Hyponatremia in Cirrhosis

Abstract

Hyponatremia is the most common electrolyte disorder encountered in clinical practice, and it is a common complication of cirrhosis reflecting an increase in nonosmotic secretion of arginine vasopressin as a result of of the circulatory dysfunction that is characteristic of advanced liver disease. Hyponatremia in cirrhosis has been associated with poor clinical outcomes including increased risk of morbidity and mortality, poor quality of life, and heightened health care utilization. Despite this, the treatment of hyponatremia in cirrhosis remains challenging as conventional therapies such as fluid restriction are frequently ineffective. In this review, we discuss the epidemiology, clinical outcomes, pathogenesis, etiology, evaluation, and management of hyponatremia in cirrhosis.

Keywords: Albumin; Arginine vasopressin; Ascites; Central pontine myelinolysis; Cirrhosis; Hyponatremia; Liver transplantation; Osmotic demyelination syndrome.

Figure 1.. Clinical Outcomes of Hyponatremia of Cirrhosis

HRQOL=health-related quality of life

Figure 2.. Pathogenesis of Hyponatremia of Cirrhosis.

NO=nitric oxide, EABV=effective arterial blood volume, RAAS=renin-angiotensin-aldosterone system, SNS=sympathetic nervous system, AVP=arginine vasopressin, V2R=vasopressin 2 receptor, AQP2=aquaporin 2, Na=sodium, H₂0=water, ↑=increased, ↓=decreased

Figure 3.. Etiology of Hyponatremia in Cirrhosis

AVP=arginine vasopressin, SVR=systemic vascular resistance, ETOH=ethanol, ↓=decreased

Figure 4.. Diagnostic Approach to Hyponatremia in Cirrhosis

SNa=serum sodium, SOsm=serum osmolality, UOsm=urine osmolality, AVP=arginine vasopressin, UNa=urine sodium, POCUS=point-of-care ultrasound, LVP=large volume paracentesis, GI=gastrointestinal. POCUS (+): presence of features of intravascular volume depletion. POCUS (−): absence of features of intravascular volume depletion.

Figure 5.. Perioperative Management of Hyponatremia in Patients Awaiting Liver Transplant

For patients with enough time to correct serum sodium (SNa) slowly (e.g., 7-day window before surgery), discontinuation of diuretics, potassium repletion, fluid restriction, and albumin should be attempted for the first 48 hours before moving to tolvaptan. For patients who are immediately going to the operating room where there is no time to correct SNa slowly, intraoperative continuous renal replacement therapy (CRRT) with low sodium dialysate or post filter fluid replacement with dextrose 5% in water (D5W) could be considered.