Mjnl Benders

Neonatal tract-based spatial statistics findings and outcome in preterm infants.

BACKGROUND AND PURPOSE: WM injury is associated with different disabilities that children born prematurely may experience during their lives. The aim of this study was to use TBSS to test the hypothesis that WM microstructure at TEA in preterm infants is correlated with cognitive and motor outcome at 2-year corrected age. MATERIALS AND METHODS: Sixty-three preterm infants, born at a mean gestational age of 28.7 weeks, underwent MR imaging and DTI at TEA. Neurodevelopmental performance was assessed by using the BSITD-III. Voxelwise analysis of the DTI data was performed by using TBSS to assess the relationship among FA, AD, and RD at TEA, and cognitive, fine-motor, and gross-motor scores at 2-year corrected age. RESULTS: Cognitive scores were correlated with FA values in the CC. Fine-motor scores were correlated with FA and RD throughout the WM. Gross-motor scores were associated with RD in the CC, fornix, and internal and external capsule. CONCLUSIONS: WM microstructure in preterm infants at TEA was associated with cognitive, fine-motor, and gross-motor performance at 2-year corrected age. This study suggests that TBSS of DTI data at TEA has the potential to be used as a biomarker for subsequent neurodevelopment.

Early postnatal allopurinol does not improve short term outcome after severe birth asphyxia

Objective: To investigate whether postnatal allopurinol would reduce free radical induced reperfusion/reoxygenation injury of the brain in severely asphyxiated neonates. Method: In an interim analysis of a randomised, double blind, placebo controlled study, 32 severely asphyxiated infants were given allopurinol or a vehicle within four hours of birth. Results: The analysis showed an unaltered (high) mortality and morbidity in the infants treated with allopurinol. Conclusion: Allopurinol treatment started postnatally was too late to reduce the early reperfusion induced free radical surge. Allopurinol administration to the fetus with (imminent) hypoxia via the mother during labour may be more effective in reducing free radical induced post-asphyxial brain damage.

Neonatal stroke: a review of the current evidence on epidemiology, pathogenesis, diagnostics and therapeutic options

Neonatal stroke, including perinatal arterial ischaemic stroke and cerebral sinovenous thrombosis, remains a serious problem in the neonate. This article reviews the current evidence on epidemiology, pathogenesis, diagnostics and therapeutic options.

Acute Effects of Indomethacin on Cerebral Hemodynamics and Oxygenation

Although an indomethacin-induced decrease of brain perfusion in preterm infants has been well established, the acute effects of this vasoactive drug on cerebral hemodynamics and oxygenation are not well documented. Using near infrared spectroscopy we monitored in 6 very preterm infants changes in cerebral blood volume (delta CBV) and cytochrome oxidase concentration (delta Cytaa3), used as relative measures of changes in brain perfusion and as an indicator for cellular oxygenation of brain tissue, during and up to 1 h after indomethacin infusion. delta CBV showed a quick blood-pressure-related increase as compared to baseline (preindomethacin values) during indomethacin infusion (averaged maximal increase 13%), followed by a sharp decrease below baseline values (averaged maximal decrease 24%). There was a sustained recovery to baseline during the registration period. delta Cytaa3 showed a small, early increase in 4 of 6 babies, followed by a substantial decrease below baseline in 5 babies. delta Cytaa3 showed only a partial recovery in those 5 babies during the study period. We conclude that a therapeutic dose of indomethacin may cause substantial swings in brain perfusion and a marked and rather longstanding decrease in Cytaa3, suggesting a decrease in cellular oxygenation of brain tissue. Awareness of these effects may be important in sick preterm babies during periods of pulmonary and cardiac instability.

Impact of neonate haematocrit variability on the longitudinal relaxation time of blood: Implications for arterial spin labelling MRI.

Background and purpose The longitudinal relaxation time of blood (T1b) is influenced by haematocrit (Hct) which is known to vary in neonates. The purpose of this study was threefold: to obtain T1b values in neonates, to investigate how the T1b influences quantitative arterial spin labelling (ASL), and to evaluate if known relationships between T1b and haematocrit (Hct) hold true when Hct is measured by means of a point-of-care device. Materials and methods One hundred and four neonates with 120 MR scan sessions (3 T) were included. The T1b was obtained from a T1 inversion recovery sequence. T1b-induced changes in ASL cerebral blood flow estimates were evaluated. The Hct was obtained by means of a point-of-care device. Linear regression analysis was used to investigate the relation between Hct and MRI-derived R1 of blood (the inverse of the T1b). Results Mean T1b was 1.85 s (sd 0.2 s). The mean T1b in preterm neonates was 1.77 s, 1.89 s in preterm neonates scanned at term-equivalent age (TEA) and 1.81 s in diseased neonates. The T1b in the TEA was significantly different from the T1b in the preterm (p < 0.05). The change in perfusion induced by the T1b was −11% (sd 9.1%, p < 0.001). The relation between arterial-drawn Hct and R1b was R1b = 0.80 × Hct + 0.22, which falls within the confidence interval of the previously established relationships, whereas capillary-drawn Hct did not correlate with R1b. Conclusion We demonstrated a wide variability of the T1b in neonates and the implications it could have in methods relying on the actual T1b as for instance ASL. It was concluded that arterial-drawn Hct values obtained from a point-of-care device can be used to infer the T1b whereas our data did not support the use of capillary-drawn Hct for T1b correction.

Haemodynamic consequences of phototherapy in term infants

Abstract The effect of blue-light phototherapy on cardiac output and brain and kidney perfusion was studied in 12 term infants with pulsed Doppler ultrasound. Mean (±SD) gestational age and birth weight were 39.0 (±1.6) weeks and 3438 (±533) g respectively. Mean (±SD) age of the infants at which phototherapy was initiated was 3.5 (±0.8) days. Left ventricular output (LVO), mean left pulmonary artery blood flow (LPA), mean blood flow velocities of the internal carotid (CBFV) and renal (RBFV) arteries were studied in all infants prior to the onset of phototherapy, 30 min, 2 h, and 12 h after initiation of phototherapy, and before and 12–24 h after discontinuation of phototherapy. LVO decreased immediately after the onset of phototherapy. However, after 12 h, LVO returned to pre-phototherapy values. LPA increased significantly after 12 h of exposure. LPA returned to pre-phototherapy values after discontinuation of phototherapy. CBFV increased, whereas RBFV decreased significantly after 2 h of exposure. After discontinuation of phototherapy CBFV as well as RBFV values returned to pre-phototherapy values. Conclusion Phototherapy does affect cardiac output and organ blood flow velocity in term infants. After termination of phototherapy the effect of phototherapy disappears.

Cardiac Biomarkers as Indicators of Hemodynamic Adaptation during Postasphyxial Hypothermia Treatment

Background: Little is known about the effects of hypothermia on the cardiovascular system in term newborns with neonatal encephalopathy. Objectives: To evaluate whether mild hypothermia for neonatal encephalopathy is cardioprotective as indicated by the cardiac biomarkers cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP). Methods: This was an observational cohort study of infants treated for perinatal asphyxia. In infants, mild total body hypothermia treatment of 33.5°C during 72 h was initiated (n = 20). Samples of cTnI and BNP were collected before the start of hypothermia, at 24 and 48 h after birth, and after rewarming (84 h). BNP and cTnI values were then compared with BNP and cTnI values of asphyxiated infants not treated with hypothermia (n = 28). Results: No differences were found between the groups in clinical patient characteristics or inotropic support. The hypothermia-treated patients seemed to be clinically more affected (5-min Apgar score, p < 0.05; umbilical artery pH, p = 0.08), but showed similar encephalopathy scores. Significantly lower values for BNP were found in hypothermia- compared to nonhypothermia-treated infants at 48 h and at normothermia after rewarming [144 pmol/l (95–286) vs. 75 pmol/l (45–143), 182 pmol/l (73–341) vs. 43 pmol/l (24–163)]. No differences were found for cTnI concentrations between both groups. Conclusions: The raised, but similar, cTnI values between hypothermia- and nonhypothermia-treated infants indicate similar myocardial damage in both groups. The lower BNP levels during hypothermia treatment suggest that hypothermia after perinatal asphyxia exerts a beneficial effect on cardiac function.

The Effect of Phototherapy on Renal Blood Flow Velocity in Preterm Infants

Mean renal blood flow velocity (RBFV) was studied with two-dimensional/pulsed Doppler ultrasound and relative renal vascular resistance (RVR) was calculated before, during, and after phototherapy treatment in 30 preterm infants (gestational age ≤32 weeks) who were treated for a minimum of 12 h with phototherapy for nonhemolytic hyperbilirubinemia. RBFV decreased, whereas RVR increased significantly after the initiation of phototherapy. In ‘healthy’ (nonventilated) infants RBFV and RVR returned to baseline values after discontinuation of phototherapy. Whereas in ‘unhealthy’ (ventilated) infants, RBFV and RVR did not return to baseline values after discontinuation of phototherapy. In 16 infants (>50% of the cases) the ductus arteriosus reopened during phototherapy.

Cerebral white matter and neurodevelopment of preterm infants after coagulase-negative staphylococcal sepsis.

Objective: Coagulase-negative staphylococci are the most common pathogens causing lateonset sepsis in the neonatal intensive care unit. Neonatal sepsis can be associated with cerebral white matter damage in preterm infants. Neurodevelopment has been shown to be correlated with apparent diffusion coefficients, fractional anisotropy, and axial and radial diffusivities of the white matter. Design: Prospective cohort study. Setting: Twenty-eight–bed neonatal intensive care unit at a tertiary care children’s hospital. Patients: Seventy preterm infants (gestational age <32 wks), 28 with coagulase-negative staphylococcal sepsis (group 1) and 42 without sepsis (group 2). Intervention: The values of apparent diffusion coefficients, fractional anisotropy, and axial and radial diffusivity of three white matter regions (parietal, frontal, and occipital), estimated with diffusiontensor magnetic resonance imaging with a 3.0-T magnetic resonance imaging system, were obtained at termequivalent age. Neurodevelopmental outcome assessments were performed at 15 months (Griffiths Mental Developmental Scales) and 24 months (Bayley Scales of Infant and Toddler Development, Third Edition) corrected age. Measurements and Main Results: Values of apparent diffusion coefficients, fractional anisotropy, and axial and radial diffusivity of the left and right white matter regions were equal in all patients. There was no significant difference in apparent diffusion coefficient values (mean of total: 1.593 ± 0.090 × 10−3mm2/sec and 1.601 ± 0.117 × 10−3mm2/sec, respectively, p = .684), fractional anisotropy values (mean of total: 0.19 ± 0.04 and 0.19 ± 0.03, respectively, p = .350), radial diffusivity (mean of total: 1.420 ± 0.09 × 10−3mm2/sec and 1.425 ± 0.12 × 10−3mm2/sec, respectively, p = .719), and axial diffusivity (mean of total: 1.940 ± 0.12 × 10−3mm2/sec and 1.954 ± 0.13 × 10−3mm2/sec, respectively, p = .590) in the three combined regions between the two groups. No significant differences were found in neurodevelopmental outcome at 24 months. Conclusions: No association was found between coagulase-negative staphylococcal sepsis in preterm infants and cerebral white matter damage as determined by values of apparent diffusion coefficients, fractional anisotropy, and radial and axial diffusivity at termequivalent age, and no adverse effect was seen on early neurodevelopmental outcome.

Rapid target allopurinol concentrations in the hypoxic fetus after maternal administration during labour

Objective Perinatal hypoxia-induced free radical formation is an important cause of hypoxic-ischaemic encephalopathy and subsequent neurodevelopmental disabilities. Allopurinol reduces the formation of free radicals, which potentially limits hypoxia-induced brain damage. We investigated placental transfer and safety of allopurinol after maternal allopurinol treatment during labour to evaluate its potential role as a neuroprotective agent in suspected fetal hypoxia. Design We used data from a randomised, double-blind multicentre trial comparing maternal allopurinol versus placebo in case of imminent fetal hypoxia (NCT00189007). Patients We studied 58 women in labour at term, with suspected fetal hypoxia prompting immediate delivery, in the intervention arm of the study. Setting Delivery rooms of 11 Dutch hospitals. Intervention 500 mg allopurinol, intravenously to the mother, immediately prior to delivery. Main outcome measures Drug disposition (maternal plasma concentrations, cord blood concentrations) and drug safety (maternal and fetal adverse events). Results Within 5 min after the end of maternal allopurinol infusion, target plasma concentrations of allopurinol of ≥2 mg/L were present in cord blood. Of all analysed cord blood samples, 95% (52/55) had a target allopurinol plasma concentration at the moment of delivery. No adverse events were observed in the neonates. Two mothers had a red and/or painful arm during infusion. Conclusions A dose of 500 mg intravenous allopurinol rapidly crosses the placenta and provides target concentrations in 95% of the fetuses at the moment of delivery, which makes it potentially useful as a neuroprotective agent in perinatology with very little side effects. Trial registration The study is registered in the Dutch Trial Register (NTR1383) and the Clinical Trials protocol registration system (NCT00189007).