Disorders of plasma sodium--causes, consequences, and correction

A step-by-step guide for the diagnosis and management of hyponatraemia in patients with stroke

Hyponatraemia is common in patients with stroke and associated with adverse outcomes and increased mortality risk. The present review presents the underlying causes and provides a thorough algorithm for the diagnosis and management of hyponatraemia in stroke patients. Concomitant diseases and therapies, such as diabetes, chronic kidney disease and heart failure, along with diuretics, antidepressants and proton pump inhibitors are the most common causes of hyponatraemia in community. In the setting of acute stroke, the emergence of hyponatraemia might be attributed to the administration of hypotonic solutions and drugs (ie. mannitol and antiepileptics), poor solute intake, infections, as well as stroke-related conditions or complications, such as the syndrome of inappropriate secretion of antidiuretic hormone, cerebral salt wasting syndrome and secondary adrenal insufficiency. Diagnostically, the initial step is to differentiate hypotonic from non-hypotonic hyponatraemia, usually caused by hyperglycaemia or recent mannitol administration in patients with stroke. Determining urine osmolality, urine sodium level and volume status are the following steps in the differentiation of hypotonic hyponatraemia. Of note, specific parameters, such as fractional uric acid and urea excretion, along with plasma copeptin concentration, may further improve the diagnostic yield. Therapeutic options are based on the duration and symptoms of hyponatremia. In the case of acute or symptomatic hyponatraemia, hypertonic saline administration is recommended. Hypovolaemic chronic hyponatremia is treated with isotonic solution administration. Although fluid restriction remains the first-line treatment for the rest forms of chronic hyponatraemia, therapies increasing renal free water excretion may be necessary. Loop diuretics and urea serve this purpose in patients with stroke, whereas sodium-glucose transport protein-2 inhibitors appear to be a promising therapy. Nevertheless, it is yet unclear whether the appropriate restoration of sodium level improves outcomes in such patients. Randomized trials designed to compare therapeutic strategies in managing hyponatraemia in patients with stroke are required.

Evaluation and management of hypernatremia in adults: clinical perspectives

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

Hyponatremia in peritoneal dialysis patients

Hyponatremia is the most common disorder of body fluid and electrolyte balance encountered in clinical practice, and also in peritoneal dialysis (PD) population. Depending on the severity and the speed of drop in sodium concentration, the symptoms can vary from asymptomatic hyponatremia to mild and non-specific symptoms or severe and life-threatening situations. Hyponatremia is associated with high morbidity and mortality. Its pathophysiology is complex, specifically in patients undergoing PD. The etiological workup can be cumbersome but is of paramount importance for early and appropriate treatment. In this article, we review the clinical manifestations as well as the pathophysiology and the specific etiologies of hyponatremia in peritoneal dialysis patients, and we propose a diagnostic algorithm.   

New Approach to Hyponatremia: High Prevalence of Cerebral/Renal Salt Wasting, Identification of Natriuretic Protein That Causes Salt Wasting

Our understanding of hyponatremic conditions has undergone major alterations. There is a tendency to treat all patients with hyponatremia because of common subtle symptoms that include unsteady gait that lead to increased falls and bone fractures and can progress to mental confusion, irritability, seizures, coma and even death. We describe a new approach that is superior to the ineffectual volume approach. Determination of fractional excretion (FE) of urate has simplified the diagnosis of a reset osmostat, Addison's disease, edematous causes such as congestive heart failure, cirrhosis and nephrosis, volume depletion from extrarenal salt losses with normal renal tubular function and the difficult task of differentiating the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) from cerebral/renal salt wasting (C/RSW). SIADH and C/RSW have identical clinical and laboratory parameters but have diametrically opposite therapeutic goals of water-restricting water-loaded patients with SIADH or administering salt water to dehydrated patients with C/RSW. In a study of nonedematous patients with hyponatremia, we utilized FEurate and response to isotonic saline infusions to differentiate SIADH from C/RSW. Twenty-four (38%) of 62 hyponatremic patients had C/RSW with 21 having no clinical evidence of cerebral disease to support our important proposal to change cerebral to renal salt wasting (RSW). Seventeen (27%) had SIADH and 19 (31%) had a reset osmostat. One each from hydrochlorothiazide and Addison's disease. We demonstrated natriuretic activity in the plasma of patients with neurosurgical and Alzheimer diseases (AD) in rat clearance studies and have now identified the natriuretic protein to be haptoglobin related protein without signal peptide (HPRWSP). We introduce a new syndrome of RSW in AD that needs further confirmation. Future studies intend to develop HPRWSP as a biomarker to simplify the diagnosis of RSW in hyponatremic and normonatremic patients and explore other clinical applications that can improve clinical outcomes.

Influence of cardioplegic solution on incidence of delirium after CABG surgery: Use of Calafiore blood cardioplegia versus HTK - Bretschneider - solution in a single-center retrospective analysis from 2017 to 2021

BACKGROUND

Purpose of the present study is an evaluation of postoperative incidence for delirium after coronary artery bypass surgery (CABG). Study addressed whether application of Histidine-Tryptophan-Ketoglutarate (HTK) solution (Bretschneider) or blood cardioplegia (Calafiore) is associated with increased of postoperative delirium cases.

MATERIALS AND METHODS

In a retrospective, single center evaluation a total number of 273 patients were enrolled in the study from January 2017 to October 2021. There were 124 patients assigned to the Calafiore group blood cardioplegic solution (BCC) and 149 patients were included in the Bretschneider group (HTK). The primary endpoint was the postoperative delirium rate in its frequency of occurrence. Definition of the dilirium status was performed using the Confusion Assessment Method in the Intensive Care Unit (CAM-ICU) score during the first three postoperative days. Secondary endpoints were the time intervals of intensive care duration of stay, mechanical ventilation, total extracorporeal circulation, ischemia and reperfusion. Serum levels of the electrolytes Sodium, Potassium, ionized Calcium, and Chloride were monitored.

RESULTS

Although no significant difference in delirium status between the groups were noticed, on third postoperative day, delirium rate dependent on cardioplegia solution used (HTK 12.0%; BCC 3.0%; p = .024) and duration of intensive care stay differed (HTK 4.5 vs. BCC 3.0 days; p = .001). Although Ischemic time (HTK 73.0 vs. BCC 83.0 min; p < .001) and reperfusion time (HTK 35.0 vs. Calafiore 24.0 min; p < .001) were extended in the BCC group less cases of delirium were diagnosed. Serum sodium levels after HTK cardioplegic infusion were decreased (HTK 129.68 vs. BCC 138.96 mmol/l; p < .001). The significant difference persists up to the hundredth extracorporeal circulation circuit min (p = .005).

CONCLUSION

The present data suggest an impact of the cardioplegic solution used upon postoperative delirium rates. Optimization of cardiac arrest protocols is needed. Present data encourage further prospective studies regarding the impact of cardioplegic solutions on electrolyte imbalance for postoperative delirium rates in CABG surgery.

Identifying encephalopathies from acute metabolic derangements

Metabolic derangements, when acute and severe, affect brain function. This presents mostly with a marked decline in the level of consciousness, resulting in impaired responsiveness, abnormal receptivity, impaired content, and loss of memory retention. The term metabolic encephalopathy has been used but is conjecture that can be challenged in the age of modern neuroimaging. We now recognize that many metabolic encephalopathies may involve structural lesions and at an early stage. Common clinical conundrums are the evaluation of the degree of brain injury and its recoverability. This review discusses the appropriate terminology for these conditions, the diagnostic approach, therapy recommendations, and prediction of recovery potential. In evaluating a presumed metabolic cause for encephalopathy, we must (1) search for and rule out structural injury to the brain despite an obvious explanatory metabolic derangement, (2) recognize that several confounding conditions often co-exist, and (3) acknowledge that resolution of brain dysfunction may be protracted despite normalization of laboratory values.

Diagnosis and treatment of brain injury complicated by hypernatremia

Hypernatremia is a common electrolyte disorder in patients with brain injury. The mortality of brain injury patients with severe hypernatremia may be as high as 86.8%. The efficacy of conventional treatment for hypernatremia is limited. Continuous renal replacement therapy (CRRT) can slowly, controllably, and continuously reduce the blood sodium concentration and gradually become an important treatment for severe hypernatremia patients. This review aims to provide important information for clinicians and clinical researchers by describing the etiology, diagnosis, hazards, conventional treatment, and CRRT treatment of hypernatremia in patients with traumatic brain injury.

Protocol for a systematic review of the validity of animal models of polydipsia with a basis in schizophrenia aetiology

OBJECTIVE

Primary polydipsia most commonly affects those with schizophrenia. The pathophysiology of this occurrence is not established. The aim of this systematic review is to critically assess the internal and external validity of the preclinical animal models available.

SEARCH STRATEGY

PubMed and Embase will be searched systematically to identify all relevant animal studies that describe polydipsia induction with a basis in schizophrenia aetiology. The SYRCLE (SYstematic Review Center for Laboratory animal Experimentation) search filters to identify all animal studies in both databases will be used. All studies published up to the date of the search will be considered.

SCREENING AND ANNOTATION

Two independent reviewers will screen the retrieved studies for eligibility based on (1) title and abstract and (2) full text. Disagreements between researchers will be resolved by discussion and referral back to the predefined eligibility criteria with involvement of a third researcher if required.

Fluid Stewardship of Maintenance Intravenous Fluids

Despite the frequent use of maintenance intravenous fluids (mIVF) in critically ill patients, limited guidance is available. Notably, fluid overload secondary to mIVF mismanagement is associated with significant adverse patient outcomes. The Four Rights (right drug, right dose, right duration, right patient) construct of fluid stewardship has been proposed for the safe evaluation and use of fluids. The purpose of this evidence-based review is to offer practical insights for the clinician regarding mIVF selection, dosing, and duration in line with the Four Rights of Fluid Stewardship.

Severe hyponatremia due to surreptitious water intoxication in a hospitalized patient

Hyponatremia is a common electrolyte abnormality among hospitalized patients and often present as first sign of other underlying medical conditions. Severe hyponatremia can be life threatening and requires prompt diagnosis and treatment. We present a case of refractory hyponatremia that was a diagnostic challenge requiring a prolonged hospitalization. Diagnosis of primary polydipsia was ultimately suspected due to improbable 24-h urine studies and confirmed through complete removal of free water access in the form of disconnecting the bathroom faucet in the patient's hospital room. Diagnosis and management of primary polydipsia is further discussed.

Association of Hypernatremia with Immune Profiles and Clinical Outcomes in Adult Intensive Care Unit Patients with Sepsis

Both hypernatremia and an abnormal immune response may increase hospital mortality in patients with sepsis. This study examined the association of hypernatremia with abnormal immune response and mortality in 520 adult patients with sepsis in an intensive care unit (ICU). We compared the mortality and ex vivo lipopolysaccharide (LPS)-induced inflammatory response differences among patients with hyponatremia, eunatremia, and hypernatremia, as well as between patients with acquired hypernatremia on ICU day 3 and those with sustained eunatremia over first three ICU days. Compared with eunatremia or hyponatremia, hypernatremia led to higher 7 day, 14 day, 28 day, and hospital mortality rates (p = 0.030, 0.009, 0.010, and 0.033, respectively). Compared with sustained eunatremia, acquired hypernatremia led to higher 7, 14, and 28 day mortality rates (p = 0.019, 0.042, and 0.028, respectively). The acquired hypernatremia group nonsignificantly trended toward increased hospital mortality (p = 0.056). Day 1 granulocyte colony-stimulating factor (G-CSF) and tumor necrosis factor (TNF) α levels were relatively low in patients with hypernatremia (p = 0.020 and 0.010, respectively) but relatively high in patients with acquired hypernatremia (p = 0.049 and 0.009, respectively). Thus, in ICU-admitted septic patients, hypernatremia on admission and in ICU-acquired hypernatremia were both associated with higher mortality. The higher mortality in patients with hypernatremia on admission was possibly related to the downregulation of G-CSF and TNF-α secretion after endotoxin stimulation. Compared to sustained eunatremia, acquired hypernatremia showed immunoparalysis at first and then hyperinflammation on day 3.

Electrolytes disturbances in cancer patients

PURPOSE OF REVIEW

Hypernatremia, hyperphosphatemia, hypocalcaemia, hyperkalaemia and hypermagnesemia are electrolytes disturbances that can arise in cancer patients in relation to unique causes that are related to the cancer itself or its treatment and can lead to delay or interruption of cancer therapy. This article summarizes these main causes, the proposed pathophysiology and the recommended management for these disturbances.

RECENT FINDINGS

There have been many cancer drugs approved in the field of oncology over the past several years and a subset of these drugs have been associated with electrolytes disturbances. This includes, for example, immune checkpoint inhibitor related hyperkalemia, fibroblast growth factor 23 inhibitor associated hyperphosphatemia and epidermal growth factor receptor inhibitor associated hypomagnesemia and hypocalcaemia.

SUMMARY

This article provides an updated review of certain electrolytes disturbance in cancer patients and allows clinicians to have a greater awareness and knowledge of these electrolyte abnormalities in efforts to early recognition and timely management.

Treatment of hyponatremia in children with acute bacterial meningitis

Purpose

Few studies have evaluated hyponatremia management in children with bacterial meningitis (BM). Thus, we aimed to describe variations in clinical practice, the effectiveness of sodium management, and adverse outcomes in children with BM and hyponatremia.

Methods

This retrospective cross-sectional study conducted at a tertiary institution analyzed participants' demographic, clinical, and sodium-altering treatment data. The sodium trigger for treatment was defined as pretreatment sodium level, with response and overcorrection defined as increments of ≥5 and &gt;10 mmol/L after 24 h, respectively.

Results

This study enrolled 364 children with BM (age: &lt;16 years; 215 boys). Hyponatremia occurred in 62.1% of patients, among whom 25.7% received sodium-altering therapies; 91.4% of those individuals had moderate/severe hyponatremia. Monotherapy was the most common initial hyponatremia treatment. After 24 h of treatment initiation, 82.4% of the patients responded. Logistic regression analyses revealed that ΔNa24 &lt;5 mmol/L [odds ratio (OR) 15.52, 95% CI 1.71–141.06, p = 0.015] and minimum Glasgow Coma Scale (GCS) score ≤ 8 (OR 11.09, 95% CI 1.16–105.73, p = 0.036) predicted dysnatremia at 48 h after treatment initiation. Although rare, persistent moderate/severe hyponatremia or hypernatremia at 48 h after treatment initiation was associated with a high mortality rate (57.1%).

Conclusion

This study found that most cases of hyponatremia responded well to various treatments. It is important to identify and institute appropriate treatment early for moderate or severe hyponatremia or hypernatremia in children with BM. This study was limited by its non-randomized nature.

Microbiological Safety and Shelf-Life of Low-Salt Meat Products-A Review

Salt is widely employed in different foods, especially in meat products, due to its very diverse and extended functionality. However, the high intake of sodium chloride in human diet has been under consideration for the last years, because it is related to serious health problems. The meat-processing industry and research institutions are evaluating different strategies to overcome the elevated salt concentrations in products without a quality reduction. Several properties could be directly or indirectly affected by a sodium chloride decrease. Among them, microbial stability could be shifted towards pathogen growth, posing a serious public health threat. Nonetheless, the majority of the literature available focuses attention on the sensorial and technological challenges that salt reduction implies. Thereafter, the need to discuss the consequences for shelf-life and microbial safety should be considered. Hence, this review aims to merge all the available knowledge regarding salt reduction in meat products, providing an assessment on how to obtain low salt products that are sensorily accepted by the consumer, technologically feasible from the perspective of the industry, and, in particular, safe with respect to microbial stability.

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

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

Severe hyponatraemia peripartum associated with omeprazole therapy

Hyponatraemia is the most commonly encountered electrolyte abnormality in pregnancy and may be associated with adverse maternal and neonatal outcomes. Rapid onset, severe hyponatraemia has been reported with proton-pump inhibitor therapy in non-pregnant individuals. Gastro-oesophageal reflux is very common during pregnancy, and proton-pump inhibitors are available without a prescription in many countries. A case of severe maternal hyponatraemia in the setting of recent omeprazole therapy is presented. Health professionals should be aware of this complication given the availability of proton-pump inhibitors without prescription and high rates of gestational gastro-oesophageal reflux.

Management of Portal Hypertension

Portal hypertension is the cause of the clinical complications associated with cirrhosis. The primary complications of portal hypertension are ascites, acute variceal bleed, and hepatic encephalopathy. Hepatic venous pressure gradient measurement remains the gold standard test for diagnosing cirrhosis-related portal hypertension. Hepatic venous pressure gradient more than 10 mmHg is associated with an increased risk of complications and is termed clinically significant portal hypertension (CSPH). Clinical, laboratory, and imaging methods can also aid in diagnosing CSPH non-invasively. Recently, deep learning methods have been demonstrated to diagnose CSPH effectively. The management of portal hypertension is always individualized and is dependent on the etiology, the availability of therapies, and the degree of portal hypertension complications. In this review, we discuss the diagnosis and management of cirrhosis-related portal hypertension in detail. Also, we highlight the history of portal hypertension and future research areas in portal hypertension.

The modulatory effect of high salt on immune cells and related diseases

BACKGROUND

The adverse effect of excessive salt intake has been recognized in decades. Researchers have mainly focused on the association between salt intake and hypertension. However, studies in recent years have proposed the existence of extra-renal sodium storage and provided insight into the immunomodulatory function of sodium.

OBJECTIVES

In this review, we discuss the modulatory effects of high salt on various innate and adaptive immune cells and immune-regulated diseases.

METHODS

We identified papers through electronic searches of PubMed database from inception to March 2022.

RESULTS

An increasing body of evidence has demonstrated that high salt can modulate the differentiation, activation and function of multiple immune cells. Furthermore, a high-salt diet can increase tissue sodium concentrations and influence the immune responses in microenvironments, thereby affecting the development of immune-regulated diseases, including hypertension, multiple sclerosis, cancer and infections. These findings provide a novel mechanism for the pathology of certain diseases and indicate that salt might serve as a target or potential therapeutic agent in different disease contexts.

CONCLUSION

High salt has a profound impact on the differentiation, activation and function of multiple immune cells. Additionally, an HSD can modulate the development of various immune-regulated diseases.

Autoimmunity Related to Adipsic Hypernatremia and ROHHAD Syndrome

Specific antibody responses to subfornical organs, including Na_x antibody, have been reported in patients with adipsic hypernatremia of unknown etiology who do not have structural lesions in the hypothalamic–pituitary gland. The subfornical organ, also referred to as the window of the brain, is a sensing site that monitors sodium and osmotic pressure levels. On the other hand, ROHHAD syndrome is a rare disease for which the etiology of the hypothalamic disorder is unknown, and there have been some reports in recent years describing its association with autoimmune mechanisms. In addition, abnormal Na levels, including hypernatremia, are likely to occur in this syndrome. When comparing the clinical features of adipsic hypernatremia due to autoimmune mechanisms and ROHHAD syndrome, there are similar hypothalamic–pituitary dysfunction symptoms in addition to abnormal Na levels. Since clinical diagnoses of autoimmunological adipsic hypernatremia and ROHAD syndrome might overlap, we need to understand the essential etiology and carry out precise assessments to accurately diagnose patients and provide effective treatment. In this review, I review the literature on the autoimmune mechanism reported in recent years and describe the findings obtained so far and future directions.

Case Report: Severe Hypernatremia From Ingestion of One's Own Urine

An often unrecognized cause of hypernatremia is the ingestion of fluids or substances with high osmolality. We hereby report a case of severe hypernatremia with acute kidney injury in a severely debilitated patient with acute gouty arthritis who resorted to ingesting his own urine. Hypernatremia induced by drinking urine could be attributed to many underlying mechanisms, one of the important possible causes is the resultant high serum urea that leads to significant osmotic diuresis and a further increase in free water clearance. To the best of our knowledge this is the first case report that describes this unique cause of hypernatremia.

Ten Rules for the Management of Moderate and Severe Traumatic Brain Injury During Pregnancy: An Expert Viewpoint

Moderate and severe traumatic brain injury (TBI) are major causes of disability and death. In addition, when TBI occurs during pregnancy, it can lead to miscarriage, premature birth, and maternal/fetal death, engendering clinical and ethical issues. Several recommendations have been proposed for the management of TBI patients; however, none of these have been specifically applied to pregnant women, which often have been excluded from major trials. Therefore, at present, evidence on TBI management in pregnant women is limited and mostly based on clinical experience. The aim of this manuscript is to provide the clinicians with practical suggestions, based on 10 rules, for the management of moderate to severe TBI during pregnancy. In particular, we firstly describe the pathophysiological changes occurring during pregnancy; then we explore the main strategies for the diagnosis of TBI taking in consideration the risks related to mother and fetus, and finally we discuss the most appropriate approaches for the management in this particular condition. Based on the available evidence, we suggest a stepwise approach consisting of different tiers of treatment and we describe the specific risks according to the severity of the neurological and systemic conditions of both fetus and mother in relation to each trimester of pregnancy. The innovative feature of this approach is the fact that it focuses on the vulnerability and specificity of this population, without forgetting the current knowledge on adult non-pregnant patients, which has to be applied to improve the quality of the care process.

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.

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

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

Dysnatremia in Gastrointestinal Disorders

The primary solute of the milieu intérieur is sodium and accompanying anions. The solvent is water. The kidneys acutely regulate homeostasis in filtration, secretion, and resorption of electrolytes, non-electrolytes, and minerals while balancing water retention and clearance. The gastrointestinal absorptive and secretory functions enable food digestion and water absorption needed to sustain life. Gastrointestinal perturbations including vomiting and diarrhea can lead to significant volume and electrolyte losses, overwhelming the renal homeostatic compensatory mechanisms. Dysnatremia, potassium and acid-base disturbances can result from gastrointestinal pathophysiologic processes. Understanding the renal and gastrointestinal contributions to homeostatis are important for the clinical evaluation of perturbed volume disturbances.

Hyponatremia and Liver Transplantation: A Narrative Review

Hyponatremia is a common electrolyte disorder in patients with end-stage liver disease (ESLD) and is associated with increased mortality on the liver transplantation (LT) waiting list. The impact of hyponatremia on outcomes after LT is unclear. Ninety-day and one-year mortality may be increased, but the data are conflicting. Hyponatremic patients have an increased rate of complications and longer hospital stays after transplant. Although rare, osmotic demyelination syndrome (ODS) is a feared complication after LT in the hyponatremic patient. The condition may occur when the serum sodium (sNa) concentration increases excessively during or after LT. This increase in sNa concentration correlates with the degree of preoperative hyponatremia, the amount of intraoperative blood loss, and the volume of intravenous fluid administration. The risk of developing ODS after LT can be mitigated by avoiding large perioperative increases in sNa concentration . This can be achieved through measures such as carefully increasing the sNa pretransplant, and by limiting the intravenous intra- and postoperative amounts of sodium infused. SNa concentrations should be monitored regularly throughout the entire perioperative period.

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

Background

Methods

Conclusion

Thiazide-associated hyponatremia in internal medicine patients: analysis of epidemiological and biochemical profiles

Thiazide-associated hyponatremia (TAH) is a clinically important side effect of the therapy with thiazide and thiazide-like diuretics. This study aims to analyze epidemiological, biochemical, and symptomatological profiles (including volume status) of patients admitted with TAH. A retrospective hospital record study was performed. Epidemiological and biochemical parameters and symptoms were compared between the thiazide (n = 143) and non-thiazide (n = 282) groups. Patients in the thiazide group were classified as hypo-, normo-, or hypervolemic. Furthermore, the comparison of epidemiological, biochemical, partially pharmacotherapeutical, and symptomatological parameters between the hypovolemic and normovolemic groups was performed. The thiazide group showed lower s-Na (p = 0.008), s-K (p <0.001), s-Cl (p <0.001), measured s-osmolality (p = 0.021), and eGFR (p <0.001); higher s-urea (p <0.001), s-creatinine (p = 0.023), s-glucose (p <0.001), u-osmolality (p = 0.012), u-Na (p <0.001), u-K (p = 0.023), and u-Cl (p <0.001). Patients using thiazide were older (p <0.001), more likely to be female (p = 0.011), and with symptoms corresponding more to chronic hyponatremia. Compared to the normovolemic group (n = 93; 65%), the hypovolemic patients (n = 47; 32.9%) showed higher s-urea (p = 0.005), s-creatinine (p = 0.045), and s-UA (p = 0.010); lower eGFR (p = 0.032), u-Na (p = 0.015), u-Cl (p = 0.016), anorexia (p <0.001), and a higher frequency of furosemide use (p <0.001). Thiazide use is a crucial etiological cause of hypotonic hyponatremia among internal medicine inpatients, associated with more severe hyponatremia, but with no difference in the in-hospital mortality. Even in hypo-osmolar conditions of TAH, 32.9% of patients exhibited signs of volume depletion. FE-UA did not differ between the hypovolemic and the normovolemic patients in TAH conditions. Anorexia and the combination of thiazide together with furosemide, rather than thiazide use alone, were risk factors for hypovolemic hyponatremia without affecting FE-UA.

The mysterious death of the beer drinking champ: potential role for hyperacute water loading and acute hyponatremia (HAWLAH)

Hyponatremia is acute when present for <48 h. Most cases of acute hyponatremia involve both excess free water intake and an at least partial urinary free water excretion defect. By contrast, hyperacute water intoxication may result from a large excess electrolyte-free water intake in such a short time that properly working urinary free water excretion mechanisms cannot cope. A hyperacute decrease in serum sodium may lead to death before medical intervention takes place. Well-documented cases have been published in the military medicine literature. In addition, news reports suggest the existence of cases of voluntary ingestion of excess free water by non-psychiatric individuals usually during ‘dare’ activities. Education of the public is required to prevent harm from these high-risk activities. Adequate training of emergency medical units may prevent lethal outcomes. Spanish media reported the case of a male who died following his triumph in a 20-min beer drinking contest. ‘From a heart attack. Man dies after drinking six litres of beer in a contest’ ran the news. We now review the physiology underlying hyperacute water intoxication and discuss the potential contribution of hyperacute water loading and acute hyponatremia to the demise of this patient.

Systemic hypertonic saline enhances glymphatic spinal cord delivery of lumbar intrathecal morphine

The blood-brain barrier significantly limits effective drug delivery to central nervous system (CNS) targets. The recently characterized glymphatic system offers a perivascular highway for intrathecally (i.t.) administered drugs to reach deep brain structures. Although periarterial cerebrospinal fluid (CSF) influx and concomitant brain drug delivery can be enhanced by pharmacological or hyperosmotic interventions, their effects on drug delivery to the spinal cord, an important target for many drugs, have not been addressed. Hence, we studied in rats whether enhancement of periarterial flow by systemic hypertonic solution might be utilized to enhance spinal delivery and efficacy of i.t. morphine. We also studied whether the hyperosmolar intervention affects brain or cerebrospinal fluid drug concentrations after systemic administration. Periarterial CSF influx was enhanced by intraperitoneal injection of hypertonic saline (HTS, 5.8%, 20 ml/kg, 40 mOsm/kg). The antinociceptive effects of morphine were characterized, using tail flick, hot plate and paw pressure tests. Drug concentrations in serum, tissue and microdialysis samples were determined by liquid chromatography-tandem mass spectrometry. Compared with isotonic solution, HTS increased concentrations of spinal i.t. administered morphine by 240% at the administration level (T13-L1) at 60 min and increased the antinociceptive effect of morphine in tail flick, hot plate, and paw pressure tests. HTS also independently increased hot plate and paw pressure latencies but had no effect in the tail flick test. HTS transiently increased the penetration of intravenous morphine into the lateral ventricle, but not into the hippocampus. In conclusion, acute systemic hyperosmolality is a promising intervention for enhanced spinal delivery of i.t. administered morphine. The relevance of this intervention should be expanded to other i.t. drugs and brought to clinical trials.

Osmotic Demyelination Syndrome in Hospitalized Patients With Cirrhosis: Analysis of the National Inpatient Sample (NIS)

GOAL

Characterize prevalence of osmotic demyelination syndrome (ODS) in hospitalized patients with cirrhosis.

BACKGROUND

ODS is a serious complication of rapid serum sodium correction. Patients with cirrhosis experience labile sodium levels related to portal hypertension and diuretic use, often with rapid correction-intentional or unintentional-during hospitalizations.

STUDY

We used validated International Classification of Diseases, Ninth Revision (ICD-9) codes to identify inpatients 18 years and older with cirrhosis from the 2009-2013 National Inpatient Sample, excluding those with liver transplantation during hospitalization. The primary outcome was ODS (ICD-9 341.8). Baveno IV defined decompensated cirrhosis (stages 3 and 4); Charlson Comorbidity Index identified severe comorbid illness (score >3). Logistic regression modeled factors associated with ODS.

RESULTS

Of 547,544 adult inpatients with cirrhosis, 94 (0.02%) had ODS. Inpatients with versus without ODS were younger (54 vs. 57 y, P=0.0001), and more likely to have alcohol-related cirrhosis (58% vs. 33%, P<0.0001). ODS did not associate with decompensated cirrhosis (33% vs. 37%, P=0.43), specific complications (ascites 33% vs. 33%, P=0.97; hepatic encephalopathy 24% vs. 17%, P=0.06), or severe comorbid illness (12% vs. 16%, P=0.24). In both univariable and multivariable analysis, age [adjusted odds ratio (ORadj): 0.97, 95% confidence interval (CI): 0.95-0.99], female gender (ORadj: 1.53, 95% CI: 1.01-2.30), Hispanic race (ORadj: 0.41, 95% CI: 0.19-0.89), alcohol-related cirrhosis (ORadj: 2.65, 95% CI: 1.71-4.09), and congestive heart failure (ORadj: 0.37, 95% CI: 0.15-0.95) significantly associated with ODS.

CONCLUSION

In hospitalized patients with cirrhosis, ODS is extremely rare, and associated with alcohol-related cirrhosis, younger age, and female gender. ODS is not associated with liver disease severity, specific complications including ascites, or comorbid disease.

Risk of Acute Myocardial Infarction in Patients with Gastroenteritis: A Nationwide Case-Control Study

Gastroenteritis promotes the development of systemic inflammation and a hypercoagulable state. There are limited data regarding the association between gastroenteritis and acute myocardial infarction (AMI). We aimed to evaluate the risk of AMI after an episode of gastroenteritis. In this nested case-control study, we selected patients who were hospitalized for AMI (N = 103,584) as a case group during 2010-2017 and performed propensity score matching (case-control ratio 1:1) to select eligible controls from insurance research data in Taiwan. We applied multivariable logistic regressions to calculate adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for the risk of AMI associated with recent gastroenteritis within 14 days before AMI. We also compared the outcomes after AMI in patients with or without gastroenteritis. A total of 1381 patients (1.3%) with AMI had a prior episode of gastroenteritis compared to 829 (0.8%) among the controls. Gastroenteritis was significantly associated with a subsequent risk of AMI (adjusted OR: 1.68, 95% CI: 1.54-1.83), which was augmented in hospitalizations for gastroenteritis (adjusted OR: 2.50, 95% CI: 1.20-5.21). The outcomes after AMI were worse in patients with gastroenteritis than in those without gastroenteritis, including increased 30-day in-hospital mortality (adjusted OR: 1.28, 95% CI: 1.08-1.52), medical expenditure, and length of hospital stay. Gastroenteritis may act as a trigger for AMI and correlates with worse post-AMI outcomes. Strategies of aggressive hydration and/or increased antithrombotic therapies for this susceptible population should be further developed.

Hypernatremia at a Tertiary Hospital Intensive Care Unit in South Africa

Background

Hypernatremia in the critical care setting is a major cause of morbidity and mortality. However, data pertaining to this has not been evaluated in South African hospitals. The aim of this study was to evaluate hypernatremia with regards to its prevalence, associated factors, and outcomes at an academic hospital intensive care unit (ICU) in Johannesburg, South Africa.

Methods

The ICU charts of patients admitted to the Charlotte Maxeke Johannesburg Academic Hospital adult general ICU from June 1, 2016 to May 31, 2017 were retrospectively reviewed. Subjects were categorized into three groups namely, ICU-acquired hypernatremia (IAH), pre-admission hypernatremia (PAH), and normonatremia. Data was compared between the three groups.

Results

Of the 833 subjects that were enrolled, 310 (37.2%) were hypernatremic. IAH was present in 144 (17.2%) and PAH in 166 (19.9%) subjects. Hypernatremia was significantly (p <0.05) associated with a higher rate of altered mental status, higher Acute Physiologic Assessment and Chronic Health Evaluation II (APACHE II) scores, a higher rate and duration of mechanical ventilation, a greater need for inotropic/vasopressor support, longer ICU stay and higher ICU mortality.

Conclusion

Hypernatremia in ICU patients remains a significant contributor to morbidity, mortality, and ICU length of stay. The prevalence of hypernatremia was much higher than that reported in higher-income countries.

Treatment of acute hypernatremia caused by sodium overload in adults: A systematic review

BACKGROUND

Rapid-onset, acute hypernatremia caused by sodium overload is a rare, life-threatening condition. Although experts recommend rapid correction of sodium concentration [Na] based on pathophysiological theories, only a few reports have documented the specific details of sodium correction methods. The objective of this study was to systematically review the reported treatment regimens, achieved [Na] correction rates, and treatment outcomes.

METHODS

PubMed, Ichushi-database, and references without language restrictions, from inception to January 2021, were searched for studies that described ≥1 adult (aged ≥18 years) patients with rapid-onset hypernatremia caused by sodium overload, whose treatment was initiated ≤12 hours from the onset. The primary outcome of interest was the [Na] correction rate associated with mortality.

RESULTS

Eighteen case reports (18 patients; median [Na], 180.5 mEq/L) were included. The cause of sodium overload was self-ingestion in 8 patients and iatrogenic sodium gain in 10 patients; baseline [Na] and symptoms at presentation were comparable for both groups. Individualized rapid infusion of dextrose-based solutions was the most commonly adopted fluid therapy, whereas hemodialysis was also used for patients already treated with hemodialysis. The correction rates were more rapid in 13 successfully treated patients than in 5 fatal patients. The successfully treated patients typically achieved [Na] ≤160 within 8 hours, [Na] ≤150 within 24 hours, and [Na] ≤145 within 48 hours. Hyperglycemia was a commonly observed treatment-related adverse event.

CONCLUSION

The limited empirical evidence derived from case reports appears to endorse the recommended, rapid, and aggressive sodium correction using dextrose-based hypotonic solutions.

Diabetic ketoacidosis with severe hypokalemia and persistent hypernatremia in an adolescent girl with COVID‐19 infection

We report a case of new‐onset type 1 diabetes in a girl presenting with severe diabetic ketoacidosis, complicated by profound hypokalemia and hypernatremia. We describe the clinical course, management challenges, and the potential role of the concomitant COVID‐19 infection in the complexity of this case.

Edelman Revisited: Concepts, Achievements, and Challenges

The key message from the 1958 Edelman study states that combinations of external gains or losses of sodium, potassium and water leading to an increase of the fraction (total body sodium plus total body potassium) over total body water will raise the serum sodium concentration ([Na]_S), while external gains or losses leading to a decrease in this fraction will lower [Na]_S. A variety of studies have supported this concept and current quantitative methods for correcting dysnatremias, including formulas calculating the volume of saline needed for a change in [Na]_S are based on it. Not accounting for external losses of sodium, potassium and water during treatment and faulty values for body water inserted in the formulas predicting the change in [Na]_S affect the accuracy of these formulas. Newly described factors potentially affecting the change in [Na]_S during treatment of dysnatremias include the following: (a) exchanges during development or correction of dysnatremias between osmotically inactive sodium stored in tissues and osmotically active sodium in solution in body fluids; (b) chemical binding of part of body water to macromolecules which would decrease the amount of body water available for osmotic exchanges; and (c) genetic influences on the determination of sodium concentration in body fluids. The effects of these newer developments on the methods of treatment of dysnatremias are not well-established and will need extensive studying. Currently, monitoring of serum sodium concentration remains a critical step during treatment of dysnatremias.

Prevalence and clinical significance of serum sodium variability in patients with acute-on-chronic liver diseases: a prospective multicenter study in China

Background

No reports exist regarding the prevalence of different Na levels and their relationship with 90-day prognosis in hospitalized patients with acute-on-chronic liver disease (AoCLD) in China. Therefore, the benefit of hyponatremia correction in AoCLD patients remains unclear.

Methods

We prospectively collected the data of 3970 patients with AoCLD from the CATCH-LIFE cohort in China. The prevalence of different Na levels (≤ 120; 120–135; 135–145; > 145) and their relationship with 90-day prognosis were analyzed. For hyponatremic patients, we measured Na levels on days 4 and 7 and compared their characteristics, based on whether hyponatremia was corrected.

Results

A total of 3880 patients were involved; 712 of those developed adverse outcomes within 90 days. There were 80 (2.06%) hypernatremic, 28 (0.72%) severe hyponatremic, and 813 (20.95%) mild hyponatremic patients at admission. After adjusting for all confounding factors, the risk of 90-day adverse outcomes decreased by 5% (odds ratio [OR] 0.95; 95% confidence interval [CI] 0.93–0.97; p < 0.001), 24% (OR 0.76; 95% CI 0.70–0.84; p < 0.001), and 42% (OR 0.58; 95% CI 0.49–0.70; p < 0.001) as Na level increased by 1, 5, and 10 mmol/L, respectively. Noncorrection of hyponatremia on days 4 and 7 was associated with 2.05-fold (hazard ratio [HR], 2.05; 95% CI, 1.50–2.79; p < 0.001) and 1.46-fold (HR 1.46; 95% CI 1.05–2.02; p = 0.028) higher risk of adverse outcomes.

Conclusions

Hyponatremia was an independent risk factor for a poor 90-day prognosis in patients with AoCLD. Failure to correct hyponatremia in a week after admission was often associated with increased mortality. (ClinicalTrials.gov number: NCT02457637, NCT03641872).

Clinical Trial Numbers

This study is registered at Shanghai www.clinicaltrials.org (NCT02457637 and NCT03641872).

Supplementary Information

The online version contains supplementary material available at 10.1007/s12072-021-10282-8.

Hyponatremia in Coronavirus Disease-19 Patients: A Retrospective Analysis

Background:

Hyponatremia (serum Na⁺ < 135 mmol/L) is the most common electrolyte abnormality detected in clinical practice and an important cause of mortality and morbidity in hospital settings. Hyponatremia in patients with pneumonia is usually mild but is associated with increased risk of intensive care unit (ICU) admission, prolonged hospital stays, and increased mortality rates. The purpose of this study is to understand the impact of varying degrees of hyponatremia and various other inflammatory markers on the severity and outcome of coronavirus disease-19 (COVID-19).

Objective:

The main objective of this study is to evaluate the prevalence of hyponatremia in COVID-19 patients and to assess the correlation between hyponatremia and severity and outcome of COVID-19. The other objective is to evaluate the correlation between various inflammatory markers and outcome (ICU vs non-ICU admission, discharged vs deceased) in patients with COVID-19 pneumonia.

Methods:

A total of 113 participants who have been diagnosed with COVID-19 infection by reverse transcriptase-polymerase chain reaction test were included in the study. Epidemiological, demographic, clinical, investigative work-up, and outcome data were extracted from electronic health records using a standard data collection form. Based on serum sodium levels, patients were divided into two groups: normonatremic (serum Na⁺ ≥ 135 mEq/L) and hyponatremic (serum Na⁺ < 135 mEq/L). Various clinical, laboratory, and outcome parameters were compared between the two groups.

Results:

Hyponatremia was present in 50 out of 113 (44%) patients in our study, and it was generally mild. There were more male patients in hyponatremia group (P = .006), and hyponatremic patients were older than normonatremic patients (P = .001). Forty (35%) of the 113 patients were transferred to the ICU, and 17 (15%) needed mechanical ventilation during their hospitalization. Interleukin-6 (IL-6) levels were higher in the hyponatremic group (P = .022). Intensive care unit admissions and oxygen requirement were significantly higher in hyponatremic patients (P = .001 and .016, respectively). Ferritin, lactate dehydrogenase (LDH), IL-6, total leucocyte count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were significantly elevated in those patients requiring ICU admission and those who died due to COVID-19.

Conclusions:

Our study revealed that demography, clinical features, radiographic findings, complications like renal insufficiency, and inflammatory markers like IL-6 play a considerable role in hyponatremic COVID-19 patients. Hyponatremia patients required significantly higher rates of ICU admissions and oxygen support. Our results suggest that monitoring inflammatory markers such as ESR, CRP, total white blood cell (WBC) count, ferritin, LDH, and IL-6 may serve as an early warning system for progression to severe COVID-19.

Clinical Implications, Evaluation, and Management of Hyponatremia in Cirrhosis

Hyponatremia is the most common electrolyte abnormality in patients with decompensated cirrhosis on Liver Transplantation (LT) waiting list. Most of these patients have dilutional or hypervolemic hyponatremia secondary to splanchnic vasodilatation. Excessive secretion of the antidiuretic hormone also plays an important role. Hypervolemic hyponatremia is commonly associated with refractory ascites, spontaneous bacterial peritonitis, and hepatic encephalopathy. Although uncommon, the use of diuretics and laxatives can cause hypovolemic hyponatremia that is characterized by the striking absence of ascites or pedal edema. Clinical features are often nonspecific and depend on the acuity of onset rather than the absolute value of serum sodium. Symptoms may be subtle, including nausea, lethargy, weakness, or anorexia. However, rarely patients may present with confusion, seizures, psychosis, or coma. Treatment includes discontinuation of diuretics, beta-blockers, and albumin infusion. Hypertonic saline (3%) infusion may be used in patients with very low serum sodium (<110 mmol/L) or when patients present with seizures or coma. Short-term use of Vasopressin (V₂) receptor antagonists may also be used to normalize sodium levels prior to LT. However, all these measures may be futile, and LT remains the definite treatment in these patients to improve survival. In this review, we describe the classification, pathogenesis of hyponatremia, and its clinical implications in patients with cirrhosis. Approach to these patients along with management will also be discussed briefly.

Extreme Hyponatremia Complicated by Osmotic Demyelination in a Previously Healthy Young Individual

Rationale:

Severe hyponatremia can lead to dramatic complications whether it is treated or not. At times, it may be very severe (serum Na concentration: NaS < 115 mmol/L) or even extreme (NaS < 105 mmol/L)a and its cause difficult to identify, especially in younger individuals with no history of water disorders. The case presented herein illustrates these points quite eloquently and leads us to believe that the current recommendations for the treatment of very severe hyponatremia require some fine-tuning.

Presenting Concerns:

A 26-year-old man was admitted to our intensive care unit for a NaS of 88 mmol/L in the absence of obvious extracellular fluid volume contraction. He had been experiencing vomiting, diarrhea, fatigue, and excessive thirst for the past 6 weeks and minor neurological symptoms just before admission. Laboratory tests at presentation also showed a urine osmolarity of 697 mOsm/L and urine Na of 40 mmol/L.

Diagnoses:

The presenting concerns were consistent with syndrome of inappropriate antidiuretic hormone secretion (SIADH) manifesting as extreme, yet mildly symptomatic hyponatremia. At the same time, they did not point toward a specific cause initially.

Interventions:

The patient was treated through water restriction, subcutaneous desmopressin, and various intravenous (IV) fluids. Our goal had been to increase NaS at a rate of 4 to 6 mmol/L/day and required the amount of NaCl and free water perfused hourly to be readjusted constantly. Access to water also had to be opposed as the patient was unable to tolerate his thirst.

Outcomes:

During the first 6 days, the rate of NaS correction achieved was ~6 mmol/L/day. The patient improved initially but at the end of day 6, he experienced severe extrapontine osmotic demyelination (with widespread pyramidal and extrapyramidal deficits) that did not respond to intravenous immunoglobulin and NaS relowering. A little more than 3 weeks later, he began to develop low blood pressure and a subfebrile state that revealed secondary to severe Addison disease. The water disorder and insatiable thirst subsided gradually upon replacing the deficient hormones but the neurological disorder went on to become permanent and highly disabling.

Teaching points:

(1) Very severe hyponatremia should always be handled as an emergency and monitored stringently in view of its potential to cause irreparable damage. (2) Because it is a major risk factor for osmotic demyelination, it should probably be corrected at a rate of less than 4 mmol/L/day especially if it is in the extreme range, chronic, or of unknown duration. (3) It can be a presenting manifestation of Addison disease.

Neurodevelopmental consequences of early plasma sodium changes in very preterm infants

BACKGROUND

Sodium fluctuations in very preterm neonates and their neurodevelopmental consequences are not well described.

METHODS

We assessed the changes in plasma sodium and glucose in the first days of life in very preterm neonates and studied the association of glucose-corrected plasma sodium fluctuations on neurodevelopmental outcomes. We included 147 consecutive neonates born before 29 weeks of gestation in our center and retrospectively obtained plasma sodium, glucose, and glucose-corrected sodium levels. Neurodevelopmental assessment was obtained from the Canadian Neonatal Follow-Up Network.

RESULTS

Mean ± standard deviation of plasma sodium changes within the first 10 days of life were 16.2 ± 6.0, 14.8 ± 5.3, and 11.1 ± 5.2 mmol/l in neonates born ≤25, 25-26, and 26-27 weeks of gestation, respectively (p < 0.001). Non-steroidal anti-inflammatory drug administration was associated with larger plasma sodium fluctuation. Eighty-six percent had a known neurological status at 18 months. Higher fluctuations in glucose-corrected plasma sodium were associated with death or neurodevelopmental impairment at 18 months corrected age (B = 3.19, 95% CI [1.24, 5.14]), and this association remained after adjustment for gestational age (B = 2.1, 95% CI [0.16, 4.04]).

CONCLUSIONS

Neonates born very preterm show fluctuations in glucose-corrected plasma sodium during the first days of life, which may increase the risk of death or developmental impairment.

IMPACT

Risk factors and neurodevelopmental consequences of plasma sodium changes in early neonatal life of preterm infants are not well characterized. This study shows for the first time that glucose-corrected plasma sodium fluctuations within the first days of life are more severe in preterm infants receiving non-steroidal anti-inflammatory drugs (NSAIDs) and are associated with death or neurodevelopmental impairment at 18 months corrected age. Large plasma sodium and glucose fluctuations should be expected more often in preterm infants receiving NSAIDs and should be avoided.

Clinical characteristics and outcomes of hyponatraemia associated with oral water intake in adults: a systematic review

INTRODUCTION

Excessive water intake is rarely associated with life-threatening hyponatraemia. The aim of this study was to determine the clinical characteristics and outcomes of hyponatraemia associated with excess water intake.

METHODS

This review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies (case reports, observational or interventional studies) reporting excess water intake and hyponatraemia in adults (1946-2019) were included.

RESULTS

A total of 2970 articles were identified and 177 were included (88.7% case reports), consisting of 590 patients. The mean age was 46±16 years (95% CI 44 to 48 years), 47% female, 52% had a chronic psychiatric disorder and 31% had no underlying condition. The median volume of water consumed and serum sodium at presentation was 8 L/day (95% CI 8.9 to 12.2 L/day) and 118 mmol/L (95% CI 116 to 118 mmol/L), respectively. The motivator for increased water consumption was psychogenic polydipsia (55%); iatrogenic (13%); exercise (12%); habitual/dipsogenic polydipsia (7%) and other reasons (13%). The clinical features on presentation were severe in 53% (seizures, coma); moderate in 35% (confusion, vomiting, agitation) and mild in 5% (dizziness, lethargy, cognitive deficit) and not reported in 5% of studies. Treatment was supportive in 41% of studies (fluid restriction, treatment of the underlying cause, emergency care), and isotonic and hypertonic saline was used in 18% and 28% of cases, respectively. Treatment-related complications included osmotic demyelination (3%) and rhabdomyolysis (7%), and death occurred in 13% of cases.

CONCLUSION

Water intoxication is associated with significant morbidity and mortality and requires daily intake to substantially exceed population-based recommendations. The limitations of this analysis are the low quality and high risk of bias of the included studies.

PROSPERO REGISTRATION NUMBER

A pre-existing protocol in the international prospective register of systematic reviews was updated to incorporate any new amendments and reregistered at http://www.crd.york.ac.uk/PROSPERO (registration no. CRD42019129809).

Dysnatremias in Chronic Kidney Disease: Pathophysiology, Manifestations, and Treatment

The decreased ability of the kidney to regulate water and monovalent cation excretion predisposes patients with chronic kidney disease (CKD) to dysnatremias. In this report, we describe the clinical associations and methods of management of dysnatremias in this patient population by reviewing publications on hyponatremia and hypernatremia in patients with CKD not on dialysis, and those on maintenance hemodialysis or peritoneal dialysis. The prevalence of both hyponatremia and hypernatremia has been reported to be higher in patients with CKD than in the general population. Certain features of the studies analyzed, such as variation in the cut-off values of serum sodium concentration ([Na]) that define hyponatremia or hypernatremia, create comparison difficulties. Dysnatremias in patients with CKD are associated with adverse clinical conditions and mortality. Currently, investigation and treatment of dysnatremias in patients with CKD should follow clinical judgment and the guidelines for the general population. Whether azotemia allows different rates of correction of [Na] in patients with hyponatremic CKD and the methodology and outcomes of treatment of dysnatremias by renal replacement methods require further investigation. In conclusion, dysnatremias occur frequently and are associated with various comorbidities and mortality in patients with CKD. Knowledge gaps in their treatment and prevention call for further studies.

Diabetes insipidus

Diabetes insipidus (DI) is a disorder characterized by a high hypotonic urinary output of more than 50ml per kg body weight per 24 hours, with associated polydipsia of more than 3 liters a day [1,2]. Central DI results from inadequate secretion and usually deficient synthesis of Arginine vasopressin (AVP) in the hypothalamus or pituitary gland. Besides central DI further underlying etiologies of DI can be due to other primary forms (renal origin) or secondary forms of polyuria (resulting from primary polydipsia). All these forms belong to the Polyuria Polydipsia Syndrom (PPS). In most cases central and nephrogenic DI are acquired, but there are also congenital forms caused by genetic mutations of the AVP gene (central DI) [3] or by mutations in the gene for the AVP V2R or the AQP2 water channel (nephrogenic DI) [4]. Primary polydipsia (PP) as secondary form of polyuria includes an excessive intake of large amounts of fluid leading to polyuria in the presence of intact AVP secretion and appropriate antidiuretic renal response. Differentiation between the three mentioned entities is difficult [5], especially in patients with Primary polydipsia or partial, mild forms of DI [1,6], but different tests for differential diagnosis, most recently based on measurement of copeptin, and a thorough medical history mostly lead to the correct diagnosis. This is important since treatment strategies vary and application of the wrong treatment can be dangerous [7]. Treatment of central DI consists of fluid management and drug therapy with the synthetic AVP analogue Desmopressin (DDAVP), that is used as nasal or oral preparation in most cases. Main side effect can be dilutional hyponatremia [8]. In this review we will focus on central diabetes insipidus and describe the prevalence, the clinical manifestations, the etiology as well as the differential diagnosis and management of central diabetes insipidus in the out- and inpatient setting.

De-novo non-convulsive status epilepticus in adult medical inpatients without known epilepsy: Analysis of mortality related factors and literature review

Background

Non-convulsive status epilepticus (NCSE) often goes unnoticed and is not easily detected in patients with a decreased level of consciousness, especially in older patients. In this sense, lack of data in this population is available.

Aims

The aim of the present study was to examine daily clinical practice and evaluate factors that may influence the prognosis of NCSE in non-epileptic medical inpatients.

Methods

We conducted a retrospective analysis including patients admitted by any cause in an Internal Medicine ward. All patients with compatible symptoms, exclusion of other causes, clinical suspicion or diagnosis of NCSE, and compatible EEG were included. Patients with a previous diagnosis of epilepsy were excluded. We also conducted a literature review by searching the PubMed/Medline database with the terms: Nonconvulsive Status OR Non-Convulsive Status.

Results

We included 54 patients, mortality rate reached 37% and the main factors linked to it were hypernatremia (OR = 16.2; 95% CI, 1.6–165.6; P = 0.019) and atrial fibrillation (OR = 6.7; 95% CI, 1.7–26; P = 0.006). There were no differences regarding mortality when comparing different diagnosis approach or treatment regimens. Our literature review showed that the main etiology of NCSE were neurovascular causes (17.8%), followed by antibiotic treatment (17.2%) and metabolic causes (17%). Global mortality in the literature review, excluding our series, reached 20%.

Discussion

We present the largest series of NCSE cases in medical patients, which showed that this entity is probably misdiagnosed in older patients and is linked to a high mortality.

Conclusion

The presence of atrial fibrillation and hypernatremia in patients diagnosed with NCSE should advise physicians of a high mortality risk.

Acute Water Intoxication With Resultant Hypo-Osmolar Hyponatremia Complicated by Hypotension Secondary to Diffuse Third-Spacing

Hypotonic hyponatremia secondary to acute water intoxication is most commonly associated with primary polydipsia in the setting of psychiatric illness. However, in certain circumstances, otherwise healthy individuals can be compelled to consume large enough volumes of water to overwhelm the kidney’s dilutional capacity of urine and cause a potentially life-threatening rapid decline in serum sodium. We present such a case of a 20-year-old basic military trainee with acute symptomatic hypotonic hyponatremia after drinking five to six liters of water prior to urine drug testing. The clinical manifestations of this disorder are non-specific and can be seen with many different pathologic processes, presenting a diagnostic challenge to the emergency clinician. This challenge can be further complicated by unclear or unobtainable history depending on clinical presentation. The authors will discuss key diagnostic and treatment elements of this potentially life-threatening disease to encourage clinicians to utilize social history when evaluating cases of acute water intoxication and resultant symptomatic hypotonic hyponatremia.