Hyponatremia in children hospitalized due to pneumonia.

The aim of this study was to evaluate the relation between hyponatremia (HN) and severity of community-acquired pneumonia (CAP) in children. The study consisted of a retrospective analysis of medical records of 312 children (165 boys, 147 girls) aged 33 days to 16 years, hospitalized with CAP. The children were divided into two age-groups: under and over the age of four. Clinical findings such as breath frequency, heart rate, capillary blood saturation, body temperature, time for defeverscence, duration of antibiotic treatment and hospital stay, and the serum inflammatory markers WBC, neutrophil count, CRP, and procalcitonin level were used as the disease severity predictors. The results demonstrate that hyponatremia was observed in 104/312 (33.3 %) patients. Children with HN of both age-groups had higher neutrophil counts (6.96 vs. 5.73*10(3)/μL; p < 0.05 and 12.46 vs. 8.22*10(3)/μL; p = 0.01), those aged > 4 had higher WBC (15.85 vs. 11.0*10(3)/μL; p = 0.02), and those aged < 4 had a lower lymphocyte count (3.74 vs. 4.75*10(3)/μL; p = 0.02) than children without HN. Hyponatremic children had higher CRP (28.82 mg/L vs. 9.18 mg/L; p < 0.01) and tended to have higher procalcitonin (0.31 vs. 0.19 ng/mL) than children without HN. Body temperature was higher (38.6 vs. 37.6 °C; p < 0.01) and duration of hospitalization was longer (9 vs. 8 days, p = 0.01) in hyponatremic compared with non-hyponatremic children. There was no correlation between the sodium level and either breath frequency, heart rate, capillary blood saturation, time for defeverscence, or time of antibiotic treatment. We conclude that hyponatremia is a frequent finding in CAP and seems associated with the disease severity.