J.L. Demarquez

Helium-oxygen mixture in respiratory distress syndrome: A double-blind study

In a randomized, controlled trial, the lungs of infants with respiratory distress syndrome were ventilated with either a helium-oxygen mixture or a nitrogen-oxygen mixture. In the helium-oxygen group, infants required a lower inspired oxygen concentration and a shorter duration of ventilation. There were also fewer deaths and fewer cases of bronchopulmonary dysplasia in the helium-oxygen group.

Fatal neonatal liver failure and mitochondrial cytopathy: An observation with antenatal ascites

Mitochondrial cytopathies are multisystemic diseases of extremely variable expression caused by a deficiency in oxidative phosphorylation. Only five cases of neonatal liver failure in the context of mitochondrial cytopathy have been reported, with incomplete morphological data of the liver in three. In the case presented here, ascites had been diagnosed prenatally and liver failure was particularly severe (factor V less than 15% with fatal coma the fourth day). Histologically there were incomplete cirrhosis, microvesicular steatosis, major canalicular cholestasis with proliferative neocholangioles, and bile duct thrombi. There were also some iron pigments in the periportal area and partial glycogen depletion. By electron microscopy, mitochondria in numerous hepatocytes appeared abnormal with occasional cristae in a fluffy matrix, some containing dense inclusions. Study of respiratory chain activity showed a defect in cytochrome c oxidase (complex IV), revealed by oxygraphic measurement on fresh muscle biopsy and confirmed by spectrophotometric enzymatic assays performed on muscle and liver homogenates. The association of neonatal liver failure with hyperlactacidemia warrants investigation into a deficiency in oxidative phosphorylation.

Early respiratory system mechanics and the prediction of chronic lung disease in ventilated preterm neonates requiring surfactant treatment.

The objective of this study was to evaluate the predictive value of the respiratory system compliance (Crs) and resistance (Rrs) measured before surfactant therapy to identify infants at risk for chronic lung disease (CLD). Measurements of Crs and Rrs were obtained on 44 ventilated neonates with respiratory distress syndrome (RDS) before and after surfactant therapy using the passive expiratory flow-volume method. It was found that in addition to a lower gestational age (GA) and a lower birth weight (BW), infants with CLD (n = 10) exhibited a lower Pa/AO2 [Pa/AO2 = PaO2/(PiO2 – PaCO2)] and higher Rrs before surfactant compared to the infants without CLD (n = 28). Improvement in gas exchange 18 h after surfactant was reduced in the CLD group. Finally, we concluded that a low GA (< 28 weeks), a low BW (< 942 g), a low Pa/AO2 before and 18 h after surfactant or a high Rrs before surfactant (>0.21 cm H2O/ml/s) were associated with an increased risk of CLD.

Cathéters centraux et épanchements péricardiques en période néonatale : étude rétrospective multicentrique

OBJECTIVE To evaluate the use of neonatal central venous catheters (CVC) in 38 french neonatal units and occurrence of pericardial effusion (PCE) over the past 5 years. MATERIALS AND METHODS We surveyed 38 units with a questionnaire and studied the cases of PCE in five units. RESULTS Response rate was 89% (34/38). Accepted CVC tip positions were: junction of right atrium (RA) and vena cava (VC) 76%, VC 58%, RA 11%. Fifty percent of the centers had been exposed to PCE. 16 cases of PCE were studied. Median gestational age was 31 weeks (range: 26.1 to 40 weeks). Median time from insertion: 3.2 days (range: 0.4-13.5). In all cases CVC tip was intracardiac at insertion with inadequate withdrawing in 13 cases. Sudden cardiac collapse was reported in eight cases, and unexplained cardiorespiratory instability in six cases. Echography showed PCE in 14 cases. One diagnosis was post-mortem. CVC was withdrawn in 12 patients and 13 underwent pericardiocentesis. Four patients died and two had neurological sequelae. CONCLUSION PCE was associated with intracardiac CVC tip. The CVC tip should be controlled with radiography or echography outside the cardiac silhouette. PCE diagnosis must be considered in face of unexplained cardiovascular decompensation of neonate with CVC.

Minimal effective dose of indomethacin for the treatment of patent ductus arteriosus in preterm infants.

The aim of this study was to determine if it was possible to decrease the number of boluses of indomethacin for the treatment of patent ductus arteriosus. This retrospective study included 46 preterm neonates (<34 weeks’ GA) who had had an ultrasound diagnosis predictive of subsequent symptomatic patent ductus arteriosus. All patients had received a daily intravenous doses of indomethacin, 0.1 mg/kg. Mean age at initiation of treatment was 4.5 ± 3.1 days. Patency of the ductus arteriosus was controlled echocardiographically each day and treatment was discontinued as soon as the ductus arteriosus was closed. The initial success rate was 84.7%, of which 6.5% reopened. The mean cumulative dose of indomethacin was 0.35 mg/kg. There was no correlation between gestational age or birth weight and total cumulative dose. Overall tolerance was satisfactory with only one case of transient acute renal failure. A weak correlation between the cumulative dose of indomethacin and natremia (r = –0.43) or weight gain (r = 0.35) was noted, and none with serum creatinine or blood urea nitrogen levels. We confirm that lower indomethacin treatment of patent ductus arteriosus in premature neonates are as effective as standard protocols.

Efficacy and tolerance of high-dose inhaled ipratropium bromide vs. terbutaline in intubated premature human neonates.

Background: There is insufficient data to reliably assess the benefit of bronchodilators in ventilated premature neonates. Objectives: To compare the efficacy/tolerance of inhaled ipratropium bromide (IB) vs. terbutaline (T) and to describe factors associated with their efficacy. Methods: A cross-over randomized controlled double-blind trial including intubated neonates with respiratory distress syndrome. Two puffs of IB or T were administered at 0, 20, 40 min. Passive respiratory system resistance (Rrs) and compliance (Crs) were measured at 0, 20, 40, 60 min. A positive response was defined as a >2 individual coefficients of variation decrease in Rrs or increase in Crs. Results: Twenty-one infants (gestational age (mean ± SD): 27.3 ± 1.6 weeks; birth weight: 947 ± 250 g; postnatal age: 20 ± 9 days) were included. At 60 min, no treatment effect for Rrs and Crs could be identified (cross-over analysis). Overall data (irrespective of order of administration) showed that after 6 puffs, the decrease in Rrs was greater in the IB vs. T group (–17.0 ± 22.2% vs. –11.3 ± 26.7%, respectively (NS)). Thirty-eight percent of infants responded to IB vs. 43% to T. However, in 19% of patients, decreased Crs was observed after 6 puffs of T. No marker of a positive or paradoxical response could be identified. Treatment was well-tolerated. Conclusion: High doses of bronchodilators are required in ventilated neonates, but the positive response rate was <50%. Their long-term benefit remains to be proven.

57 Présentation d’un cédérom pédagogique : les détresses respiratoires néonatales

Objectifs La prise en charge des detresses respiratoires neonatales a ete revolutionnee par le developpement de nouvelles techniques diagnostiques et therapeutiques. Nous avons developpe un cederom pedagogique pour l’acquisition et larevision de connaissances a destination des internes, pediatres et medecins urgentistes confrontes a cette pratique. Materiel et methodes Cet outil a ete realise en collaboration avec le D.C.A.M. de l’Universite de Bordeaux 2. Il a ete developpe a l’aide du logiciel Authorware®. Il comprend deux parties : une presentation didactique expose la physiopathologie, les elements du diagnostic avec une iconographie comprenant schemas, imagerie pulmonaire et cardiaque et les elements de prise en charge des nouveau-nes ; une simulation de cas cliniques interactifs propose l’histoire et l’examen de nouveau-nes, associes a des images radiologiques, echographiques et des videos. Ceux-ci permettent de presenter de maniere interactive les gestes cliniques pertinents, l’analyse radiologique et celle de la gazometrie, de discuter les autres examens complementaires eventuels, les diagnostics differentiels et la prise en charge therapeutique. Une approche de la ventilation est proposee avec reglages d’un respirateur virtuel. Resultats Cet outil innovant offre un complement didactique a la formation theorique et pratique actuelle par la resolution des problemes cliniques. Les limites sont techniques, liees au support et au caractere virtuel des cas proposes.

66 L’hypomagnésémie : une cause possible de convulsion néonatale

Les troubles hydro-electrolytiques et glycemiques sont recherches systematiquement en cas de crise convulsive neonatale, l’hypomagnesemie plus rarement. L. est une jumelle nee prematurement a 27 SA (HELLP syndrome), atteinte de dysplasie broncho-pulmonaire (traitement par diuretiques et corticoides), recevant une nutrition parenterale prolongee du fait d’une intolerance alimentaire. A 38 SA d’âge corrige elle presente des crises convulsives tonico-cloniques subintrantes avec apnees. Biologiquement, il existe une hypokaliemie, une hypophosphoremie et une alcalose metabolique moderees. Glycemie, calcemie et examen cytobacteriologique du liquide cephalorachidien sont normaux. L’echographie transfontanellaire est stable (hemorragie de grade 1). L’electroencephalogramme met en evidence des paroxysmes alternant sur les deux hemispheres. Devant la persistance des crises malgre un traitement anti-convulsivant, L. est transferee dans le service de reanimation pour assistance respiratoire. La magnesemie demandee en seconde intention est effondree (0,13 mmol/l). La correction progressive de l’hypomagnesemie permet un arret des convulsions sans recidive. L’hypomagnesemie est responsable d’une symptomatologie neuromusculaire et/ou cardiovasculaire riche. Elle est favorisee par la prematurite et liee a un defaut d’apport (nutrition parenterale prolongee, troubles de l’absorption) et/ou des pertes excessives digestives ou renales (diuretiques, aminosides). La teneur en magnesium des laits maternels ou artificiels est suffisante alors que certaines solutions pour nutrition parenterale n’en contiennent que de faibles quantites. L’hypomagnesemie est une cause de convulsion neonatale a rechercher. Une surveillance des apports en magnesium des nouveau-nes recevant une alimentation parenterale est necessaire, surtout si celle-ci est exclusive et en cas de traitement par diuretique ou aminoside.

Traitement fibrinolytique intrapleural et pleurésies infectieuses : à propos de trois observations pédiatriques

Resume L’instillation intrapleurale d’agents fibrinolytiques est proposee au cours du traitement medical des epanchements pleuraux lorsque les caracteristiques biochimiques du liquide pleural (pH, glycopleurie, lacticodeshydrogenase) definissent un epanchement complique qui laisse presager l’evolution vers un empyeme. Il n’existe pas actuellement de consensus concernant l’utilisation de la fibrinolyse intrapleurale chez l’enfant. Observations. – Nous avons pratique ce traitement, associe a un drainage conventionnel, chez trois enfants atteints de pleuresies d’origine infectieuse, et avons observe un bon resultat dans tous les cas. Conclusion. – Le benefice attendu, en termes de reduction de la duree d’hospitalisation et de diminution du recours a la chirurgie, merite d’etre evalue de facon prospective.