[Couder's maneuver. Knowledge and practices in a French university maternity hospital]

BACKGROUND

During childbirth, the performance of a systematic Couder's maneuver could be linked to a reduction in the risk of perineal tear.

OBJECTIVE

To know the practices and knowledge of childbirth professionals regarding the Couder's maneuver. To measure the effect of a training program for juniors.

MATERIALS AND METHODS

Single-center questionnaire survey of senior and junior obstetricians and midwives. Before-and-after study in juniors to evaluate maneuver training.

RESULTS

One hundred and twenty-five caregivers responded to the questionnaire: (19 physicians and 46 senior midwives; 21 residents and 39 midwifery students). Only one third of the respondents said they practiced the Couder's maneuver "always or almost always" (41/125, 32.8%) and less than one third felt "very comfortable" with the maneuver (34/125, 27.2%), with large differences according to profession and senior vs junior status. Being a doctor (vs midwife) was significantly related to systematic or frequent practice of the maneuver (70.0 vs 15.3%, ORMH=42.7 [9.4; 192.3]) as was being a senior (vs junior) (46.2 vs 18.3%, ORMH=15.9 [3.5; 72.9]). Less than half of the seniors surveyed had received education in maneuvering. Of those who did not practice the maneuver, the majority did not consider its systematic practice to be useful (19/26, 73.1%), and one third considered it potentially harmful (8/26, 30.8%). Theoretical and practical training of the juniors significantly improved their knowledge.

CONCLUSION

There are great differences in the practice of the Couder's maneuver. It deserves to be better known, practiced and evaluated.

Does an intrauterine exchange transfusion improve the fetal prognosis in parvovirus infection cases?

BACKGROUND

Almost 20% of parvovirus B19 foetal infections require intrauterine transfusions. In addition, myocardial dysfunction has been observed in severe parvovirus B19 infections. One objective of an intrauterine exchange transfusion (IUET) is to avoid an overload during the transfusion. Our aim was to study the obstetrical and neonatal outcomes in cases of IUETs performed for foetal parvovirus infections and to compare our survival rate to those studies in which simple in utero transfusions were chosen.

STUDY DESIGN AND METHODS

This was a retrospective monocentre study of all patients followed up for parvovirus B19 infections in which IUETs were performed. An IUET was indicated when foetal hydrops was observed and/or when severe foetal anaemia was diagnosed though an elevation in the middle cerebral artery peak systolic velocity. The characteristics of each pregnancy and the neonatal outcomes were studied until hospital discharge.

RESULTS

Thirty-five IUETs were performed in 26 foetuses. The median gestational age of the first IUET was 22.6 weeks. Only one foetal bradycardia incidence was recorded during the procedure. Three medical pregnancy terminations were observed in our series, secondary to severe cerebral anomalies confirmed in the magnetic resonance imaging. Five in utero deaths occurred, in which 2 of the foetuses underwent multiple IUETs. All the neonates had normal haemoglobin levels at birth, and none were transferred to the neonatal intensive care unit. The overall survival rate was 70%.

CONCLUSION

IUETs exhibit a survival rate similar to that of simple intrauterine transfusions in foetal parvovirus infection cases.

Review shows that implementing a nationwide protocol for congenital diaphragmatic hernia was a key factor in reducing mortality and morbidity

The French Rare Disease Reference Center for congenital diaphragmatic hernia (CDH) was created in 2008, to implement a national protocol for foetuses and children with this serious condition. Neonatal mortality from CDH is 30-40%, mainly due to pulmonary hypoplasia and persistent pulmonary hypertension, and half of those who live have high respiratory, nutritional and digestive morbidity. CDH management requires long-term and specialised multidisciplinary care. It has been well established that a standardised management protocol improves the prognosis of children with CDH.

CONCLUSION

Organising health care and implementing a nationwide French protocol were key factors for reducing mortality and morbidity from CDH.

Management of red blood cell alloimmunization in pregnancy

The main cause of fetal anemia is maternal red blood cell alloimmunization (AI). The search of maternal antibodies by indirect antiglobulin test allows screening for AI during pregnancy. In case of AI, fetal genotyping (for Rh-D, Rh-c, Rh-E and Kell), quantification (for anti-rhesus antibodies) and antibody titration, as well as ultrasound monitoring, are performed. This surveillance aims at screening for severe anemia before hydrops fetalis occurs. Management of severe anemia is based on intrauterine transfusion (IUT) or labor induction depending on gestational age. After intrauterine transfusion, follow-up will focus on detecting recurrence of anemia and detecting fetal brain injury. With IUT, survival of fetuses with alloimmunization is greater than 90% but 4.8% of children with at least one IUT have neurodevelopmental impairment.

Safety and tolerability of subcutaneous treprostinil in newborns with congenital diaphragmatic hernia and life-threatening pulmonary hypertension

BACKGROUND

Prolonged pulmonary hypertension (PH) is highly predictive for pulmonary morbidity and death in infants with congenital diaphragmatic hernia (CDH).

OBJECTIVES

To report the effects and tolerability of subcutaneous treprostinil in newborns with severe CDH and late life-threatening PH.

METHODS

We recorded clinical and echocardiography data before and after starting subcutaneous treprostinil, on patients with severe CDH and late PH, refractory to inhaled nitric oxide and oral sildenafil.

RESULTS

14 patients were treated with treprostinil (gestational age: 39.1±2.0weeks; birth weight: 3200±600g). Prior to treatment, the pre- and post-ductal SpO2 difference (Δ SpO2) was 14±10%. Treprostinil was initiated at a median age of 12days [5-157]. After starting treprostinil, ΔSpO2 decreased to 3% at day 7 (p<0.05), and the mean blood flow velocities in the right pulmonary arteries increased by 110% (p<0.05). 2 of the 14 patients died. At the age of follow up (12months to 3years), the 12 surviving infants were all weaned from respiratory support and discharged home.

CONCLUSION

The subcutaneous treprostinil improves pulmonary hemodynamics and outcomes in infants with CDH and life-threatening PH. We suggest that the treatment should be considered in infants with severe CDH and late PH.

TYPE OF STUDY

Case series with no comparison group.

LEVEL OF EVIDENCE

Level IV.

Impact of skin-to-skin contact on the autonomic nervous system in the preterm infant and his mother

Before, during and after mother-newborn skin-to-skin contact (SSC), parasympathetic activity was evaluated by heart rate variability (HRV) analysis. SSC had a favorable impact on maternal and premature infant parasympathetic activities with a more pronounced response for neonates when the basal HRV values were lower, without modifications of EDIN scores, temperatures or oxygen saturation.

Neonatal outcome after fetal anemia managed by intrauterine transfusion

In-utero transfusion is now well under control and improves the survival of foetuses monitored for fetal anemia with a survival rate of more than 80 %. The aim was to evaluate short-term neonatal outcome after fetal severe anemia managed by intrauterine transfusions. We did a retrospective study of all neonates born after management of severe fetal anemia (n = 93) between January 1999 and January 2013 in our regional center. The two main causes of anemia were maternal red blood cell alloimmunization (N = 81, 87 %) and Parvovirus B19 infection (N = 10, 10.8 %). In the alloimmunization group, phototherapy was implemented in 85.2 % of cases with a maximum level of bilirubin of 114.4 ± 60.7 (mg/dl). Transfusion and exchange transfusion were, respectively, required in 51.9 % and in 34.6 % of cases. One neonate presented a convulsive episode, and we observed three neonatal deaths. In the parvovirus group, none of the child had anemia at birth and no management was necessary.

CONCLUSION

Contemporary management of Rhesus disease is associated with encouraging neonatal outcomes. In case of Parvovirus infection, no specific management is necessary at. But, in all cases of fetal anemia, children should be followed up with particular attention to neurologic development.

WHAT IS KNOWN

• In-utero transfusion is now well under control and improves the survival of fetuses monitored for fetal anemia. • Limited studies are available on the effect of IUT on postnatal outcome in infants with a history of fetal anemia. What is New: • Contemporary management of severe Rhesus disease is associated with encouraging neonatal outcomes. • The majority of infants can be managed with phototherapy and a limited number of top-up transfusions and exchange transfusions. In case of Parvovirus infection, the short-term neonatal outcome is excellent.

[Is self-confidence a factor for successful breastfeeding?]

CONTEXT

Maternal self-confidence and self-efficacy in breastfeeding are recognized as factors positively associated with the initiation and duration of breastfeeding.

OBJECTIVE

To evaluate the importance of this association using the Breast Feeding Self-Efficacy Scale (BSES).

METHOD

This prospective study was conducted in 2012 in the Jeanne-de-Flandre maternity department in the Lille University Hospital (France). During their time in the maternity department, breastfeeding mothers who participated in the study completed the BSES, a brief self-assessment of their feelings of self-efficacy relating to breastfeeding. They then received follow-up telephone interviews at 1 and 3 months postpartum.

RESULTS

One hundred and forty-nine mothers were included in the study. Breastfeeding rates were 86.5% at 1 month and 60% at 3 months. The BSES score of mothers who continued to breastfeed at 1 and 3 months was significantly higher than the score of mothers who had already weaned their children, with an AUROC of 0.72 at 3 months. This confirmed the reliability of the BSES for predicting adherence to breastfeeding. The BSES score of mothers who had previously breastfed was significantly higher than for those breastfeeding for the first time. The threshold score for the BSES was determined as 116/165.

CONCLUSION

It is important that mothers who lack confidence in their ability to breastfeed be identified early, whether on the maternity ward or even before this point. The value of BSES-based breastfeeding support intervention needs to be evaluated through randomized trials.

[Infusion of vasoactive drugs at low flow rate: effects of the syringe switch and syringe volume (experimental study)]

OBJECTIVE

The flow rate of intravenous administration of vasoactive agents should be steady in order to prevent changes in hemodynamics. In the newborns, because the flow rate is often lower than 1mL/h, it is difficult to switch of the syringe. The aim of our study was to compare the variations of concentration of active substance delivered after a manual or an automatic switch off the syringe with three different volumes (10mL, 20mL and 50mL).

MATERIALS AND METHODS

Glucose solution (10g/L) was used to simulate the administered substance. Saline was administered in "Y" simultaneously with the glucose solution through a catheter. The infused substance was collected at the tip of the catheter. The glucose concentration was measured at 15min-interval for 3hours.

RESULTS

The manual switch of the syringe was associated with a significant alteration of the flow rate, lasting more than 15min. In contrast, the automatic switch of syringes was associated with no change of the flow rate, especially with small-volume syringes (10mL).

CONCLUSION

In newborns, in order to prevent the change in flow rate of drugs after a switch of syringes, our results suggest the use of syringe-pump with built-in automatic switch and small-volume syringes.

[Impact of the instrumental vaginal delivery on pain perception at two months]

INTRODUCTION

Although instrumental vaginal delivery reduces the risk of neonatal mortality, it increases the risk of specific morbidity including prolonged neonatal discomfort. Previous studies suggest that neonatal exposure to acute pain could have long-term effects on the pain response later in life. The aim of the study was to investigate whether instrumental vaginal delivery may alter the response to a noxious stimulus at the age of two months.

METHOD

Newborn infants were enrolled in this prospective observational study after parental consent. A group of children born by instrumental vaginal delivery (group 2) were compared to matched controls born by vaginal delivery (group 1). Pain was assessed in each newborn infant between two and four hours after birth using the scale of pain and discomfort of the newborn baby (EDIN). These children were reassessed for pain response to immunizations (Infanrix(®) and Prevenar(®)) at two months of age using the DAN scale.

RESULTS

Thirteen children were enrolled in this study, six in group 1 and seven in group 2. Gestational age, birth weight, Apgar score, and umbilical arterial blood were similar in both groups. The EDIN measured between H2 and H4 was significantly higher in group 2 (median, 4 [IQ, 3] versus 0 [3.25], P<0.05). While the DAN score before and during immunization was similar in the two groups, it was statistically higher in group 2 than in group 1 (4 [3] versus 2 [2.25], P<0.01) within the15 min following the injections.

CONCLUSION

These results indicate that birth by instrumental vaginal delivery causes discomfort after birth and increases the pain response to immunization at the age of two months. This study supports the hypothesis that instrumental vaginal delivery may alter pain perception later in life.

Transposition of the great arteries: factors influencing prenatal diagnosis

OBJECTIVE

The objective of this study is to highlight the factors that may affect prenatal diagnosis of transposition of the great arteries (TGA) in order to improve it.

METHODS

This is a retrospective study performed between 2004 and 2009 in the maternity units from North of France. We identified a total of 68 cases of TGA (isolated or associated with only VSD or coarctation of aorta), of which 32 (47.1%) had prenatal diagnosis (PND+) and 36 did not (PND-). Maternal characteristics and ultrasound factors were studied in relation to PND.

RESULTS

Maternal weight and body mass index were significantly higher in the PND- group (70.4 kg and 26.5 kg/m(2) vs 63.6 kg and 23.6 kg/m(2) , respectively). Maternal obesity (body mass index >30) was significantly more frequent in the PND- group (27.8% vs 12.5%). More than a quarter of TGA (28.1%) were diagnosed during the third trimester.

CONCLUSION

Obesity is the main cause of missed PND of TGA. Obese patients with suboptimal prenatal scans may benefit from reassessment of fetal cardiac anatomy and/or from referral for fetal echocardiography.

[Impact of cocooning and maternal voice on the autonomic nervous system activity in the premature newborn infant]

INTRODUCTION

Discomfort, pain, and stress have an adverse impact on the psychomotor development in the premature newborn infant. Recent studies indicate that pain and stress are associated with a reduction of parasympathetic outflow. We hypothesized that cocooning associated with the human voice has a favorable impact on parasympathetic activity in the premature newborn infant.

METHOD

We compared heart rate variability (HRV) before and after standardized cocooning phases associated with the human voice and carried out: 1) by the mother and 2) by a third person. HRV was assessed and expressed as an index reflecting the parasympathetic tone.

RESULTS

Ten children were included (median gestational age, 33 weeks (30(+4)-33(+2))). We observed a higher HRV index after the period of cocooning associated with the human voice compared with the baseline measurement (P<0.05), whether the procedure was carried out by the mother or a third person.

CONCLUSION

This study shows that cocooning associated with the human voice enhances HRV in the preterm newborn infant, indicating an increase in parasympathetic activity after cocooning associated with the human voice. However, the impact is similar whether the cocooning associated with the human voice is performed by the mother or a third person. This result suggests that cocooning associated with the human voice carried out either by the mother or a third person contributes to decreasing stress and discomfort in the premature newborn infant.

Heart rate variability analysis for newborn infants prolonged pain assessment

Pain management is a general concern for healthcare quality. In the particular context of neonatal care, it's well known that an efficient pain management will decrease mortality and morbidity of newborn infants. Furthermore, the plasticity of developing brain is vulnerable to pain and/or stress, that in turn may cause long term neurodevelopmental changes, including altered pain sensitivity and neuroanatomic and behavioural abnormalities. During neonatal intensive care stay, large number of painful procedures are performed, the majority of which are not accompanied by adequate analgesia. Optimal management requires competent pain assessment which can be especially difficult to perform in this non verbal population. We have developed an instantaneous heart rate variability (HRV) analysis method, non intrusive and user-friendly, based on the ECG signal acquisition. This analysis method enabled us to design parameters related to the influence of pain on the Autonomic Nervous System (ANS) activity. This paper presents the application of this method, previously validated for adults under general anesthesia, to the domain of newborn infants prolonged pain assessment.

[Congenital diaphragmatic hernia: respiratory and vascular outcomes]

Congenital diaphragmatic hernia (CDH) is a life-threatening anomaly associated with a variable degree of pulmonary hypoplasia (PH) and persistent pulmonary hypertension (PPH). Despite remarkable advances in neonatal resuscitation and intensive care, and new postnatal treatment strategies, the rates of mortality and morbidity in the newborn with CDH remain high as the result of severe respiratory failure secondary to PH and PPH. Later, lung function assessments show obstructive and restrictive impairments due to altered lung structure and lung damage due to prolonged ventilatory support. The long-term consequences of pulmonary hypertension are unknown. Other problems include chronic pulmonary aspiration caused by gastro-oesophageal reflux and respiratory manifestations of allergy such as asthma or rhinitis. Finally, failure to thrive may be caused by increased caloric requirements due to pulmonary morbidity. Follow-up studies that systematically assess long-term sequelae are needed. Based on such studies, a more focused approach for routine multidisciplinary follow-up programs could be established. It is the goal of the French Collaborative Network to promote exchange of knowledge, future research and development of treatment protocols.

[Risk of accumulation of CO₂ in the oxygen chamber in "HOOD" (Experimental study on test bed)]

OBJECTIVES

Oxygen hood is largely used to deliver O₂ to newborn infants with respiratory failure in the northern region of France. The oxygen flow is set to obtain the target arterial blood oxygen saturation. Thus, O₂ flow delivers into the hood may be below the recommended gas flow of 6L/min. However, gas flow below 6L/min exposes to CO₂ rebreathing. The aim of this study was to evaluate the effect of various rates of gas flows on the values of partial pressure of CO₂ into the hood.

MATERIAL AND METHODS

We measured CO₂ and O₂ partial pressure into hoods of two different volumes (4 and 10L) under two experimental bench test conditions. Protocol 1: gas flow was constant at 6L/min, while oxygen fraction varied from 0.21 to 1. Partial pressure of CO₂ and O₂ were recorded. Protocol 2: while O₂ fraction was kept constant, oxygen flow varied from 0.5 to 7L/min (by step of 0.5L/min). Partial pressure of CO₂ and O₂ were recorded.

RESULTS

Partial pressure of CO₂ increases proportionally to the decrease in the gas flow delivered into the hood, and reached 14 mmHg at gas flow of 0.5L/min.

CONCLUSION

Risk of CO₂ rebreathing exists as soon as the gas is delivered into the hood at minimal flow rates below 6L/min.

[Increased success rate in umbilical venous catheter positioning by posterior liver mobilization]

OBJECTIVE

To evaluate prospectively the benefit of posterior liver mobilization during umbilical venous catheterization to place the umbilical venous catheter (UVC) in the central position (inferior vena cava).

PATIENTS AND METHODS

Sixty-five successive newborn infants admitted in 3 neonatal intensive care units who required a UVC were enrolled over a 4-month period. UVC positions were assessed by X-ray. UVCs were placed either in an adequate position (at the right atrial-inferior vena cava junction, indicating success) or inserted within the portal system (failure). In this case, the UVC was drawn back to the 3cm mark and then, an additional attempt to insert the UVC was made during lateroposterior liver mobilization by the operator's hand. The success and failure rates at 1st and 2nd attempts were evaluated and compared. Characteristics of the population and possible catheter-related complications were recorded.

RESULTS

A total of 31 of 65 (55%) UVC insertions failed at the 1st attempt. Among these UVCs, 16 (52%) were correctly repositioned in the central position by hepatic mobilization. The success rate increased by 50% (p<0.05). No life-threatening complications were observed during the procedure.

CONCLUSION

Hand liver mobilization during umbilical venous catheterization improves the rate of adequate insertion of the UVC into the inferior vena cava. It is a simple, quick, and safe procedure.

Early hemodynamic consequences of patent ductus arteriosus in preterm infants with intrauterine growth restriction

OBJECTIVE

To test the hypothesis that significant patent ductus arteriosus (PDA) may occur very early after birth in preterm infants with intrauterine growth restriction (IUGR), we compared the longitudinal changes in left-to-right shunting through DA between eutrophic and preterm infants with IUGR.

STUDY DESIGN

The preterm infants -26 to 32 weeks gestational age (GA), admitted in our neonatal intensive care unit from February to May 2004 were included. They were separated into an "IUGR of placental origin" group and an "eutrophic" group. Significant PDA was assessed by Doppler echocardiography at 6, 24, and 48 hours of age.

RESULTS

Thirty-one eutrophic (GA = 29 +/- 1.4 weeks; birth weight [BW] = 1300 +/- 160 g) and 17 infants with IUGR (GA = 29.3 +/- 1.5 weeks; BW = 810 +/- 140 g) were studied. Six hours after birth, the rate of significant PDA was higher in the IUGR than in the eutrophic group (10/17 [60%] vs 5/31 [15%]; P < .05). More DA became significant in infants with IUGR (11/17 [65%]) than in eutrophic infants (12/31 [40%]) (P < .05) within the 48 hours after birth.

CONCLUSION

Markers of high pulmonary blood flow and systemic vascular steal occur more frequently and earlier after birth in IUGR of placental origin than in eutrophic preterm infants. The management of preterm infants with severe IUGR of placenta origin should include early echocardiographic monitoring to assess for markers of significant PDA.

[Invasive fungal dermatitis in extremely premature newborns: a specific clinical form of systemic candidiasis]

BACKGROUND

Fungal agents, chiefly Candida albicans, are the cause of rising morbidity and mortality in newborn infants weighing less than 1500 g. We studied the particular cutaneous effects during the course of these infections.

PATIENTS AND METHODS

This was a retrospective 3-year study in premature infants weighing less than 1500 g and hospitalized in the neonatal department of the Lille University Teaching Hospital. The patients included in the study presented sepsis with isolation of Candida in blood and/or urine culture.

RESULTS

Twelve infants were included (1.8%). The risk factors seen are those described in literature (broad-spectrum antibiotics, prolonged mechanical ventilation and parenteral nutrition, corticosteroids and central venous catheters). Infection occurred early (mean: D12) and affected extremely premature infants (mean: 25 weeks' amenorrhea) of low birth weight (mean: 758 g) generally born by vaginal delivery (9 of 12 infants). The sole fungal agent isolated was Candida albicans. In 10 of the 12 patients, a characteristic skin disorder was observed (erythema with erosion and desquamation). In 10 of the 12 patients, too, Candida was isolated from skin and/or mucosal samples.

DISCUSSION

Although it is now universally accepted that antifungal treatment should be initiated without delay for candidemia in septic newborn infants at risk, diagnosis of systemic candidiasis remains delicate. However, a specific pattern of skin involvement is very commonly seen that is atypical for candidiasis, but which in addition to its diagnostic value indicates early colonization with Candida (first 2 weeks of life). In this setting of immaturity of the skin and immune system, colonization and proliferation in skin and/or mucosa appear to constitute the first stage of systemic infection and we may speak of invasive cutaneous-mucosal candidiasis in extremely premature infants and initiate treatment designed to prevent the disease becoming systemic..

Anesthésie maternofœtale pour « ex utero intrapartum » traitement (EXIT) procédure : à propos de deux cas

The ex utero intrapartum treatment (EXIT) procedure is a surgical procedure maintaining utero-placental circulation during caesarean section. Anaesthetic implications are described: foetal transplacental anaesthesia to avoid first breathing and to permit surgical procedure on obstructed foetal airway, deep maternal haemodynamically stable anaesthesia to relax uterine smooth muscle during a long caesarean procedure but avoiding post-partum haemorrhage. Volatile anaesthesia with sevoflurane seems to be adequate for these aims. Two cases are described.

[Acute per-partum feto-fetal transfusion. A case study on two sets of twins]

Description of acute per-partum feto-fetal transfusion. The risk of twin-twin transfusion syndrome in monochorionic twin pregnancies is well known. This pathology starts in the second trimester and has a chronic course. Acute per-partum feto-fetal transfusion seems to be less frequent and has not been studied. In the study, we described two cases of acute per-partum feto-fetal transfusion. The outcomes of the pregnancies were as follows: following a successful delivery, the first set of twins presented hypovolemic shock at birth due to an acute anemia. The second set of twins was polyglobulic, but otherwise healthy at birth. The risk of hypovolemic shock seems to be unpredictable, even if the pregnancy is monitored. Obstetricians and pediatricians must keep this pathology in mind when dealing with this kind of pregnancy. Moreover, it would be interesting to obtain systematically a full blood count of each set of twins of monochorionic pregnancies, in order to detect every case of feto-oetal transfusion.

Severity of the ductal shunt: a comparison of different markers

BACKGROUND

When the ductus arteriosus (DA) is patent, the ductal shunt is proportional to the ratio of left ventricular output (LVO) to systemic blood flow. Systemic blood flow can be estimated by measuring flow in the superior vena cava (SVC).

OBJECTIVE

To re-evaluate the accuracy of standard echocardiographic markers of patent ductus arteriosus (PDA) using LVO/SVC flow ratio.

METHODS

Prospective study. Preterm infants of 24-30 weeks gestational age and postnatal age less than 48 hours. The following echocardiographic criteria were measured: left atrial to aortic root ratio (LA/Ao); DA diameter by B mode and colour Doppler; mean and end diastolic flow velocity of the left pulmonary artery (LPA); LVO; SVC flow.

RESULTS

Twenty three preterm infants were enrolled (median gestational age 28 weeks (range 24-30), median birth weight 840 g (500-1440)). The DA was closed in eight (mean (SD) LVO/SVC 2.4 (0.3)) and open in 15 (mean (SD) LVO/SVC 4.5 (0.6)). An LA/Ao ratio > or =1.4, a DA diameter > or =1.4 mm/kg, and a mean and end diastolic flow velocity of LPA respectively > or =0.42 and > or =0.20 m/s identified an LVO/SVC > or =4 with a sensitivity and a specificity above 90%.

CONCLUSION

This study indicates that LA/Ao ratio, DA diameter, and mean and end diastolic flow velocity of the LPA are accurate markers of PDA. These standard echocardiographic variables are easy to measure and need less skill and resources than direct measurements of ductal shunt.

Facteurs influençant la délivrance de substances perfusées à faible débit par seringue autopulsée : conséquences sur la perfusion de médicaments vasoactifs chez l'enfant prématuré

The infusion of vasoactive drugs in preterm babies using syringe pumps can be complicated by important variations in the infusion rate.

AIMS OF THE STUDY

1) to assess the time between pump start and the actual presence of a substance in the circulation, when using slow rates; 2) to evaluate the effects of changes in the main infusion rate on substance rates infused on the same line.

METHODS

We used 10% glucose to mimic vasoactive drugs. The main infusion consisted of saline, and both were infused on the same line using syringe pumps. Glucose concentration was measured at the end of the line.

RESULTS

The time between pump start and the actual infusion of glucose depended on syringe volume and on the adjustment of the syringe in the pump. There was a transient increase in glucose rate when the main rate increased, and a transient decrease when the main rate decreased.

CONCLUSION

To minimize the time before a substance is actually infused, one should use low volume syringes and correctly adjust the syringe in the pump. Moreover, when a steady infusion rate is necessary, one should avoid variations in the main infusion rate.

Pulmonary vascular effects of sildenafil on the development of chronic pulmonary hypertension in the ovine fetus

We investigated the pulmonary vascular effects of prophylactic use of sildenafil, a specific phosphodiesterase-5 inhibitor, in late-gestation fetal lambs with chronic pulmonary hypertension. Fetal lambs were operated on at 129 +/- 1 days gestation (term = 147 days). Ductus arteriosus (DA) was compressed for 8 days to cause chronic pulmonary hypertension. Fetuses were treated with sildenafil (24 mg/day) or saline. Pulmonary vascular responses to increase in shear stress and in fetal PaO2 were studied at, respectively, day 4 and 6. Percent wall thickness of small pulmonary arteries (%WT) and the right ventricle-to-left ventricle plus septum ratio (RVH) were measured after completion of the study. In the control group, DA compression increased PA pressure (48 +/- 5 to 72 +/- 8 mmHg, P < 0.01) and pulmonary vascular resistance (PVR) (0.62 +/- 0.08 to 1.15 +/- 0.11 mmHg x ml(-1) x min(-1), P < 0.05). Similar increase in PAP was observed in the sildenafil group, but PVR did not change significantly (0.54 +/- 0.06 to 0.64 +/- 0.09 mmHg x ml(-1) x min(-1)). Acute DA compression, after brief decompression, elevated PVR 25% in controls and decreased PVR 35% in the sildenafil group. Increased fetal PaO2 did not change PVR in controls but decreased PVR 60% in the sildenafil group. %WT and RVH were not different between groups. Prophylactic sildenafil treatment prevents the rise in pulmonary vascular tone and altered vasoreactivity caused by DA compression in fetal lambs. These results support the hypothesis that elevated PDE5 activity is involved in the consequences of chronic pulmonary hypertension in the perinatal lung.

Pulmonary vasodilator effects of norepinephrine during the development of chronic pulmonary hypertension in neonatal lambs

BACKGROUND

This experimental study was performed to determine the effects of norepinephrine on: (i) the pulmonary vascular tone during the development of pulmonary hypertension (PH) in the fetus and (ii) the circulatory adaptation at birth after chronic intrauterine PH.

METHODS

Chronically instrumented fetal lambs were randomized into two groups: (i) a group with PH obtained by antenatal partial ligation of the ductus arteriosus (DA) (n=9) and (ii) a control group without DA ligation (n=6). Pulmonary vascular responses to norepinephrine (1.5 microg min(-1)) were measured in utero 7 days after surgery. At day 8 post-surgery, after delivery, animals were ventilated for 3 h with oxygen 100%. The group with PH was randomly assigned to receive norepinephrine or saline.

RESULTS

Mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) were higher in the PH group (P<0.01). Norepinephrine-induced decrease in PVR was more pronounced in the PH group than in the control group (63 vs 35%, respectively; P<0.01). In the PH group, the decrease in PVR during mechanical ventilation was greater in the animals receiving norepinephrine than in the animal receiving saline (from 1.05 (0.12) to 0.1 (0.02) vs from 1.04 (0.1) to 0.2 (0.04) mm Hg ml(-1) min(-1), respectively; P<0.01). After 3 h of ventilation, mean PVR in the PH lambs treated by norepinephrine was similar to those measured in the control lambs. Aortic pressure was higher in the group treated with norepinephrine.

CONCLUSION

The data suggest that norepinephrine may improve post-natal pulmonary adaptation in the newborn with persistent PH both by increasing systemic vascular pressure and by increasing pulmonary blood flow.

Dynamic behavior of respiratory system during nasal continuous positive airway pressure in spontaneously breathing premature newborn infants

The end-expiratory lung-volume level of premature newborn infants is maintained above passive resting volume during active breathing, through the combination of reduced time constant and high respiratory rate. To determine whether nasal continuous positive airway pressure (NCPAP) alters this characteristic dynamic breathing pattern, we studied the effects of various NCPAP levels on the dynamic elevation of end-expiratory lung volume level (DeltaEELV) in spontaneously breathing premature newborn infants, using respiratory inductive plethysmography (RIP). Eleven premature newborn infants with moderate respiratory failure were included. NCPAP levels were set in a random order to 0, 2, 4, and 6 cm H2O. Tidal volume (Vt), rib-cage contribution to Vt (%RC), phase angle between abdominal and thoracic motions (theta), respiratory rate (RR), and inspiratory and expiratory times (Ti and Te) were continuously recorded by RIP. The slope of the linear part of the expiratory flow-volume relation was extrapolated up to zero flow level to evaluate the dynamic elevation of the functional residual capacity (FRC) (DeltaEELV). The time-constant of the respiratory system (tauRS) was calculated as the slope of the linear part of the expiratory flow-volume loop. At NCPAP = 6 cm H2O, DeltaEELV reached 0.6 +/- 0.2 times the Vt at NCPAP = 0 cm H2O. An increase in NCPAP level resulted in a significant decrease in DeltaEELV (P < 0.01). A decrease in DeltaEELV during NCPAP was associated with a significant increase in Te from 0.62 +/- 0.13 sec at NCPAP = 0 cm H2O to 0.80 +/- 0.07 sec at NCPAP = 6 cm H2O (P < 0.05), and a decrease in tauRS from 0.4 +/- 0.1 sec at NCPAP = 0 cm H2O to 0.24 +/- 0.04 sec at NCPAP = 6 cm H2O (P < 0.01). These results indicate that the characteristic spontaneous breathing pattern causing a dynamic elevation of FRC is abolished by NCPAP. We speculate that the dynamic volume-preserving mechanisms resulting from expiratory flow braking are no longer required during NCPAP, as the constant pressure may passively elevate FRC.

Successful management of severe chylothorax with argon plasma fulguration and fibrin glue in a premature infant

Post-traumatic neonatal chylothorax is a rare entity. Management includes medical and surgical treatment. We describe here a newborn who developed a severe chylothorax after repair of an oesophageal atresia. The chylothorax was treated successfully by a combination of argon beam coagulation of the mediastinum and fibrin glue application. However, the patient developed complete thrombosis of the left femoral vein with clot extension to the inferior vena cava which resolved after infusion of recombinant tissue plasminogen activator (rt-PA). The use of argon plasma coagulation and mediastinal fibrin glue application for treating postoperative chylothorax appears to be attractive and is easy to perform even in small premature infants and may replace a more extensive surgical procedure. However, the coagulation profile should be monitored and special care should be taken to prevent vascular thrombosis after surgery.

[Ruptured mycotic aneurysm with hemoperitoneum: an unusual septic complication of umbilical arterial catheter]

Arterial aneurysms are rare in infants and are usually associated with cardiovascular malformations or connective tissue disorders. Mycotic aneurysms of the aorta or its major branches have been described in newborn infants with septicemia originating from an indwelling umbilical artery catheter. We report a case of a newborn infant with a mycotic aneurysm complicated by massive hemoperitoneum. Surgical treatment allowed a complete recovery. Newborn infants with Staphylococcus aureus bacteremia in the context of a current or recent umbilical artery catheterisation should be followed up closely to detect arterial aneurysms.

[Recombinant human erythropoietin: analysis of a policy of treatment in an hospital based population of very-low-birthweight infants]

AIM OF THE STUDY

To evaluate a policy of treatment with human recombinant erythropoietin (rhEPO) and to describe factors related to red blood cell transfusions (RBCTs) in treated neonates.

STUDY

Prospective, observative study.

PATIENTS AND METHODS

One-hundred and sixty-five neonates with gestational age (GA) < 30 weeks and/or birthweight < 1000g admitted between may 1998 and october 1999. Ninety were excluded (congenital malformations n = 6, deaths n = 16, referral to a general hospital before discharge n = 67, ECMO n = 1). Data about the characteristics of the population, the severity of the neonatal period, hemoglobin at birth, blood loses, treatment with rhEPO, number of red blood cells transfusions (RBCTs) and donors were recorded in all infants.

RESULTS

Thirty-eight in seventy-five (51%) neonates received 112 blood transfusions. Eighty-eight were prescribed after day 15. In most of the cases (n = 68), RBCTs were done according to the protocol. In 20 cases (23%) infants were transfused during a late-onset infection. No difference was observed between the non-transfused (group I) and the transfused neonates (group II) with regards to the drug administration: first dose on day 3 +/- 2, number of injections (17 +/- 4 vs 18 +/- 1, ns). The start of oral supplementation with iron was late (12j +/- 8 vs 19j +/- 10, ns). Infants in group II had a lower birthweight (850 +/- 240 vs 1050 +/- 160 g, p < 0,01) for a similar GA (28 +/- 1SA vs 28 +/- 2SA, ns) in association with an increased number of small for date babies (p = 0.03). Antenatal steroïds administration (89 vs 74%, ns), administration of surfactant (59 vs 81%, ns) were similar in the two groups. The Clinical Risk Index for Babies was higher in group II: 5 +/- 3 vs 2 +/- 1 (p < 0,001) as was the duration of oxygen delivery (53 +/- 44 vs 14 +/- 20 days, p < 0,01) and postnatal administration of corticosteroïds ( 38% vs 3%, p < 0.01).

CONCLUSION

The quality of iron administration, RBCTs and the limitation of donors could be improved in our population. Transfusions among neonates born before 30 weeks and/or with a birthweight of less than 1000 g and treated with rhEPO are associated with intrauterine malnutrition and a worse clinical condition on admission. Early identification of at risk neonates could improve prevention of RBCTs and the efficacy of rhEPO administration to preterm infants.

Effects of catecholamines on the pulmonary circulation in the ovine fetus

High levels of circulating catecholamines are found in the fetus, and fetal stress and birth induce a marked surge in catecholamine secretion. Little is known about the role of catecholamines on the fetal pulmonary circulation. To determine the effects of catecholamines on the pulmonary vascular tone, we tested the hemodynamic response to norepinephrine and dopamine infusion in chronically prepared late-gestation fetal lambs. We found that norepinephrine infusion (0.5 microg. kg(-1). min(-1)) increased pulmonary artery pressure (PAP) by 10 +/- 1% (P < 0.01), left pulmonary artery blood flow by 73 +/- 14% (P < 0.01), and decreased pulmonary vascular resistance (PVR) by 33 +/- 6% (P < 0.01). The pulmonary vasodilator effect of norepinephrine was abolished after nitric oxide synthase inhibition. Dopamine infusion at 5 microg. kg(-1). min(-1) did not significantly change PVR. Conversely, dopamine infusion at 10 microg. kg(-1). min(-1) increased PAP (P < 0.01) and progressively increased PVR by 30 +/- 14% (P < 0.01). These results indicate that catecholamines may modulate basal pulmonary vascular tone in the ovine fetus. We speculate that catecholamines may play a significant role in the maintenance of the fetal pulmonary circulation and in mediating changes in the transitional pulmonary circulation.

[Experimental study of changes in FiO2 during manual ventilation]

Discrepancies exist in the recommendations about the oxygen flow to deliver during manual ventilation. The aim of the present study was to determine the effects of ventilatory frequency (FR), inspiratory pressure (P) and oxygen flow on the concentration of the delivered oxygen (FiO2) to obtain FiO2 near 1.

MATERIAL AND METHODS

Experimental study with self-inflating resuscitation bag (Ambu with oxygen reservoir) tested on a mono-compartmental test lung (resistant tube and elastic bag [Draeger]; characteristics: compliance = 0.6 mL/cmH2O; resistance = 85 cmH2O.L-1.s-1). Protocol 1: six neonatologists ventilated this model as if they were ventilating premature newborn infants with RDS at various ventilatory rates from 30 to 120 bpm and at various oxygen flows (from 2 to 12 L/min). Tidal volumes (Vt), inspiratory times (Ti), P and FiO2 were recorded continuously during the study. Protocol 2: a graduated manometer was added to visualize pressure. The same protocol was then applied.

RESULTS

Protocol 1 (without visual control of the pressure): increase in oxygen flow delivered with the Ambu increases the FiO2 values (P < 0.0001); the higher the ventilatory frequency, the lower the FiO2 (P < 0.0001). The mean value of delivered FiO2 was related to the operator (extreme: 47-86%) (P < 0.001). Multivariate statistical analysis showed that O2 flow, ventilator rate and operator modulated independently the FiO2. Ti and Vt did not change the FiO2. Protocol 2 (with visual control of the pressure: the mean inflating pressures were less than those obtained without visual control of the pressure (26 vs 40 cmH2O respectively; P < 0.05). FiO2 was independent of O2 flow and ventilatory rate.

CONCLUSIONS

A special device for continuous visual control of airway pressure is recommended during neonatal manual ventilation. It prevents ventilatory rate-induced FiO2 fluctuations and overdistention.

[Anastomotic stenosis after surgical treatment of esophageal atresia: frequency, risk factors and effectiveness of esophageal dilatations]

Anastomotic stricture is the most common complication following the surgical repair of esophageal atresia, and is usually treated by esophageal dilation.

OBJECTIVES

The aims of this study were to assess in an infant population operated on at birth for type III or IV esophageal atresia: 1) the frequency of esophageal stenosis following the repair of esophageal atresia, and associated factors; 2) the efficacy of esophageal dilation by the Savary-Gaillard bougie technique.

MATERIALS AND METHODS

The medical records of 52 children presenting with esophageal atresia over a 5-year period were retrospectively reviewed. Gestional age and birth weight, duration of mediastinal and transanastomotic drainage, and anastomotic complications including leakage, stricture, and the presence of gastroesophageal reflux were recorded and analysed. Patients presenting with anastomotic stricture were compared with a group of children without stricture. The number of esophageal dilations, their efficacy and the complication rate were analyzed.

RESULTS

Anastomotic stricture developed in 20 (40%) of the 50 patients undergoing primary repair for esophageal atresia. The occurrence of anastomotic stricture was related to anastomotic tension during esophageal surgical repair (p < 0.03). Young children required esophageal dilation at a mean age of 142 days (24-930 days). Stricture resolution occurred after a mean of 3.2 dilations (1-15) over an average period of 7.9 months (range: 0-30 months). Dilation was successful in 90% of the 20 patients. Seven patients required only one dilation. Perforation of the esophagus occurred in one case, and this severe complication led to the death of the child. Esophageal dilation was unsuccessful in two patients, who presented prolonged severe dysphagia.

CONCLUSION

Anastomotic stricture following repair of esophageal atresia is connected with the length of the gap that has to be repaired, and tension during suture. Esophageal dilation by the Savary-Gaillard bougie technique is an effective method for treating esophageal stricture. Several dilations are usually needed before the disappearance of dysphagia.

Combined effects of inhaled nitric oxide (iNO) and oxidant agents on the production of methemoglobinemia in newborn piglets

OBJECTIVE

To investigate the effects of the association of inhaled nitric oxide (iNO) and oxidant drugs (acetaminophen, phytomenadione, and EMLA cream) on methemoglobinemia during the neonatal period.

DESIGN

Prospective, randomized, experimental study.

SETTING

University Experimental Pharmacology laboratory.

SUBJECTS

Sixty newborn piglets weighing 1.5-2.0 Kg.

INTERVENTIONS

Twelve groups of five piglets were anaesthetized, mechanically ventilated, and studied for 3 hrs. Eight groups received iNO (40 ppm or 80 ppm) alone or in association with a single intravenous dose of acetaminophen (120 mg/kg propacetamol), phytomenadione (5 mg vitamin K1) or EMLA cream (2.5 g) applied to the ventral lower abdomen for 3 hrs. Three other groups received, respectively, acetaminophen, phytomenadione, or EMLA cream without iNO. The last group (control group) received neither drugs nor iNO.

MEASUREMENTS AND MAIN RESULTS

Methemoglobinemia was measured before the beginning of each experiment, 30 mins later, and every hour for 3 hrs. There was no significant difference in methemoglobinemia at any time between groups receiving acetaminophen (0.90%+/-0.12%), phytomenadione (0.88%+/-0.11%), or EMLA cream alone (0.97%+/-0.11%) and the control group (0.92%+/-0.12%). At 3 hrs, methemoglobinemia was slightly but significantly increased in group receiving iNO alone (1.04%+/-0.17% at 40 ppm iNO and 1.14%+/-0.16% at 80 ppm iNO; p < .05). Conversely, methemoglobinemia increased as a function of time in groups in which iNO was associated to drug administration and was significantly greater than the control group at 3 hrs (80 ppm iNO + acetaminophen, 2.80%+/-0.47%; 80 ppm iNO + phytomenadione, 2.38%+/-0.45%; 80 ppm iNO + EMLA cream, 2.33%+/-046%; p < .001).

CONCLUSIONS

These results demonstrate that if oxidant drugs (acetaminophen, phytomenadione, or EMLA cream) did not increase blood methemoglobinemia in neonatal piglets, their association with iNO caused an increase in methemoglobin. Special care should be taken to monitor methemoglobinemia when iNO is combined to such drugs in newborn infants.

[Congenital hernia of the diaphragm. A retrospective study of 123 cases recorded in the Neonatal Medicine Department, URHC in Lille between 1985 and 1996]

BACKGROUND

During the last ten years, new therapeutic strategies have been used in order to improve the management of congenital diaphragmatic hernia (CDH). CDH is associated with pulmonary hypoplasia, abnormal pulmonary vascular reactivity and pulmonary immaturity. Between 1985 and 1990, mechanical hyperventilation and early surgery were provided systematically. Since 1991, the management of CDH in our institution has involved a preoperative stabilization with exogenous surfactant replacement, gentle ventilation, high-frequency oscillation, nitric oxide or extracorporeal membrane oxygenation.

PURPOSE

To analyse the impact of the new therapeutic strategy on the survival and outcome of newborns with CDH.

METHODS

Retrospective review of all infants with CDH admitted to our institution from 1985 through 1996. Mortality and morbidity were compared between period I (1985-1990) and period II (1991-1996).

RESULTS

Between 1985 and 1996, 123 neonates were admitted to our Neonatal Department. Nine of them had another severe congenital malformation and were excluded from the study. Survival was 23% (12/52) in period I and 56% (35/62) in period II (p < 0.001). In period II, complications were more frequent among survivors in whom an extracorporeal membrane oxygenation was required (13 infants): bronchopulmonary dysplasia 77% (10/13), gastroesophageal reflux 61% (8/13), and hypotrophy 61% (8/13).

CONCLUSION

These data demonstrate a significant improvement in survival in CDH since the implementation of new therapeutic modalities. Nevertheless, a significant morbidity exists among the infants who survive a severe respiratory failure.

[For or against the early use of nasal continuous positive pressure and exogenous surfactant in hyaline membrane disease. Physiopathologic arguments]

The use of nasal CPAP in the treatment of respiratory distress syndrome in very premature newborns follows pathophysiological basis. The authors emphasize the usefulness of nasal CPAP and surfactant in the treatment of respiratory distress syndrome. The aim of this strategy is to reduce alveolar atelectasis, thus reducing the incidence and the severity of respiratory distress syndrome, together with a possible reduction of the incidence of bronchopulmonary dysplasia.

[Use of double-lumen umbilical vein catheters in a neonatal intensive care unit]

BACKGROUND

The aim of the study was to compare the success/failure rate and complications of insertion into the umbilical vein, of either double-lumen catheters (Charrière diameter 04, length 13 and 30 cm) or single-lumen catheters (Charrière diameter 05, length 40 cm) in a population of neonates admitted to a neonatal intensive care unit. The numbers of insertions of additional peripheral venous catheters were also compared.

PATIENTS AND METHODS

The population was divided into two groups according to the severity of the respiratory failure. Group 1 (n = 52): normal hemodynamic parameters and moderate respiratory failure (FiO2 < 0.6): only single-lumen catheters were used. Group 2 (n = 56): low systemic pressure requiring vascular filling and/or inotropic drugs infusion and/or severe respiratory failure (FiO2 > 0.6): in this group, either single-lumen catheters or double-lumen catheters were inserted.

RESULTS

The success rate of insertion of double-lumen catheters and of single-lumen catheters were similar (61% vs 71%: P = 0.7). Nineteen double-lumen catheters were inserted in the group 2. The average duration of double-lumen umbilical catheterization was not significantly different from simple-lumen catheterization (4.9 +/- 2.2 vs 4.6 +/- 2.2 days). Complications relating to the umbilical venous catheterization were uncommon: three catheter obstructions (two with single-lumen catheter, one with double-lumen catheters), two nosocomial infections (both with single-lumen catheter), one hydropericardium (with single-lumen catheter). In group 2, more peripheral venous catheters were required during the first 72 hours of life after insertion of single-lumen catheter than after insertion of double-lumen catheters (average number of peripheral venous catheters per infant: 1.6 +/- 0.83 vs 1 +/- 0.35 respectively; P < 0.01).

CONCLUSION

Feasibility and complication rate of umbilical double-lumen catheters were similar to those of single-lumen catheters. The use of umbilical double-lumen catheters reduces the need of peripheral venous catheters.