# Sodium Values During the First 10 Postnatal Days in Extremely-Low-Birth-Weight Infants and Long-Term Neurocognitive Outcomes: A Systematic Review

## TL;DR

This review suggests that early sodium imbalances in extremely low birth weight infants may be linked to brain bleeding and long-term cognitive issues, highlighting the need for better studies on sodium management.

## Contribution

The study systematically reviews the association between early sodium disturbances and neurodevelopmental outcomes in ELBW infants, identifying gaps and suggesting future research directions.

## Key findings

- Hypernatremia in ELBW infants is possibly associated with intraventricular hemorrhage.
- Hyponatremia is linked to long-term neurocognitive outcomes like hearing loss.
- Sodium fluctuations are a risk factor for severe IVH and may relate to neurodevelopmental impairment.

## Abstract

What are the main findings?
Based on our systematic review, we found a possible association between hypernatremia in ELBW infants and IVH.Hyponatremia was associated with long-term neurocognitive outcomes (i.e., hearing loss and a trend to neurocognitive impairment).

Based on our systematic review, we found a possible association between hypernatremia in ELBW infants and IVH.

Hyponatremia was associated with long-term neurocognitive outcomes (i.e., hearing loss and a trend to neurocognitive impairment).

What are the implementations of the main findings?
This systematic review suggests a possible association between early sodium disturbances and adverse neurodevelopmental outcomes in ELBW infants, emphasizing the need for further high-quality, prospective studies, especially since sodium management can be modulated.

This systematic review suggests a possible association between early sodium disturbances and adverse neurodevelopmental outcomes in ELBW infants, emphasizing the need for further high-quality, prospective studies, especially since sodium management can be modulated.

Purpose: To synthesize all existing literature on the association between sodium disturbances during the first 10 days of life in Extremely-Low-Birth-Weight (ELBW) infants and the risk of developing severe intraventricular hemorrhage (IVH > grade 1) or long-term neurodevelopmental impairment. Methods: Applying systematic review (ID CDR42024622933) principles, five major databases were explored. Any study was included if it reported on ELBW infants, on serum sodium values within the first 10 postnatal days, or was related these to neurocognitive or neurodevelopmental outcomes. Results: Ten studies (13,276 infants) met inclusion criteria. Six studies evaluated the association between hypernatremia (>145 or >150 mmol/L) and severe IVH, and two reported a significant association. Among two studies studying hyponatremia (ranging <130 or <120 mmol/L), one found a significant association with severe IVH. Evidence regarding sodium fluctuations (difference between the maximum and minimum serum sodium values) identified fluctuations >13 mmol/L as a strong risk factor for severe IVH, while another study showed that glucose-corrected sodium fluctuations were independently associated with severe IVH. Long-term neurodevelopmental outcomes were reported in four studies; hyponatremia was significantly associated with hearing loss in one study (OR 5.6 (95% CI 1.1–27.8)), while another study reported that glucose-corrected sodium fluctuations were associated with neurodevelopmental impairment at 18–21 months, although significance disappeared after adjustment for confounding factors. Conclusion: Considering the limitations related to heterogeneity in study design, threshold sodium values and cohort size, this systematic review suggests a possible association between early sodium disturbances and adverse neurodevelopmental outcomes in ELBW infants, emphasizing the need for further high-quality, prospective studies, especially since sodium management can be modulated.