Bernhard Schwaberger

Cerebral haemorrhage in preterm neonates: does cerebral regional oxygen saturation during the immediate transition matter?

Objectives To investigate the occurrence of peri/intraventricular haemorrhage (P/IVH) in preterm infants and its potential association with cerebral regional oxygen saturation (crSO2) during the immediate transition. Methods In this two-centre prospective observational cohort study, crSO2 was measured with near-infrared spectroscopy in preterm infants (<32 weeks of gestational age) during the immediate neonatal transition (15 min). In addition, arterial oxygen saturation (SpO2) and heart rate (HR) were monitored with pulse oximetry. Cranial ultrasound scans were performed on day 4, day 7 and day 14 after birth and before discharge. Neonates with IVH of any grade (IVH group) were matched to the neonates without IVH (Non-IVH group) on gestational age (±1 week) and birth weight (±100 g). The duration and magnitude of deviation from the 10th centile in crSO2 during immediate transition was analysed and expressed in %minutes. Results IVH was found in 12 of the included neonates, who were matched to 12 neonates without IVH. There was no difference in SpO2 and HR between these two groups. The duration and magnitude of centiles-deviation of crSO2 was significantly pronounced in the IVH group compared with the Non-IVH group (1870%min vs 456%min). Conclusions The neonates of the IVH group showed significantly lower crSO2 values during the immediate transition, although there was no difference concerning SpO2 and HR. The additional monitoring of crSO2 during the immediate transition could reveal neonates with higher risk of developing an IVH later in the course.

Reference Ranges for Cerebral Tissue Oxygen Saturation Index in Term Neonates during Immediate Neonatal Transition after Birth.

Background: Non-invasive monitoring of the brain with near-infrared spectroscopy (NIRS) during immediate transition after birth is of growing interest. Objective: The aim of this work was to define reference ranges and centile charts for a regional cerebral tissue oxygenation index (cTOI), measured with the NIRO 200NX (NIRO, Hamamatsu, Japan), and cerebral fractional tissue oxygen extraction (cFTOE) during the first 15 min after birth in preterm and term neonates without any medical support. Methods: cTOI was measured with the NIRO 200NX during the first 15 min after delivery via Caesarean section in preterm and term infants. The NIRS-sensor was placed on the right forehead. Peripheral arterial oxygen saturation (SpO2) and heart rate were continuously measured by pulse oximetry. cFTOE was calculated out of cTOI and SpO2. Neonates with a requirement for any medical support were excluded. Results: A total of 230 neonates were enrolled, from which 90 had to be excluded. Therefore, 140 term neonates were included and data were used to define reference ranges and centile charts. The 50th centile (10th to 90th centiles) of cTOI was 56% (39-75) at 2 min, 66% (50-78) at 5 min, 75% (62-85) at 10 min and 73% (61-84) at 15 min after birth. The 50th centile of cFTOE was 0.24 (0.11-0.44) at 2 min, 0.20 (0.10-0.35) at 5 min, 0.21 (0.09-0.35) at 10 min and 0.24 (0.13-0.37) at 15 min after birth. Conclusion: The present observational study adds the reference ranges and centile charts of cTOI measured with the NIRO 200NX and cFTOE calculated out of cTOI and SpO2 in neonates during the immediate neonatal transition. Centiles for each instrument will be necessary for future clinical application, since the differences between cTOI and cerebral regional tissue oxygen saturation measured with INVOS 5100C change with increasing regional oxygenation.

Do Sustained Lung Inflations during Neonatal Resuscitation Affect Cerebral Blood Volume in Preterm Infants? A Randomized Controlled Pilot Study.

Background Sustained lung inflations (SLI) during neonatal resuscitation may promote alveolar recruitment in preterm infants. While most of the studies focus on respiratory outcome, the impact of SLI on the brain hasn’t been investigated yet. Objective Do SLI affect cerebral blood volume (CBV) in preterm infants? Methods Preterm infants of gestation 28 weeks 0 days to 33 weeks 6 days with requirement for respiratory support (RS) were included in this randomized controlled pilot trial. Within the first 15 minutes after birth near-infrared spectroscopy (NIRS) measurements using ‘NIRO-200-NX’ (Hamamatsu, Japan) were performed to evaluate changes in CBV and cerebral tissue oxygenation. Two groups were compared based on RS: In SLI group RS was given by applying 1–3 SLI (30 cmH2O for 15 s) continued by respiratory standard care. Control group received respiratory standard care only. Results 40 infants (20 in each group) with mean gestational age of 32 weeks one day (±2 days) and birth weight of 1707 (±470) g were included. In the control group ΔCBV was significantly decreasing, whereas in SLI group ΔCBV showed similar values during the whole period of 15 minutes. Comparing both groups within the first 15 minutes ΔCBV showed a tendency toward different overall courses (p = 0.051). Conclusion This is the first study demonstrating an impact of SLI on CBV. Further studies are warranted including reconfirmation of the present findings in infants with lower gestational age. Future investigations on SLI should not only focus on respiratory outcome but also on the consequences on the developing brain. Trial Registration German Clinical Trials Register DRKS00005161 https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_EN.do

Cardiocirculatory monitoring during immediate fetal-to-neonatal transition: a systematic qualitative review of the literature.

Background: The fetal-to-neonatal transition is a complex process that includes changes in cardiac and respiratory systems. Objective: The aim of this study is to review the different methods of cardiocirculatory monitoring during the immediate neonatal transition period. Methods: A systematic search of PubMed and Ovid Embase was performed using the following terms: infant, newborn, newborn infant, neonate, neonates, heart, cardiac, blood pressure, haemodynamic, hemodynamics, blood circulation, circulation, echocardiography, ultrasonography, sonography, electrocardiography, ECG, oximetry, pulse, pulse oximetry, monitoring, measurement, acclimatization, adaptation, transition, after birth and delivery room. Additional articles were identified by manual search of cited references. Only human studies describing cardiocirculatory monitoring during the first 15 min after birth were included. Results: Thirteen studies were identified that described heart rate (HR). Additional five studies were identified that measured blood pressure. Four studies performed functional echocardiography during neonatal transition; two in addition to blood pressure monitoring and three in addition to HR monitoring. Conclusion: Routine HR monitoring using electrocardiography or pulse oximetry is used to evaluate adequate hemodynamic transition, and reference ranges have been established. Measuring blood pressure noninvasively though noncontinuously might be of some value in future, considering that the normative data have been established recently. Echocardiographic monitoring during the immediate transition period will improve the knowledge about cardiac function changes, but introduction in clinical routine remains questionable.

Borderline hypotension: how does it influence cerebral regional tissue oxygenation in preterm infants?

Abstract Aim: To monitor cerebral regional tissue oxygenation (crSO2) of preterm infants continuously and to analyze the influence of arterial hypotension on crSO2. Methods: In this prospective, observational study crSO2, peripheral oxygen saturation (SpO2), heart rate (HR) and mean arterial blood pressure (MABP) were monitored continuously for 24 h, starting within the first 6 h after birth. Furthermore, cerebral fractional tissue oxygen extraction (cFTOE) was calculated. Preterm neonates with and without arterial hypotension (MABP below the gestational age in weeks) were compared to each other. Results: Forty-six preterm infants could be analyzed, 17 with (33.4 ± 1.9 weeks, 2016.5 ± 548.5 g) and 29 without arterial hypotension (33.3 ± 1.3 weeks, 1924.7 ± 451.9 g). Altogether, we detected 30 episodes of hypotension, with a mean duration of 1.6 ± 1.2 h per infant and a mean decrease in MABP of 2.2 ± 0.9 mmHg. During hypotension mean crSO2 was 7 5 ± 11%, 2 h prior to that 76 ± 10% and 2 h after the hypotension 7 7 ± 10%, therefore no significant alterations could be observed. Moreover, there was no significant difference in mean 24-h crSO2, SpO2 and cFTOE between the two groups. Conclusion: Mild short-term hypotensive episodes in preterm infants did not affect crSO2. This suggests that cerebral autoregulation is maintained in case of borderline-hypotension and may protect infants from cerebral injury.

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.

Haemodynamic Transition after Birth: A New Tool for Non-Invasive Cardiac Output Monitoring

Background: Substantial haemodynamic changes occur during the first minutes after birth. Currently, only heart rate (HR) and arterial oxygen saturation are routinely used to monitor haemodynamic transition after birth. Objectives: The aim of the present study was to continuously assess haemodynamic changes during transition in term infants for the first time by using electrical velocimetry (EV), a new method of non-invasive cardiac output monitoring (NICOM), based on impedance cardiography technology. Methods: In this prospective observational study, term neonates delivered by elective caesarean section underwent NICOM measurements within the first 15 min after birth. The beat-to-beat measurement over a 10-second period was used to calculate cardiac output (CO) for each minute after birth. The data of CO were only accepted when the signal quality index (SQI) remained >80% during the measurement period of 10 s. Results: 100 term neonates underwent 1,500 NICOM measurements. 1,143 (76.2%) measurements were excluded because of a SQI <80%. HR and CO showed a trend to increase within the first minutes, and decreased significantly from minute 3 (HR) and 4 (CO), until minute 12 and 10, respectively. Stroke volume remained stable during the observation period. Conclusion: The present study was the first using EV for NICOM during the transition period in a larger cohort of newborn infants. Results of NICOM were similar to available echocardiography data. The possibility of NICOM offers continuous CO measurement. The present study supports the idea that CO is closely related to HR in newborn infants.

Peripheral Muscle Near-Infrared Spectroscopy in Neonates: Ready for Clinical Use? A Systematic Qualitative Review of the Literature

Background: Peripheral muscle near-infrared spectroscopy (NIRS) measurements are of increasing interest especially in the care of critically ill patients. Objective: The aim was to perform a systematic qualitative review on peripheral muscle NIRS measurements in the clinical care of term and preterm neonates. Methods: A systematic search of PubMed and Ovid Embase was performed using the following terms: neonate, neonates, newborn, newborns, infant, infants, near-infrared spectroscopy, NIRS, oxygenation, perfusion, oxygen extraction, peripheral, tissue, muscle, calf, forearm and thigh. Additional articles were identified by a manual search of the cited references. Only human studies were included. Results: Twenty-one studies were identified to use peripheral muscle NIRS measurements as a single method, 17 studies combined cerebral and peripheral muscle NIRS measurements and 1 study used multi-site NIRS measurements in human neonates. Two randomized studies were identified. Two additional publications were included because they provided important general information about peripheral muscle NIRS measurements. Conclusion: In the care of critically ill neonates peripheral muscle NIRS measurements alone or in combination with cerebral or multi-site NIRS measurements provide useful additional information about peripheral circulation and oxygenation. This method is a promising tool in the recognition of early states of centralization (compensated shock) in this vulnerable group of patients. However, before this method can be used in the clinical routine it has to be tested as monitoring to guide interventions in further studies.

Lung-protective ventilatory strategies in intubated preterm neonates with RDS

This article provides a narrative review of lung-protective ventilatory strategies (LPVS) in intubated preterm infants with RDS. A description of strategies is followed by results on short-and long-term respiratory and neurodevelopmental outcomes. Strategies will include patient-triggered or synchronized ventilation, volume targeted ventilation, the technique of intubation, surfactant administration and rapid extubation to NCPAP (INSURE), the open lung concept, strategies of high-frequency ventilation, and permissive hypercapnia. Based on this review single recommendations on optimal LPVS cannot be made. Combinations of several strategies, individually applied, most probably minimize or avoid potential serious respiratory and cerebral complications like bronchopulmonary dysplasia and cerebral palsy.