Risk factors and clinical impact of sodium and potassium disorders in community-acquired pneumonia

Dysnatremia and dyskalemia are common electrolyte disturbances in patients hospitalized with community-acquired pneumonia (CAP) and have been associated with increased disease severity and adverse clinical outcomes. This study aimed to evaluate the relationship between sodium and potassium disturbances at hospital admission and clinical outcomes, including morbidity and early and late mortality, in patients with CAP.

A total of 998 patients hospitalized with CAP were retrospectively analyzed. Demographic characteristics, comorbidities, admission laboratory parameters, CURB-65 scores, intensive care unit (ICU) admission, ventilatory support requirements, in-hospital mortality, and six-month mortality were recorded. Patients were classified according to the presence and type of electrolyte disturbances at hospital admission and compared accordingly.

The mean age of the study population was 71.4 ± 15.6 years, and 46.0% (n = 459) were female. Mean serum sodium and potassium levels at admission were 138.9 ± 5.6 mmol/L and 4.38 ± 0.72 mmol/L, respectively. Hyponatremia was the most frequent electrolyte abnormality (22.7%). Patients with potassium disturbances had significantly higher procalcitonin levels (p < 0.001). The need for ICU and MV and in-hospital mortality was higher in patients with hypernatremia and hypokalemia, while 6 months mortality was more frequent in patients with hyperkalemia(p < 0,001) and hospital stay was longer among patients with hypernatremia (p = 0.002).

Electrolyte disturbances at hospital admission are common in patients with CAP and are associated with greater disease severity and increased supportive care requirements. These abnormalities should be interpreted primarily as markers of underlying physiological stress and comorbidity burden rather than independent predictors of mortality. Early recognition of dysnatremia and dyskalemia may support clinical risk awareness and prompt evaluation of potentially reversible contributing factors during inpatient management of CAP.