Correction of hyponatraemia in cirrhosis: treating more than a number!

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.

Clinical Significance and Management of Hyponatremia in Liver Cirrhosis

The overall prevalence of hyponatremia in cirrhotics is around 50%. Hypovolemic hyponatremia is a result of excessive fluid loss caused mostly by diuretic treatment or diarrhea. More common is hypervolemic hyponatremia, which results from excessive activation of water and sodium-retaining mechanisms caused by effective arterial hypovolemia. This review focuses on the associations of hyponatremia with clinical outcomes and reviews the available data on its management. Hyponatremia is a strong predictor of mortality and is also associated with an increased probability of hepatorenal syndrome, disturbance of consciousness, infections, and unfavorable post-transplant outcomes. In the management of hyponatremia, it is crucial to distinguish between hypovolemic and hypervolemic hyponatremia. The treatment of hypervolemic hyponatremia should be started only in symptomatic patients. The cessation of the treatment with traditional diuretics and fluid restriction may prevent further decrease in natremia. Pharmacological treatment is directed towards cirrhosis itself, precipitating factor, or hyponatremia directly. Currently, only albumin infusions can be recommended routinely. Other possibilities, such as vaptans, splanchnic vasoconstrictors, niravoline, or osmotic diuretics, are restricted to specific use cases (e.g., imminent liver transplantation) or need more research to determine their efficacy. We tried to summarize the management of hyponatremia into a concise flowchart.

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.

Natremia and liver transplantation: The right amount of salt for a good recipe

An adequate balance between electrolytes and clear water is of paramount importance to maintaining physiologic homeostasis. Natremia imbalance and, in particular, hyponatremia is the most frequent electrolyte abnormality observed in hospitalized subjects, involving approximately one-fourth of them. Pathological changes occurring during liver cirrhosis predispose patients to an increased risk of sodium imbalance, and hypervolemic hyponatremia has been reported in nearly 50% of subjects with severe liver disease and ascites. Splanchnic vasodilatation, portal-systemic collaterals' opening and increased excretion of vasoactive modulators are all factors impairing clear water handling during liver cirrhosis. Of concern, sodium imbalance has been consistently reported to be associated with increased risk of complications and reduced survival in liver disease patients. In the last decades clinical interest in sodium levels has been also extended in the field of liver transplantation. Evidence that [Na+] in blood is an independent risk factor for in-list mortality led to the incorporation of sodium value in prognostic scores employed for transplant priority, such as model for end-stage liver disease-Na and UKELD. On the other hand, severe hyponatremic cirrhotic patients are frequently delisted by transplant centers due to the elevated risk of mortality after grafting. In this review, we describe in detail the relationship between sodium imbalance and liver cirrhosis, focusing on its impact on peritransplant phases. The possible therapeutic approaches, in order to improve transplant outcome, are also discussed.

Hyponatremia in Cirrhosis: An Update

Hyponatremia is frequently seen in patients with ascites secondary to advanced cirrhosis and portal hypertension. Although not apparent in the early stages of cirrhosis, the progression of cirrhosis and portal hypertension leads to splanchnic vasodilation, and this leads to the activation of compensatory mechanisms such as renin-angiotensin-aldosterone system (RAAS), sympathetic nervous system, and antidiuretic hormone (ADH) to ameliorate low circulatory volume. The net effect is the avid retention of sodium and water to compensate for the low effective circulatory volume, resulting in the development of ascites. These compensatory mechanisms lead to impairment of the kidneys to eliminate solute-free water in decompensated cirrhosis. Nonosmotic secretion of antidiuretic hormone (ADH), also known as arginine vasopressin, further worsens excess water retention and thereby hyponatremia. The management of hyponatremia in this setting is a challenge as conventional therapies for hyponatremia including fluid restriction and correction of hypokalemia are frequently inefficacious. In this review, we discuss the pathophysiology, complications, and various treatment modalities, including albumin infusion, selective vasopressin receptor antagonists, or hypertonic saline for patients with severe hyponatremia and those awaiting liver transplantation.

Impact of Vaptans on Clinical Outcomes in Cirrhosis Patients: A Meta-Analysis of Randomized Controlled Trials

Background: Vaptans have been confirmed to mobilize ascites and improve hyponatremia in cirrhosis patients. However, the effects of vaptans on all-cause mortality, ascites-related complications, and adverse events in cirrhosis patients have not been fully determined.

Objectives: To systematically evaluate the impact of vaptans on the clinical outcomes in patients with cirrhosis.

Materials and Methods: A systematic review and meta-analysis was performed. The PubMed, Embase, and Cochrane’s Library electronic databases were systematically searched for randomized controlled trials (RCTs) investigating the clinical efficacy of vaptans in cirrhosis patients. The results were pooled with a random-effect model.

Results: Eighteen RCTs containing 3,059 cirrhosis patients with ascites and/or hyponatremia were included. Meta-analysis showed that vaptans did not significantly affect the risk of all-cause mortality (RR: 1.02, 95% CI: 0.87 to 1.08, p = 0.83; I² = 2%), consistent with studies with short-term (< 26 weeks) and long-term (≥ 26 weeks) follow-up durations. Additionally, vaptans did not affect the incidence of variceal bleeding (RR: 0.96, p = 0.86), showed a trend of reduced incidence of hepatic encephalopathy (RR: 0.86, p = 0.09), significantly reduced the incidence of spontaneous bacterial peritonitis (RR: 0.75, p = 0.03), but did not significantly affect the risk of hepatorenal syndrome or renal failure (RR: 1.09, p = 0.36). Vaptans did not affect the incidence of adverse events in cirrhosis patients.

Discussion: Treatment with vaptans is not associated with improved survival in cirrhosis patients, although it may reduce the risk of hepatic encephalopathy and spontaneous bacterial peritonitis in these patients. The limitations of the current study include limited number of available studies, small sample sizes of the included studies, variations of baseline patient characteristics, and differences in the dose and duration of vaptans.

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.

MELDNa score is associated with psychopathology and reduced quality of life in cirrhotic patients with a liver transplant perspective

Psychopathological symptoms and reduced health related quality of life (HRQoL) are frequent in cirrhotics, but no data on their association with cirrhosis prognosis assessed by the MELDNa score are available. Prospective data on the long-term effect of deceased donor liver transplantation (LT) on psychopathological symptoms are needed. Before entering the LT waiting list, 44 consecutive LT cirrhotic candidates without a major psychiatric disorder underwent a psychopathological assessment, including Symptom Checklist-90-revised (SCL-90-R) and Defense Style Questionnaire (DSQ). HRQoL was measured by Short Form 36 Health Survey (SF-36). Abnormal performance at each questionnaire was defined by using 44 age, gender, BMI and education-matched healthy subjects. Separate binary logistic regression models were used to test the association of the Child-Pugh, MELD and MELDNa scores with abnormal performance at each questionnaire. Fourteen patients repeated the battery tests 3 years after LT. Before LT, increasing MELDNa was the only prognostic score independently associated with an abnormal SCL-90-R global psychopathological score index (OR: 1.207; 95% CI: 1.026-1.420; P = 0.02) and the best independent predictor of reduced HRQoL. After LT, compared to status prior to LT, performance at SF-36 general health perception scale ameliorated (P = 0.02), performance at SCL-90-R somatization scale (P = 0.001) and global psychopathological score index (P < 0.001) worsened and the negative correlation between the psychopathological global score index and HRQoL disappeared. The severity of cirrhosis in LT candidates should be monitored by the MELDNa score to better establish the right psychological counselling. Psychopathology, and in particular somatization, worsens after LT and should be carefully investigated.

Incidence and Predictors of Advanced Liver Fibrosis by a Validated Serum Biomarker in Liver Transplant Recipients

Background and Aims. Serum fibrosis biomarkers have shown good accuracy in the liver transplant (LT) population. We employed a simple serum biomarker to elucidate incidence and predictors of advanced fibrosis after LT over a long follow-up period. Methods. We included 440 consecutive patients who underwent LT between 1991 and 2013. Advanced liver fibrosis was defined as FIB-4 > 3.25 beyond 12 months after LT. Results. Over 2030.5 person-years (PY) of follow-up, 189 (43%) developed FIB-4 > 3.25, accounting for an incidence of 9.3/100 PY (95% confidence interval [CI], 8.1-10.7). Advanced fibrosis was predicted by chronic HCV infection (adjusted hazard ratio (aHR) = 3.96, 95% CI 2.92-5.36, p < 0.001), hypoalbuminemia (aHR = 2.31, 95% CI 1.72-3.09; p < 0.001), and hyponatremia (aHR = 1.48, 95% CI 1.09-2.01; p = 0.01). LT recipients with more than 1 predictor had a higher incidence of advanced fibrosis, the highest being when all 3 predictors coexisted (log-rank: p < 0.001). Conclusions. Chronic HCV infection, hypoalbuminemia, and hyponatremia predict progression to advanced liver fibrosis following LT. Patients with these risk factors should be serially monitored using noninvasive fibrosis biomarkers and prioritized for interventions.