Reference Ranges for Arterial Oxygen Saturation, Heart Rate, and Cerebral Oxygen Saturation during Immediate Postnatal Transition in Neonates Born Extremely or Very Preterm.

OBJECTIVE: To define percentile charts for arterial oxygen saturation (SpO2), heart rate (HR), and cerebral oxygen saturation (crSO2) during the first 15 minutes after birth in neonates born very or extremely preterm and with favorable outcome. STUDY DESIGN: We conducted a secondary-outcome analysis of neonates born preterm included in the Cerebral regional tissue Oxygen Saturation to Guide Oxygen Delivery in preterm neonates during immediate transition after birth III (COSGOD III) trial with visible cerebral oximetry measurements and with favorable outcome, defined as survival without cerebral injuries until term age. We excluded infants with inflammatory morbidities within the first week after birth. SpO2 was obtained by pulse oximetry, and electrocardiogram or pulse oximetry were used for measurement of HR. crSO2 was assessed with near-infrared spectroscopy. Measurements were performed during the first 15 minutes after birth. Percentile charts (10th to 90th centile) were defined for each minute. RESULTS: A total of 207 neonates born preterm with a gestational age of 29.7 (23.9-31.9) weeks and a birth weight of 1200 (378-2320) g were eligible for analyses. The 10th percentile of SpO2 at minute 2, 5, 10, and 15 was 32%, 52%, 83%, and 85%, respectively. The 10th percentile of HR at minute 2, 5, 10, and 15 was 70, 109, 126, and 134 beats/min, respectively. The 10th percentile of crSO2 at minute 2, 5, 20, and 15 was 15%, 27%, 59%, and 63%, respectively. CONCLUSIONS: This study provides new centile charts for SpO2, HR, and crSO2 for neonates born extremely or very preterm with favorable outcome. Implementing these centiles in guiding interventions during the stabilization process after birth might help to more accurately target oxygenation during postnatal transition period.

Cerebral oxygenation during immediate fetal-to-neonatal transition and fidgety movements between six to 20 weeks of corrected age: An ancillary study to the COSGOD III trial.

Fidgety movements provide early information about a potential development of cerebral palsy in preterm neonates. The aim was to assess differences in the combined outcome of mortality and fidgety movements defined as normal or pathological in very preterm neonates according to the group allocation in the randomised-controlled multicentre COSGOD III trial. Preterm neonates of two centres participating in the COSGOD III trial, whose fidgety movements were assessed as normal or pathological at six to 20 weeks of corrected age, were analysed. In the COSGOD III trial cerebral oxygen saturation (crSO2) was measured by near-infrared spectroscopy (NIRS) during postnatal transition and guided resuscitation in preterm neonates randomised to the NIRS-group, whereby medical support was according routine, as it was also in the control group. Fidgety movements were classified in normal or abnormal/absent at six to 20 weeks of corrected age. Mortality and fidgety movements of preterm neonates allocated to the NIRS-group were compared to the control-group. Normal outcome was defined as survival with normal fidgety movements. One-hundred-seventy-one preterm neonates were included (NIRS-group n = 82; control-group n = 89) with a median gestational age of 29.4 (27.4-30.4) and 28.7 (26.7-31.0) weeks in the NIRS-group and the control-group, respectively. There were no differences in the combined outcome between the two groups: 90.2% of the neonates in the NIRS-group and 89.9% in the control-group survived with normal outcome (relative risk [95% CI]; 0.96 [0.31-2.62]).Conclusions: In the present cohort of preterm neonates, monitoring of crSO2 and dedicated interventions in addition to routine care during transition period after birth did not show an impact on mortality and fidgety movements defined as normal or pathological at six to 20 weeks corrected age. What is Known • Fidgety movements display early spontaneous motoric pattern and may provide early information about a potential development of cerebral palsy in preterm neonates.  What is New  â€¢ This retrospective observational study of the randomised-controlled multicentre COSGOD III trial is the first study investigating the potential influence of cerebral oxygenation guided resuscitation during postnatal transition period on combined outcome of mortality and fidgety movements up to 20 weeks of corrected age in very preterm neonates. • This study adds to the growing interest of assessing cerebral oxygenation, that monitoring of cerebral oxygen saturation and dedicated interventions during postnatal transition period according to the COSGOD III trial has no significant influence on mortality and fidgety movements defined as normal or pathological in very preterm neonates.

Acid base and metabolic parameters of the umbilical cord blood and cerebral oxygenation immediately after birth.

Objective: Aim was to investigate whether acid-base and metabolic parameters obtained from arterial umbilical cord blood affect cerebral oxygenation after birth in preterm neonates with respiratory support and in term neonates without respiratory support. Study design: This was a post-hoc analysis of secondary outcome parameters of a prospective observational study including preterm neonates with and term neonates without respiratory support. Non-asphyxiated neonates with cerebral oxygenation measured with near-infrared spectroscopy during the first 15 min and with blood gas analyses from arterial umbilical cord blood were included. Arterial oxygen saturation (SpO2) and heart rate (HR) were monitored with pulse oximetry. Potential correlations were investigated between acid-base and metabolic parameters (pH-value, bicarbonate, base-excess, and lactate) and crSO2/cFTOE 5 min after birth. Results: Seventy-seven neonates were included: 14 preterm neonates with respiratory support (mean gestational age [GA] 31.4 ± 4.1 weeks; mean birth weight [BW] 1,690 ± 640 g) and 63 term neonates without respiratory support (GA 38.7 ± 0.8 weeks; BW 3,258 ± 443 g). Mean crSO2 5 min after birth was 44.0% ± 24.2% in preterm and 62.2% ± 20.01% in term neonates. Mean cFTOE 5 min after birth was 0.46 ± 0.06 in preterm and 0.27 ± 0.19 in term neonates. In preterm neonates with respiratory support higher lactate was significantly associated with lower crSO2 and SpO2 and tended to be associated with higher cFTOE. In term neonates without respiratory support no significant correlations were found. Conclusion: In non-asphyxiated preterm neonates with respiratory support, lactate levels were negatively associated with crSO2 and SpO2, whereas in term neonates without respiratory support no associations were observed.

Fisiología respiratoria: el pulmón al momento de nacer / Respiratory Physiology - the lung at the moment of birth

La adaptación fisiológica de los recién nacidos de la vida intrauterina a la extrauterina incluye cambios fisiológicos complejos. Para que se complete con éxito la transición fetal a neonatal, los recién nacidos deben lograr el aclaramiento de líquido pulmonar, la generación de CRF e inicio de la respiración, para permitir el intercambio de gases y la oxigenación de los tejidos. En este artículo se describen estos mecanismos, algunas bases del desarrollo pulmonar y de la circulación fetal; y las medidas que se requieren para asistir al recién nacido cuando no logran completar esta transición espontáneamente, lo que ocurre en el 5 al 10 % de los casos.

The physiological adaptation of newborns from intrauterine to extrauterine life includes complex physiological changes. For the fetal to neonatal transition to be successfully completed, neonates must achieve lung fluid clearance, FRC generation, and initiation of respiration to allow gas exchange and tissue oxygenation. This article describes these mechanisms, some bases of lung development and fetal circulation; and the measures required to assist the newborn, when they fail to complete this transition spontaneously, which occurs in the 5 to 10% of cases.