Hyponatremia is a predictor of hospital length and cost of stay and outcome in cancer patients

Purpose: Hyponatremia is the most common electrolyte disorder in hospitalized patients, and it might be an indicator of poor prognosis and might have negative effects on hospitalization length and quality of life in non-malignant as well as in malignant diseases. The aim of this study is to determine the impact of hyponatremia on the length and on the cost of hospitalization as well as on outcome in cancer patients. Methods: The present study includes 105 consecutive cancer patients hospitalized at our institution from June 2013 to December 2013. Data regarding age, sex, staging, histology, chemotherapy, and serum sodium levels at admission, during hospitalization, and at discharge were recorded and statistically analyzed. Impact of hyponatremia on length and cost of hospitalization and on outcome was evaluated. Results: A significant difference in overall survival since the date of admission was observed between eunatremic and hyponatremic patients (p = 0.0255). A statistically significant correlation was also found between the length of stay and the detection of hyponatremia. At multivariate analysis, hyponatremia at admission, severity of hyponatremia, and stage of disease resulted independent prognostic factors. Furthermore, a patient with moderate or severe hyponatremia cost, in rate terms, 128 and 299 % more than a normonatremic patient, respectively. Conclusions: The occurrence of hyponatremia at the admission or during the hospitalization may represent a significant factor influencing the outcome and the length of hospitalization. Acting effective and timely on the normalization of sodium levels might have a positive effect on prognosis in this setting of patients, as well as on the length of stay in hospital, thus potentially resulting in savings.