Serum Sodium Level and Its Correlation with Curb-65 Score in Community Acquired Pneumonia – A Study from Bangalore, India

BACKGROUND Community acquired pneumonia (CAP) refers to pneumonia contracted by a person with little or no contact with health care system. Severity scores like CURB 65 severity score are useful in estimating the outcome. Hyponatremia is defined as serum sodium level < 135 mEq/L. The incidence of hyponatremia at hospital admission among CAP patients is found to be 28 %and the mechanism behind it has been found to be due to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hence this study is an effort to explore how hyponatremia is associated with severity and outcomes, in hospitalized patients with pneumonia. The purpose of this study was to assess the proportion of hyponatremia in patients with community acquired pneumonia and compare hyponatremia with CURB-65 as an initial screening tool for assessment of severity of CAP. METHODS This is a hospital-based cross-sectional study. 75 community acquired pneumonia patients admitted as inpatients are included in this study. Information is collected and detailed history is taken using pre-formed proforma at the time of admission. Serum sodium levels were measured, after initial assessment of patients. The lab values of serum sodium levels were analysed with the clinical profile and outcome in these study groups. RESULTS In our study, it was observed that as the sodium levels are decreasing, the CURB 65 score increases. Study subjects who had sodium levels < 125 mg/dl, presented with CURB 65 score as 4 (30 %). Inversely, the study subjects with high sodium levels (> 135 mg/dl) had CURB 65 scores as 1 (75 %). The association between sodium levels and CURB 65 score was significant in patients who got discharged but not in patients who expired. CONCLUSIONS Present study of serum sodium levels as biomarkers in CAP showed that hyponatremia carried poor prognosis which correlated with high CURB 65 score. KEYWORDS Sodium, Community Acquired Pneumonia, SIADH, CURB 65, Hyponatremia, COPD