Rapid correction of early metabolic acidaemia in comparison with placebo, no intervention or slow correction in LBW infants (Review)

BACKGROUND: Metabolic or mixed (metabolic and respiratory) acidosis are commonly encountered problems in the low birth weight (LBW) infant after delivery, and they may contribute to mortality and morbidity. Causes for the lactic acidosis are multiple and include maternal, placental and fetal factors. It is unclear whether metabolic acidaemia in the first 24 hours of life in LBW infants should be corrected by rapid infusion of alkali. OBJECTIVES: The main objective was to assess the short and long-term effects of the rapid correction of early (first 24 hours) metabolic acidaemia in LBW

Structural and mechanical properties of TiB 2 and TiC prepared by self-propagating high-temperature synthesis/dynamic compaction

Titanium-diboride and titanium-carbide compacts with diameters of 100 mm and thicknesses of 25 mm were fabricated by self-propagating high-temperature synthesis/dynamic compaction (SHS/DC) of the elemental powders. Under the best conditions, the densities were greater than 99% and 96.8% of the theoretical densities for TiB 2 and TiC, respectively. The microhardness, compressive strength, and elastic modulus of the TiB 2 prepared by the SHS/DC method were comparable to reported values for hot-pressed TiB 2 . While the microhardness and elastic modulus of the TiC compacts were comparable to those for hotpressed TiC, the compressive strength was lower due to extensive cracks in the compacts. The TiB 2 prepared using a low-purity boron powder (1–5% carbon impurity) compacted to higher densities and had less cracking than that prepared using a high-purity boron powder (0.2% carbon). This result could have an impact on the cost of producing TiB 2 /TiC structural components by the SHS/DC process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44732/1/10853_2005_Article_BF01162518.pd

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

© 2017 The Author(s). Background: Compared to very low gestational age (<32 weeks, VLGA) cohorts, very low birth weight (<1500 g; VLBW) cohorts are more prone to selection bias toward small-for-gestational age (SGA) infants, which may impact upon the validity of data for benchmarking purposes. Method: Data from all VLGA or VLBW infants admitted in the 3 Networks between 2008 and 2011 were used. Two-thirds of each network cohort was randomly selected to develop prediction models for mortality and composite adverse outcome (CAO: mortality or cerebral injuries, chronic lung disease, severe retinopathy or necrotizing enterocolitis) and the remaining for internal validation. Areas under the ROC curves (AUC) of the models were compared. Results: VLBW cohort (24,335 infants) had twice more SGA infants (20.4% vs. 9.3%) than the VLGA cohort (29,180 infants) and had a higher rate of CAO (36.5% vs. 32.6%). The two models had equal prediction power for mortality and CAO (AUC 0.83), and similarly for all other cross-cohort validations (AUC 0.81-0.85). Neither model performed well for the extremes of birth weight for gestation (<1500 g and ≥32 weeks, AUC 0.50-0.65; ≥1500 g and <32 weeks, AUC 0.60-0.62). Conclusion: There was no difference in prediction power for adverse outcome between cohorting VLGA or VLBW despite substantial bias in SGA population. Either cohorting practises are suitable for international benchmarking

Outcomes of Two Trials of Oxygen-Saturation Targets in Preterm Infants

BACKGROUN

Hypoxia alters GABAA-subunit composition: Implications for neural rescue therapy?

Background:: Insulin Like Growth Factor Binding Proteins (IGFBPs) may be more directly related to ischaemic injury than factors such as pH and lactate, which relate to hypoxia and anaerobic metabolism. We sought to determine if IGFBP1 increases following a hypoxic insult in an animal model and to establish its possible role as an early predictor of outcome. Methods: 26 piglets were anaesthetised and ventilated. The oxygen intake was decreased to 3 to 7%, in order to create a hypoxic insult. Measurements of IGFBP1 were made before and in regular intervals after the insult. At 72 hours the piglets were sacrificed, the brains perfusion fixed and histologically examined. Results: There was no difference of birth weight or postnatal age of the animals between the groups. The histology score in the severe insult group was significantly higher than in the control or mild insult group (15.6 vs 0, p< 0.001). At 48 and 72 hours there was a significant difference of IGFBP1 between the groups with the short and prolonged hypoxia group having higher IGFBP1 levels (43.31 vs 77.9 μmol/L at 48 hours, 30.13 vs 79.68 μmol/L at 72 hours, p< 0.05) Conclusion: IGFBP1 is expressed after a hypoxic insult. The sustained increase may represent hepatic damage as is often seen in neonates following perinatal asphyxia. These findings need to be verified in neonates, however, timing of the insult is often not possible in babies. It may be that IGFBP1 may be used as a predictor of outcome following perinatal asphyxia in neonates

Cerebral impedance following hypoxia/ischaemia in the human infant

Changes in cerebral impedance are able to discriminate, within 1-2 hours of acute hypoxia in the newborn piglet, between animals which will have a good neurological outcome, and those who have suffered a more severe insult resulting in a poor outcome. The aim of this study was to determine if cerebral impedance is useful in the human infant for early identification of those who will have a poor neurological outcome following acute hypoxia, and thus may benefit from neural rescue treatment. Forty newborn term infants with a history consistent with severe acute intrapartum hypoxia and encephalopathy were studied. Bio-impedance spectroscopy was commenced as soon as possible after birth and repeated every 30 minutes until the infant was 12 hours old. Neurodevelopmental outcome was determined at 12 months of age by medical examination and Bayley score. Infants were retrospectively divided into Group A with both evidence of acute intrapartum hypoxia and a poor neurological outcome (cerebral palsy, mental impairment or cortical blindness); and Group B with all other infants. There were no significant differences in cerebral or whole body impedance between groups