Impaired autoregulation in preterm infants identified by using spatially resolved spectroscopy.

Area of Science:

• Neonatal physiology
• Cerebrovascular regulation
• Medical instrumentation

Background:

• Cerebral autoregulation is crucial for protecting the immature brain in preterm infants, but its bedside assessment is challenging.
• Impaired cerebral autoregulation is linked to adverse neurological outcomes in neonates.

Purpose of the Study:

• To evaluate the use of spatially resolved spectroscopy for continuous bedside assessment of cerebral autoregulation in preterm infants.
• To correlate tissue-oxygenation index (TOI) with mean arterial blood pressure (MABP) fluctuations to assess autoregulatory capacity.

Main Methods:

• Continuous measurement of TOI and MABP in 24 very premature infants.
• Application of cross-spectral analysis (coherence and transfer-function gain) to assess the correlation between TOI and MABP in the frequency domain.

Main Results:

• High coherence (≥0.5) between TOI and MABP was observed in infants with lower gestational age, birth weight, and MABP.
• High coherence was associated with higher Clinical Risk Index for Babies scores and increased neonatal mortality.
• Coherence ≥0.5 predicted mortality with 67% positive and 100% negative predictive values.

Conclusions:

• High coherence between MABP and TOI signifies impaired cerebral autoregulation in sick preterm infants, strongly predicting mortality.
• Cross-spectral analysis provides a potential method for continuous bedside monitoring of cerebral autoregulation.
• This technique may guide therapeutic interventions to improve outcomes in preterm neonates.