Acid-base and metabolic parameters and cerebral oxygenation during the immediate transition after birth-A two-center observational study.

OBJECTIVE: The association between blood glucose level and cerebral oxygenation (cerebral regional oxygen saturation [crSO2] and cerebral fractional tissue oxygen extraction [FTOE]) in neonates has already been described. Aim of the present study was to investigate if acid-base and other metabolic parameters have an impact on cerebral oxygenation immediately after birth in preterm and term neonates. STUDY DESIGN: Post-hoc analyses of secondary outcome parameters of two prospective observational studies were performed. Preterm and term neonates born by caesarean section were included, in whom i) cerebral near-infrared spectroscopy (NIRS) measurements were performed during the first 15 minutes after birth and ii) a capillary blood gas analysis was performed between 10 and 20 minutes after birth. Vital signs were routinely monitored with pulse oximetry (arterial oxygen saturation [SpO2] and heart rate [HR]). Correlation analyses were performed to investigate potential associations between acid-base and metabolic parameters (lactate [LAC], pH-value [pH], base-excess [BE] and bicarbonate [HCO3]) from capillary blood and NIRS-derived crSO2 and FTOE at 15 minutes after birth. RESULTS: One-hundred-fifty-seven neonates, 42 preterm neonates (median gestational age [IQR] 34.0 weeks [3.3], median birth weight 1845g [592]) and 115 term neonates (median gestational age [IQR] 38.9 weeks [1.0], median birth weight 3230g [570]) were included in the study. Median crSO2 [IQR] values at 15 minutes after birth were 82% [16] in preterm neonates and 83% [12] in term neonates. Median FTOE [IQR] values at 15 minutes after birth were 0.13 [0.15] in preterm neonates and 0.14 [0.14] in term neonates. In preterm neonates, higher LAC and lower pH and BE were associated with lower crSO2 and higher FTOE. In term neonates, higher HCO3 was associated with higher FTOE. CONCLUSION: There were significant associations between several acid-base and metabolic parameters and cerebral oxygenation in preterm neonates, while in term neonates only HCO3 correlated positively with FTOE.

Does physiological-based cord clamping improve cerebral tissue oxygenation and perfusion in healthy term neonates? - A randomized controlled trial.

Objectives: To evaluate cerebral tissue oxygenation index (cTOI) during neonatal transition in a group of healthy full-term neonates receiving either a physiological-based approach of deferred cord clamping (CC) after the onset of stable regular breathing (PBCC group) or a standard approach of time-based CC < 1 min (control group). Secondary aim was to evaluate changes in cerebral blood volume (ΔCBV), peripheral arterial oxygen saturation (SpO2) and heart rate (HR) in those neonates. Materials and Methods: We conducted a randomized controlled trial (clinicaltrials.gov: NCT02763436) including vaginally delivered healthy full-term neonates. Continuous measurements of cTOI and ΔCBV using near-infrared spectroscopy, and of SpO2 and HR using pulse oximetry were performed within the first 15 min after birth. Data of each minute of the PBCC group were compared to those of the control group. Results: A total of 71 full-term neonates (PBCC: n = 35, control: n = 36) with a mean (SD) gestational age of 40.0 (1.0) weeks and a birth weight of 3,479 (424) grams were included. Median (IQR) time of CC was 275 (197-345) seconds and 58 (35-86) seconds in the PBCC and control group, respectively (p < 0.001). There were no significant differences between the two groups regarding cTOI (p = 0.319), ΔCBV (p = 0.814), SpO2 (p = 0.322) and HR (p = 0.878) during the first 15 min after birth. Conclusion: There were no significant differences in the course of cTOI as well as ΔCBV, SpO2 and HR during the first 15 min after birth in a group of healthy full-term neonates, who received either deferred CC after the onset of stable regular breathing or standard CC < 1 min. Thus, deferring CC ≥ 1 min following a physiological-based approach offers no benefits regarding cerebral tissue oxygenation and perfusion after uncomplicated vaginal delivery compared to a time-based CC approach.

Precision of time-resolved near-infrared spectroscopy-based measurements of cerebral oxygenation in preterm infants.

Significance: Time-resolved near-infrared spectroscopy (t-NIRS) is a new technology; at the moment, data on its precision in preterm infants are rare. Aim: Therefore, the aim of this study was to analyze the precision of t-NIRS-based measurements of the cerebral oxygenation in preterm infants. Approach: In 70 neonates [age: 4.7 ± 2.0 days, sex (f/m): 33/37], cerebral oxygenation ( t - rSO 2 ) was measured with an optode placed over the left frontotemporal lobe on the head, measurement duration was 1 min, and a reapplication was done for four further times (five applications). Results: Overall mean for t - rSO 2 values was 62.2 % ± 4.1 % . We found a within-patient variation for t - rSO 2 of 2.6%. Furthermore, 95% of all observed values were within a range of ± 5 % from the mean when looking on several reapplications and ± 2 % when looking within one application. Most of the variation in t - rSO 2 (60.4%) contributed to differences between patients. The remaining 39.6% of the variation was due to measurement errors and real changes of the measured signal within the neonates. Conclusions: Since within-patient variation of t - rSO 2 measures were below a clinical meaningful threshold of 5%, the measurement can be denoted as precise.

Blood Glucose and Lactate Levels and Cerebral Oxygenation in Preterm and Term Neonates-A Systematic Qualitative Review of the Literature.

Background: Cerebral oxygenation monitored non-invasively by near-infrared spectroscopy (NIRS) is of increasing interest in neonatal care. Cerebral oxygenation is determined by cerebral oxygen delivery and cerebral oxygen consumption. Oxygen delivery as well as oxygen consumption might be influenced by metabolic parameters like blood glucose and lactate. Objective: The aim of the present systematic qualitative review is therefore to identify and summarize all studies, which describe cerebral oxygenation measured with NIRS and blood glucose and/or blood lactate levels in neonates. Data sources: A systematic search of Ovid Embase and PubMed was performed. Search terms included near-infrared spectroscopy, fractional tissue oxygen extraction, cerebral tissue oxygen saturation, regional cerebral tissue oxygen saturation, oxygenation, term, and preterm neonates, cesarean delivery, transition, after-birth, newborn, vaginal delivery, cesarean delivery, baby, neonatal transition, metabolism, lactate, glucose, and blood glucose level. Study selection/data synthesis: Studies analyzing cerebral oxygenation and blood glucose and/or blood lactate levels in neonates were included. Animal studies, duplicates, or studies in non-English language were excluded. Results: Twenty-five studies were identified that describe blood glucose and/or blood lactate levels as primary or secondary outcome parameters with additional measured cerebral oxygenation by NIRS in neonates. Twelve studies were included with blood glucose measurements: four described an association between blood glucose levels and cerebral oxygenation, two show no association, and six do not report on possible associations. Eighteen studies were included with lactate measurements: one describe an association between lactate levels and cerebral oxygenation, while three show no association and 14 do not report on possible associations. Discussion: The influence of blood glucose and blood lactate levels on the cerebral oxygenation in neonates is still controversial. However, there seems to be an association between cerebral oxygenation and the metabolic parameter blood glucose and lactate, which need further investigation.

Feasibilty of Transcutaneous pCO2 Monitoring During Immediate Transition After Birth-A Prospective Observational Study.

Background: According to recommendations, non-invasive monitoring during neonatal resuscitation after birth includes heart rate (HR) and oxygen saturation (SpO2). Continuous transcutaneous monitoring of carbon dioxide partial pressure (tcpCO2) may further offer quantitative information on neonatal respiratory status. Objective: We aimed to investigate feasibility of tcpCO2 measurements in the delivery room during immediate neonatal transition and to compare the course of tcpCO2 between stable term and preterm infants. Methods: Neonates without need for cardio-respiratory intervention during immediate transition after birth were enrolled in a prospective observational study. In these term and preterm neonates, we measured HR and SpO2 by pulse oximetry on the right wrist and tcpCO2 with the sensor applied on the left hemithorax during the first 15 min after birth. Courses of tcpCO2 were analyzed in term and preterm neonates and groups were compared. Results: Fifty-three term (gestational age: 38.8 ± 0.9 weeks) and 13 preterm neonates (gestational age: 34.1 ± 1.5 weeks) were included. First tcpCO2 values were achieved in both groups at minute 4 after birth, which reached a stable plateau after the equilibration phase at minute 9. Mean tcpCO2 values 15 min after birth were 46.2 (95% CI 34.5-57.8) mmHg in term neonates and 48.5 (95%CI 43.0-54.1) mmHg in preterm neonates. Preterm and term infants did not show significant differences in the tcpCO2 values at any time point. Conclusion: This study demonstrates that tcpCO2 measurement is feasible during immediate neonatal transition after birth and that tcpCO2 values were comparable in stable term and preterm neonates.

Parental Stress Experience and Age of Mothers and Fathers After Preterm Birth and Admission of Their Neonate to Neonatal Intensive Care Unit; A Prospective Observational Pilot Study.

Background: Preterm birth is associated with increased stress of parents that might influence the parental-child interaction, thus potentially having influence on the neurobehavioral development of the preterm infants. However, little is known concerning the age dependency of parental stress after preterm birth. Objective: The aim of the present study was to examine the age dependency of stress in mothers and fathers after preterm birth and neonatal intensive care unit (NICU) admission of their infant. Methods: In a prospective observational pilot study 47 mothers and 47 fathers completed the parental stress scale:NICU (PSS:NICU) questionnaire within 72 h after delivery. This questionnaire measures parental stress after preterm birth with three subscales: "Looks and Behave" of the child, "Parental Role Alteration," and "Sights and Sounds." Stress levels of mothers and fathers were compared and correlated to the age of mothers and fathers, respectively. Results: Parental stress experience after preterm birth tended to be higher in mothers compared to fathers. Mothers showed a significant positive correlation of the "Sights and Sounds" scale and age, whereas fathers did not show any significant age dependency of stress. Conclusion: In mothers stress level increases with increasing maternal age after preterm birth and admission of their infant to NICU, whereas fathers did not show any significant age dependency of stress.