Impact of Hyponatremia on Morbidity, Mortality, and Resource Utilization in Portal Hypertensive Ascites: A Nationwide Analysis

Abstract

Background and aims: Ascites and hyponatremia are important milestones of worsening portal hypertension in those with cirrhosis. The objective of our study was to evaluate the differences in clinical characteristics, resource utilization, and disposition of hospitalized cirrhotic patients with ascites with and without hyponatremia. Methods: The National Inpatient Sample (NIS) database was used to identify all adult hospitalized patients with a diagnosis of cirrhosis and ascites with or without hyponatremia from 2016 to 2017 using ICD-10 codes. Results: During the study period, 10,187 (7.6%) hospitalized patients with cirrhosis had ascites and hyponatremia and 34,555 (24.3%) had ascites but no hyponatremia. Elixhauser comorbidity score, excluding liver disease, was higher in hyponatremic patients (median 21 vs. 12, P < 0.001). Acute kidney injury (50.3% vs. 32.8%, P < 0.001) and sepsis (16.8% vs. 11.8%, P < 0.001) were more common in hyponatremic patients compared to those without hyponatremia. Similarly, acute respiratory failure, coagulopathy, hepatorenal syndrome, spontaneous bacterial peritonitis, acute (on chronic) liver failure, and liver cancer were more common in hyponatremic patients. Hyponatremia patients had a higher number of inpatient procedures, longer (6 days vs. 4 days, P < 0.001) hospital stay, and had higher hospital charges ($97,327 vs. $72,278, P < 0.01) than those without hyponatremia. Inpatient mortality was 38% higher in hyponatremic patients (9.8% vs. 7.1%, P < 0.001) compared to those without hyponatremia. Additionally, hyponatremic patients were less likely to have routine home discharges with self-care. Conclusion: In conclusion, using a large and diverse national cohort of unselected patients, we were able to show that hyponatremia in patients with cirrhosis and ascites is associated with poor clinical outcomes and increased resource utilization.