Continuous tracheal gas insufflation enables a volume reduction strategy in hyaline membrane disease: technical aspects and clinical results.

OBJECTIVE: Instrumental dead space wash-out can be used to improve carbon dioxide clearance. The aim of this study was to define, using a bench test, an optimal protocol for long-term use, and to assess the efficacy of this technique in neonates. DESIGN: A bench test with an artificial lung model, and an observational prospective study. Dead space wash-out was performed by continuous tracheal gas insufflation (CTGI), via six capillaries molded in the wall of a specially designed endotracheal tube, in 30 preterm neonates with hyaline membrane disease. SETTING: Neonatal intensive care unit of a regional hospital. RESULTS: The bench test study showed that a CTGI flow of 0.5 l/ min had the optimal efficacy-to-side-effect ratio, resulting in a maximal or submaximal efficacy (93 to 100%) without a marked increase in tracheal and CTGI circuit pressures. In the 30 newborns, 15 min of CTGI induced a significant fall in arterial carbon dioxide tension (PaCO2), from 45 +/- 7 to 35 +/- 5 mmHg (p = 0.0001), and in 14 patients allowed a reduction in the gradient between Peack inspirating pressure and positive end-expiratory pressure from 20.8 +/- 4.6 to 14.4 +/- 3.7 cmH2O (p < 0.0001) while keeping the transcutaneous partial pressure of carbon dioxide constant. As predicted by the bench test, the decrease in PaCO2 induced by CTGI correlated well with PaCO2 values before CTGI (r = 0.58, p < 0.002) and with instrumental dead space-to-tidal volume ratio (r = 0.54, p < 0.005). CONCLUSION: CTGI may be a useful adjunct to conventional ventilation in preterm neonates with respiratory disease, enabling an increase in CO2 clearance or a reduction in ventilatory pressure.

Estimation of inspiratory pressure drop in neonatal and pediatric endotracheal tubes.

Endotracheal tubes (ETTs) constitute a resistive extra load for intubated patients. The ETT pressure drop (DeltaP(ETT)) is usually described by empirical equations that are specific to one ETT only. Our laboratory previously showed that, in adult ETTs, DeltaP(ETT) is given by the Blasius formula (F. Lofaso, B. Louis, L. Brochard, A. Harf, and D. Isabey. Am. Rev. Respir. Dis. 146: 974-979, 1992). Here, we also propose a general formulation for neonatal and pediatric ETTs on the basis of adimensional analysis of the pressure-flow relationship. Pressure and flow were directly measured in seven ETTs (internal diameter: 2.5-7.0 mm). The measured pressure drop was compared with the predicted drop given by general laws for a curved tube. In neonatal ETTs (2.5-3.5 mm) the flow regime is laminar. The DeltaP(ETT) can be estimated by the Ito formula, which replaces Poiseuille's law for curved tubes. For pediatric ETTs (4.0-7.0 mm), DeltaP(ETT) depends on the following flow regime: for laminar flow, it must be calculated by the Ito formula, and for turbulent flow, by the Blasius formula. Both formulas allow for ETT geometry and gas properties.

[Psychologic management of extreme prematurity]. / Prise en charge psychique de l'extrême prématurité.

The ongoing progress in neonatal intensive care is modifying the psychic context of prematurity for all the partners, infants as well as parents and physicians. Comfort and prognosis of preterm infants have much improved. Since newborns under 24 weeks of gestational age are now surviving, they spend approximately half the duration of pregnancy out of the maternal uterus. All the psychological issues of such an early separation have to be considered, including the developmental outcome of a sensorial environment which is quite different from the intra-uterine one. Research has been developing in this field. The cooperation between neonatalogists and psychologists has been profitable to parents. Problems linked to the separation, such as difficulty in representing the infant, are no more frequent owing to the attention paid to the mother-child bond and subsequent early contacts. What is forward now is the impact of an hyper technical world of intensive care on the parents, and of the strange aspect of the tiny baby surrounded by engines and tubes. Such an overpresence of reality often results in a reaction of traumatic daziness among parents. The cooperation of the whole staff is necessary for the resumption of an imaginary process of psychic functioning. Finally, the survival of very-low-birth-weight infants confronts the neonatalogists with some delicate ethical questions. Psychiatrists and psychologists might have an important part to play in aiding the profession in its sorting out of these ethical issues.

[Physiopathological approach and antenatal diagnosis of diabetes mellitus insulin resistant: apropos of a case with leprechaunism]. / Approche physiopathologique et diagnostic anténatal du diabète insulinorésistant: à propos d'un cas de lepréchaunisme.

BACKGROUND: Leprechaunism is characterized by severe intrauterine growth retardation, elfin-like face, relatively large hands, feet and genitalia and abnormal skin with hypertrichosis, acanthosis nigricans and low subcutaneous fat. The insulin receptors have multiple defects. CASE REPORT: A boy was born after cesarean section at the 35th week of gestation because of intrauterine growth retardation: weight: 930 g; height: 36 cm; head circumference: 27 cm. He had trigonocephaly, coarse features and hyperkeratosis. Ultrasonography confirmed the presence of a ventricular septal defect detected during pregnancy. Hyperglucosemia (3 g/l) was associated with insulinemia above 350 mU/l; his C-peptide concentration was above 20 ng/ml. The patient was given intravenous insulin, up to 2,500 U/kg/d. He died at the age of 95 days, weighing 1500 g, with persistent hyperglucosemia and cholestasis. Postmortem examination showed adrenal and thymus hypoplasia and hyperplasia of pancreatic islet cells. Molecular biology studies showed that this patient was heterozygotic for two mutations, one in exon 20 inherited from his father, the other in exon 18 inherited from his mother; both mutations are associated with tyrosine-kinase activity of the insulin receptor. These results will be used for antenatal diagnosis in any future pregnancy. CONCLUSION: Molecular biology can indicate specific defects in the insulin receptor. It may also allow antenatal diagnosis in some families.

[The incidence of prescriptions without marketing product license in a neonatal intensive care unit]. / Incidence des prescriptions hors autorisation de mise sur le marché en réanimation néonatale.

UNLABELLED: Most of the drugs prescribed in pediatric units have no product licence. The lack of clinical studies in children and appropriate drug formulations decrease their safety. The lack of a legal framework makes the prescriber insecure. Even if the debate is not recent, few studies have been carried out in this field. The aim of the present study was to evaluate the rate of prescriptions of unlicensed and off-label drugs in a neonatal intensive care unit. PATIENTS AND METHODS: The present study was carried out in our neonatal intensive care unit, from January 12 to February 12, 1998. Forty babies aged 0 to 128 days were included (90% newborns), with a gestational age between 25 to 40 weeks (88% were premature, with a birth weight lower than 1000 g). RESULTS: Two hundred and fifty-seven prescriptions were administered with 55 different types of drugs during this period. Ten percent of the prescribed drugs had no product licence. Sixty-two percent were off-label for premature infants and 64% for newborns: 90% due to age, 9.3% due to dose and 0.7% to method of administration. No therapeutic alternatives to these prescriptions were found among the few available licensed drugs. CONCLUSION: The prescriptions of unlicensed and off-label drugs in neonatal intensive care units are daily and repeated events. The prescribers are usually not aware of the exact status of the drug and do not realize neither he importance of the problem nor the legal and potential consequences. The lack of pediatric clinical studies is to a large extent responsible for the absence of drug registration in pediatrics. The pharmaceutical industry has few incentives to develop the pediatric product licences.

[Video recording of newborn resuscitation in the delivery room: technique and advantages]. / Enregistrement vidéo de situations réelles de réanimation en salle de naissance: technique et avantages.

An extreme attentiveness is mandatory when caring about extremely-low-gestational-age neonates at birth because of their innate vulnerability. The interventions performed during resuscitation of these infants may have direct influence on the immediate survival and also on long-term morbidity. Although stressfull, each resuscitation step is crucial and needs to be precise, fast and harmless. In order to determine our compliance to the international guidelines and to assess our neonatal performances in delivery room, we used a Mobotix camera to record all resuscitations of extremely-low-gestational-age neonates during the decisive first minutes of life. Neonatal medical and nursing staff agreed to be recorded. Our local ethics committee approved that videotaping neonatal resuscitation is an audit of clinical practice and thus does not require informed consent. During debriefing sessions, we reviewed the videotaped recordings, which allowed us to identify frequent deviations from the international guidelines and to re-educate and improve performance. The most frequent errors we recognized were errors of hygiene, not re-evaluating oxygen titration and airway obstruction during mask ventilation. We observed team behaviour and coordination during resuscitation and focused on quality of care. We believe that this method may be very effective as a teaching tool.

[Short-term respiratory outcome of late preterm newborn in a center of level III]. / Devenir respiratoire à court terme d'une population d'enfants nés à 34, 35 et 36 SA dans une maternité de niveau III.

The rate of infants born at 34-36 weeks gestation has increased over the last 10 years. These babies are at higher risk of morbidity and mortality than full-term infants. At present, prenatal steroids are given until 34 weeks. The purpose of this study was to present the epidemiologic data of the late preterm infants and look for respiratory distress risk factors. This is a descriptive, single-center study including 59, 55 and 72 children born at 34, 35 and 36 weeks gestation, respectively, in a level III center in 2005 and 2006 for babies born at 34 weeks and in 2006 for the babies born at 35 and 36 weeks. Of the mothers who delivered at 34 and 35 weeks, 63% and 49%, respectively, had a morbidity. The cesarean-section delivery rate before labor was 36% for the infants born at 34 weeks and 25% for the infants born at 35 weeks. Prenatal steroids were used for 57% of the mothers who delivered at 34 weeks and for 27% of the mothers who delivered at 35 weeks. In the population of the babies born at 34 weeks, a mean delay between the last dose of steroid and delivery was 18.9 days. Of the infants born at 34, 35 and 36 weeks, 27%, 18% and 8% suffered from respiratory distress. The mechanical ventilation rate was 8.5% and 5.5% for the infants born at 34 and 35 weeks' gestation. Surfactant was given to all infants born at 34 weeks who were intubated. Twenty percent of the 34-week-gestation infants and 12.7% of the 35-week-gestation infants required mechanical ventilation or noninvasive continuous positive airway pressure. Respiratory distress was mainly caused by respiratory distress syndrome or transient tachypnea of the newborn. There were no cases of meconium aspiration syndrome. There was 1 case of infection and 2 cases of pneumothorax. One-third of the infants born at 34-35 weeks were admitted to the neonatal intensive care unit. The number dropped to 11% at 36 weeks' gestation. The gestational age was the only significant risk factor for respiratory distress. There was a strong tendency of the respiratory distress rate to decrease in the babies whose mothers had received steroids (odds ratio = 0.39, p = 0.06).

[Evidence versus experience in neonatal practice: the example of extremely premature infants]. / Niveaux de preuves versus pratiques cliniques: l'exemple de l'extrême prématurité

We focused on current nutritional and ventilation strategies of extremely preterm infants and reviewed the evidence and the practical experience in four French neonatal intensive care units. The recommendations from reviews and the local clinical guidelines were compared and were overall in agreement. We wanted then to evaluate if different ventilatory and nutritional styles existed between four French intensive neonatal units, and if these approaches had an effect on short term outcomes. 399 infants delivered at a gestational age <28 weeks between January 2005 and December 2006 were retrospectively studied (unit I = 141, unit II = 97, unit III = 85, unit IV = 76). Data were collected from birth to discharge. The study groups were similar with regard to gestational age, birth weight, gender, prenatal steroids, rate of inborn. There were significant differences in ventilatory and nutritional strategies between the units. Incidence of NEC, IVH grade 3-4 and PVL were similar between the units. Mortality rate during the hospitalization stay was 14.9 %, 35.0 %, 29.4 % and 29 % (p<0.05). A national database would be useful to analyse differences in strategies and long term outcomes.

Efficacy of dead-space washout in mechanically ventilated premature newborns.

The prosthetic dead space makes a significant contribution to the total dead space in low-birth-weight premature newborns receiving artificial ventilation in response to respiratory distress. Use of an endotracheal tube with capillaries molded into the tube wall enables washout of the dead space without insertion of a tracheal catheter. In 10 premature newborns (mean gestational age, 27.5 +/- 2.2 wk; mean weight, 890 +/- 260 g) receiving continuous positive-pressure ventilation (Paw = 12.7 +/- 1.8 cm H2O; FIO2 = 39 +/- 17%), tracheal gas insufflation (TGI) for CO2 washout was conducted using this technique. The flow of tracheal insufflation (0.5 L/min) was derived from the inspiratory line of the ventilator circuit and blown into the trachea. Intratracheal pressures showed little or no TGI-related modification ( < 1 cm H2O). A control system enabled TGI discontinuation in the event of a pressure rise. At constant ventilation pressure, PaCO2 decreased by 12.1 +/- 5.9 mm Hg (delta PaCO2 = -26 +/- 12%) under TGI, whereas PaO2 remained unchanged. While maintaining PaCO2 constant, peak inspiratory pressure (PIP) was decreased by 5.4 +/- 1.7 cm H2O (delta PIP = -22.0 +/- 8.3%). TGI showed immediate efficacy (PCO2 reduction of at least 5 mm Hg) in nine of the 10 newborns who then received chronic TGI (14 to 138 h). TGI appears to be an effective method, suitable for long-term clinical application, enabling a reduction in the aggressive nature of conventional ventilation.

Continuous tracheal gas insufflation in preterm infants with hyaline membrane disease. A prospective randomized trial.

In mechanically ventilated neonates, the instrumental dead space is a major determinant of total minute ventilation. By flushing this dead space, continuous tracheal gas insufflation (CTGI) may allow reduction of the risk of overinflation. We conducted a randomized trial to evaluate the efficacy of CTGI in reducing airway pressure over the entire period of mechanical ventilation while maintaining oxygenation. A total of 34 preterm newborns, ventilated in conventional pressure-limited mode, were enrolled in two study arms, to receive or not receive CTGI. Transcutaneous Pa(CO(2)) (tcPa(CO(2))) was maintained at 40 to 46 mm Hg in both groups to ensure comparable alveolar ventilation. Respiratory data were collected several times during the first day and daily until Day 28. Both groups were similar at the time of inclusion. During the first 4 d of the study, the difference between peak pressure and positive end-expiratory pressure was significantly lower in the CTGI group by 18% to 35%, with the same tcPa(CO(2)) level and with no difference in the ratio of tcPa(O(2)) to fraction of inspired oxygen (245 +/- 29 versus 261 +/- 46 mm Hg [mean +/- SD] over the first 4 d). Extubation occurred sooner in the CTGI group (p < 0.05), and the duration of mechanical ventilation was shorter (median: 3.6 d; 25th to 75th quartiles: 1.5 to 12.0 d; versus median: 15.6 d; 25th to 75th quartiles: 7.9 to 22.2; p < 0.05) than in the non-CTGI group. CTGI allows the use of low-volume ventilation over a prolonged period and reduces the duration of mechanical ventilation.

[Allergy to latex gloves. A cause of surgical shock]. / Allergie aux gants de latex. Une cause de choc peropératoire.

Latex induced anaphylaxis was observed in 2 children during surgical procedures. Anaphylaxis was due to exposure to surgical latex gloves. The diagnosis should be suspected in patients with a previous history of rubber induced urticaria and is confirmed by positive skin tests to latex. In patients presenting with allergy to latex, prophylaxis is based on the use or surgical gloves made of vinyl or neoprene.