Objective:

To investigate the associations among umbilical cord arterial or early postnatal arterial blood gas parameters, clinical findings, and cranial imaging results in neonates who underwent therapeutic hypothermia for suspected or confirmed HIE.

Approach:

• Study Design: Retrospective observational study conducted at Biruni University Hospital, including neonates aged 0–28 days treated with therapeutic hypothermia for suspected HIE.
• Data Collection: Demographic and perinatal characteristics, blood gas parameters, seizure status, EEG findings, antiepileptic treatment, cranial ultrasonography, and MRI results were obtained from medical records.

Key Findings:

• Final HIE classification identified no final evidence of HIE in 16 patients (72.7%), stage 1 HIE in 1 (4.5%), stage 2 HIE in 3 (13.6%), and stage 3 HIE in 2 (9.1%).
• Lower bicarbonate levels were significantly associated with any-stage HIE (p = 0.010).
• Neonates with seizures had lower gestational age (p = 0.002) and more negative base excess values (p = 0.029).
• Concordance between cranial ultrasonography and MRI was low; many neonates with normal ultrasonography had abnormal MRI findings.

Interpretation:

Lower bicarbonate levels correlate with the presence of HIE, and metabolic acidosis severity is linked to seizure occurrence. The discordance between imaging modalities aligns with established findings regarding MRI sensitivity.

Limitations:

• Retrospective design may limit the ability to establish causality.
• Small sample size (22 neonates) may affect the generalizability of findings.

Conclusion:

The study provides insights into the relationship between early blood gas parameters and HIE classification, supporting the need for further research in this area.