Hyponatremia in melioidosis: Analysis of 10-year data from a hospital-based registry

Introduction: Hyponatremia is a frequent finding in hospitalized patients and is associated with poor clinical outcomes. While hyponatremia is known to commonly occur in certain infections, its association with melioidosis has not been studied previously. We studied incidence and impact of hyponatremia on clinical outcomes in melioidosis. Methods: This was a retrospective analysis of a single-center hospital registry of culture-positive patients with melioidosis hospitalized during a 10-year period (January 01, 2010, through January 31, 2021). Hyponatremia was defined as serum sodium of <135 mmol/L, and severe hyponatremia as serum sodium <120 mmol/L. The association of hyponatremia with in-hospital mortality, need for intensive care unit (ICU) stay and mechanical ventilation was studied. Results: Of 201 patients with melioidosis, 169 (84.1%) had hyponatremia, with severe hyponatremia in 35 (17.4%) patients. Older age (adjusted odds ratios [OR] 1.03, 95% confidence intervals [CI]: 1.00-1.06; P = 0.049) and acute kidney injury (AKI) (adjusted OR 3.30, 95% CI: 1.19-9.19; P = 0.02) were independently associated with hyponatremia. Twenty-two patients had been evaluated for cause of hyponatremia and of these, 11 (50%) had syndrome of inappropriate antidiuresis. Severe hyponatremia was associated with in-hospital mortality (adjusted OR 3.75, 95% CI: 1.37-10.27; P = 0.01), need for ICU stay (adjusted OR 7.04, 95% CI: 2.88-17.19; P < 0.001) and mechanical ventilation (adjusted OR 3.99, 95% CI: 1.54-10.32; P = 0.004). Conclusion: Hyponatremia occurs in 84.1% of hospitalized patients with melioidosis. Older age and AKI are associated with a higher incidence of hyponatremia. The presence of severe hyponatremia is an independent predictor of in-hospital mortality, need for mechanical ventilation and ICU stay.