RESUMO
OBJECTIVE: The objective of the study was to evaluate the etiology of hospital-acquired hyponatremia (HAH) and its effects on morbidity and mortality in the Pediatric Intensive Care Unit (PICU) patients. DESIGN: This study design was a prospective observational case-control study. SETTING: this study was conducted at tertiary care PICU. MATERIALS AND METHODS: All consecutive cases admitted with at least one measured serum sodium (PNa) value were evaluated. Those with normal admission PNa were followed till they develop hyponatremia (PNa < 35 mEq/L) 7 days or PICU discharge whichever was earlier. RESULTS: During the study period, 123 (19.6%) cases developed HAH and 126 patients remained isonatremic (control group). The admission PNa 138.8 ± 3.03 mEq/L decreased to 132 ± 2.58 mEq/L (drop of 6.68 ± 3.39 mEq/L, P < 0.001) in HAH cases. The use of antidiuretic hormone (ADH)-stimulating drugs (odds ratio [OR]: 2.83, P = 0.01), postsurgical status (OR: 2.95, P = 0.006), and fluid intake ml/kg (OR: 1.0, P = 0.001) were found to be significant risk factors in HAH group on multivariate analysis. HAH cases had prolonged PICU stay (P = 0.000) and mechanical ventilation (P = 0.01), but no difference in the mortality when compared to controls. CONCLUSIONS: HAH is associated with increased fluid intake, presence of ADH-stimulating drugs or conditions, and postsurgical status and has an adverse effect on the outcome of PICU patients.