Calcium concentration in hypoxic-ischemic encephalopathy during hypothermia

Background: The aim of this study was to investigate the relationship between prognosis and the changes in serum-ionized calcium concentration in neonates with hypoxic-ischemic encephalopathy (HIE) before and during brain hypothermia (BHT).

Methods: Serum samples were obtained from 16 HIE neonates who underwent BHT. All patients underwent developmental testing at 18 months of age.

Results: Mean serum-ionized calcium concentration in the poor outcome group (developmental quotient [DQ], <80; nine infants) was significantly lower than in the good outcome group (DQ >80; seven infants), both immediately before and after 6 h of BHT. Mean serum-ionized calcium concentration significantly decreased in both groups for 6 h, and the lowest adjusted serum-ionized calcium during 6 h of BHT was <1.05 mmol/L, known as the cut-off value for poor outcome, in 57.1% of the good outcome group.

Conclusion: The influx of calcium into cells continues regardless of neurological prognosis during the early phase of BHT, but BHT might protect some high-risk patients against neurological damage at low adjusted serum-ionized calcium concentration.