Direct Measurement of Tissue Oxygenation in Neonates via Resonance Raman Spectroscopy: A Pilot Study

The ability to monitor tissue oxygenation in neonates remains a challenge due to limited blood supply and the reliance on invasive procedures. Resonance Raman spectroscopy noninvasively measures tissue oxygenation (RRS-StO2). Peripheral tissue oxygenation using this novel technology has not been described in neonates.

To examine the relationship between short-term RRS-StO2 measurements and central venous saturation (ScvO2) and pulse oximetry (SpO2) in preterm and term neonates.

Ninety-seven term neonates had buccal and plantar RRS-StO2 measurements performed. In 15 preterm neonates, similar measurements were obtained in conjunction with ScvO2 in the first week of life. Simultaneous SpO2 and heart rate were also recorded.

In healthy neonates, buccal RRS-StO2 values negatively correlated with the day of life. No correlation existed between buccal and plantar RRS-StO2 values and ScvO2 or SpO2. Greater intra-patient plantar RRS-StO2 variability was seen in preterm neonates with increasing respiratory support.

Neonatal RRS-StO2 measurements are feasible short term but do not correlate with ScvO2 and SpO2. Healthy neonates had greater differences and variability in RRS-StO2 values, illustrating an evolving microcirculation not detected with pulse oximetry. Greater RRS-StO2 variability in sick neonates requiring respiratory support may indicate microcirculatory instability despite being within target SpO2 ranges. Further study is needed to establish if RRS-StO2 monitoring is an accurate representation of tissue oxygenation.