Corinna Binder

Reference Ranges for Regional Cerebral Tissue Oxygen Saturation and Fractional Oxygen Extraction in Neonates during Immediate Transition after Birth

OBJECTIVE To define reference ranges for regional cerebral tissue oxygen saturation (crSO2) and regional cerebral fractional tissue oxygen extraction (cFTOE) during the first 15 minutes after birth in neonates requiring no medical support. STUDY DESIGN The crSO2 was measured using near infrared spectroscopy (Invos 5100 cerebral/somatic oximeter monitor; Somanetics Corp, Troy, Michigan) during the first 15 minutes after birth for term and preterm neonates. The near infrared spectroscopy sensor was placed on the left forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry, and cFTOE was calculated. Neonates were excluded if they required any medical support. RESULTS A total of 381 neonates were included: 82 term neonates after vaginal delivery, 272 term neonates after cesarean delivery, and 27 preterm neonates after cesarean delivery. In all neonates, median (10th-90th percentiles) crSO2 was 41% (23-64) at 2 minutes, 68% (45-85) at 5 minutes, 79% (65-90) at 10 minutes, and 77% (63-89) at 15 minutes of age. In all neonates, median (10th-90th percentiles) cFTOE was 33% (11-70) at 2 minutes, 21% (6-45) at 5 minutes, 15% (5-31) at 10 minutes, and 18% (7-34) at 15 minutes of age. CONCLUSION We report reference ranges of crSO2 and cFTOE in neonates requiring no medical support during transition immediately after birth. The use of cerebral oxygenation monitoring and use of these reference ranges in neonates during transition may help to guide oxygen delivery and avoid cerebral hypo-oxygenation and hyperoxygenation.

Cerebral and Peripheral Regional Oxygen Saturation during Postnatal Transition in Preterm Neonates

OBJECTIVE To evaluate peripheral regional oxygen saturation (rpSO₂) and cerebral regional oxygen saturation (rcSO₂) during the immediate postnatal transition in late preterm infants with and without the need for respiratory support. STUDY DESIGN This was a prospective observational study using near-infrared spectroscopy to evaluate changes in rpSO₂ and rcSO₂. These variables were measured during the first 15 minutes of life after elective cesarean delivery. Peripheral oxygen saturation (SpO₂) and heart rate were measured continuously by pulse oximetry, and cerebral fractional tissue oxygen extraction (cFTOE) was calculated. Two groups were compared based on their need for respiratory support: a respiratory support group and a normal transition group. Positive-pressure ventilation was delivered with a T-piece resuscitator, and oxygen was adjusted based on SpO₂ values. A Florian respiratory function monitor was used to record the ventilation variables. RESULTS There were 21 infants in the normal transition group and 21 infants in the respiratory support group. Changes in heart rate over time were similar in the 2 groups. SpO₂, rcSO₂, and rpSO₂ values were consistently higher in the normal transition group. In the respiratory support group, cFTOE values remained significantly elevated for a longer period. CONCLUSION This systematic analysis of rpSO₂, rcSO₂, and cFTOE in late preterm infants found significantly lower oxygen saturation values in infants who received respiratory support compared with a normal transition group. We hypothesize that the elevated cFTOE values in the respiratory support group represent compensation for lower oxygen delivery.

aEEG and NIRS during transition and resuscitation after birth: Promising additional tools; an observational study

AIM OF THE STUDY During resuscitation no routine cerebral monitoring is available. We aimed at monitoring cerebral activity and oxygenation continuously during neonatal transition and resuscitation. METHODS Neonates ≥34 weeks of gestation born via cesarean section were included. Cerebral activity was continuously measured with amplitude-integrated-EEG (aEEG) and cerebral oxygenation (rSO2) with near-infrared-spectroscopy (NIRS) during the first 10 min after birth. For quantitative analysis of aEEG every minute the mean minimum amplitude (V(min)) and maximum amplitude (V(max)) was determined. Uncompromised neonates were compared to neonates in need of resuscitation. RESULTS Out of 224 eligible neonates 31 uncompromised and 15 in need of respiratory support were included. Uncompromised neonates showed higher values for V(min) in the third minute and higher values for V(max) in the third and fourth minute compared to the tenth minute post-partum. In uncompromised neonates rSO2 values during the first 6 min after birth were lower compared to minute ten. Neonates in need of respiratory support had lower rSO2 values over the first 8 min after birth compared to minute ten. CONCLUSIONS This is the first study demonstrating that monitoring of aEEG and NIRS to measure cerebral activity and oxygenation during immediate postpartum transition is feasible. During transition compromised neonates requiring resuscitation showed a different cerebral activity pattern compared to uncompromised neonates.

Right ventricular performance in preterm and term neonates: reference values of the tricuspid annular peak systolic velocity measured by tissue Doppler imaging.

Background: The tricuspid annular peak systolic velocity (S′) is an echocardiographic measurement to assess systolic right ventricular function in adults and children. Objective: We determined growth and birth weight-related changes of S′ to establish reference values in preterm and term neonates. Methods: A prospective study was conducted in a group of 290 preterm and term neonates (gestational age 26 + 0 to 40 + 6 weeks of gestation; birth weight 660-4,460 g). A correlation of S′ values with established tricuspid annular plane systolic excursion (TAPSE) values was performed. Results: The S′ ranged from a mean of 4.5 cm/s (Z-score ± 2 SD: 3.6-5.5 cm/s) in preterm neonates in week 260-6 of gestation to 7.8 cm/s (Z-score ± 2 SD: 5.5-10.1 cm/s) in term neonates in week 400-6 of gestation. The S′ values increased from 26 to 40 weeks of gestation. S′ and week of gestation are strongly correlated: Pearsons correlation coefficient was 0.66 for week of gestation - S′ (p < 0.001). A significant correlation was found between S′ and TAPSE values (r = 0.67; p < 0.001). Conclusion: Z-scores of S′ values were calculated and percentile charts were established to serve as reference data for preterm and term neonates with structurally normal hearts.

Time Course Study of Blood Pressure in Term and Preterm Infants Immediately after Birth

Objective To describe temporal changes in systolic, diastolic, and mean blood pressure (SBP, DBP, and MBP, respectively) in term and preterm infants immediately after birth. Methods Prospective observational two-center study. In term infants SBP, DBP, and MBP were assessed non-invasively every minute for the first 15 minutes, and in preterm infants every minute for the first 15 minutes, as well as at 20, 25, 30, 45, and 60 minutes after birth. Regression analyses were performed by gender and respiratory support in all neonates; and by mode of delivery, cord clamping time, and development of ultrasound-detected brain injury in preterm neonates. Results Term infants (n = 54) had a mean (SD) birth weight of 3298 (442) g and gestational age of 38 (1) weeks, and preterm infants (n = 94) weighed 1340 (672) g and were 30 (3) weeks gestation. Term infants’ SBP, DBP and MBP within the first 15 minutes after birth were independent of gender or respiratory support. Linear mixed regression analysis showed that preterm infants, who were female, born vaginally, had delayed cord clamping and did not require positive pressure ventilation nor develop periventricular injury or ventriculomegaly, had significantly higher SBP, DBP, and MBP at some measurement points within the first hour after birth. Conclusions We present novel reference ranges of BP immediately after birth in a cohort of term and preterm neonates. They may aid in optimization of cardiovascular support during early transition at all gestations.

Human or monitor feedback to improve mask ventilation during simulated neonatal cardiopulmonary resuscitation

Objective To investigate if external chest compressions (ECC) increase mask leak, and if human or technical feedback improves mask ventilation during simulated neonatal cardiopulmonary resuscitation (CPR). Study design In this observational study, 32 participants delivered positive pressure ventilation (PPV) to a modified, leak-free manikin via facemask. Mask leak, tidal volume (VT), positive end expiratory pressure (PEEP) and respiratory rate (RR) were measured with a respiratory function monitor (RFM). Participants had to perform four studies. In the first study, participants performed PPV alone as baseline. Thereafter, three studies were performed in random order. In the PPV+ECC+manometer group, participants had to observe the manometer while the RFM was covered; in the PPV+ECC+RFM group, the RFM was used while the manometer was covered; and in the PPV+ECC+verbal feedback group, the RFM and manometer were covered while a team leader viewed the RFM and provided verbal feedback to the participants. Results Median (IQR) mask leak of all studies was 15% (5–47%). Comparing the studies, PPV+ECC+RFM and PPV+ECC+verbal feedback had significantly less mask leak than PPV+ECC+manometer. Mean (SD) VT of all studies was 9.5±3.5 mL. Comparing all studies, PPV+ECC+RFM had a significantly higher VT than PPV and PPV+ECC+manometer. As well, PPV+ECC+verbal feedback had a significantly higher VT than PPV. PEEP and RR were within our target, mean (SD) PEEP was 6±2 cmH2O and RR was 36±13/min. Conclusions During simulated neonatal CPR, ECCs did not influence mask leak, and a RFM and verbal feedback were helpful methods to reduce mask leak and increase VT significantly.

The influence of perinatal asphyxia on peripheral oxygenation and perfusion in neonates

BACKGROUND Perinatal asphyxia influences peripheral oxygenation and perfusion in neonates. OBJECTIVES The aim was to investigate the influence of perinatal asphyxia on peripheral oxygenation and perfusion in neonates by using near-infrared spectroscopy (NIRS). METHODS Prospective observational study. Neonates with gestational age >34 weeks and birth weight >2000 g without infection or congenital malformations were included. Peripheral muscle NIRS measurements in combination with venous occlusion were performed once in the first 48 h of life. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO2), fractional oxygen extraction (FOE), haemoglobin flow (Hbflow), oxygen delivery (DO2) and oxygen consumption (VO2) were assessed. Furthermore arterial oxygen saturation, heart rate, blood pressure and temperatures were measured. Neonates with a UapH≤7.15 and an Apgar 5≤6 were compared to neonates with a UapH≥7.15, an Apgar 5≥7 (control group) and a UapH was correlated to NIRS parameters. RESULTS 8 asphyxiated neonates were compared to 30 neonates in the control group. TOI (67.7±5.5%) and DO2 (29.0±14.2 μmol/100 mL/min) were significantly lower in asphyxiated neonates compared to the controls (TOI 71.8±4.9%, p=0.045; DO2 43.9±16.9 μmol/100 mL/min, p=0.028) and FOE was significantly higher (0.33±0.05) compared to the controls (0.28±0.06, p=0.028). Furthermore significant correlations between UapH and DO2 (r=0.78, p=0.022), VO2 (r=0.80, p=0.018) and FOE (r=-0.75, p=0.034) in the asphyxiated group were found. CONCLUSION Peripheral oxygenation and perfusion measured with NIRS are compromised in neonates with perinatal asphyxia with worsening of parameters and degree of acidosis in the umbilical cord blood.

PO-0465 Regional Cerebral Tissue Oxygen Saturation During Neonatal Transition: Is There An Influence Of Gender?

Objective Gender definitely plays an important role for mortality and morbidity in preterm infants. Furthermore, recent studies have shown gender-specific differences favouring females with the use of supplemental oxygen during resuscitation. Female preterm infants showed less oxidative stress and increased antioxidant activity. Therefore, the aim of the present study was to investigate, whether there are differences due to gender in the course of regional cerebral tissue oxygen saturation (crSO2) during transition after birth. Material and methods In a prospective observational study during 2009–2012, crSO2 was measured using near infrared spectroscopy (NIRS) (Invos 5100 cerebral/somatic oximeter monitor; Somanetics Corp, Troy, Michigan) during the first 15 min after birth for term and preterm neonates requiring no medical support and/or supplemental oxygen. The NIRS sensor was placed on the left forehead. Peripheral oxygen saturation (SpO2) and heart rate (HR) were continuously measured by pulse oximetry. Cerebral fractional oxygen extraction (cFTOE) was calculated. Data were analysed regarding gender for all study groups (term/vaginally delivered-VDterm; term/caesarean delivered-CDterm; preterm/caesarean delivered-CDpreterm). Results Out of a total of 479 measured infants during the study period, 374 were considered for further analysis. In the group of term infants, there was a gender difference in those with cesarian delivery (CDterm group, n = 268): males showed significantly higher values for SpO2 (p = . 009) and crSO2 (p = . 009); whereas no difference was seen in HR. FTOE values were lower in males, very close to significance (p = 0.055). There was no significant difference in any parameter in vaginally delivered term infants (VDterm group, n = 80), as well as in preterm infants (CDpreterm group, n = 26). The power analysis showed, that in these two groups the number of infants was too small to draw significant conclusions. Conclusion There was a significant difference in course of crSO2 and SpO2 due to gender in term infants after cesarian section delivery, male infants did show significantly higher oxygen saturation values compared to female infants.

PS-099 Transitional Changes In Cerebral Blood Volume At Birth

Background and aims Near-infrared spectroscopy (NIRS) is a non-invasive method to measure changes in the concentration of oxygenated (ΔO2Hb) and deoxygenated haemoglobin (ΔHHb). Changes in total haemoglobin (ΔcHb = ΔO2Hb+ΔHHb) give information on changes in cerebral blood volume (CBV). Moreover cerebral tissue oxygenation index (cTOI = ΔO2Hb/ΔcHb*100%) is detected. The aim was to evaluate changes of CBV during postnatal transition in term newborns. Methods This observational study was conducted at the Medical University Graz. Included were term infants without need for respiratory support after caesarean section. NIRS measurements were carried out with ‘NIRO-200-NX’ (Hamamatsu; Japan) over 15 min. Results 109 term infants (55 female) with mean gestational age of 39+0 weeks (±7 days) and birth weight of 3245 g (±441) were included. CBV: Related to the baseline at 2 min of age (min), median (25th; 75th percentiles) ΔcHb was 0 micromoles (µM) (-5;4) at 3 min, -1 µM (-8;5) at 5 min, -7 µM (-17;0) at 10 min, and -13 µM (-26;1) at 15 min. ΔcHb, representing the behaviour of CBV, was slowly decreasing during transition period. cTOI: Median (25th;75th percentiles) cTOI was 56% (50;65) at 2 min, 57% (51;64) at 3 min, 64% (58;72) at 5 min, 74% (69;79) at 10 min, and 72% (67;78) at 15 min. cTOI was slowly increasing from 2 min to 7 min, reaching a steady state after 8 min. Conclusion In healthy newborns CBV was slowly decreasing over the whole study period. We hypothesise, that increasing left-to-right shunt via ductus arteriosus may account for decreasing CBV in this period. These findings add information for a better understanding of haemodynamic processes during transition.

O-025 Do Sustained Lung Inflations During Resuscitation Of Preterm Infants Affect Cerebral Blood Volume And Cerebral Regional Oxygen Saturation?

Background and aim Sustained lung inflations (SLI) promote lung aeration and alveolar recruitment. Changes in total haemoglobin (ΔcHb) and cerebral tissue oxygenation index (cTOI) measured by near-infrared spectroscopy (NIRS) give information on changes in cerebral blood volume (CBV) and regional oxygen saturation, respectively. Do SLI during resuscitation affect CBV and cTOI? Methods Preterm infants ≥28+0 and <34+0 gestational weeks and need for respiratory support (RS) during postnatal transition were included. Within the first 15 min of life of each subject ΔcHb and cTOI were continuously detected by using ‘NIRO-200-NX’ (Hamamatsu; Japan). Two groups were compared based on RS: SLI group: RS was started by applying 1–2 SLI for 15sec at 25 cmH2O and continued by continuous positive airway pressure (CPAP) or positive pressure ventilation (PPV). Control group: CPAP/PPV depending on respiratory insufficiency. Results 40 preterm infants (23 female) with mean gestational age of 32+1 weeks (±3 days) and mean birth weight of 1707 g (±470) were included. Demographic data did not show significant differences between groups. Median ΔcHb was in SLI/control group -0.38/0.20 µM 30 sec after initializing RS, –1.33/–0.43 µM after 60 sec, 3.37/2.30 µM after 2 min, –0.19/–0.46 µM after 3 min, 2.52/1.05 µM after 5min and 2.93/–4.78 µM after 10 min. Median cTOI increased in SLI/control group from 49/47% 30 sec after initialising RS to 54/50% after 60 sec, to 56/51% after 2 min, to 56/58% after 3 min, to 61/61% after 5 min, and to 65/69% after 10 min. Conclusion Initialising RS immediately after birth by using SLI in preterm infants did not show significant differences in CBV and cTOI compared to control group.