Tissue oxygen saturation measured by near infrared spectrophotometry correlates with arterial oxygen saturation during induced oxygenation changes in neonates

Body temperature (BT) management remains a challenge in neonatal intensive care, especially during resuscitation after birth. Our aim is to analyze whether there is an association between the BT and cerebral and peripheral tissue oxygen saturation (crSO2/cTOI and prSO2), arterial oxygen saturation (SpO2), and heart rate (HR). The secondary outcome parameters of five prospective observational studies are analyzed. We include preterm and term neonates born by Caesarean section who received continuous pulse oximetry and near-infrared spectroscopy monitoring during the first 15 min, and a rectal BT measurement once in minute 15 after birth. Four-hundred seventeen term and 169 preterm neonates are included. The BT did not correlate with crSO2/cTOI and SpO2. The BT correlated with the HR in all neonates (ρ = 0.210, p < 0.001) and with prSO2 only in preterm neonates (ρ = −0.285, p = 0.020). The BT was lower in preterm compared to term infants (36.7 [36.4–37.0] vs. 36.8 [36.6–37.0], p = 0.001) and prevalence of hypothermia was higher in preterm neonates (29.5% vs. 12.0%, p < 0.001). To conclude, the BT did not correlate with SpO2 and crSO2/cTOI, however, there was a weak positive correlation between the BT and the HR in the whole cohort and a weak correlation between the BT and prSO2 only in preterm infants. Preterm neonates had a statistically lower BT and suffered significantly more often from hypothermia during postnatal transition.

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Pilot study of cerebral and somatic autoregulation using NIRS in preterm neonates

Journal of Neonatal-Perinatal Medicine ◽

10.3233/npm-200601 ◽

2021 ◽

pp. 1-8

Author(s):

T.M. Traub ◽

R. Grabowski ◽

K. Rais-Bahrami

Keyword(s):

Pilot Study ◽

Oxygen Saturation ◽

Near Infrared ◽

Arterial Oxygen Saturation ◽

Severity Of Illness ◽

Arterial Oxygen ◽

Tissue Oxygen Saturation ◽

Preterm Neonates ◽

Arterial Access ◽

Arterial Blood

Background: As neonates transition from a relatively hypoxic environment to extra-uterine life, arterial oxygen saturation dramatically increases. This transition occurs while most organs have not fully matured. The ability for immature tissue to adequately extract and utilize oxygen remains largely unknown. With the development of near-infrared spectroscopy (NIRS), measuring specific tissue oxygen saturation (StO2) noninvasively, clinicians can measure StO2 and determine if adequate tissue oxygenation is maintained. The objective of this study is to determine the relationships of NIRS brain and somatic autoregulation function to patients’ severity of illness. Methods: In this prospective cohort pilot study, after parental consent, neonates less than 34 weeks with arterial access, were enrolled. The FORE-SIGHT NIRS probe was placed on the forehead and abdominal wall for 24 hours. Continuous arterial blood pressure, SpO2 and cerebral and somatic NIRS were used to derive autoregulation function. Results: Data was obtained from 17 neonates (0.540 to 2.37 kg, gestation 23.0 to 33.2 weeks). The autoregulation function categorizes pressure passive index (PPI) values as good, borderline, or poor. For normal autoregulation function, PPI values tend to be low and fairly constant for a range of MAP. The PPI borderline zone is a hypothetical range of PPI values where autoregulation function transitions from good to poor. Conclusion: Our results show most premature neonates, as long as they maintained normal BP and systemic circulation can autoregulate cerebral perfusion. When BP are above or below the normal MAP for age, the neonate is at risk for losing brain and somatic autoregulation.

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