The immediate transition from foetus to neonate includes substantial changes, especially concerning the cardiovascular system. Furthermore, the brain is one of the most vulnerable organs to hypoxia during this period. According to current guidelines for postnatal stabilization, the recommended parameters for monitoring are heart rate (HR) and arterial oxygen saturation (SpO₂). Recently, there is a growing interest in advanced monitoring of the cardio-circulatory system and the brain to get further objective information about the neonate’s condition during the immediate postnatal transition after birth. The aim of the present study was to combine cardiac output (CO) and brain oxygenation monitoring in term neonates after caesarean section in order to analyse the potential influence of CO on cerebral oxygenation during neonatal transition. This was a monocentric, prospective, observational study. For non-invasive cardiac output measurements, the electrical velocimetry (EV) method (Aesculon Monitor, Osypka Medical, CA, USA) was used. The pulse oximeter probe for SpO₂ and HR measurements was placed on the right hand or wrist. The cerebral tissue oxygen index (cTOI) was measured using a NIRO-200NX monitor with the near-infrared spectroscopy (NIRS) transducer on the right frontoparietal head. Monitoring started at minute 1 and was continued until minute 15 after birth. At minutes 5, 10, and 15 after birth, mean CO was calculated from six 10 s periods (with beat-to-beat analysis). During the study period, 99 term neonates were enrolled. Data from neonates with uncomplicated transitions were analysed. CO showed a tendency to decrease until minute 10. During the complete observational period, there was no significant correlation between CO and cTOI. The present study was the first to investigate a possible correlation between CO and cerebral oxygenation in term infants during the immediate neonatal transition. In term infants with uncomplicated neonatal transition after caesarean section, CO did not correlate with cerebral oxygenation.

Aim: We investigated the influence of physiological‐based cord clamping (PBCC) on cardiorespiratory stability in very low birth weight (VLBW) infants during the first 72 h of life.Methods: This retrospective study comprised VLBW infants born at <32 + 0 weeks of gestation and admitted to the neonatal intensive care unit of the Medical University of Graz, Austria, from December 2014 to April 2021. VLBW infants delivered with PBCC were matched by gestational age and birth weight to delayed cord clamping controls. The PBCC group was stabilised after birth with an intact cord. Routine monitoring parameters were compared between the groups.Results: We included 54 VLBW infants. The mean gestational ages of the PBCC group and controls were 27.4 ± 1.9 versus 27.4 ± 1.8 weeks (p = 0.87), and the mean birth weights were 912 ± 288 versus 915 ± 285 g (p = 0.96), respectively. The mean cord clamping time was 191 ± 78 s in the PBCC group. Heart rate was lower in the PBCC group during the first 3 days after birth, reaching significance by 10 h. Other monitoring parameters did not reveal any differences between the two groups.Conclusion: PBCC stabilised cardiorespiratory parameters in VLBW infants. The lower heart rate in the PBCC group suggested higher blood volume following intact cord resuscitation.

Aim: The aim was to define reference ranges for cerebral oxygen saturation (crSO ₂ ‐ROOT) during immediate transition after birth in stable neonates. Methods: In a prospective observational study, the crSO ₂ ‐ROOT was continuously measured in neonates during the first 15 min after birth. The neonatal sensor was placed on the head and fixed with a bandage. Median values and 10th and 90th centiles were calculated for each minute. Additionally, cerebral fractional tissue oxygen extraction (cFTOE‐ROOT) was calculated using crSO ₂ ‐ROOT and arterial oxygen saturation (SpO ₂ ) measured with pulse oximetry. These crSO‐ROOT values were compared with already published reference ranges of cerebral oxygen saturation measured using different devices: crSO ₂ ‐INVOS and cTOI‐NIRO. Results: The data of 122 neonates (14 preterm/108 term neonates) were analysed. The crSO ₂ ‐ROOT values had a similar course when compared to cTOI‐NIRO values, whereas crSO ₂ ‐INVOS values were initially lower and exceeded during the first minutes after birth. Conclusion: The present observational study added reference ranges of crSO ₂ ‐ROOT in stable neonates immediately after birth. As there are differences regarding reference ranges of various near‐infrared spectroscopy (NIRS) devices, it is important to be aware of this information for future clinical use.

Background: Peripheral-muscle-fractional-oxygen-extraction (pFOE) and peripheral-muscle-fractional-tissue-oxygen-extraction (pFTOE) are often equated, since both parameters are measured with near-infrared-spectroscopy (NIRS) and estimate oxygen extraction in the tissue. The aim was to investigate the comparability of both parameters and their potential regarding detection of impaired microcirculation. Methods: Term and preterm neonates with NIRS measurements of upper (UE) and lower extremities (LE) were included. pFOE was calculated out of peripheral-muscle-mixed-venous-saturation (pSvO₂), measured with NIRS and venous occlusion, and arterial oxygen saturation (SpO₂). pFTOE was calculated out of peripheral-muscle-tissue-oxygen-saturation and SpO₂. Both parameters were compared using Wilcoxon-Signed-Rank-test and Bland–Altman plots. Results: 341 NIRS measurements were included. pFOE was significantly higher than pFTOE in both locations. Bland–Altman plots revealed limited comparability, especially with increasing oxygen extraction with higher values of pFOE compared to pFTOE. Conclusion: The higher pFOE compared to pFTOE suggests a higher potential of pFOE to detect impaired microcirculation, especially when oxygen extraction is elevated.

Background: The impact of arterial blood pressure on cerebral oxygenation during immediate postnatal transition is poorly understood.Purpose: Here we investigated the association between arterial blood pressure (BP), cerebral tissue oxygenation index (cTOI), and cerebral fractional tissue oxygen extraction (cFTOE) during the immediate postnatal transition in preterm and full-term neonates.Methods: This prospective observational study included preterm and term neonates who did versus did not require respiratory support. Oscillometric BP was measured at 5, 10, and 15 minutes after birth. cTOI was continuously monitored using near-infrared spectroscopy, while arterial oxygen saturation (SpO2) was recorded using pulse oximetry. cFTOE was calculated from cTOI and SpO. cTOI and cFTOE values were correlated with systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) at all time points. Correlation and mixed-model analyses were then performed.Results: A total of 102 neonates were enrolled: 51 preterm (33 with, 18 without respiratory support) and 51 term (14 with, 37 without respiratory support). In preterm neonates requiring respiratory support, cTOI was positively correlated with DABP at all time points and with MABP at 15 minutes. cFTOE was negatively correlated with MABP and DABP throughout the experiment and with SABP at 5 minutes. No significant correlations were observedamong the other groups. A mixed-model analysis showed that MABP and DABP were significantly associated with cFTOE but not cTOI independent of gestational age or respiratory support.Conclusion: Among preterm neonates requiring respiratory support, cTOI and cFTOE were associated with arterial BP during the immediate neonatal transition. Only cFTOE showed a slight association with BP among stable preterm and full-term neonates. These findings suggest impaired cerebral autoregulation in compromised preterm infants during the immediate postnatal transition.

Aim: To establish reference ranges of peripheral‐muscle regional oxygen saturation (prSO₂) and peripheral fractional tissue oxygen extraction (pFTOE) during the first 15 min after birth in stable term neonates.Methods: Secondary outcome parameters of prospective observational studies in healthy term neonates delivered by Caesarean section were analysed. prSO₂ was measured on the right forearm using the INVOS 5100C monitor. pFTOE was calculated out of prSO₂ and arterial oxygen saturation (SpO₂). Centile charts (10th–90th) of prSO₂ and pFTOE were defined during the first 15 min after birth.Results: Three‐hundred‐five term neonates with a mean gestational age and birth weight of 39.0 ± 0.9 weeks and 3321 ± 454 g, respectively, were included. The 50th centiles of prSO₂ were 39% (minute two), 52% (minute five), 71% (minute 10), and 73% (minute 15). The 50th centiles of pFTOE were 0.529 (minute two), 0.378 (minute five), 0.237 (minute 10), and 0.231 (minute 15).Conclusion: Reference ranges of prSO₂ and pFTOE were established for term neonates delivered by Caesarean section during the immediate transition after birth. These reference ranges increase knowledge of physiological processes taking place immediately after birth and are necessary for possible future clinical applications.