Anne Pardou

Auditory arousal thresholds are higher when infants sleep in the prone position

OBJECTIVE To evaluate the possibility that infants sleeping in the prone position have higher arousal thresholds to auditory challenges than when sleeping in the supine position. STUDY DESIGN Polygraphic recordings were performed for 1 night in 25 healthy infants with a median age of 9 weeks. The infants were exposed to white noises of increasing intensities while sleeping successively in the prone and supine positions, or vice versa. Arousal thresholds were defined by the auditory stimuli needed to induce polygraphic arousals. RESULTS Three infants were excluded from the study because they awoke while their position was being changed. For the 22 infants included in the analysis, more intense auditory stimuli were needed to arouse the infants in the prone position than those in the supine body position (p = 0.011). Arousal thresholds were higher in the prone than in the supine position in 15 infants; unchanged in 4 infants; and lower in the prone position in 3 infants (p = 0.007). CONCLUSIONS Infants show higher arousal thresholds to auditory challenges when sleeping in the prone position than when sleeping in the supine position. The finding could be relevant to mechanisms concerned with the reported association between sudden deaths and the prone sleeping position in infants.

Central venous catheter-related bacteraemia in critically ill neonates: Risk factors and impact of a prevention programme

Risk factors for central venous catheter (CVC)-related bacteraemia among infants admitted to a neonatal intensive care unit (NICU) were analysed and the impact of surveillance and continuing education on the incidence of this complication investigated. Among patients admitted to a NICU, CVC-related bacteraemia increased from 1/15 (7%) in 1987 to 11/26 (42%) in 1988 (P = 0.01). Coagulase-negative staphylococci isolated from bacteraemia patients showed clonal diversity by plasmid and chromosomal fingerprinting. A review of CVC care procedures suggested breaches in aseptic techniques. Catheter-care technique was revised to ensure maximal aseptic precautions, including the use of sterile gloves, gown and drapes. The new policy was promoted by a continuing education programme and regular feed-back of CVC-related bacteraemia incidence to NICU staff. In the four-year follow-up period, the attack-rate of CVC-related bacteraemia decreased to 18/156 (12%) patients [relative risk (RR): 0.27, 95% confidence interval (CI); 0.15-0.51; P < 0.001 vs the previous period]. By using the Coxs model proportional hazards, very low birthweight and the period before use of strict aseptic CVC care were found to be predictors of increased risk of catheter-related bacteraemia after adjustment for duration of catheterization. These data provide further evidence that strict aseptic precautions during the maintenance and utilization of CVC can contribute to lower the risk of catheter infection in critically ill neonates. Regular feedback of surveillance data was associated with a progressive decrease in incidence of infection, suggesting that it improved staff compliance with aseptic precautions.

Structural asymmetries in motor and language networks in a population of healthy preterm neonates at term equivalent age: A diffusion tensor imaging and probabilistic tractography study

In this MRI study, we aimed to provide new in vivo structural markers of asymmetry in motor and language networks in a population of healthy preterm neonates scanned at term equivalent age. Using diffusion tensor imaging and probabilistic tractography, we showed that, besides volume and microstructural asymmetries in the parieto-temporal part of the superior longitudinal fasciculus (SLF) and a trend towards microstructural asymmetry in the corticospinal tract (CST), volume asymmetry in the motor part of the superior thalamic radiations (STR) and a trend towards volume asymmetry in the CST are already present in the neonatal period. No asymmetry was found in the sensory part of the STR, the anterior thalamic radiations (ATR), and posterior thalamic radiations (PTR) neither in the fronto-parietal part of the SLF. These results suggest that structural asymmetries in the motor and language networks are present in healthy preterm neonates at term equivalent age, well before the development of speech and hand preference.

Human Milk Banking: Influence of Storage Processes and of Bacterial Contamination on Some Milk Constituents

This paper reviews the effects of storage and bacterial content contaminating human milk on some milk constituents. Moreover, it reviews the inhibitory effect of refrigeration and freezing on bacterial growth. Our results suggest that the type and length of storage have an effect on some milk constituents, that this effect is modulated by the bacterial contamination of the milk and that refrigeration has a significant inhibitory effect on bacterial growth which is not observed after freezing. This stresses the importance of collecting noncontaminated milk and justifies the choice of refrigeration at 0-4 degrees C for storage up to 8 days.

Mapping of normal brain maturation in infants on phase-sensitive inversion-recovery MR images

SummaryIt is illustrated that phase-sensitive inversion-recovery MR images are particularly well suited for the monitoring of brain maturation and myelination in the neonate and young infant. Provided appropriate timings are applied with the inversion-recovery MR pulse sequence, the myelinated areas show up as bright spots in the phase-sensitive images. The chronology of the appearance, and the location of these hyperintense zones correlate well with the chronology of brain maturation, as assessed by other means. In particular, the progressive functional capabilities of the infant correlate well with the progress of myelination, as exhibited by the MR images.

Withdrawal of iodinated disinfectants at delivery decreases the recall rate at neonatal screening for congenital hypothyroidism.

Certainly, healthy breast fed babies may have frequent loose stools. While it is difficult to define pathological diarrhoea, this infants diarrhoea was sufficient to get him admitted to hospital despite the adequate weight gain. Both the mother and experienced ward staff felt that the infants diarrhoea was excessive, despite my attempts to reassure them. Reducing substances were identified in the stools repeatedly, at a concentration of 1%. The diarrhoea immediately resolved on changing to a succession of two other milks (Pregestimil and SMA), and has never returned since. If the baby had continued to be breast fed we do not know whether he would have thrived adequately. His mother declined my suggestion to resume breast feeding. In these circumstances, I believe, it is reasonable to assume that the milk oligosaccharides were responsible for the troublesome diarrhoea (associated with perianal soreness) and that he benefited by the change of milk. Our observations do not contradict those of Whyte et al but underline the importance of diet in the interpretation of analytical findings and of collecting samples before dietary or other therapeutic manipulations.

Diagnosis of severe birth asphyxia and early prediction of neonatal neurological outcome in term asphyxiated newborns.

Ten indicators available during the first two hours of life, such as clinical criteria of neonatal distress and postnatal arterial blood gases, were compared with the neonatal neurological course in sixty full term newborns with significant birth asphyxia in order to test their value for the diagnosis and the short-term prognosis of severe birth asphyxia. Birth asphyxia was defined as severe when it was followed by symptoms of moderate or severe post-asphyxial encephalopathy. We calculated a sensitivity lower than fifty percent for clinical criteria such as delay in establishing regular respiration and Apgar scores. It was clear that normal delay in establishing regular respiration and normal Apgar scores do not exclude severe birth asphyxia. Arterial pH and base deficit at thirty minutes of life were found to be the best criteria for the diagnosis of severe birth asphyxia, but lacked positive predictive value. The best predictive tool for the short-term neurological prognosis of birth asphyxia was a single score established at 30 minutes of life and based on the evaluation of consciousness, respiration and neonatal reflexes. Some aspects of the pathophysiology of birth asphyxia and the rationale for treatment of post-asphyxial metabolic acidosis are discussed.

Neonatal hemochromatosis and Martinez-Frias syndrome of intestinal atresia and diabetes mellitus in a consanguineous newborn.

Neonatal hemochromatosis is a heterogeneous disorder of iron metabolism characterized by hepatic failure and marked iron accumulation in liver and extrahepatic tissues. Autosomal recessive transmission is found in most cases. Neonatal hemochromatosis shares cellular features with the adult disease but is clinically and genetically distinct, the causal gene(s) being presently unknown. We report on a newborn from consanguineous parents who presented with multiple congenital anomalies and neonatal hemochromatosis. The syndrome consisted of intra-uterine growth retardation, intestinal atresia, gallbladder aplasia and diabetes mellitus, and fitted with the diagnosis of Martinez-Frias syndrome, a very rare autosomal recessive phenotype, the gene of which remains to be identified. We suggest that neonatal hemochromatosis may be part of the Martinez-Frias syndrome. Molecular analyses in this and other reported patients with the Martinez-Frias syndrome should shed light on gut development and iron metabolism.

High-frequency ventilation and conventional mechanical ventilation in newborn babies with respiratory distress syndrome: A prospective, randomized trial

ObjectiveMorbidity and mortality remain high amongst babies ventilated for a respiratory distress syndrome (RDS). Whether newly developed ventilators allowing high frequency ventilation such as high frequency flow interrupted ventilation (HFFIV) could decrease the morbidity and the mortality was investigated in a randomized study.DesignPreterm babies weighing ≤1800g suffering from RDS and ventilated by conventional mechanical ventilation (CMV) were randomized to be further ventilated either by CMV (group CMV) or by HFFIV (group HFFIV) when peak inspiratory pressure (PIP) on CMV was ≥20cmH2O.SettingThe study was undertaken in the neonatal intensive care unit of the Erasmus Hospital.Patients24 patients entered into the investigation and were randomized but 2 patients were removed from the study because the switch over to HFFIV failed. Eight of the 12 CMV patients and 5 of the 10 HFFIV patients completed the study.Measurements and resultsClinical variables, blood gas analysis and ventilatory variables were looked at. There were no differences in mortality, in incidence of air leaks and pulmonary complications or in blood gas analysis. Bronchopulmonary dysplasia was not decreased by the use of HFFIV.ConclusionIt is concluded that HFFIV is safe although it offers no concrete advantages over CMV when applied as we did in a low pressure approach.

Non-invasive measurement of intracranial pressure in the newborn and the infant: the Rotterdam teletransducer.

Knowledge of intracranial pressure may be important in many clinical situations in neonates and young infants. The best way to obtain this information would be a non-traumatic procedure. In order to test the reliability of a new fontanometer, the Rotterdam teletransducer, 25 simultaneous measurements of cerebrospinal fluid (CSF) pressure and anterior fontanelle pressure (AFP) were performed. Mean (SD) difference between CSF pressure and AFP was -0.2 (1.8) mm Hg (95% confidence interval from -0.48 to -0.88 mm Hg). The AFP was also measured in 60 healthy children (15 premature, 30 term newborn babies, and 15 infants). The different aspects of AFP were analysed and normal values computed. These results suggest that the Rotterdam teletransducer gives reliable continuous information about intracranial pressure and can be used in clinical practice. Interpretation of AFP plots must take the influence of postconceptional age and the physiological occurrence of pressure waves into account.