Serum Sodium Predicts Prognosis in Critically Ill Cirrhotic Patients

Background: End-stage liver disease is often complicated by hyponatremia. Cirrhotic patients with hyponatremia admitted to intensive care units (ICUs) have high mortality rates. This study analyzed the outcomes of critically ill cirrhotic patients and identified the prognostic value of serum sodium concentration. Methods: One hundred twenty-six consecutive cirrhotic patients admitted to the ICU of a tertiary center during a 1.5-year period were enrolled in this study. Demographic, clinical, and laboratory variables on the first day of ICU admission were prospectively recorded for post hoc analysis. Results: Overall hospital mortality was 65.1%. Comparing with serum sodium > 135 mmol/L, patients with serum sodium <= 135 mmol/L had a greater frequency of ascites, illness severity scores, hepatic encephalopathy, sepsis, renal failure, and in-hospital mortality (55.9% vs. 73.1%, P=0.043). Multiple Cox proportional hazards analysis revealed that serum sodium levels, hepatocellular carcinoma, and sequential organ failure assessment scores on the first day of ICU admission were independent risk factors for 6-month mortality. Cumulative survival rates at 6-month follow-up after hospital discharge differed significantly (P<0.05) between patients with serum sodium > 135 mmol/L versus those with serum sodium <= 135 mmol/L. Conclusions: Low serum sodium levels in critically ill cirrhotic patients are associated with high complications of liver cirrhosis, in-hospital mortality, and poor short-term prognosis. The serum sodium concentration is important predictor of survival among candidates for liver transplantation. Future research with sequential application of serum sodium may reflect the dynamic aspects of clinical conditions, thus providing complete data for mortality risk.