N W Svenningsen

Lund University, Lund, Skane, Sweden

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Publications (119)372.16 Total impact

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    ABSTRACT: A new method has been evaluated for measuring ventilation and lung mechanics in spontaneously breathing infants by means of a face chamber. Airway flow is measured with a pneumotachograph inserted between the face chamber and a stable pressure source. Oesophageal pressure is measured via a water-filled oesophageal catheter. The method is suitable for use in conjunction with continuous positive airway pressure (CPAP) treatment in neonatal intensive care. A flat frequency response curve up to 15 Hz for the two measuring systems (i.e., airway flow and oesophageal pressure), and a time shift between the two respective signals of less than 2 msec are prerequisites for correct evaluation of respiratory mechanics. In preterm infants with chest distortion, the inhomogeneity of pleural pressure affects the significance of resistance and compliance values, as calculated from oesophageal pressure. Supra-diaphragmatic pressure variations reflect the resistive and elastic load on the diaphragm exerted by the lungs and thorax. Thus, oesophageal pressure is still useful in studies of respiratory mechanics in preterm infants.
    Acta Paediatrica 01/2008; 78(2):194 - 204. · 1.97 Impact Factor
  • K. Stjernqvist, N. W. Svenningsen
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    ABSTRACT: In a population of extremely low-birthweight (ELBW) infants with birthweights from 500 to 900g, born at 24 to 30 weeks gestation, neurobehavioural development at term was evaluated with the Brazelton Neonatal Behaviour Assessment Scale (BNBAS) and a standardized neurological examination. Compared with a control group of fullterm infants, no significant group differences were found for 19 of 27 BNBAS items; in seven other items they scored significantly lower and in one item they scored significantly higher. The BNBAS and the neurological examination showed abnormal responses in most ELBW infants with intracranial haemorrhage, especially those with grades III or IV. In spite of these differences the ELBW infants at term had a wide behavioural repertoire, with repeated, but short, periods of alertness and high performance. Parental awareness of the fluctuating state of ELBW infants at term is important for adequate parent-infant interactions.RÉSUMÉDéveloppement neuro-comportemental à terme chez les nourrissons d'extrêmement faible poids de naissanceDans une population d'extrême nt faible poids de naissance (PNEF) avec poids de naissance allant de 500 à 900 g. née entre 24 et 30 semaines de gestation, le développement neuro-comportemental à terme a été avec les scores d'appréciation de comportement néonatal de Brazelton (BNBAS) et un examen neurologique standardisé. Par comparaison avec un groupe contrôle de nourrissons nés à terme, aucune différence significative n'a été noté pour 19 des 27 items BNBAS; pour sept autres items le score était significativement plus bas et pour un item le score était significativement plus élevé. Le BNBAS et l'examen neurologique donnaient des réponses anormales chez la plupart des nourrissons PNEF avec hémorragie intra-cranienne, spécialement pour les niveaux trois ou quatre. En dépit de ces différences les nourrissons PNEF avaient un large répertoire comportemental, avec des périodes répétées mais courtes de vigilance et de performances élevées. La perception parentale de la fluctuation de vigilance des nourrissons PNEF à terme est importante pour la mise en place d'interactions parents-nourrissons adéquates.ZUSAMMENFASSUNGEntwicklungsneurologie am Termin bei Kindern mit extrem niedrigem GeburtsgewichtBei einer Gruppe von Kindern mit extrem niedrigem Geburtsgewicht (ELBW) von 500 bis 900g und einem Gestationsalter von 24 bis 30 Wochen wurde der entwicklungsneurologische Status am Termin anhand des Brazelton Neonatal Behaviour Assessment Score (BNBAS) und einer standardisierten neurologischen Untersuchung beurteilt. Im Vergleich zu einer Kontrollgruppe reifgeborener Kinder wurden für 19 von 27 BNBAS Aufgaben keine Gruppenunterschiede gefunden; bei sieben Aufgaben hatten sie signifikant niedrigere Scores und bei einer signifikant höhere. Der BNBAS und die neurologische Untersuchung ergaben bei den meisten ELBW Kindern mit intracranieller Blutung, besonders bei denen mit Grad III und IV, abnorme Befunde. Trotz dieser Unterschiede hatten die ELBW Kinder am Termin ein breites Verhaltensspektrum mit wiederholten, aber kurzen Wachphasen und guten Funktionen. Es ist wichtig, daβ die Eltern über den wechselden Zustand der ELBW Kinder am Termin informiert sind, damit adäquate Eltern-Kind Interaktionen gewährleistet sind.RESUMENDesarrollo neuroconductual al término en lactantes con un peso al nacer extremadamente bajoA una población de lactantes con peso de nacimiento extremadamente bajo (PNEB) con peso nacimiento de 500 a 900 g, nacidos entre las 24 y 30 semanas de gestación se evaluó el desarrollo neuroconductual al término usando el puntaje del comportamiento neonatal de Brazelton (PCNB) y un examen neurológico estandar. En comparación con un grupo control de lactantes nacidos a término, no se observó ninguna diferencia de grupo en 19 de 27 items de PCNB; en otros siete items sus puntajes eran significativamente más bajos y en un caso el puntaje era significativamente más alto. El PCNB y el examen neurológico mostraron respuestas anormales en la mayoria de lactantes PNEB con hemorragia endocraneana, especialmente en los grados III y IV. A pesar de estas diferencias los lactantes PNEB al término tenían un amplio repertorio conductual con periodos repetidos aunque cortos de realización alta. El que los padres sean conscientes de esta situacióon fluctuante de los lactantes PNEB al término, es importante para una adecuada interacción padres-hijo.
    Developmental Medicine & Child Neurology 01/2008; 32(8):679-688. · 2.68 Impact Factor
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    ABSTRACT: Total and regional cerebral glucose metabolism (CMRgl) was measured by positron emission tomography with 2-((18)F) fluoro-2-deoxy-D-glucose ((18)FDG) in 20 term infants with hypoxic ischemic encephalopathy (HIE) after perinatal asphyxia. All infants had signs of perinatal distress, and 15 were severely acidotic at birth. Six infants developed mild HIE, twelve moderate HIE, and two severe HIE during their first days of life. The positron emission tomographic scans were performed at 4-24 d of age (median, 11 d). One hour before scanning, 2-3.7 MBq/kg (54-100 microCi/kg) (18)FDG was injected i.v. No sedation was used. Quantification of CMRgl was based on a new method employing the glucose metabolism of the erythrocytes, requiring only one blood sample. In all infants, the most metabolically active brain areas were the deep subcortical parts, thalamus, basal ganglia, and sensorimotor cortex. Frontal, temporal, and parietal cortex were less metabolically active in all infants. Total CMRgl was inversely correlated with the severity of HIE (p < 0.01). Six infants with mild HIE had a mean (range) CMRgl of 55.5 (37.7-100.8) micromol.min(-1).100 g(-1), 11 with moderate HIE had 26.6 (13.0-65.1) micromol.min(-1).100 g(-1), and two with severe HIE had 10.4 and 15.0 micromol.min(-1).100 g(-1), respectively. Five of six infants who developed cerebral palsy had a mean (range) CMRgl of 18.1 (10.2-31.4) micromol.min(-1).100 g(-1) compared with 41.5 (13.0-100.8) micromol.min(-1).100 g(-1) in the infants with no neurologic sequela at 2 y. We conclude that CMRgl measured during the subacute period after perinatal asphyxia in term infants is highly correlated with the severity of HIE and short-term outcome.
    Pediatric Research 05/2001; 49(4):495-501. · 2.67 Impact Factor
  • K Stjernqvist, N W Svenningsen
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    ABSTRACT: Since the mid-1990s several studies have reported poor school performance in extremely preterm infants. The necessity to provide a full picture of the child's situation has been indicated. In a southern Swedish population 32,120 infants were born during the 2-y period 1985-1986. In total, 121 infants (0.4%) were reported liveborn before the 29th gestational wk and 12 (0.04%) were reported stillborn. Only 65 infants (50%) survived to the age of 10 y. The aim of this study was to evaluate the situation of extremely preterm (EPT) children at school, compared with that of full-term (FT) control children, at the age of 10 y. Health, cognitive development, school achievement and behaviour were measured. Ninety-two percent of the preterm children had no major neurological disability and most were in good health. The EPT children had an IQ of 90 +/- 15 vs 106 +/- 15 (mean +/- SD) for the FT children (p <0.001), and on the test of Visual-Motor Integration, the EPT children had 93.3 +/- 12.2 vs 109.6 +/- 14.2 for FT peers (p < 0.001). On both tests the differences between the groups corresponded to approximately one standard deviation. Thirty-eight percent of the EPT children performed below grade level at school. Thirty-two percent had general behavioural problems and 20% had attention deficit hyperactivity disorder, compared with 10% and 8%, respectively, in the FT group. EPT children require interventions to support their development and reduce behavioural problems.
    Acta Paediatrica 06/1999; 88(5):557-62. · 1.97 Impact Factor
  • Pediatric Research 01/1999; 45. · 2.67 Impact Factor
  • D Ley, M Lindroth, S Polberger, N W Svenningsen
    Pediatric Research - PEDIAT RES. 01/1999; 45(6).
  • Pediatric Research 01/1999; 45. · 2.67 Impact Factor
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    ABSTRACT: We tested the hypothesis that controlled hypoxemic resuscitation improves early cerebral metabolic and electrophysiological recovery in hypoxic newborn piglets. Severely hypoxic anesthetized piglets were randomly divided into three resuscitation groups: hypoxemic, 21% O2, and 100% O2 groups (8 in each group). The hypoxemic group was mechanically ventilated with 12-18% O2 adjusted to achieve a cerebral venous O2 saturation of 17-23% (baseline; 45 +/- 1%). Base excess (BE) reached -22 +/- 1 mM at the end of hypoxia. During a 2-h resuscitation period, no significant differences in time to recovery of electroencephalography (EEG), quality of EEG at recovery, or extracellular hypoxanthine concentrations in the cerebral cortex and striatum were found among the groups. BE and plasma hypoxanthine, however, normalized significantly more slowly during controlled hypoxemic resuscitation than during resuscitation with 21 or 100% O2. We conclude that early brain recovery during controlled hypoxemic resuscitation was as efficient as, but not superior to, recovery during resuscitation with 21 or 100% O2. The systemic metabolic recovery from hypoxia, however, was delayed during controlled hypoxemic resuscitation.
    Journal of Applied Physiology 04/1998; 84(4):1208-16. · 3.48 Impact Factor
  • Ingrid Hansen, Staffan Polberger, Nils Svenningsen
    Pediatric Research 01/1998; 43. · 2.67 Impact Factor
  • Pediatric Research 01/1998; 43. · 2.67 Impact Factor
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    ABSTRACT: Doppler-derived indices of cerebral blood flow velocity (CBFV) and echocardiographic parameters of left ventricular function were measured in 18 patients with hypoxic-ischaemic encephalopathy HIE (group I) and in 28 normal controls (group II). Group-I infants had a subnormal distribution of CBFV values increasing over the first 85 h postnatally. CBFV values were constantly higher in the internal carotid than in the anterior cerebral artery. During the first 24 h postnatally, pulsatility and resistance indices of cerebral blood flow were significantly higher in group-I patients. From 30 to 85 h after birth, resistance indices were lower in group-I infants with severe HIE. Depressed left ventricular function and/or hypotension was documented in 50% of group-I patients.
    Biology of the Neonate 01/1998; 73(5):275-86. · 1.90 Impact Factor
  • H. Klette, K. Thorngren-Jerneck, N. W. Svenningsen
    Pediatric Research 01/1998; 44(3). · 2.67 Impact Factor
  • Pediatric Research 01/1998; 43. · 2.67 Impact Factor
  • N W Svenningsen, L Björklund, M Lindroth
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    ABSTRACT: Perinatal care of the extremely preterm and low birthweight (ELBW) infant is founded on basic principles of physiology and knowledge about the prevailing pathophysiological mechanisms. New therapies in clinical care are usually introduced non-uniformly, so more often there is a gradual rather than a sudden change in the development of perinatal care, conceivably involving also an important learning process. This was confirmed in an evaluation of respiratory care for ELBW infants (n = 325) over a 9-year period (1986-1994). Although birthweight (mean 815 g) and degree of immaturity at birth (mean 26.7 weeks of gestation) did not change over the years, our trend analysis showed that the survival rate increased from 47% to 70% (p < 0.04) and the percentage of survivors without bronchopulmonary dysplasia and/or major intracranial haemorrhages (ICH grades 3 and 4) increased from 67% to 87% (p < 0.006). We suggest that besides medical treatment per se, refinement and tuning of nursing and medical care procedures will also affect the total outcome of ELBW infants.
    Acta paediatrica (Oslo, Norway: 1992). Supplement 08/1997; 422:89-91.
  • Pediatric Research 01/1997; 41(4). · 2.67 Impact Factor
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    ABSTRACT: The effect of natural surfactant on respiratory system mechanics in infants with respiratory distress syndrome (RDS) is incompletely understood, possibly because the analysis has usually been confined to the tidal breath. We studied 11 paralyzed neonates weighing 540 to 1,850 g before and approximately 30 min after surfactant, which was instilled at 4 to 41 h of age. Diagrams relating airway pressure to expired volume were obtained by having the infant exhale passively through a flowmeter, starting at 30 and ending at 0 cm H20 of pressure. An interrupter intermittently stopped the flow so that pressure could be recorded under static conditions. FRC was measured by sulfur hexafluoride washout, and TLC was calculated from FRC and the pressure-volume (P-V) curve. Ventilation homogeneity was assessed from the washout curve as pulmonary clearance delay (PCD). TLC increased by 10% or more in five infants, but it remained unchanged in the others. Median TLC was 19 ml/kg before and 21.5 ml/kg after surfactant (p = 0.39). The P-V curve became markedly steeper at low pressures after surfactant in most infants, the slope of the steepest segment, i.e., maximal compliance, increasing from 0.65 to 1.22 ml/cm H20/kg (medians, p = 0.008). Dynamic compliance (Cdyn) was unchanged at 0.28 ml/cm H20/kg, whereas specific dynamic compliance (Cdyn/FRC) decreased (p = 0.04). There was no significant immediate change in PCD. The findings imply that during the first 30 min surfactant acted mainly by stabilizing already ventilated air spaces.
    American Journal of Respiratory and Critical Care Medicine 11/1996; 154(4 Pt 1):918-23. · 11.04 Impact Factor
  • K Stjernqvist, N W Svenningsen
    Lakartidningen 03/1996; 93(6):483-4.
  • N W Svenningsen
    Acta Paediatrica 02/1996; 85(1):5-6. · 1.97 Impact Factor
  • Pediatric Research 01/1996; 39. · 2.67 Impact Factor
  • K Stjernqvist, N W Svenningsen
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    ABSTRACT: In a long-term, prospective, control study, 20 extremely low-birth-weight (ELBW) infants with birth weights between 500 and 900 g (mean 755 (SD 109) g) and gestational ages between 24 and 30 weeks (mean 26.2 (SD 1.8) weeks) were compared with 20 full-term infants at 4 years of age for growth, health, development and quality of life. Four of 20 (20%) ELBW children had major neurological disorders, which were all identified at the 1-year assessment. Seventeen (85%) ELBW children had cognitive development, assessed with the Griffiths mental development scale, within the normal range for age but lower than for full-term controls. The greatest deviations between ELBW and full-term children were found in locomotor and visual-motor integration functions. Eight ELBW children in all (40%), four with recurrent respiratory tract infections after neonatal mechanical ventilation and the four children with major neurological disorders had a higher rate of visits to physicians and hospital admissions. The behavioural symptom interview showed an increased rate of hyperactivity and difficulties in concentrating but not of general behavioural deviations in the ELBW group. Only by school age can all aspects of an extremely early birth be evaluated, but at 4 years of age, 85% of the ELBW children in our group had a good quality of life according to Scheffzek's categorizations.
    Acta Paediatrica 06/1995; 84(5):500-6. · 1.97 Impact Factor

Publication Stats

2k Citations
372.16 Total Impact Points

Institutions

  • 1972–2001
    • Lund University
      • • Department of Paediatrics
      • • Department of Psychology
      • • Department of Pediatric Cardiology
      • • Department of Clinical Physiology
      • • Department of Obstetrics and Gynecology
      Lund, Skane, Sweden