P2.H143: Sodium Levels and Severe Intraventricular Hemorrhage: Tale of Two Extremes

Background: Severe intraventricular hemorrhage (IVH) is a serious morbidity in the extremely low birth weight (ELBW) infant. Most IVH cases occur within three days post-birth and are associated with risk factors such as low gestational age (GA), blood pressure changes, and lack of prenatal steroids. Both low and high sodium levels have been linked to IVH, with hyponatremia often overlooked due to old, scarce reports. We aim to assess whether extreme sodium levels are associated with higher rates of mortality/severe IVH in ELBW infants.

Methods: We reviewed medical records of infants born with GA < 27 weeks, BW < 1200 g, admitted to a regional NICU from Jan 2018 to Dec 2022. Data on blood gases and electrolyte parameters, including sodium and hemoglobin levels in the first 3 days, were collected. Infants were categorized into four groups based on their median sodium levels. Analysis was conducted on blood gas parameters collected 4-6 hours before the hemoglobin nadir. We assessed the association between sodium levels and death ( < 72 hours of age) or severe IVH using logistic regression.

Results: We studied 364 infants, half of whom had low sodium levels, with an overall median of 135 meq/L. None had levels above 145 meq/L. Basic characteristics were similar among the four quartile groups, except for higher antenatal steroid completion and lower birth weights in the fourth quartile. Rates of death or severe IVH decreased with rising sodium levels, from 22% in the first quartile to 7% in the fourth quartile (p=0.042). After adjusting for relevant factors, low sodium levels remained associated with higher rates of death or severe IVH, with an odds ratio (95% CI) of 1.12 (1.01-1.26), p=0.031.

Conclusion: Avoiding hypernatremia in infants may lead many to become hyponatremic. Surprisingly, we discovered that hyponatremia is linked to increased severe IVH rates. Only accepting normal sodium levels in ELBW infants could lower severe IVH rates. Additional research is needed to confirm our findings.