Hyponatremia could be an important prognostic factor for oncology patients: Result of a retrospective study.

Abstract

7055 Background: Hyponatraemia is the most common electrolyte disorder encountered in clinical practice. Hyponatraemia in hospitalized people is associated with an increased morbidity, mortality and longer hospital stay compared with people with normal serum sodium concentrations. It is a negative prognostic indicator for survival in oncology patients. Incidence of hyponatremia in malignancy is largely underestimated. Methods: Retrospective analysis of patients admitted to oncology ward in our institution between August to September 2018 was conducted. Patients were identified from admission register and data were analysed from electronic medical records. Primary aim was to evaluate the incidence of hyponatraemia in oncology in-patients and impact on survival. Data were also analysed for patients demography, cancer types, grade of hyponatremia and treatment approach. Results: 119 patients were admitted to oncology ward during study period. Out of them 38% were identified to be Hyponatraemic and 51 % patients were male. Lung cancer was the predominant cancer type followed by breast, upper GI and ovarian respectively. Of hyponatraemic patients, 63% were asymptomatic, among symptomatic patients vomiting, confusion and headaches are common. According to severity, 42% patients had grade 1, 40% grade 2 and 18% grade 3 hyponatraemia respectively. When it comes to status of hydration, 62.2% were noted to be euvolaemic, 6.66% were hypervolaemic and 15.5% were hypovolaemic and the hydration status of the rest of 15.5% were not known. Considering mortality, 53% patients died within 30 days of diagnosis of hyponatremia compared to 17% deaths among non-hyponatraemic patients. Median survival of patients with grade 3, 2 and 1 hyponatremia were 29, 35 and 62 days respectively. Out of 45 patients 14 (31.1%) had acute onset hyponatraemia and they had considerably poorer survival compared to their chronic hyponatraemic counterparts. 80% of acute hyponatraemic patients have died within 30 days of diagnosis, compared to 140 days for chronic hyponatraemics with similar death rate. Out of 48% non-hyponatraemic patients who died within next 6 months, 31% developed hyponatraemia at some point before their death and amongst them, 5.7% had severe, 8.5% had moderate and 17% had mild hyponatraemia respectively. Conclusions: Our study indicated that hyponatremia is poor prognostic factor among oncology patients, with mortality being significantly higher when the grade is higher and when acute in onset. Identifying and early intervention could improve patient outcome.