Cerebral oxygenation and blood flow in term infants during postnatal transition: BabyLux project

Abstract

ObjectivesA new device that combines, for the first time, two photonic technologies (time-resolved near-infrared spectroscopy and diffuse correlation spectroscopy) was provided and tested within the BabyLux project. Aim was to validate the expected changes in cerebral oxygenation and blood flow.MethodsA pulse oximeter and the BabyLux device were held in place (right hand/wrist and frontoparietal region, respectively) for 10 min after birth in healthy term infants delivered by elective caesarean section. Pulse oximeter saturation (SpO2), cerebral tissue oxygen saturation (StO2) and blood flow index (BFI) were measured over time. Tissue oxygen extraction (TOE) and cerebral metabolic rate of oxygen index (CMRO2I) were calculated.ResultsThirty infants were enrolled in two centres. After validity check of data, 23% of infants were excluded from TOE and CMRO2I calculation due to missing data. As expected, SpO2 (estimate 3.05 %/min; 95% CI 2.78 to 3.31 %/min) and StO2 (estimate 3.95 %/min; 95% CI 3.63 to 4.27 %/min) increased in the first 10 min after birth, whereas BFI (estimate −2.84×10−9 cm2/s/min; 95% CI −2.50×10−9 to −3.24×10−9 cm2/s/min) and TOE (estimate −0.78 %/min; 95% CI −1.12 to –0.45 %/min) decreased. Surprisingly, CMRO2I decreased (estimate −7.94×10−8/min; 95% CI −6.26×10−8 to −9.62×10−8/min).ConclusionsBrain oxygenation and BFI during transition were successfully and simultaneously obtained by the BabyLux device; no adverse effects were recorded, and the BabyLux device did not limit the standard care. The preliminary results from clinical application of the BabyLux device are encouraging in terms of safety and feasibility; they are consistent with previous reports on brain oxygenation during transition, although the interpretation of the decreasing CMRO2I remains open.Trial registration number NCT02815618.

Accuracy and precision of tissue optical properties and hemodynamic parameters estimated by the BabyLux device: a hybrid time-resolved near-infrared and diffuse correlation spectroscopy neuro-monitor

“…The last point was to check how the physiological variability of a given hemodynamic parameter propagates into measurements and to the determination of the hemodynamic parameters by DCS and TRS. The single level of Hb and HbO 2 concentration considered in the simulation were comparable to those that were obtained on healthy term neonates by the BabyLux device [49]. At 10 5 acquired photon level, the obtained CV of Hb and HbO 2 concentration were already close to the ones used for simulation.…”

“…To this purpose, TRS and DCS data with added noise were simulated and analyzed with different settings in order to investigate the influence of each parameter in the precision and the accuracy of the retrieved results. We have used reference optical and hemodynamic parameters that were in line with results of the infants studies conducted with the BabyLux device [49]. The experimental parameters were chosen accordingly to the characteristics (e.g.…”

“…In particular, the experimental parameters were chosen considering the BabyLux device [48] as the reference system. The tissue hemodynamics and optical properties were chosen according to what was previously measured in newborns with the BabyLux device [49].…”

Validation of diffuse correlation spectroscopy against 15O-water PET for regional cerebral blood flow measurement in neonatal piglets

“…Considering all this, we have applied the conversion factor to data from a population of twenty-five healthy term newborns measured in a clinical study employing the BabyLux device. 55 The median value of the baseline BFI was found to be 25 inter-quartile range (IQR): [19, 35] ×10 −9 cm 2 /s, which can be converted to 22 IQR: [17, 31] ml/100 g/min. It is generally accepted that normal gCBF in healthy newborn infants is around 20 ml/100 g/min, 56 not far from our estimation.…”

How lung injury and therapeutic oxygen could alter white matter development

“…Using nearinfrared spectroscopy (NIRS) to measure sO 2 in human fetuses during labor, cerebral sO 2 was measured at 43% ± 10% (Peebles et al, 1992). In a recent NIRS study, the human newborn frontoparietal cortex median sO 2 at 3min of life was 46%, plateauing at 65.6% after 10min of life (De Carli et al, 2019). While we do not know the sO 2 of less superficial human brain regions, rodent studies indicate that the pO 2 in cortical white matter is much lower than in cortical gray matter (6-16 mmHg vs. 19-40 mmHg) (Silver & Erecinska, 1998;Stacpoole et al, 2013).…”