Updates in hyponatremia and hypernatremia

PURPOSE OF REVIEW

Hyponatremia and hypernatremia are commonly encountered electrolyte abnormalities that require timely and careful intervention, as they can be associated with significant morbidity and mortality.

RECENT FINDINGS

This review article addresses the etiology, presentation, diagnosis, and management of both hyponatremia and hypernatremia, emphasizing the latest advancements and emerging trends in pediatric care.

SUMMARY

A methodical approach is needed to accurately assess and treat hyponatremia and hypernatremia. Both conditions continue to rely on serum and urine testing, however newer tests such as copeptin and stimulated testing may hold promise to further refine testing in the future.

Hyponatremia as a Marker for Predicting Surgical Intervention in Necrotizing Enterocolitis: A Retrospective Cohort Study

INTRODUCTION

To investigate the predictive value of plasma sodium at the onset of necrotizing enterocolitis (NEC) diagnosis in distinguishing surgical NEC from medical NEC.

METHODS

A retrospective review of all NEC neonates treated at our hospital between 2008 and 2022. Patients were divided into two groups based on treatment methods: surgical intervention and medical treatment. Patient demographics, laboratory parameters, and outcomes were all documented. The values of laboratory parameters were collected at the onset of NEC and after treatment. To identify potential predictors of surgical NEC, multivariate logistic regression analyses were used. The receiver operating characteristic curve was applied to determine predictive factors.

RESULTS

Surgical treatment was performed in 111 infants (44.6%), and medical treatment in 138 cases (55.4%). Of 249 infants with NEC, 22 patients exhibited Bell stage I, 91 infants had Bell stage II, and 136 patients displayed Bell stage III. We discovered that white blood cell (WBC), C-reactive protein (CRP), fibrinogen, and sodium were independent predictors of NEC receiving surgery based on the results of the multivariate logistic regression analysis. Hyponatremia was found in 122 of the 249 patients (49%). At the onset of NEC diagnosis, hyponatremia was found in 83.8% of surgical intervention group and in 21.0% of medical treatment group (P < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for WBC, CRP, fibrinogen, and sodium were calculated. The cutoff values were determined using receiver operating characteristic analysis. The area under the curve of hyponatremia for surgical intervention was 0.875, with 84% sensitivity, 80% specificity, 77% positive predictive value, and 86% negative predictive value, which had a greater specificity (0.80) for predicting surgical intervention than WBC (0.67), CRP (0.50), and fibrinogen (0.70).

CONCLUSIONS

When a surgical evaluation is necessary, hyponatremia can effectively distinguish surgical NEC from medical NEC. It could be used as a predictive marker to guide parental counseling for surgical intervention and rapid transfer of patients to tertiary centers when they have a surgical condition.

Syndrome of inappropriate antidiuretic hormone secretion as an adverse reaction of ciprofloxacin: a case report and literature review

Antidiuretic hormone (ADH) is secreted by the posterior pituitary gland. Unsuppressed release of ADH leads to hyponatremia. This condition is referred to as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hereby, a case report is presented on ciprofloxacin-induced SIADH. A 67-year-old male patient was examined in the emergency room with symptoms of lethargy, headache, lack of attention, and a generally depressed mood lasting for three days. One week prior, empirical antimicrobial therapy involving ciprofloxacin for prostatitis was initiated. Laboratory analysis showed no relevant abnormalities except for hyponatremia (Na = 129 mmol/L). Chronic hyponatremia, thyroid dysfunction, and adrenal dysfunction were ruled out. Serum osmolality was 263 mOsmol/kg, urine osmolality was 206 mOsmol/kg, and urine sodium was 39 mmol/L. Given that all criteria for SIADH were met, ciprofloxacin was discontinued, and fluid restriction was advised. Four days later, the patient's serum sodium concentrations nearly normalized (Na = 135 mmol/L), and all symptoms resolved. The Naranjo Scale yielded a score of 8, supporting the likelihood of a probable adverse reaction to ciprofloxacin. This case is presented to raise awareness among clinicians about the potential of ciprofloxacin to cause even mild hyponatremia.

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

BACKGRUOUND

Delayed postoperative hyponatremia (DPH) is the most common cause of readmission after pituitary surgery. In this study, we aimed to evaluate the cutoff values of serum copeptin and determine the optimal timing for copeptin measurement for the prediction of the occurrence of DPH in patients who undergo endoscopic transsphenoidal approach (eTSA) surgery and tumor resection.

METHODS

This was a prospective observational study of 73 patients who underwent eTSA surgery for pituitary or stalk lesions. Copeptin levels were measured before surgery, 1 hour after extubation, and on postoperative days 1, 2, 7, and 90.

RESULTS

Among 73 patients, 23 patients (31.5%) developed DPH. The baseline ratio of copeptin to serum sodium level showed the highest predictive performance (area under the curve [AUROC], 0.699), and its optimal cutoff to maximize Youden's index was 2.5×10-11, with a sensitivity of 91.3% and negative predictive value of 92.0%. No significant predictors were identified for patients with transient arginine vasopressin (AVP) deficiency. However, for patients without transient AVP deficiency, the copeptin-to-urine osmolarity ratio at baseline demonstrated the highest predictive performance (AUROC, 0.725). An optimal cutoff of 6.5×10-12 maximized Youden's index, with a sensitivity of 92.9% and a negative predictive value of 94.1%.

CONCLUSION

The occurrence of DPH can be predicted using baseline copeptin and its ratio with serum sodium or urine osmolarity only in patients without transient AVP deficiency after pituitary surgery.

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

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

Severe osmotic demyelination syndrome with cortical involvement in the context of severe hyponatremia and central diabetes insipidus: an uncommon presentation of an unusual combination

BACKGROUND

Osmotic demyelination syndrome (ODS) with cerebral cortical involvement is a rare complication of severe hyponatremia correction. Careful management of hyponatremia is crucial, particularly in patients with risk factors, such as alcohol use disorder and diabetes insipidus.

CASE

A patient in his 40s with a history of alcohol use disorder and central diabetes insipidus developed ODS after a 24 mEq/L osmolar increase during the treatment of hyponatremia. The patient's condition progressed into locked-in syndrome and then improved to spastic tetraparesis after cortical basal ganglia ODS improved.

DISCUSSION

The differential diagnosis of cortical demyelination includes laminar cortical necrosis, being the interpretation of Apparent Diffusion Coefficient (ADC) MRI sequence is a useful tool.This case underscores the need to investigate and improve diagnosis and treatment strategies in patients with ODS. It also emphasises the significance of careful hyponatremia correction and frequent monitoring, particularly in patients with known risk factors for ODS.

Desmopressin to prevent and treat bleeding in pregnant women with an inherited bleeding disorder: a systematic literature review

BACKGROUND

Although desmopressin (DDAVP) is an accessible and inexpensive hemostatic drug, its use in pregnancy is still debated due to safety uncertainties.

OBJECTIVES

We aimed to review the safety and effectiveness of DDAVP in women with an inherited bleeding disorder during pregnancy and delivery.

METHODS

Databases were searched for articles up to July 25, 2022, reporting maternal and/or neonatal outcomes. PRISMA methodology for systematic reviews and meta-analyses was followed (PROSPERO CRD42022316490).

RESULTS

Fifty-three studies were included, comprising 273 pregnancies. Regarding maternal outcomes, DDAVP was administered in 73 women during pregnancy and in 232 during delivery. Safety outcome was reported in 245 pregnancies, with severe adverse events reported in 2 (1%, hyponatremia with neurologic symptoms). Overall, DDAVP was used as monotherapy in 234 pregnancies, with effectiveness reported in 153 pregnancies (82% effective; 18% ineffective). Regarding neonatal outcomes, out of 60 pregnancies with reported neonatal outcomes after DDAVP use during pregnancy, 2 children (3%) had a severe adverse event (preterm delivery n = 1; fetal growth restriction n = 1). Of the 232 deliveries, 169 neonates were exposed to DDAVP during delivery, and in 114 neonates, safety outcome was reported. Two children (2%) experienced a moderate adverse event (low Apgar score n = 1; transient hyperbilirubinemia not associated with DDAVP n = 1).

CONCLUSION

DDAVP use during pregnancy and delivery seems safe for the mother, with special attention to the occurrence of hyponatremia and for the child, especially during delivery. However, due to poor study designs and limited documentation of outcomes, a well-designed prospective study is warranted.

Precipitation of hyponatremia and seizures by esmolol in sterile water formulation

PURPOSE

Acute hyponatremia can lead to severe neurological symptoms such as confusion, obtundation, seizures, coma, and respiratory depression, contributing to increased morbidity and mortality. Patients with acute hyponatremia should be evaluated based on volume status and serum osmolality to determine potential causes and appropriate treatment. The aim of this case report is to illustrate the importance of using a multidisciplinary approach to evaluate medication formulation and the potential impact on a patient's clinical course.

SUMMARY

A 34-year-old male was admitted for type A aortic dissection and was treated with an esmolol infusion and underwent operative repair. Two days after initiation of esmolol, the patient developed seizures and antiepileptics were initiated. The patient's serum sodium concentration was found to have decreased by a total of 14 mEq/L since admission. The patient had received more than 6 L of esmolol formulated in sterile water over the course of 2 days. The esmolol infusion was converted to another antihypertensive agent, and 0.9% sodium chloride injection was initiated, after which the serum sodium concentration began to recover. No further seizures were observed on continuous electroencephalography, and all antiepileptic drugs were discontinued with no seizure activity.

CONCLUSION

The esmolol product utilized in this case was formulated in 250 mL of sterile water, which is suspected to have contributed to the patient's hyponatremia. It is important to be aware of the formulation and excipients of medications and their potential for adverse effects.

Usage of mineralocorticoids and isotonic crystalloids in subarachnoid hemorrhage patients in the United States

BACKGROUND

The usage rates of mineralocorticoids (fludrocortisone) to treat hyponatremia and isotonic crystalloids (saline and balanced crystalloids) to maintain intravascular volume in patients with aneurysmal subarachnoid hemorrhage (aSAH) patients across the United States are unknown.

METHODS

We surveyed National Institute of Neurologic Disorders and Stroke (NINDS) StrokeNet sites in 2023, which are mostly large, tertiary, academic centers, and analyzed subarachnoid hemorrhage encounters from 2010 to 2020 in the Premier Healthcare Database that is representative of all types of hospitals and captures about 20 % of all acute inpatient care in the United States.

RESULTS

Although mineralocorticoids are used by 70 % of the NINDS StrokeNet sites, it is used in less than 20 % of the aSAH encounters in the Premier Database. Although saline is ubiquitously used, balanced crystalloids are increasingly used for fluid therapy in aSAH patients. Its use in the NINDS StrokeNet sites and the Premier Healthcare Database is 41 and 45 %, respectively.

CONCLUSIONS

The use of mineralocorticoids remains low, and balanced crystalloids are increasingly used as fluid therapy in aSAH patients. The effectiveness of mineralocorticoids and balanced crystalloids in improving outcomes for aSAH patients must be rigorously tested in randomized clinical trials.

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.

Pituitary Apoplexy-associated Cerebral Salt Wasting Syndrome: A Case Report and Literature Review

PURPOSE

This is a case report of a patient experiencing hyponatremia who was ultimately diagnosed with pituitary apoplexy-associated cerebral salt wasting syndrome (CSWS).

METHODS

Laboratory tests, clinical evaluations, and magnetic resonance imaging were performed by specialists.

FINDINGS

The patient presented with severe headache, thirst, and polyuria. Results of laboratory tests indicated hyponatremia, decreased plasma osmolality, and elevated urine osmolality. Fluid restriction worsened the situation, and normal saline treatment helped return serum sodium and chloride levels to normal. Pituitary apoplexy-associated CSWS was finally considered.

IMPLICATIONS

Pituitary apoplexy is a rare but reasonable etiology for CSWS with hyponatremia. Saline therapy is usually effective.

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.

[Reset osmostat syndrome - when hyponatremia become «a normal»: diagnostics, case report]

Reset osmostat syndrome (ROS) is characterized by a change of normal plasma osmolality threshold (decrease or increase), which leads to chronic dysnatremia (hypo- or hypernatremia). We have described a clinical case of ROS and chronic hyponatremia in a patient with chordoid glioma of the III ventricle. It is known that the patient had previously been diagnosed with hyponatremia (131-134 mmol/l). She has not hypothyroidism and hypocorticism. There is normal filtration function of the kidneys was (CKD-EPI 91.7 ml/mi/1,73m2). Urine osmolality and sodium level were studied to exclude of concentration kidney function disorder. During first three days after removal of the tumor of the third ventricle (chordoid glioma, WHO Grade II), the sodium level decreased to 119 mmol/l. Repeated infusions of 200-300 ml hypertonic 3% sodium chloride solution, gluco- and mineralocorticoid therapy was ineffective, increasing plasma sodium levels by 2-3 mmol/l with the return to the initial level during 6-8 hours. Hypopituitary disorders did not develop after surgery. With further observation, the sodium level remained within 126-129 mmol/l for 6 months after surgery. The water load test make exclude the classic syndrome of inappropriate secretion of antidiuretic hormone, and confirmed the diagnosis of RSO. Because of absence of clinical symptoms associated with hyponatremia, no medical correction was required, patient was recommended to clinical follow-up.

Hyponatremia and other potential markers of ultrasound abnormalities after a first febrile urinary tract infection in children

Urinary tract infections are the initial manifestation in 30% of urinary tract malformations. Identifying these patients, who could benefit from a specific treatment, is still challenging. Hyponatremia during urinary tract infection has been proposed as a urinary tract malformation marker. We evaluate the prevalence of hyponatremia during febrile urinary tract infections and its association with subjacent urinary tract malformations. We performed a retrospective study of healthy patients under 16 years, diagnosed with a first episode of febrile urinary tract infection, who had undergone blood testing in the acute episode and at least one renal ultrasound during follow-up (January 2014-November 2020). Hyponatremia was defined as (serum sodium ≤ 130 mEq/L). According to imaging findings, we classified patients into three groups: normal kidney ultrasound, mild pelviectasis, and significant urinary tract malformation. We performed logistic regression models to identify independent risk factors for urinary tract malformation and mild pelviectasis. We included 492 patients and 2.8% presented hyponatremia. We identified normal ultrasound in 77%, mild pelviectasis in 10.8%, and urinary tract malformation in 12% of patients. We found an association between mild pelviectasis and hyponatremia [OR 6.6 (CI95% 1.6-26.6)]. However, we found no association between hyponatremia and urinary tract malformation. The parameters that were associated with malformations were presenting a non-E. coli infection, C-reactive-protein levels over 80 mg/L, and bacteremia.

CONCLUSION

Hyponatremia during the first episode of febrile urinary tract infection is present in 2.8% of patients and is associated with mild pelviectasis in imaging. However, hyponatremia does not indicate a greater need for complementary tests to screen for urinary tract malformations.

WHAT IS KNOWN

• Urinary tract infection is the first manifestation in 30% of children with urinary tract malformation. • Hyponatremia could be a marker to identify these children and guide the imaging approach.

WHAT IS NEW

• Around 12% of children with a first episode of febrile urinary tract infection have a urinary tract malformation. • Non-E. coli infection, C-reactive protein levels over 80 mg/L, and bacteremia are markers for malformations to guide diagnostic imaging tests, but hyponatremia (Na ≤ 130 mEq/l) is not a reliable marker.

Electrolyte Imbalance in Anti-LGI1 Encephalitis: It Is Not All in Your Head

BACKGROUND AND OBJECTIVES

Antileucine-rich glioma-inactivated 1 (anti-LGI1) autoimmune encephalitis was first described in 2010 and is today the most common type of limbic encephalitis. During the course of the disease, 60%-88% of the patients develop hyponatremia. The etiology of the sodium disorder is unclear, often presumed to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Other electrolyte abnormalities have not been reported in association with anti-LGI1 antibody encephalitis. Due to the presence of hypomagnesemia and hypophosphatemia in our patients, we set out to try to find the expression of LGI1 protein in the kidney as an explanation for these abnormalities.

METHODS

We reviewed the medical files of all patients diagnosed with anti-LGI1 antibody encephalitis, at the Department of Neurology in the Tel Aviv Medical Center between January 2011 and December 2020, exploring for electrolyte abnormalities. Using tissue staining, Western blot, mass spectrometry, and RNA expression techniques, we tried to demonstrate the expression of LGI1 protein in the human kidney.

RESULTS

We identified 15 patients diagnosed with anti-LGI1 antibody encephalitis. Their average age was 65 years (44-80), and 9 were male individuals. Thirteen of the 15 patients (87%) developed varying degrees of hyponatremia. Laboratory studies demonstrated low serum osmolality, low serum blood urea nitrogen, and low uric acid, with a high urinary sodium and inappropriately high urine osmolality, supporting the presumable diagnosis of SIADH. One patient with hyponatremia that was tested, had high levels of copeptin, supporting the diagnosis of SIADH. In addition to hyponatremia, 7 patients (47%) exhibited other electrolyte abnormalities; 5 patients (33%) had overt hypophosphatemia, 4 patients (27%) had overt hypomagnesemia, and 2 other patients (13%) had borderline low magnesium levels. Western blot analysis of human kidney lysate, mass spectrometry, and qRT-PCR failed to demonstrate the expression of LGI1 protein in the kidney.

DISCUSSION

Hyponatremia in patients with anti-LGI1 antibody encephalitis is due to SIADH as previously assumed. Other electrolyte abnormalities such as hypomagnesemia and hypophosphatemia occur in at least 40% of patients and may be another clue for the diagnosis of anti-LGI1 antibody encephalitis. Because we failed to demonstrate LGI1 expression in the kidney, the results of our study suggest that renal losses lead to these disturbances, most probably due to SIADH.

Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia

Hyponatremia and hypernatremia are electrolyte disorders that can be associated with poor outcomes. Hyponatremia is considered mild when the sodium concentration is 130 to 134 mEq per L, moderate when 125 to 129 mEq per L, and severe when less than 125 mEq per L. Mild symptoms include nausea, vomiting, weakness, headache, and mild neurocognitive deficits. Severe symptoms of hyponatremia include delirium, confusion, impaired consciousness, ataxia, seizures, and, rarely, brain herniation and death. Patients with a sodium concentration of less than 125 mEq per L and severe symptoms require emergency infusions with 3% hypertonic saline. Using calculators to guide fluid replacement helps avoid overly rapid correction of sodium concentration, which can cause osmotic demyelination syndrome. Physicians should identify the cause of a patient's hyponatremia, if possible; however, treatment should not be delayed while a diagnosis is pursued. Common causes include certain medications, excessive alcohol consumption, very low-salt diets, and excessive free water intake during exercise. Management to correct sodium concentration is based on whether the patient is hypovolemic, euvolemic, or hypervolemic. Hypovolemic hyponatremia is treated with normal saline infusions. Treating euvolemic hyponatremia includes restricting free water consumption or using salt tablets or intravenous vaptans. Hypervolemic hyponatremia is treated primarily by managing the underlying cause (e.g., heart failure, cirrhosis) and free water restriction. Hypernatremia is less common than hyponatremia. Mild hypernatremia is often caused by dehydration resulting from an impaired thirst mechanism or lack of access to water; however, other causes, such as diabetes insipidus, are possible. Treatment starts with addressing the underlying etiology and correcting the fluid deficit. When sodium is severely elevated, patients are symptomatic, or intravenous fluids are required, hypotonic fluid replacement is necessary.

Disorders of Sodium

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

Construction of risk prediction model for hyponatremia in patients with acute decompensated heart failure

BACKGROUND

Patients with Heart failure (HF) commonly have a water-electrolyte imbalance due to various reasons and mechanisms, and hyponatremia is one of the most common types. However, currently, there are very few local studies on hyponatremia risk assessment in patients with acute decompensated heart failure (ADHF), and there is a lack of specific screening tools. The aim of this study is to identify a prediction model of hyponatremia in patients with acute decompensated heart failure (ADHF) and verify the prediction effect of the model.

METHODS

A total of 532 patients with ADHF were enrolled from March 2014 to December 2019. Univariate and multivariate logistic regression analyses were performed to investigate the independently associated risk factors of hyponatremia in patients with ADHF. The prediction model of hyponatremia in patients with ADHF was constructed by R software, and validation of the model was performed using the area under the receiver operating characteristic curve (AUC) and calibration curves.

RESULTS

A total of 65 patients (12.2%) had hyponatremia in patients with ADHF. Multivariate logistic regression analysis demonstrated that NYHA cardiac function classification (NYHA III vs II, OR = 12.31, NYHA IV vs II, OR = 11.55), systolic blood pressure (OR = 0.978), serum urea nitrogen (OR = 1.046) and creatinine (OR = 1.006) were five independent prognostic factors for hyponatremia in patients with ADHF. The AUC was 0.757; The calibration curve was near the ideal curve, which showed that the model can accurately predict the occurrence of hyponatremia in patients with ADHF.

CONCLUSIONS

The prediction model constructed in our study has good discrimination and accuracy and can be used to predict the occurrence of hyponatremia in patients with ADHF.

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.

[Hyponatremia and Electrolyte Disorders in Cancer Patients]

Onconephrology is a rising and rapidly expanding field of medicine in which nephrology and oncology meet each other. Besides multidisciplinary meetings, oncologists and nephrologists often discuss on timing of the treatment, dosage, and side effects management. Cancer patients often encounter different electrolyte disorders. They are mostly secondary to the tumor itself or consequences of its treatment. In the last years, the great efforts to find new therapies like targeted, immune, and cell-based led us to many new side effects. Hyponatremia, hypokalemia, hyperkalemia, hypercalcemia, and hypomagnesemia are among the most common electrolyte disorders. Data have shown a worse prognosis in patients with electrolytic imbalances. Additionally, they cause a delay in chemotherapy or even an interruption. It is important to diagnose promptly these complications and treat them. In this review, we provide a special focus on hyponatremia and its treatment as the most common electrolytes disorder in cancer patients, but also on newly described cases of hypo- and hyperkalemia and metabolic acidosis.

Hyponatremia as a Prognostic Factor in Advanced Stage Ovarian Cancer Patients

Background: hyponatremia represents one of the most commonly encountered conditions in hospitalized patients, multiple mechanisms being cited so far, neoplastic syndromes being an important cause. The aim of the current paper is to analyse the presence and influence of the short- and long-term outcomes of hyponatremia on ovarian cancer patients submitted to surgery for advanced stage ovarian cancer. Method: 57 patients diagnosed with advanced stage ovarian cancer were submitted to surgery between 2014-2020. The patients were further classified according to the preoperative value of sodium into two groups. Results: there were 21 cases with preoperative normal values of sodium and respectively 36 cases with hyponatremia. Patients with preoperative hyponatremia associated a significantly higher rate of early postoperative complications and a significantly poorer long-term outcome. Therefore, cases with hyponatremia reported a mean disease-free survival of 10.8 months and respectively a mean overall survival of 18.5 months while cases with normal natrium levels reported a mean disease-free survival of 31.4 months and respectively a mean overall survival of 49.7 months (p=0.0001 and p 0.001). Conclusions: patients with lower preoperative values of sodium have a higher risk of developing postoperative complications and a significantly poorer outcome when compared to cases presenting normal levels of sodium preoperatively.

Idiopathic Isolated Adrenocorticotropic Hormone Deficiency: A Single-Center Retrospective Study

Idiopathic isolated adrenocorticotrophic hormone deficiency (IIAD) is rare, with high clinical omission and misdiagnosis rates. This study retrospectively collected information on clinical presentation, laboratory findings, and treatment response of 17 patients with IIAD at Jining No. 1 People's Hospital from January 2014 to December 2022. The clinical characteristics were summarized, and the pertinent data were analyzed. As a result, most of the patients with IIAD were male (94.12%), with age at onset ranging from 13 to 80 years. The primary manifestations were anorexia (88.24%), nausea (70.59%), vomiting (47.06%), fatigue (64.71%), and neurological or psychiatric symptoms (88.24%). The median time to diagnosis was 2 months and the longest was 10 years. Laboratory tests mostly showed hyponatremia (88.24%) and hypoglycemia (70.59%). The symptoms and laboratory indicators returned to normal after supplementing patients with glucocorticoids. IIAD has an insidious onset and atypical symptoms; it was often misdiagnosed as gastrointestinal, neurological, or psychiatric disease. The aim of this study was to improve clinicians' understanding of IIAD, patients with unexplained gastrointestinal symptoms, neurological and psychiatric symptoms, hyponatremia, or hypoglycemia should be evaluated for IIAD and ensure early diagnosis and treatment.

Evidence-based hyponatremia management in liver disease

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

Late-Onset Hyponatremia in Premature Infants

Late-onset hyponatremia (LOH) frequently affects premature infants 2 or more weeks of age due to inadequate sodium intake and excessive kidney loss. Late-onset hyponatremia typically occurs in infants who are physiologically stable and is defined as serum sodium of 132 mEq/L or less or between 133 and 135 mEq/L if receiving sodium supplementation. Recent evidence suggests that spot urine sodium levels may improve the recognition of LOH, as low levels of excreted urine reflect a total body sodium deficit and negative balance. Untreated LOH may result in poor somatic growth, neurodevelopmental delay, higher incidence of bronchopulmonary dysplasia, and more severe retinopathy of prematurity. The primary prevention of LOH is to maintain serum sodium between 135 and 145 mEq/L; however, there are currently no formal protocols guiding sodium supplementation. The purpose of this article is to present on overview of LOH pathophysiology and its effect on somatic growth, neurodevelopment outcomes, and other related sequelae. We further discuss general management strategies and describe a protocol for sodium supplementation that is presently undergoing an evaluation for effectiveness.

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.

[Hyponatremia : Etiology, diagnosis and acute therapy]

Hyponatremia is one of the most common electrolyte disorders in emergency departments and hospitalized patients. Serum sodium concentration is controlled by osmoregulation and volume regulation. Both pathways are regulated via the release of antidiuretic hormone (ADH). Syndrome of inappropriate release of ADH (SIADH) may be caused by neoplasms or pneumonia but may also be triggered by drug use or drug abuse. Excessive fluid intake may also result in a decrease in serum sodium concentration. Rapid alteration in serum sodium concentration leads to cell swelling or cell shrinkage, which primarily causes neurological symptoms. The dynamics of development of hyponatremia and its duration are crucial. In addition to blood testing, a clinical examination and urine analysis are essential in the differential diagnosis of hyponatremia.

Improving management of hyponatraemia by increasing urine testing in the emergency department

Hyponatraemia on hospital admission is associated with increased length of stay, healthcare expenditures and mortality. Urine studies collected before fluid or diuretic administration are essential to diagnose the underlying cause of hyponatraemia, thereby empowering admitting teams to employ the appropriate treatment. A multidisciplinary quality improvement (QI) team led by internal medicine residents performed a QI project from July 2020 through June 2021 to increase the rate of urine studies collected before fluid or diuretic administration in the emergency department (ED) in patients admitted with moderate to severe hyponatraemia. We implemented two plan-do-study-act (PDSA) cycles to address this goal. In PDSA Cycle #1, we displayed an educational poster in employee areas of the ED and met with nursing staff at their monthly meetings to communicate the project and answer questions. We also obtained agreement from ED attending physicians and nursing leaders to support the project. In PDSA Cycle #2, we implemented a structural change in the nursing triage process to issue every patient who qualified for bloodwork with a urine specimen container labelled with a medical record number on registration so that the patient could provide a sample at any point, including while in the waiting area. After PDSA Cycle #1, urine specimen collection increased from 34.5% to 57.5%. After PDSA Cycle #2, this increased further to 59%. We conclude that a combination of educational and structural changes led to a significant increase in urine specimen collection before fluid or diuretic administration among patients presenting with moderate-to-severe hyponatraemia in the ED.

Chloride and Potassium Assessment Is a Helpful Tool for Differential Diagnosis of Thiazide-Associated Hyponatremia

CONTEXT

Differential diagnosis of thiazide-associated hyponatremia (TAH) is challenging. Patients can either have volume depletion or a syndrome of inappropriate antidiuresis (SIAD)-like presentation.

OBJECTIVE

To evaluate the impact of the simplified apparent strong ion difference in serum (aSID; sodium + potassium - chloride) as well as the urine chloride and potassium score (ChU; chloride - potassium in urine) in the differential diagnosis of TAH, in addition to assessment of fractional uric acid excretion (FUA).

METHODS

Post hoc analysis of prospectively collected data from June 2011 to August 2013 from 98 hospitalized patients with TAH < 125 mmol/L enrolled at University Hospital Basel and University Medical Clinic Aarau, Switzerland. Patients were categorized according to treatment response in volume-depleted TAH requiring volume substitution or SIAD-like TAH requiring fluid restriction. We computed sensitivity analyses with ROC curves for positive predictive value (PPV) and negative predictive value (NPV) of aSID, ChU, and FUA in differential diagnosis of TAH.

RESULTS

An aSID > 42 mmol/L had a PPV of 79.1% in identifying patients with volume-depleted TAH, whereas a value < 39 mmol/L excluded it with a NPV of 76.5%. In patients for whom aSID was inconclusive, a ChU < 15 mmol/L had a PPV of 100% and a NPV of 83.3%, whereas FUA < 12% had a PPV of 85.7% and a NPV of 64.3% in identifying patients with volume-depleted TAH.

CONCLUSION

In patients with TAH, assessment of aSID, potassium, and chloride in urine can help identifying patients with volume-depleted TAH requiring fluid substitution vs patients with SIAD-like TAH requiring fluid restriction.

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.

Esthesioneuroblastoma presenting as syndrome of inappropriate antidiuretic hormone secretion

Hyponatremia is the most common fluid electrolyte disorder in hospitalized patients. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the main cause of normovolemic hyponatremia, it can be caused by diverse etiologies: malignant tumors are the most feared cause that clinician persists in finding. Exceptionally, SIADH can complicate Esthesioneuroblastoma (ENB) or olfactory neuroblastoma, a rare tumor of the nasal sinus cavities. We report the case of a 26-year-old female patient admitted for recurrent headaches and vomiting, with a profound normovolemic hyponatremia at the initial assessment. Biological explorations have concluded in a SIADH. Imaging showed a mass of the left nasal cavity with extensions to the ipsilateral paranasal sinuses. The biopsy of the lesion, under endoscopic control, was inconclusive. The anatomopathological study, after surgical removal, concluded in ENB. The postoperative evolution was marked by the normalization of the natremia.

Pearls & Oy-sters: Syndrome of Inappropriate Antidiuretic Hormone Secretion Presenting as Neuromyelitis Optica Spectrum Disorder Flare

While it was previously believed that neuromyelitis optic spectrum disorder (NMOSD) mostly affected the optic nerves and the spinal cord, it is increasingly recognized that NMOSD can involve any area of the CNS where aquaporin-4 is highly expressed. These other areas can include the hypothalamus and the circumventricular organs that surround the third and fourth ventricles, serving as osmoregulators. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most common causes of hyponatremia and has been associated with NMOSD due to these lesions. In this report, we present a case of a patient with known NMOSD, who presented with dizziness, fatigue, and generalized weakness and whose workup revealed hyponatremia in the setting of SIADH and hypothalamic demyelinating lesions. This case illustrates an atypical presentation of NMOSD and the importance of looking for syndromes, such as SIADH. This can guide diagnostic testing, such as getting thin MRI cuts through the hypothalamus and brainstem, as well as advanced management techniques such as immunotherapy.

[Neonatal systemic pseudohypoaldosteronism type I]

An 18-day-old male infant was admitted to the hospital due to recurrent hyperkalemia for more than 10 days. The neonate had milk refusal and dyspnea. The blood gas analysis revealed recurrent hyperkalemia, hyponatremia and metabolic acidosis. Adrenocortical hormone replacement therapy was ineffective. Additional tests showed a significant increase in aldosterone levels. Family whole exome sequencing revealed that the infant had compound heterozygous in the SCNNIA gene, inherited from both parents. The infant was diagnosed with neonatal systemic pseudohypoaldosteronism type I. The infant's electrolyte levels were stabilized through treatment with sodium polystyrene sulfonate and sodium supplement. The infant was discharged upon clinical recovery. This study provides a focused description of differential diagnosis of salt-losing syndrome in infants and introduces the multidisciplinary management of neonatal systemic pseudohypoaldosteronism type I.

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.

Challenge in hyponatremic patients - the potential of a laboratory-based decision support system for hyponatremia to improve patient's safety

OBJECTIVES

Hyponatremia is the most frequent electrolyte disorder in hospitalized patients with increased mortality and morbidity. In this study, we evaluated the follow-up diagnostic, the risk of inadequate fast correction and the outcome of patients with profound hyponatremia (pHN), defined as a blood sodium concentration below 120 mmol/L. The aim was to identify a promising approach for a laboratory-based clinical decision support system (CDSS).

METHODS

This retrospective study included 378,980 blood sodium measurements of 83,315 cases at a German tertiary care hospital. Hospitalized cases with pHN (n=211) were categorized into two groups by the time needed for a follow-up measurement to be performed (time to control, TTC) as either <12 h (group 1: "TTC≤12 h", n=118 cases) or >12 h (group 2: "TTC>12 h", n=93 cases). Length of hospital stay, sodium level at discharge, ward transfers, correction of hyponatremia, and risk of osmotic demyelination syndrome (ODS) due to inadequate fast correction were evaluated with regard to the TTC of sodium blood concentration.

RESULTS

pHN was detected in 1,050 measurements (0.3%) in 211 cases. Cases, in which follow-up diagnostics took longer (TTC>12 h), achieved a significantly lower sodium correction during their hospitalization (11.2 vs. 16.7 mmol/L, p<0.001), were discharged more frequently in hyponatremic states (<135 mmol/L; 58 (62.4%) vs. 43 (36.4%), p<0.001) and at lower sodium blood levels (131.2 vs. 135.0 mmol/L, p<0.001). Furthermore, for these patients there was a trend toward an increased length of hospital stay (13.1 vs. 8.5 days, p=0.089), as well as an increased risk of inadequate fast correction (p<0.001).

CONCLUSIONS

Our study shows that less frequent follow-up sodium measurements in pHN are associated with worse outcomes. Patients with a prolonged TTC are at risk of insufficient correction of hyponatremia, reduced sodium values at discharge, and possible overcorrection. Our results suggest that a CDSS that alerts treating physicians when a control time of >12 h is exceeded could improve patient care in the long term. We are initiating a prospective study to investigate the benefits of our self-invented CDSS (www.ampel.care) for patients with pHN.

Hyponatremia-related liver steatofibrosis and impaired spermatogenesis: evidence from a mouse model of the syndrome of inappropriate antidiuresis

PURPOSE

Hyponatremia is the most frequent electrolytic disorder in clinical practice. In addition to neurological symptoms, hyponatremia, even when mild/moderate and chronic, has been related to other manifestations, such as bone demineralization and increased risk of fractures. To better elucidate tissue alterations associated with reduced serum sodium concentration [Na⁺], we developed an in vivo model of hyponatremia secondary to the Syndrome of Inappropriate Antidiuresis.

METHODS AND RESULTS

Hyponatremia was induced in Foxn1^nu/nu mice by subcutaneous infusion of the vasopressin analog 1-deamino [8-D-arginine] vasopressin (dDAVP) for 14 days via osmotic mini-pumps. Mice in the control group were infused with isotonic saline solution. Serum [Na⁺] progressively decreased, with a nadir of 123.4 ± 2.3 mEq/L (mean ± SD, dDAVP 0.3 ng/h) and 111.6 ± 4.7 mEq/L (mean ± SD, dDAVP 0.5 ng/h). Evident signs of liver steatofibrosis were observed at histology in hyponatremic mice. Accordingly, the expression of proteins involved in lipid metabolism (SREBP-1, PPARα and PPARγ) and in myofibroblast formation (αSMA and CTGF) significantly increased. Furthermore, heme oxygenase 1 expression was up-regulated in Kupffer and hepatic stellate cells in the liver of hyponatremic mice. Testis alterations were also observed. In particular, the thickness of the seminiferous epithelium appeared reduced. The expression levels of PCNA and PTMA, which are involved in DNA replication and germ cells maturation, were markedly reduced in the testis of hyponatremic mice.

CONCLUSION

Overall, these findings shed new light on the possible consequences of chronic hyponatremia and prompt a more thorough evaluation of hyponatremic patients.

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Differential diagnosis of hyponatremia and hypernatremia

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