Assessment of association between rapid fluctuations in serum sodium and intraventricular hemorrhage in hypernatremic preterm infants.

Aim: This study aims to determine the association between the rapid fluctuations in serum sodium and intraventricular hemorrhage (IVH) or death in hypernatremic preterm infants.

Study Design: Single center observational study including 216 infants < 1,000 g birth weight and <29 weeks gestational age, who had serum sodium levels monitored at least every 12 hours. Logistic regression analyses were used to identify which of the commonly cited risk factors for IVH, including the rapid (to the extent of ≥10 and ≥15 mmol/L/d) rise or fall in serum sodium, was associated with the primary outcome of any IVH, or the secondary composite outcome of severe IVH or death during the first 10 days of life in hypernatremic infants.

Results: Of 216 infants, 126 (58%) studied developed hypernatremia (serum sodium ≥ 150 mmol/L). IVH was more frequent in hypernatremic infants (p = 0.01). Presence of hypernatremia was an independent risk factor for IVH on logistic regression analysis (p = 0.022, odds ratio 2.0, 95% confidence interval: 1.1-3.8). Rapid (≥ 10 and ≥ 15 mmol/L/d) rise or fall in serum sodium in hypernatremic infants was not associated with the outcomes.

Conclusion: Hypernatremia per se, but not the rapid fluctuations (not exceeding 10-15 mmol/L/d) in serum sodium was independently associated with IVH.