Prevalence of hyponatremia in patients admitted with heart failure at the Kenyatta National Hospital.

Abstract

Background Hyponatremia is a common electrolyte disturbance in hospitalized patients with heart failure. It is associated with high morbidity, longer in-hospital stay and is a well known predictor of mortality in patients with heart failure. There is a paucity of data on the prevalence of hyponatremia in patients with heart failure in Kenya. Objectives The aim of the study was to determine the prevalence of hyponatremia in patients admitted with heart failure in the medical wards at the Kenyatta National Hospital. Methodology This was a prospective, observational cohort study conducted over a period of about 3 months in patients above 13 years with heart failure in the medical wards. Patients were screened using the Modified Framingham „Criteria for eligibility and recruited upon signing an informed consent or assent. Sodium levels were done within 24 hours of admission and patients were followed up to determine their outcome at two weeks. The outcomes included, in hospital mortality, discharged home and prolonged stay in hospital beyond the 2 weeks. Results The study was conducted from December 2015 to February 2016. Eighty nine patients with heart failure based on the Modified Framingham‟s Criteria were recruited. 53.9% were males and the mean age of the patients was 51.6±18.8 years with a range of 14-86 years. On admission 94.4% of the patients were in NYHA class 3 and 4. 79.8% (95% CI 71.9-87.6) of the patients had hyponatremia at admission. The mean sodium level was 128.2±8.1 mmol/L. Of these, 84.3% were on a loop diuretic at admission while 6.7% were on a thiazide diuretic. During the 2 week follow up period, 13.5% of all the patients admitted with heart failure died while 48.5% were discharged from the hospital. 38.2% of the patients had a prolonged stay and were still undergoing treatment at the lapse of the 2 weeks. Of those who died 66.7% had hyponatremia while 88.2% of those who were still admitted at the lapse of the 2 weeks had hyponatremia. Conclusion This study found a high prevalence of hyponatremia in patients admitted with heart failure at the KNH. Hyponatremia did not affect the short term outcomes in a statistically significant way; however, the trend suggests worse outcomes in the hyponatremia patients.