such as malnutrition, chronic alcoholism, hypokalaemia and hypophosphataemia are thought to play a role in its pathogenesis. Approximately half of the patients survived and became functionally independent.

Efficacy and safety of tolvaptan in cirrhotic patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Tolvaptan has been approved for the management of cirrhosis-related complications according to the Japanese and Chinese practice guidelines, but not the European or American practice guidelines in view of FDA warning about its hepatotoxicity. This study aimed to systematically evaluate its efficacy and safety in cirrhosis.

METHODS

The PubMed, EMBASE, and Cochrane library databases were searched to identify randomized controlled trials (RCTs) evaluating the efficacy and/or safety of tolvaptan in cirrhosis. Risk ratios (RRs) and weight mean differences (WMDs) were calculated. The incidence of common adverse events (AEs) was pooled.

RESULTS

Eight RCTs were included. Tolvaptan was significantly associated with higher rates of improvement of ascites (RR = 1.49, P < 0.001) and hyponatremia (RR = 1.80, P = 0.005) and incidence of any AEs (RR = 1.18, P = 0.003), but not serious AEs (RR = 0.86, P = 0.410). Tolvaptan was significantly associated with reductions in body weight (WMD = -1.30 kg, P < 0.001) and abdominal circumference (WMD = -1.71 cm, P < 0.001), and increases in daily urine volume (WMD = 1299.84 mL, P < 0.001) and serum sodium concentration (WMD = 2.57 mmol/L, P < 0.001). The pooled incidences of dry mouth, thirst, constipation, and pollakiuria were 16%, 24%, 6%, and 17%, respectively.

CONCLUSION

Short-term use of tolvaptan may be considered in cirrhotic patients with ascites who have inadequate response to conventional diuretics and those with hyponatremia.

Children with mild hyponatremia at the emergency department are at higher risk of hospitalization

BACKGROUND

Mild hyponatremia is frequently encountered in the pediatric emergency department (PED). Although usually of little clinical concern, its prognostic meaning as a possible marker of more severe disease has not yet been well established.

METHODS

We retrospectively analyzed data from children and adolescents who performed a blood sample with plasmatic sodium measurement on admission to the PED of IRCCS "Burlo Garofolo" Pediatric Hospital in Trieste, Italy, in 2019. We compared the rate, length of admissions and laboratory characteristics of patients with hyponatremia to those with normal sodium.

RESULTS

Among 807 subjects, hyponatremia (sodium < 135 mEq/L) was present in 17.6%, being mild (between 130 and 134 mEq/L) in 16.5%. Hyponatremic patients were younger, more frequently males, with an infection diagnosis, mainly of the respiratory tract and viral aetiology. They presented higher C-reactive protein (CRP) levels and erythrocyte sedimentation rates (ESR). Compared to normonatremic individuals, hyponatremic patients presented a higher risk of underlying infection (aOR 2.02; 95%CI 1.33-3.08), hospital admission (aOR 1.72; 95%CI 1.06-2.48), and a hospital stay of > 5 days (aOR 1.99; 95%CI 1.03-3.85). When considering only subjects with mild hyponatremia, we found similar results.

CONCLUSION

Hyponatremia and mild hyponatremia in the PED are associated with an increased admission rate and extended hospital stays. Mild hyponatremia should be considered a warning sign for a possibly more serious condition.

Hyponatremia after craniotomy in children: a single-institution review

PURPOSE

Hyponatremia after craniotomy can be associated with increased morbidity. However, the incidence of and factors associated with post-craniotomy hyponatremia in children are not known.

METHODS

We performed a retrospective cohort study of patients aged 0-21 years who underwent craniotomy in 2017-2019 at a single center to determine the incidence of and to identify risk factors for hyponatremia after craniotomy. Indications for craniotomy included tumors (excluding craniopharyngioma), epilepsy, intracranial infection, trauma, craniofacial, suboccipital decompression for the treatment of Chiari malformation, and cerebrovascular disease. Hyponatremia was defined as a serum sodium level ≤ 135 mEq/L any time during the postoperative hospital stay. Statistical significance was defined a priori at p < 0.05.

RESULTS

Postoperative hyponatremia occurred in 61 (25%) of 240 children. On univariate analysis, hyponatremia was associated with younger age (8.5 vs 6.3 years, p = 0.01), use of preoperative anti-epileptic drugs (p = 0.02), need for blood transfusion (p = 0.02), government/private insurance (p = 0.04), and pre-existing hydrocephalus, defined as the requirement for permanent cerebrospinal fluid (CSF) diversion (p = 0.04). On multivariate analysis, only hydrocephalus (OR 2.95, 95% CI 1.03-8.40) remained statistically significant. Hyponatremia most occurred on the first postoperative day, with normonatremia achieved in a median of 14 (IQR 9.8-24.3) h. Hyponatremia was significantly associated with longer length of stay (median 8 vs 3 days, p < 0.01).

CONCLUSION

Hyponatremia was present in 25% of children after craniotomy. Preoperative hydrocephalus as an independent risk factor for hyponatremia after craniotomy.

Community-based serum chloride abnormalities predict mortality risk

INTRODUCTION

This population-based study aimed to investigate the prognostic value of ambulatory serum chloride abnormalities, often ignored by physicians.

METHODS

The study population included all non-hospitalized adult patients, insured by "Clalit" Health Services in Israel's southern district, who underwent at least 3 serum chloride tests in community-based clinics during 2005-2016. For each patient, each period with low (≤97 mmol/l), high (≥107 mmol/l) or normal chloride levels were recorded. A Cox proportional hazards model was used to estimate the mortality risk of hypochloremia and hyperchloremia periods.

RESULTS

664,253 serum chloride tests from 105,655 subjects were analyzed. During a median follow up of 10.8 years, 11,694 patients died. Hypochloremia (≤ 97 mmol/l) was independently associated with elevated all-cause mortality risk after adjusting for age, co-morbidities, hyponatremia and eGFR (HR 2.41, 95%CI 2.16-2.69, p<0.001). Crude hyperchloremia (≥107 mmol/L) was not associated with all-cause mortality (HR 1.03, 95%CI 0.98-1.09 p = 0.231); as opposed to hyperchloremia ≥108 mmol/l (HR 1.14, 95%CI 1.06-1.21 p<0.001). Secondary analysis revealed a dose-dependent elevated mortality risk for chloride levels of 105 mmol/l and below, well within the "normal" range.

CONCLUSION

In the outpatient setting, hypochloremia is independently associated with an increased mortality risk. This risk is dose-dependent where the lower the chloride level, the higher is the risk.

Delayed postoperative hyponatremia in patients with acromegaly: incidence and predictive factors

PURPOSE

Delayed postoperative hyponatremia (DPH) is a unique complication of transsphenoidal surgery (TSS) in pituitary tumors. Growth hormone (GH) enhances renal sodium reabsorption; however, the association between postoperative GH reduction and DPH in acromegaly is unclear. This study was performed to clarify the incidence of and the predictive factors for DPH in patients with acromegaly who underwent TSS.

METHODS

Ninety-four patients with active acromegaly were examined retrospectively. During the postoperative course, patients with serum sodium levels ≤ 134 mEq/L were classified into the DPH group. We compared basic clinical characteristics, tumor characteristics, and preoperative and postoperative examination findings between the DPH and non-DPH groups.

RESULTS

DPH occurred in 39 patients (41.5%), and the lowest serum sodium levels were generally observed during postoperative days (PODs) 7-9. They needed a 3-day longer hospital stay than those without DPH. The DPH group had lower preoperative body weight and body mass index. In addition, a transient increase in body weight during PODs 5-7 occurred with a transient decrease in urinary volume in the DPH group. Preoperative and postoperative GH and insulin-like growth factor-1 levels did not differ between the two groups.

CONCLUSION

The findings suggested that lower preoperative weight and a postoperative transient gain in body weight are associated with an increased risk of DPH in acromegaly patients undergoing transsphenoidal surgery.

Hyponatremia as a predictor of outcome and mortality: results from a second-level urban emergency department population

BACKGROUND

Hyponatremia is the most common electrolyte disorder and it has been associated with increased mortality.

AIMS

This study evaluated hyponatremia as a prognostic factor for severity and mortality.

METHODS

We compared the prevalence of hyponatremia among patients who died during the year 2017 (from 1 January 2017 to 31 December 2017) with the prevalence of hyponatremia among subgroups of patients, i.e. outpatients, patients hospitalized for more than 2 days and patients admitted in the intensive care unit (ICU). We also described the mortality rate and the prevalence of comorbidities among hyponatremic patients, according to hyponatremia degree (slight, moderate, severe), basal characteristics, comorbidities and their outcome (discharged, hospitalized or died).

RESULTS

In our population of a public hospital setting, hyponatremia was present at admission in 17% of deaths, and the comparison between hyponatremic and normonatremic patients in terms of mortality confirms the hypothesis that this disorder is in anyway strictly associated with vulnerability and with a poor prognosis.

CONCLUSIONS

We conclude that hyponatremia is a predictive marker for a bad clinical course, therefore patients with this electrolyte disorder should be carefully monitored.

Comparison of Incidence of Hyponatremia between Linezolid and Vancomycin by Propensity Score Matching Analysis

Several cases of severe hyponatremia induced by linezolid (LZD) were reported. However, severe infections could also cause hyponatremia by increasing vasopressin secretion. To prove that hyponatremia is associated with LZD rather than infection, we compared the incidence and risk of developing hyponatremia between patients receiving LZD and those receiving vancomycin (VCM). A retrospective, single-center, observational cohort study was conducted in patients aged 18 years or older who received intravenous LZD or VCM for 7 d or longer. Hyponatremia was defined as serum sodium level lower than 134 mEq/L and more than 5% decrease from baseline after treatment initiation. The incidence and risk of developing hyponatremia were analyzed between LZD and VCM groups using chi-square test. Four hundred and fifty patients who satisfied the selection criteria were divided into LZD (n = 97) and VCM groups (n = 353). Significant differences in patient characteristics between LZD and VCM groups were observed before propensity score matching, but no significant differences were found after matching. LZD group showed a significantly higher incidence and risk of developing hyponatremia compared to VCM group both before (LZD: 16.5%, VCM: 5.4%; p < 0.001, odds ratio 3.472 [95% confidence interval (CI) 1.711-7.048]) and after (LZD: 17.8%, VCM: 5.5%; p = 0.020, odds ratio 3.738 [95% CI 1.157-12.076]) propensity score matching. In conclusion, propensity score analyses suggest that the risk of hyponatremia associated with LZD is approximately 3.7-fold higher than that associated with VCM, regardless of patient background.

The prevalence and prognostic effect of hyponatremia in children with COVID-19 pneumonia: a retrospective study

BACKGROUND

The aim of the study was to examine the effect of hyponatremia at admission as a negative prognostic factor in children hospitalized with COVID-19 pneumonia.

METHODS

The data of patients aged 1 month-18 years, who were followed with the diagnosis of pneumonia at Çanakkale Onsekiz Mart University Hospital, Department of Pediatrics, between January 2018 and May 2021 were examined, retrospectively. Patients (n=661) were divided into two main groups; COVID-19 pneumonia (n=158) and the other pneumonias [other viral pneumonia (n=161) and pneumonia of unknown etiology (n=342)].

RESULTS

Six hundred and twenty-three patients with a median (Q1-Q3) age of 4 (1.5-8) years, 59.4% of whom were male were included in the study. The overall prevalence of hyponatremia at admission was 11.2% and was lower in those with COVID-19 pneumonia than in those with other viral pneumonia (6.4% vs. 15.2%, p=0.013). When evaluated irrespective of their COVID-19 status, hyponatremic patients had a higher supplemental oxygen requirement (OR 2.5 [1.4-4.3], p < 0.001), higher need for intensive care unit (ICU) admission (OR 3.7 [1.3-10.2], p=0.009) and longer duration of hospitalization (p=0.016) than the normonatremic patients. In patients with COVID-19 pneumonia, being hyponatremic had no effect on supplemental oxygen requirements or the duration of hospitalization. When hyponatremic patients were evaluated, the supplemental oxygen requirements and duration of hospitalization of those with COVID-19 pneumonia were similar to the other pneumonias (p > 0.05 for all comparisons). However, normonatremic COVID-19 pneumonias had higher supplemental oxygen requirements than other viral pneumonias and pneumonia of unknown etiology (OR 4.7 [2.2-10.3], p < 0.001; OR 1.6 [1 -2.7], p=0.043, respectively).

CONCLUSION

This study found that hyponatremia at admission is rarer in children with COVID-19 pneumonia than other viral pneumonias and has no effect on supplemental oxygen requirements or the duration of hospitalization.

Prevalence of Hyponatremia in Acute Stroke Patients in a Federal Teaching Hospital, Abakaliki, Nigeria

BACKGROUND

Hyponatremia is a common electrolyte imbalance which is readily observed in patients with neurological disorders such as stroke. It is associated with increased morbidity and mortality during and after hospitalization. There has not been any study to demonstrate the frequency of admission hyponatremia in acute stroke patients in Nigeria. It is against this backdrop that we embarked on this study to determine the frequency and pattern of admission hyponatremia in acute stroke patients in a Federal Teaching Hospital, Abakaliki, Nigeria.

METHODS

This was a cross-sectional observational hospitalbased study undertaken at the Emergency unit of the Alex Ekwueme Federal University Teaching Hospital Abakaliki, Nigeria from November 2021 to April 2022.

RESULTS

Amongst the 177 acute stroke patients enrolled in the study, 58 (32.8%) had hyponatremia. Advanced age, alteration in consciousness, and haemorrhagic (intracerebral and subarachnoid haemorrhage) stroke were significantly associated with presence of hyponatremia.

CONCLUSION

Admission hyponatremia is prevalent amongst acute stroke patients in Abakaliki, Nigeria and commonly associated with advanced age, alteration in consciousness and haemorrhagic stroke.

Analysis of Electrolyte Abnormalities in Adolescents and Adults and Subsequent Diagnosis of an Eating Disorder

IMPORTANCE

Eating disorders lead to increased mortality and reduced quality of life. While the acute presentations of eating disorders frequently involve electrolyte abnormalities, it remains unknown whether electrolyte abnormalities may precede the future diagnosis of an eating disorder.

OBJECTIVE

To determine whether outpatient electrolyte abnormalities are associated with the future diagnosis of an eating disorder.

DESIGN, SETTING, AND PARTICIPANTS

This population-level case-control study used provincial administrative health data for residents of Ontario, Canada aged 13 years or older from 2008 to 2020. Individuals without an eating disorder (controls) were matched 4:1 to individuals diagnosed with an incident eating disorder (cases) based on age and sex. Both groups had outpatient electrolyte measurements between 3 years and 30 days prior to index. Index was defined as the date of an eating disorder diagnosis in any inpatient or outpatient clinical setting for cases. Controls were assigned a pseudo-index date according to the distribution of index dates in the case population. Individuals with any prior eating disorder diagnosis were excluded. The data analyzed was from January 1, 2008, through June 30, 2020.

EXPOSURES

Any electrolyte abnormality, defined as abnormal test results for a composite of hypokalemia, hyperkalemia, hyponatremia, hypernatremia, hypomagnesemia, hypophosphatemia, metabolic acidosis, or metabolic alkalosis.

OUTCOMES AND MEASURES

Eating disorder diagnosis including anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified.

RESULTS

A total 6970 eligible Ontario residents with an eating disorder (mean [SD] age, 28 (19) years; 6075 [87.2%] female, 895 [12.8%] male) were matched with 27 878 age- and sex-matched residents without an eating disorder diagnosis (mean [SD] age, 28 [19] years; 24 300 [87.2%] female, 3578 [12.8%] male). Overall, 18.4% of individuals with an eating disorder had a preceding electrolyte abnormality vs 7.5% of individuals without an eating disorder (adjusted odds ratio [aOR], 2.12; [95% CI, 1.86-2.41]). The median (IQR) time from the earliest electrolyte abnormality to eating disorder diagnosis was 386 (157-716) days. Specific electrolyte abnormalities associated with a higher risk of an eating disorder were: hypokalemia (aOR, 1.98; 95% CI, 1.70-2.32), hyperkalemia (aOR, 1.97; 95% CI, 1.48-2.62), hyponatremia (aOR, 5.26; 95% CI, 3.32-8.31), hypernatremia (aOR, 3.09; 95% CI, 1.01-9.51), hypophosphatemia (aOR, 2.83; 95% CI, 1.82-4.40), and metabolic alkalosis (aOR, 2.60; 95% CI, 1.63-4.15).

CONCLUSIONS AND RELEVANCE

In this case-control study, individuals with an eating disorder were associated with a preceding outpatient electrolyte abnormality compared with matched controls. Otherwise unexplained electrolyte abnormalities may serve to identify individuals who may benefit from screening for an underlying eating disorder.

Association of early hyponatremia and the development of acute kidney injury in critically ill children

BACKGROUND

Hyponatremia is an independent prognostic factor for mortality; however, the reason for this remains unclear. An observed relationship between hyponatremia and the development of acute kidney injury (AKI) has been reported in certain disease states, but hyponatremia has not been evaluated as a predictor of AKI in critically ill patients or children.

METHODS

This is a single-center retrospective cohort study of critically ill children admitted to a tertiary care center. We performed regression analysis to assess the association between hyponatremia at ICU admission and the development of new or worsening stage 2 or 3 (severe) AKI on days 2-3 following ICU admission.

RESULTS

Among the 5057 children included in the study, early hyponatremia was present in 13.3% of children. Severe AKI occurred in 9.2% of children with hyponatremia compared to 4.5% of children with normonatremia. Following covariate adjustment, hyponatremia at ICU admission was associated with a 75% increase in the odds of developing severe AKI when compared to critically ill children with normonatremia (aOR 1.75, 95% CI 1.28-2.39). Evaluating sodium levels continuously, for every 1 mEq/L decrease in serum sodium level, there was a 0.05% increase in the odds of developing severe AKI (aOR 1.05, 95% CI 1.02-1.08). Hyponatremic children who developed severe AKI had a higher frequency of kidney replacement therapy, AKI or acute kidney disease at hospital discharge, and hospital mortality when compared to those without.

CONCLUSIONS

Hyponatremia at ICU admission is associated with the development of new or worsening AKI in critically ill children. A higher resolution version of the Graphical abstract is available as Supplementary information.

Hyponatremia among preeclampsia patients - a potential sign of severity

OBJECTIVES

Although hyponatremia in preeclamptic patients was previously described, its significance remains unknown. We aimed to describe the prevalence and clinical significance of hyponatremia among a cohort of preeclamptic patients.

METHODS

An electronic medical record based retrospective cohort study included all singleton deliveries at Hadassah University Medical Center between 2003 and 2015. Preeclampsia, with and without severe features, was defined using the American College of Obstetrics and Gynecology (ACOG) Hypertension in Pregnancy Guidelines. Hyponatremia was defined as a sodium (Na) level ≤130 mEq/L, and severe hyponatremia as <125 mEq/L. A group of normotensive pregnant women, matched for gestational age, gravdity and parity, served as control.

RESULTS

A total of 700 preeclamptic patients were identified during the study period. Hyponatremia was noted in 14.6% compared to 0 of 79 patients in the control group. Hyponatremia was strongly correlated with severe features of preeclampsia, adverse neonatal and obstetrical outcome. Severe hyponatremia was strongly correlated with preeclampsia with severe features. Furthermore, even among subgroup of preeclamptic patients without severe features, hyponatremia correlated with less favorable pregnancy outcomes.

CONCLUSIONS

Among relatively large cohort of preeclamptic patients, hyponatremia was not a rare finding. We found it more common in patients with preeclampsia and severe features. As women with preeclampsia are at risk for hyponatremia, serum sodium levels should be monitored, especially in those with severe features. In preeclamptic patients without severe features, hyponatremia may indicate a need for closer surveillance. However, larger studies are needed to establish hyponatremia as a marker of severity.

Use of normal saline and incidence of dyselectrolytaemia in children following kidney transplantation

BACKGROUND

The use of hypotonic fluid, such as 0.45% saline, following kidney transplantation (KT) in children is associated with a high incidence of electrolyte imbalance, especially hyponatraemia. This can result in serious adverse events, such as cerebral oedema and seizures. The aim of this study was to investigate the incidence of electrolyte disturbance in children when 0.9% saline was the intravenous fluid used in the first 72 h following KT.

METHODS

This is a retrospective, observational study of 50 consecutive KT undertaken between January 2017 and January 2019 at a single centre.

RESULTS

The median age at KT was 9.2 years (IQR 4-14) and 16 (32%) were females. Thirty-two (64%) were living related donor (LRD) KT and 22 (44%) were carried out in children < 20 kg. The mean volume of fluid administered intra-operatively, and on Day 1, Day 2 and Day 3, were 73 ml/kg, 124 ml/kg, 97 ml/kg and 86 ml/kg, respectively. Hyponatraemia was noted in 4%, hypernatraemia in 18%, hyperkalaemia in 18%, hyperchloraemia in 68% and low bicarbonate was seen in 88%. Fifteen percent of the children had an episode of hyperglycaemia. None of the children developed symptomatic dyselectrolytaemia. There was delayed graft function (DGF) in 4 (8%) recipients - all deceased donor (DD) KT, including 2 who received donations after circulatory death.

CONCLUSIONS

While the use of 0.9% saline is associated with a high incidence of electrolyte disturbances, including hyperkalaemia, it reduces the risk of hyponatraemia. None of the children developed a symptomatic electrolyte abnormality. A higher resolution version of the Graphical abstract is available as Supplementary information.

Prognostic value of dysnatremia for survival in neuroendocrine neoplasm patients

OBJECTIVE

Hyponatremia and hypernatremia are common electrolyte abnormalities in patients with malignancy and have been independently associated with worse survival outcomes. To date, there are no data on the impact of dysnatremia on survival outcomes in patients with neuroendocrine neoplasms (NENs).

DESIGN

This study involves retrospective cohort analysis from a tertiary care center of NEN patients treated with peptide receptor radionuclide therapy (PRRT) with a cumulative activity of at least 3.7 GBq 177Lu-DOTATATE between the years 2000 and 2015.

METHODS

Comparison of overall survival of patients with the occurrence of hyponatremia (serum sodium < 135 mmol/L) or hypernatremia (serum sodium > 145 mmol/L) before starting or during PRRT was perfomed.

RESULTS

A total of 649 patients were included. Hyponatremia occurred in 57 patients during the observation period and was associated with a shorter median overall survival (95% CI) of 25 months (14-36) compared to 55 months (48-61) of the 512 normonatremic patients (P < 0.001), adjusted hazard ratio (HR): 1.48 (95% CI: 1.04-2.12). Overall survival time was reduced regardless of whether hyponatremia was present at baseline or during PRRT. In contrast, hypernatremia occurred in 80 patients and was associated with a longer median overall survival (95% CI) of 94 months (47-140) compared with the 512 normonatremic patients (P = 0.018), adjusted HR: 0.61 (95% CI: 0.40-0.92). This association was driven by the patients with hypernatremia during PRRT. No association between dysnatremia and progression-free survival after PRRT was observed.

CONCLUSIONS

The occurrence of hypo- or hypernatremia in PRRT-treated NET patients is associated with opposing outcomes with regard to overall survival. Sodium levels might have a prognostic role in these patients.

Current and Future Burdens of Heat-Related Hyponatremia: A Nationwide Register-Based Study

CONTEXT

A seasonal variation in hyponatremia, with higher incidence rates during hot summer days, has been demonstrated. Whether this applies to cool temperate regions is currently unknown.

OBJECTIVE

The aim of this study was to investigate the influence of ambient temperature on hyponatremia in the Swedish population under current and future climate scenarios.

METHODS

This nationwide cohort study identified all patients hospitalized with a first-ever principal diagnosis of hyponatremia between October 2005 and December 2014. Incidence rates for hyponatremia were calculated as number of hospitalizations divided by person-days at risk in the adult Swedish population at a given temperature, in increments of 1 °C.

RESULTS

The incidence of hyponatremia was stable at 0.3 per million person-days from -10 to 10 °C, but increased rapidly at 24-hour mean temperatures above 15 °C, with 2.26 hospitalizations per million days at the highest recorded temperature of 25 °C. Women and elderly carried the greatest risk, with an incidence of 35 hospitalizations per million days in individuals ≥ 80 years of age on the hottest days, corresponding to a 15-fold increase in incidence compared with cool days. A future 1 or 2 °C increase in mean temperature is expected to increase the incidence of hyponatremia by 6.3% and 13.9%, respectively.

CONCLUSION

The risk of hospitalization due to hyponatremia increases rapidly at temperatures above 15 °C, indicating a threshold effect. Over the next decades, rising global temperatures are expected to increase the inpatient burden of hyponatremia by approximately 10%. Strategies for protecting vulnerable groups are necessary to reduce this risk.

Acute Kidney Injury and Hyponatremia in Ultra-Trail Racing: A Systematic Review

Background and objectives: Ultra-trail races can cause episodes of acute kidney injury (AKI) and exercise-associated hyponatremia (EAH) in healthy subjects without previous renal pathology. This systematic review aims to review the incidence of these two syndromes together and separately taking into account the length and elevation of the ultra-trail race examined. Materials and Methods: A systematic review was conducted through electronic search in four electronic databases (PubMed, EBSCO, Web of Science and Alcorze). Results: A total of 1127 articles published between January 2006 and December 31, 2021 were included, 28 of which met the inclusion criteria. The studies were categorized according to the length and stages of the race in four categories: medium (42 to 69 km), long (70 to 99 km), extra (>100 km) and multi-stage if they included various stages. A total of 2950 runners (666 females and 2284 males) were extracted from 28 publications. The AKI incidence found was 42.04% (468 cases of 1113), and 195 of 2065 were diagnosed with EAH, accounting for 9.11%. The concurrence of both pathologies together reached 11.84% (27 individuals) from a total of 228 runners with AKI and EAH simultaneously analyzed. Sorted by race category, the AKI+EAH cases were distributed as follows: 18 of 27 in the extra (13.63% and n = 132), 4 in the large (5.79% and n = 69) and 5 in the medium category (18.15% and n = 27). Conclusions: According to these results, extra and medium races showed a similar incidence of AKI+EAH. These findings underline the importance of the duration and intensity of the race and may make them responsible for the etiology of these medical conditions. Due to their variable incidence, EAH and AKI are often underdiagnosed, leading to poorer prognosis, increased condition seriousness and hindered treatment. The results of this review urge participants, coaches and race organizers to take measures to improve the early diagnosis and urgent treatment of possible EAH and AKI cases.

Febrile Seizures among Children Admitted to the Department of Paediatrics of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction:

Febrile seizure is the most common convulsive event in children younger than 60 months. Fever plays an important role in causing disturbances in fluid and electrolyte balance, also hyponatremia has been thought to enhance the susceptibility to seizures. The objective of this study is to find out the prevalence of febrile seizures among children admitted to the Department of Paediatrics of a tertiary care centre.

Methods:

A descriptive cross-sectional study among children admitted to the Department of Paediatrics was done at a tertiary care centre between December, 2020 to September, 2021. Ethical approval was taken from the Institutional Review Committee (Reference number: 077/078-098). A total of 1052 children were included in this study. A convenience sampling technique was used. Statistical Package for the Social Sciences version 25.0 was used for data analysis. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.

Results:

Among 1052 children, the prevalence of febrile seizure was 100 (9.50%) (7.73-11.27 at 95% Confidence Interval). Among these 100 patients, 68 (68%) had simple febrile seizures while 32 (32%) had recurrent febrile seizures.

Conclusions:

The prevalence of febrile seizures was found to be higher than in other studies conducted in similar settings. This knowledge may be of practical value in advising parents or caregivers of the risk of a febrile seizure and its recurrence.

Update: Exertional hyponatremia, active component, U.S. Armed Forces, 2006-2021

From 2006 through 2021, there were 1,669 incident diagnoses of exertional hyponatremia among active component service members, for a crude overall incidence rate of 7.8 cases per 100,000 person-years (p-yrs). Compared to their respective counterparts, female service members, those less than 20 years old, and recruit trainees had higher overall incidence rates of exertional hyponatremia diagnoses. The overall incidence rate during the 16-year period was highest in the Marine Corps, intermediate in the Army and Air Force, and lowest in the Navy. Overall rates during the surveillance period were highest among non-Hispanic White service members and lowest among non-Hispanic Black service members. Between 2006 and 2021, crude annual incidence rates of exertional hyponatremia peaked in 2010 (12.7 per 100,000 p-yrs) and then decreased to a low of 5.3 cases per 100,000 p-yrs in 2013. Crude annual rates fluctuated between 2016 and 2021, reaching the highest rate in 2020 (8.3 per 100,000 p-yrs) and then decreased to 6.8 per 100,000 p-yrs in 2021. Service members and their supervisors must be knowledgeable of the dangers of excessive water consumption and the prescribed limits for water intake during prolonged physical activity (e.g., field training exercises, personal fitness training, and recreational activities) in hot, humid weather.

Prevalence of Dysnatremia in Pulmonary Tuberculosis

Pulmonary tuberculosis is one of the common diseases with high prevalence of mortality and morbidity in developing countries. It is one of the rare pulmonary infections which can induce hyponatremia and it is important to recognise hyponatremia because of its potential hazards.

OBJECTIVES

To assess the serum sodium levels in patients with pulmonary tuberculosis and to establish a relation between the serum sodium levels and its effect on illness in these patients.

MATERIAL

This is a single-center prospective observational Study conducted on patients with Pulmonary Tuberculosis, irrespective of treatment, in the department of General Medicine, B. R. Ambedkar Medical College, Bangalore from August 2019 to June 2021after obtaining ethical clearance. A total of 100 patients were enrolled in the study who met the predefined inclusion criteria of age more than 18 years and having been diagnosed with active tuberculosis. The collected data was analysed using student's T test and Chi-Square Test and the analysis was done using SPSS software version 24.0.

OBSERVATION

The mean age was 46.46+/- 15.69, with majority of participants in the age group 46-60 years. Gender wise there was male preponderance in our study with 60%. The average serum sodium concentration in our study was 134.20 +/- 5.59 mmol/l, with 44% prevalence of hyponatremia and 4% SIADH Conclusion: Although mild hyponatremia was seen in more than 50% of patients, we found out that hyponatremia in pulmonary tuberculosis is detected in 44% of our patients with male preponderance. The predominant mechanism of hyponatremia was syndrome of inappropriate anti- diuretic hormone secretion (SIADH), which was present in 65% of cases with hyponatremia. Early detection and treatment of underlying electrolyte abnormality can potentially reduce mortality and morbidity associated with tuberculosis and reduce duration of hospitalization. Further research into the prevalence of potassium, magnesium and chloride abnormalities can add to the lacunae of knowledge.

Prevalence of hyponatremia in chronic liver disease patients and it's correlation with the severity of the disease

Hyponatremia has been most common electrolyte abnormality found among the patients with advanced cirrhosis indicating a poor prognosis. Hyponatremia is noted to be a marker of the severity of cirrhosis. However, there are limited studies conducted on this in the current study setting and hence the current study was conducted to estimate the prevalence of hyponatremia in chronic liver disease patients and to assess the correlation of hyponatremia with the severity of the chronic liver disease.

MATERIAL

This was an observational study conducted among 100 chronic liver disease patients admitted in a tertiary care hospital. The socio-demographic data, clinical history and details about the risk factors of CLD were collected using a semi-structured questionnaire by interview method. Blood investigations were performed along with upper GI endoscopy. Severity of cirrhosis was assessed according to Child-Pugh score. Data were analyzed using SPSS version 18.0. A P value of &lt; 0.05 was considered statistically significant.

OBSERVATION

The mean age of the study subjects was 45.19±10.01 years and 92.0% were males. The prevalence of hyponatremia was 75.0% at the cut off of ≤135 mEq/L and it was 52.0% at the cut off of ≤130 mEq/L. Higher proportions of those with moderately impaired hepatic function and advanced hepatic dysfunction (class B/ Class C) had hyponatremia compared to those without hyponatremia (76.6% vs 50.0%) but it was not statistically significant (P&gt;0.05). Significantly higher proportions of those with hyponatremia had hepatic encephalopathy (85.4%) compared to those with no hyponatremia (67.8%) (P&lt;0.05).

CONCLUSION

The prevalence of hyponatremia was noted to be 75.0% but the severity as per Child-Pugh score had no association with hyponatremia. However, hepatic encephalopathy was significantly associated with hyponatremia.

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.