Low adjusted serum ionized calcium concentration shortly after birth predicts poor outcome in neonatal hypoxic-ischemic encephalopathy.
OBJECTIVE
Hypoxic-ischemic reperfusion injury causes either necrosis or apoptosis, and the influx of ionized calcium into cells is the major cause of both types of cell death. The aim of this study was to investigate whether or not the serum ionized calcium concentration in neonates with hypoxic-ischemic encephalopathy (HIE) could be used to predict their outcome.


METHODS
Serum samples were obtained shortly after birth from 20 HIE neonates who had not urinated or received treatment with calcium. Serum ionized calcium concentrations were adjusted for pH using a correction formula. Twelve neonates without any disease were selected as a control. The results were compared between nine HIE neonates who made a full recovery, 11 who died or had neurologic deficits, and 12 normal neonates.


RESULTS
Considered together, the two HIE groups had lower serum ionized calcium concentrations (1.05 +/- 0.10 mmol/L) than the control group (1.22 +/- 0.07 mmol/L; P < 0.0001). Moreover, serum ionized calcium concentrations in the group with the poor outcome (0.99 +/- 0.07 mmol/L) were lower than those in the group that made a full recovery (1.13 +/- 0.06 mmol/L; P=0.0016).


CONCLUSIONS
The serum ionized calcium concentrations shortly after birth were significantly lower in neonates with HIE who had a poor outcome. Low concentrations may reflect multiple organ damage, particularly involving the brain.
Yoneda
Satoshi
S
Department of Obstetrics and Gynecology, Toyama Medical and Pharmaceutical University, Toyama, Japan.
Ibara
Satoshi
S
Kobayashi
Kosuke
K
Kato
Eiji
E
Maruyama
Yuko
Y
Maruyama
Hideki
H
Sumida
Yumi
Y
Sunami
Rei
R
Sakai
Masatoshi
M
Ikenoue
Tsuyomu
T
Saito
Shigeru
S
D001238:Asphyxia Neonatorum / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000097:blood / Q000175:diagnosis; D007231:Infant, Newborn; D008297:Male; D011237:Predictive Value of Tests
D015415:Biomarkers; D002118:Calcium