P. Hubert

Impact of delayed repair and elective high-frequency oscillatory ventilation on survival of antenatally diagnosed congenital diaphragmatic hernia: first application of these strategies in the more “severe” subgroup of antenatally diagnosed newborns

Objective: a) To analyze the influence of a new management strategy on the outcome of neonates with antenatally diagnosed congenital diaphragmatic hernia (CDH); b) to determine early prognosis respiratory factors with the new strategy.¶Design: Retrospective study. Setting: Level III perinatal center. Patients and method: Between 1985 and 1997, 51 consecutive neonates with antenatally diagnosed CDH were admitted to our level III neonatal intensive care unit. Before 1992 (period 1; n = 19), we used conventional mechanical ventilation and early surgery requiring transfer. Since 1992 (period 2; n = 32), we prospectively tested a new approach including (a) systematically use of high-frequency oscillatory ventilation (HFOV) regardless of the initial clinical severity, (b) delayed surgery following stabilization requiring transfer to a different surgical unit, but (c) no transfer of unstable patients with surgery under HFOV in our neonatal intensive care unit (n = 10). The two cohorts were comparable in terms of potential ante and postnatal prognostic indicators. Results: Survival was improved with the new strategy: 21/32 (66 %) vs. 5/19 (26 %); P < 0.02. This improvement between periods 1 and 2 was due to a decrease in both preoperative and postoperative deaths in the later period. The better survival during period 2 was associated with the appearance of very late deaths, frequent pleural effusions, and the survival of more severe forms having evolved to a chronic respiratory insufficiency. Survivors were ventilated for longer time with longer duration of oxygen supplementation. The best oxygenation index (OI), alveolar arterial difference and oscillation amplitude (P/P) during the first 24 h, but not the best PaCO2, were the most reliable prognostic indicators during period 2. An OI ≤ 10 with a P/P ≤ 55 cmH2O was associated with a very good prognosis (94 % survival). Conclusions: The prognosis of antenatally diagnosed CDH was improved by systematic HFOV on admission, no systematic transfer, and delayed surgery. This improvement is associated with modification of postnatal outcome.

Intravenous nicardipine in hypertensive children

Fourteen hypertensive patients hospitalized in a paediatric intensive care unit were studied to evaluate safety and hypotensive efficacy of intravenous nicardipine. Systolic and diastolic blood pressure significantly decreased 1 h after the beginning of the treatment (1 μg/kg per minute). Mean decrease in systolic blood pressure during the first 24 h was between 9.9% and 13.4% of the initial value. Mean lowering of diastolic blood pressure was between 16.7% and 25.6%. Nicardipine did not significantly affect heart rate with dose of 1 μg/kg per minute. No clinical side-effects were observed. Nicardipine could be a first line drug for the treatment of hypertension in paediatric intensive care units.

Assessment of high-frequency neonatal ventilator performances

AbstractObjective: To assess the efficacy and reliability of neonatal high-frequency ventilators. Design: Bench evaluation of neonatal high-frequency ventilators. Setting: Physiology department and university hospital neonatal intensive care unit. Interventions: HFV-Babylog 8000 (Dräger Medical), OHF 1 (Dufour), and SensorMedics 3100A (SensorMedics) ventilators were connected to a neonatal test-lung. Tidal volume, peak-to-peak pressure amplitude, and mean airway pressure were measured for several ventilator settings, endotracheal tube sizes, and lung compliances. Measurements and results: Increasing peak-to-peak pressure resulted in a linear increase in tidal volume delivery in the 0–30% range of maximum amplitude. No significant increase in tidal volume was observed with the HFV-Babylog8000 when pressure amplitude was above 50%. The maximum tidal volume delivered was substantially smaller with the HFV-Babylog8000 than with the OHF1 or SensorMedics3100A. Tidal volume increased with endotracheal tube size with all three ventilators. Increasing test-lung compliance resulted in lower tidal volumes only with OHF1. Decreasing mean airway pressure was responsible for a decrease in tidal volume delivery with HFV-Babylog8000. Conclusion: We found that under our test conditions two of the three ventilators delivered adequate tidal volumes at the usual frequency of 15Hz, regardless of the size of the endotracheal tube and of the mechanical properties of the respiratory system. When lung compliance increased or mean airway pressure decreased, both of which are common events during the recovery phase of hyaline membrane disease, we found that the intrinsic properties of two of the ventilators tested were responsible for a decrease in tidal volume. This decrease may account for some cases of heretofore unexplained hypercapnia.

Nitric oxide 2

Introduction: Permissive hypercapnia (PH) is a beneficial strategy for patients with acute respiratory distress syndrome (ARDS) to minimize barotrauma by decreasing the peak inspiratory pressure (PIP). Hypercapnia and hypoxia cause pulmonary vasoconstriction, pulmonary artery (PA) hypertension, and, thus, an increased afterload to the right ventricle. This increased afterload may result in increased right ventricular (RV) work load and subsequent RV dysfunction. One therapeutic approach is the use of inhaled nitric oxide (iNO), a selective PA vasodilator. The objectives of this study were to test the hypothesis that in a swine model of ARDS with PH, iNO would improve RV work load and not change intrinsic RV contractility. Methods: In 11 swine (25-35 kg), ARDS was induced by surfactant depletion. Hypercapnia was achieved by decreasing the PIP while increasing the PEEP to maintain a constant mean airway pressure. iNO was administered in concentrations of 2, 5, and 10 ppm in a random order, Pulmonary blood flow (Qpa) was determined by an ultrasonic flow probe. RV total power (TP) and stroke work (SW) were calculated by Fourier transformation of the PA pressure (Ppa) and Qpa data. Preload recruitable stroke work (PRSW), a preload and afterload independent measure of ventricular contractility, was determined by a shell-subtraction method and vena caval occlusion) Results: Data are represented as mean ± sent and compared by two-way analysis of variance with repeated measures. (* n < 0.05 vs. 0 nnm) 0 ppm 2 ppm 5 ppm 10 ppm er s*1000 /mL 24.6 ± 1.6 25.2 ± 2.4 23.3 ± 1.8 22.9 ± 2.5 mW 92±11 74±6* 66±6 75±8* [RSW

LE DYSFONCTIONNEMENT NEONATAL ISOLE DU TRONC CEREBRAL

Background. - Brainstem dysfunction in newborns (BDN) is an association of symptoms originally described in the Pierre-Robin sequence. BDN is thought to result from a deficiency of the sucking and swallowing embryonic organization. Population and methods. - Between 1983 to 1993, 48 infants without cleft polate were referred for suck and swallow abnormalities. They were considered to have BDN because they presented three of the four following criteria: neonatal suck and swallow difficulties: pharyngeo-oesophageat uncoordination with abnormal oesophageal mutometria; upper airway obstruction, either clinically obvious or detected on laryngoscopy; vagal overactivity, either clinically obvious or detected during Holter recording with ocular compression. Results. - Among these 48 infants, 30 were affected with polymalformative syndrome often involving embryonic fields derived from the neural crest. Three infants had a conotruncal cardiac malformation and 15 had no associated malformation. These latter 15 infants presented with facial dysmorphic features including reciding chin, glossoptosis. U-shape polate and a vertical tongue. From birth or the first weeks of life, they had suck and swallow difficulties with various functional symptoms: slow babybottle intake, cough or velo-pharyngeal incoordination, upper airway obstruction or apparent life threatening events (ALTE). Diagnosis was confirmed by both clinical observation and three simple investigations namely: laryngoscopy, vesoplungeal monometria and Holter recording with ocular compression. Ten children were nasogastric tube or gastrostomy fed, one had a tracheostomy and one had a nightly O2 supplementation. While the overall functional prognosis was good whatever the initial symptoms. 50% of these children had mental retardation, most moderate. Conclusion. - Examination of short-term follow-up in these children has stressed that BDN requires a specific management of both nutritional and respiratory troubles. Finally, BDN should lead to the active search of an underlying polymalformative syndrome and to an accurate neurologic evalution.

Paludisme grave de l’enfant en réanimationEnquête nationale 1990-1995

BACKGROUND Severe malaria is a frequent complication of Plasmodium falciparum infections. More than one million children die of malaria each year. MATERIAL AND METHODS A French survey was carried out on 15 cases admitted to pediatric intensive care units between 1990 and 1995. The aim of this work was to evaluate the occurrence, mortality, morbidity and treatment of severe malaria in French intensive care units. RESULTS All cases were imported from Africa except one case of airport malaria. Diagnosis of many of these cases was delayed. All cases were treated with quinine, and five children received a loading dose. One child died and one has neurological sequelae. DISCUSSION Despite improvement in management, the prognosis of severe malaria remains poor. With reference to the literature, we propose management of severe malaria, emphasizing the necessity of a rapid effect with a loading dose of quinine.Resume Le paludisme grave est une complication des infections a Plasmodium falciparum chez l’enfant. Plus d’un million d’enfants decedent de paludisme chaque annee dans le monde. Les pays temperes sont egalement concernes. Materiel et methodes. – L’objectif du travail etait d’effectuer une enquete retrospective sur la periode 1990–1995 parmi les centres francais de reanimation pediatrique afin d’apprecier la frequence, la mortalite, la morbidite et la prise en charge du paludisme grave. Resultats. – Quinze observations ont ete recensees. Tous les cas etaient importes d’Afrique, sauf un cas de paludisme d’aeroport. Des prodromes et un retard diagnostique etaient frequents. La quinine a ete utilisee pour tous les enfants. Cinq enfants ont recu une dose de charge. Un enfant est decede et un a des sequelles neurologiques. Discussion. – Malgre une amelioration de la prise en charge, la mortalite et la morbidite restent lourdes. A partir de ces observations et des donnees de la litterature, nous proposons un schema therapeutique en insistant sur la necessite de traiter rapidement avec une dose de charge de quinine.

Assessment of neonatal ventilator performances

ObjectiveTo analyze efficiency and reliability of 4 modern neonatal ventilators under difficult test conditions. The ventilators tested were: Babylog 8000 (Dräger Medical), BP 2001 (Bear Medical Systems), Sechrist IV 100 B (Sechrist Industries), Infant Star (Infrasonics INC).Measurements and resultsGas flow generation was tested by comparison of preset flow values with no resistance in the circuit to flow values obtained during interposition of a resistance in the inspiratory circuit. A decrease in gas flow was observed when interposition of a resistance in the inspiratory circuit increased peak inspiratory pressure to 60 cmH2O (gas flow decreased by 8% to 24% depending on the ventilator tested). The pressure limiting valve and the positive end-expiratory pressure valve were also evaluated in order to test their behaviour under different flow conditions. Flow-dependence of the pressure was noted for all ventilators except Babylog 8000. Assessment of the reliability of pressure monitoring revealed either ‘under’ or ‘over’ estimation of peak inspiratory pressure and positive end-expiratory pressure depending on the ventilator tested.ConclusionFor the best clinical use of mechanical ventilators, neonatologists should be aware of these limitations. Therefore a regular assessment of ventilator performance and monitoring reliability is recommended.