Neurodevelopmental consequences of early plasma sodium changes in very preterm infants

Background Sodium fluctuations in very preterm neonates and their neurodevelopmental consequences are not well described. Methods We assessed the changes in plasma sodium and glucose in the first days of life in very preterm neonates and studied the association of glucose-corrected plasma sodium fluctuations on neurodevelopmental outcomes. We included 147 consecutive neonates born before 29 weeks of gestation in our center and retrospectively obtained plasma sodium, glucose, and glucose-corrected sodium levels. Neurodevelopmental assessment was obtained from the Canadian Neonatal Follow-Up Network. Results Mean ± standard deviation of plasma sodium changes within the first 10 days of life were 16.2 ± 6.0, 14.8 ± 5.3, and 11.1 ± 5.2 mmol/l in neonates born ≤25, 25–26, and 26–27 weeks of gestation, respectively ( p < 0.001). Non-steroidal anti-inflammatory drug administration was associated with larger plasma sodium fluctuation. Eighty-six percent had a known neurological status at 18 months. Higher fluctuations in glucose-corrected plasma sodium were associated with death or neurodevelopmental impairment at 18 months corrected age ( B = 3.19, 95% CI [1.24, 5.14]), and this association remained after adjustment for gestational age ( B = 2.1, 95% CI [0.16, 4.04]). Conclusions Neonates born very preterm show fluctuations in glucose-corrected plasma sodium during the first days of life, which may increase the risk of death or developmental impairment. Impact Risk factors and neurodevelopmental consequences of plasma sodium changes in early neonatal life of preterm infants are not well characterized. This study shows for the first time that glucose-corrected plasma sodium fluctuations within the first days of life are more severe in preterm infants receiving non-steroidal anti-inflammatory drugs (NSAIDs) and are associated with death or neurodevelopmental impairment at 18 months corrected age. Large plasma sodium and glucose fluctuations should be expected more often in preterm infants receiving NSAIDs and should be avoided.