Hyponatremia in patients with liver diseases: not just a cirrhosis-induced hemodynamic compromise

Hyponatremia in the Context of Liver Disease

Hyponatremia is common in patients with liver disease and is associated with increased mortality, morbidity, and a reduced quality of life. In liver transplantation, the inclusion of hyponatremia in organ allocation scores has reduced waitlist mortality. Portal hypertension and the resulting lowering of the effective arterial blood volume are important pathogenetic factors, but in most patients with liver disease, hyponatremia is multifactorial. Treatment requires a multifaceted approach that tries to reduce electrolyte-free water intake, restore urinary dilution, and increase nonelectrolyte solute excretion. Albumin therapy for hyponatremia is a peculiarity of advanced liver disease. Its use appears to be increasing, while the vaptans are currently only given in selected cases. Osmotic demyelination is a special concern in patients with liver disease. Serial checks of serum sodium concentrations and urine volume monitoring are mandatory.

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.

Secondary Central Nervous System Demyelinating Disorders in the Elderly: A Narrative Review

Secondary demyelinating diseases comprise a wide spectrum group of pathological conditions and may either be attributed to a disorder primarily affecting the neurons or axons, followed by demyelination, or to an underlying condition leading to secondary damage of the myelin sheath. In the elderly, primary demyelinating diseases of the central nervous system (CNS), such as multiple sclerosis, are relatively uncommon. However, secondary causes of CNS demyelination may often occur and in this case, extensive diagnostic workup is usually needed. Infectious, postinfectious, or postvaccinal demyelination may be observed, attributed to age-related alterations of the immune system in this population. Osmotic disturbances and nutritional deficiencies, more commonly observed in the elderly, may lead to conditions such as pontine/extrapontine myelinolysis, Wernicke encephalopathy, and demyelination of the posterior columns of the spinal cord. The prevalence of malignancies is higher in the elderly, sometimes leading to radiation-induced, immunotherapy-related, or paraneoplastic CNS demyelination. This review intends to aid clinical neurologists in broadening their diagnostic approach to secondary CNS demyelinating diseases in the elderly. Common clinical conditions leading to secondary demyelination and their clinical manifestations are summarized here, while the current knowledge of the underlying pathophysiological mechanisms is additionally presented.

Pseudohyponatremia: Mechanism, Diagnosis, Clinical Associations and Management

Pseudohyponatremia remains a problem for clinical laboratories. In this study, we analyzed the mechanisms, diagnosis, clinical consequences, and conditions associated with pseudohyponatremia, and future developments for its elimination. The two methods involved assess the serum sodium concentration ([Na]_S) using sodium ion-specific electrodes: (a) a direct ion-specific electrode (ISE), and (b) an indirect ISE. A direct ISE does not require dilution of a sample prior to its measurement, whereas an indirect ISE needs pre-measurement sample dilution. [Na]_S measurements using an indirect ISE are influenced by abnormal concentrations of serum proteins or lipids. Pseudohyponatremia occurs when the [Na]_S is measured with an indirect ISE and the serum solid content concentrations are elevated, resulting in reciprocal depressions in serum water and [Na]_S values. Pseudonormonatremia or pseudohypernatremia are encountered in hypoproteinemic patients who have a decreased plasma solids content. Three mechanisms are responsible for pseudohyponatremia: (a) a reduction in the [Na]_S due to lower serum water and sodium concentrations, the electrolyte exclusion effect; (b) an increase in the measured sample's water concentration post-dilution to a greater extent when compared to normal serum, lowering the [Na] in this sample; (c) when serum hyperviscosity reduces serum delivery to the device that apportions serum and diluent. Patients with pseudohyponatremia and a normal [Na]_S do not develop water movement across cell membranes and clinical manifestations of hypotonic hyponatremia. Pseudohyponatremia does not require treatment to address the [Na]_S, making any inadvertent correction treatment potentially detrimental.

Hyponatremia in Patients with Hematologic Diseases

Hyponatremia is the most common electrolyte disorder in clinical practice and is associated with increased morbidity and mortality. It is frequently encountered in hematologic patients with either benign or malignant diseases. Several underlying mechanisms, such as hypovolemia, infections, toxins, renal, endocrine, cardiac, and liver disorders, as well as the use of certain drugs appear to be involved in the development or the persistence of hyponatremia. This review describes the pathophysiology of hyponatremia and discusses thoroughly the contributing factors and mechanisms that may be encountered specifically in patients with hematologic disorders. The involvement of the syndrome of inappropriate antidiuretic hormone (SIADH) secretion and renal salt wasting syndrome (RSWS) in the development of hyponatremia in such patients, as well as their differential diagnosis and management, are also presented. Furthermore, the distinction between true hyponatremia and pseudohyponatremia is explained. Finally, a practical algorithm for the evaluation of hyponatremia in hematologic patients, as well as the principles of hyponatremia management, are included in this review.

A retrospective analysis of hyponatremia during terlipressin treatment in patients with esophageal or gastric variceal bleeding due to portal hypertension

Background and Aim

To explore the risk factors of hyponatremia caused by terlipressin.

Methods

Forty‐four patients with acute variceal bleeding treated with terlipressin from December 2016 to December 2018 were analyzed.

Results

During the treatment, serum sodium levels decreased from 137.78 to 126.59 mmol/L (P < 0.05), with an average decrease of 11.19 mmol/L. The serum sodium level decreased by less than 5 mmol/L in 12 patients (27.27%), by 5–10 mmol/L in 13 patients (27.27%), and by more than 10 mmol/L in 19 patients (43.18%). The difference in baseline serum sodium levels was statistically significant (P < 0.05), and the differences in baseline total bilirubin levels, Child‐Pugh scores, and model for end‐stage liver disease scores were also significant. Logistic regression analysis suggested that the initial sodium level was an independent risk factor for the decrease in the serum sodium concentration caused by terlipressin.

Conclusion

The incidence of hyponatremia is not low during treatment with terlipressin; a higher baseline serum sodium level is a risk factor for hyponatremia during treatment with terlipressin, and the mechanism may be related to endogenous vasopressin preconditioning.

Coronary artery bypass graft combined with liver transplantation in patients with advanced alcoholic liver cirrhosis: A case report

Performing cardiothoracic surgery on patients with advanced liver failure and liver cirrhosis is high-risk for patients. Coronary artery bypass grafting is the most effective treatment for patients with liver failure that is complicated with severe coronary heart disease, and who cannot be treated using coronary stent intervention. In the current study, one case of coronary artery bypass grafting combined with liver transplantation was assessed, with the patient exhibiting advanced alcoholic liver cirrhosis. A coronary artery bypass graft was performed to relieve angina pectoris. Following surgery, wound exudation, secondary infection, liver failure, pleuroperitoneal fluid leakage, hypoproteinemia and other adverse treatment results occurred, and the chest wound did not heal. Allograft liver transplantation was subsequently performed and, following surgery, the chest wound healed gradually after debridement, and the patient recovered.

Mechanisms in fluid retention - towards a mutual concept

Fluid retention is a common and challenging condition in daily clinical practice. The normal fluid homoeostasis in the human body is based on accurately counter-balanced physiological mechanisms. When compromised fluid retention occurs and is seen in pathophysiologically different conditions such as liver cirrhosis, heart and kidney failure, and in preeclampsia. These conditions may share pathophysiological mechanisms such as functional arterial underfilling, which seems to be a mutual element in cirrhosis, cardiac failure, cardiorenal and hepatorenal syndromes, and in pregnancy. However, there are also distinct differences and it is still unclear whether kidney dysfunction or arterial underfilling is the initiating factor of fluid retention or if they happen simultaneously. This review focuses on similarities and differences in water retaining conditions and points to areas where important knowledge is still needed.

Pharmacological management of hyponatremia

INTRODUCTION

Hyponatremia is the most common electrolyte disorder with a prevalence of up to 30% in hospitalized patients. Furthermore, it is associated with increased morbidity and mortality.

AREAS COVERED

This review discusses the efficacy and side effects of the currently available treatment options for hyponatremia and the differences in the pharmacological approach between the European and USA guidelines. Additionally, the authors provide their expert perspectives on current treatment strategies and what they expect from this field in the future.

EXPERT OPINION

Several pharmacological options are available for the treatment of hyponatremia, but data from trials examining and comparing these treatments are missing. Regarding chronic hyponatremia, the role of vaptans should be further analyzed, focusing on comparisons with other active treatments on patient-relevant outcomes and not only on serum sodium concentration. Clinicians should be cautious to an overly rapid increase in serum sodium levels with all available treatment strategies. Finally, it is important to ascertain whether correction of serum sodium levels improves mortality in hyponatremic patients.

Hyponatremia in the elderly: challenges and solutions

Decreased serum sodium concentration is a rather frequent electrolyte disorder in the elderly population because of the presence of factors contributing to increased antidiuretic hormone, the frequent prescription of drugs associated with hyponatremia and also because of other mechanisms such as the “tea and toast” syndrome. The aim of this review is to present certain challenges in the evaluation and treatment of hyponatremia in the elderly population and provide practical solutions. Hyponatremia in elderly subjects is mainly caused by drugs (more frequently thiazides and antidepressants), the syndrome of inappropriate antidiuretic hormone secretion (SIAD) or endocrinopathies; however, hyponatremia is multifactorial in a significant proportion of patients. Special attention is needed in the elderly population to exclude endocrinopathies as a cause of hyponatremia before establishing the diagnosis of SIAD, which then requires a stepped diagnostic approach to reveal its underlying cause. The treatment of hyponatremia depends on the type of hyponatremia. Special attention is also needed to correct serum sodium levels at the appropriate rate, especially in chronic hyponatremia, in order to avoid the osmotic demyelination syndrome. In conclusion, both the evaluation and the treatment of hyponatremia pose many challenges in the elderly population.

Prevention of the Osmotic Demyelination Syndrome After Liver Transplantation: A Multidisciplinary Perspective

The osmotic demyelination syndrome (ODS) is a serious neurologic condition that occurs in the setting of rapid correction of hyponatremia. It presents with protean manifestations, from encephalopathy to the "locked-in" syndrome. ODS can complicate liver transplantation (LT), and its incidence may increase with the inclusion of serum sodium as a factor in the Mayo End-Stage Liver Disease score. A comprehensive understanding of risk factors for the development of ODS in the setting of LT, along with recommendations to mitigate the risk of ODS, are necessary. The literature to date on ODS in the setting of LT was reviewed. Major risk factors for the development of ODS include severe pretransplant hyponatremia (serum sodium [SNa] < 125 mEq/L), the magnitude of change in SNa pre- versus posttransplant, higher positive intraoperative fluid balance, and the presence of postoperative hemorrhagic complications. Strategies to reduce the risk of ODS include correcting hyponatremia pretransplant via fluid restriction and/or ensuring an appropriate rate of increase from the preoperative SNa via close attention to fluid and electrolyte management both during and after surgery. Multidisciplinary management involving transplant hepatology, nephrology, neurology, surgery, and anesthesiology/critical care is key to performing LT safely in patients with hyponatremia.

Electrolyte and Acid-Base Disturbances in End-Stage Liver Disease: A Physiopathological Approach

Electrolyte and acid-base disturbances are frequent in patients with end-stage liver disease; the underlying physiopathological mechanisms are often complex and represent a diagnostic and therapeutic challenge to the physician. Usually, these disorders do not develop in compensated cirrhotic patients, but with the onset of the classic complications of cirrhosis such as ascites, renal failure, spontaneous bacterial peritonitis and variceal bleeding, multiple electrolyte, and acid-base disturbances emerge. Hyponatremia parallels ascites formation and is a well-known trigger of hepatic encephalopathy; its management in this particular population poses a risky challenge due to the high susceptibility of cirrhotic patients to osmotic demyelination. Hypokalemia is common in the setting of cirrhosis: multiple potassium wasting mechanisms both inherent to the disease and resulting from its management make these patients particularly susceptible to potassium depletion even in the setting of normokalemia. Acid-base disturbances range from classical respiratory alkalosis to high anion gap metabolic acidosis, almost comprising the full acid-base spectrum. Because most electrolyte and acid-base disturbances are managed in terms of their underlying trigger factors, a systematic physiopathological approach to their diagnosis and treatment is required.

Use of intravenous fluids/solutions: a narrative review

OBJECTIVE

Intravenous fluids are broadly categorized into colloids and crystalloids. The aim of this review is to present under a clinical point of view the characteristics of intravenous fluids that make them more or less appropriate either for maintaining hydration when enteral intake is contraindicated or for treating hypovolemia.

METHODS

We considered randomized trials and meta-analyses as well as narrative reviews evaluating the effects of colloids or crystalloids in patients with hypovolemia or as maintenance fluids published in the PubMed and Cochrane databases.

RESULTS

Clinical studies have not shown a greater clinical benefit of albumin solutions compared with crystalloid solutions. Furthermore, albumin and colloid solutions may impair renal function, while there is no evidence that the administration of colloids reduces the risk of death compared with resuscitation with crystalloids in patients with trauma, burns or following surgery. Among crystalloids, normal saline is associated with the development of hyperchloremia-induced impairment of kidney function and metabolic acidosis. On the other hand, the other commonly used crystalloid solution, the Ringer's Lactate, has certain indications and contraindications. These matters, along with the basic principles of the administration of potassium chloride and bicarbonate, are meticulously discussed in the review.

CONCLUSIONS

Intravenous fluids should be dealt with as drugs, as they have specific clinical indications, contraindications and adverse effects.

Hyponatremia and risk factors for death in human visceral leishmaniasis: new insights from a cross-sectional study in Brazil

Background

Visceral leishmaniasis (VL) is an important and potentially fatal neglected tropical disease. The aim of this study was to investigate hyponatremia and risk factors for death among VL patients.

Methods

This is a cross-sectional study with VL patients admitted to a tertiary hospital in Northeast Brazil, from 2002 to 2009. Patients were divided into two groups: non-survivors and survivors. Hyponatremia was defined as serum sodium < 135 mEq/L. A logistic regression model was done to investigate risk factors for death.

Results

A total of 285 VL patients were included, with mean age 37 ± 15 years, and 74% were males. Thirty-four patients died (11.9%). Non-survivors had a significantly higher prevalence of dyspnea (38.2 vs. 16.7%, p = 0.003), pulmonary crackles (11.8 vs. 4.0%, p = 0.049), dehydration (23.5 vs. 10.8%, p = 0.033), oliguria (8.8 vs. 0.8%, p = 0.001) and jaundice (47.1 vs. 14.3%, p < 0.001). They also presented higher prevalence of hyponatremia (41.9 vs. 24.1%, p = 0.035), thrombocytopenia (91.2 vs. 65.3%, p = 0.002) and severe hypoalbuminemia (78.3 vs. 35.3%, p < 0.001). In multivariate analysis, moderate/severe hyponatremia (OR = 2.278, 95% CI = 1.046–4.962), thrombocytopenia (OR = 5.482, 95% CI = 1.629–18.443), jaundice (OR = 5.133, 95% CI = 1.793–14.696) and severe hypoalbuminemia (OR = 6.479, 95% CI = 2.124–19.766) were predictors of death.

Conclusion

Higher prevalence of dehydration, oliguria, pulmonary symptoms and liver involvement was found in non-survivors VL patients. Hypoalbuminemia and hyponatremia were frequent and significantly associated with mortality.