Clinical relevance of hyponatraemia for the hospital outcome of cirrhotic patients

Background. Hyponatraemia frequently develops in cirrhotic patients whose a bility to excrete free water is impaired. The role of hyponatraemia in the prognosis of such patients is unclear. Aim. To evaluate prevalence, clinical associations and prognostic impact of hyponatraemia in cirrhotic inpatients. Patients. A series of 156 cirrhotic patients consecutively admitted to our department, for a total of 191 admissions, were studied. Methods. Serum sodium levels were determined at admission and repeated at l east weekly in all patients. The clinical status and the survival of patien ts with hyponatraemia (less than or equal to 130 mmol/l) were compared to t hose of patients with normal sodium levels. Results. Hyponatraemia was found in 57 out of 191 admissions (29.8%). Bacte rial infections, ascites, chronic diuretic therapy, but not gastrointestina l bleeding or renal failure, were more frequent in patients with hyponatrae mia than in those with normal sodium levels. In 3 cases, none of these cond itions were present and hyponatraemia was defined as "spontaneous': Hospita l death rate was increased in patients with hyponatraemia (26.3% versus 8.9 %, chi (2)=8.55, p=0.003). By multivariate analysis, the only parameters in dependently associated with survival were high serum bilirubin (p=0.006) an d high serum urea levels (p=0.019). Twenty-five patients developed severe h yponatraemia (<125 mmol/l] during hospital stay. This event was associated with a concomitant bacterial infection in 21 cases. The mortality rate of t hese patients was very high (48%). Conclusions. Hyponatraemia is frequent in cirrhotic inpatients. It is seldo m a spontaneous event but rather occurs in association with ascites, chroni c use of diuretics or bacterial infections. It is a negative prognostic fac tor associated with increased short-term mortality.