Outbreak of infections caused by Enterobacter cloacae producing the integron-associated beta-lactamase IBC-1 in a neonatal intensive care unit of a Greek hospital

Nineteen of 27 ceftazidime-resistant Enterobacter cloacae isolates from a neonatal intensive care unit in Thessaloniki, Greece, had genes coding for the novel extended-spectrum beta-lactamase IBC-1; 18 of those 19 harbored similar conjugative plasmids and belonged to two distinct genetic lineages. A synergy test with ceftazidime and imipenem enabled us to identify five unrelated bla(IBC-1)-carrying E. cloacae isolates from other wards of the hospital. It seems that this integron-associated gene is capable of dispersing both by clonal spread and by gene dissemination.

Evaluation of the HemoCue compared with the Coulter STKS for measurement of neonatal haemoglobin

OBJECTIVE

To compare the measurement of haemoglobin concentration ([Hb]) using the HemoCue haemoglobinometer with that using the Coulter STKS haemoglobinometer.

DESIGN

Thirty two EDTA samples were taken from neonates. [Hb] was measured in these samples using the HemoCue; the samples were then transferred to the haematology laboratory for [Hb] determination with the Coulter STKS. In addition, [Hb] was determined in 50 different random EDTA neonatal samples already held in the laboratory, using the HemoCue and Coulter STKS.

PATIENTS

Neonates in the intensive care and low dependency Units of the Royal Devon and Exeter Hospital.

INTERVENTIONS

Samples were collected from arterial lines or by venepuncture or heel prick into an EDTA bottle.

MAIN OUTCOME MEASURES

[Hb] using the HemoCue and Coulter STKS methods.

RESULTS

The mean [Hb] measured using the HemoCue was 150.3 g/l (range 78-215) compared with 152.8 g/l (range 78-217) measured using the Coulter STKS, with a mean of the differences of 2.5 g/l. The standard deviation of the differences of the 82 samples was 3.73 g/l. The limits of agreement of the two methods (mean difference +/- 2SD) were -4.8 to +9.8 g/l.

CONCLUSION

With adequate training and monitoring, the HemoCue can be used directly on the neonatal unit for rapid determination of [Hb] to within 7.5 g/l compared with the laboratory Coulter STKS, using much smaller sample volumes.

Alagille syndrome: prenatal diagnosis and pregnancy outcome

The Alagille syndrome (AGS) is a multisystem autosomal dominant condition. In this case report, we describe a pregnant woman with this unusual disorder, in whom serial fetal sonography revealed severe pulmonary stenosis and progressively severe intrauterine growth retardation, suggesting that the fetus also had AGS, a diagnosis which was confirmed postnatally. In this report, the potential complications for pregnancy, labor and delivery when both mother and fetus are affected with AGS are described.

Magnetic resonance imaging of the infant brain: anatomical characteristics and clinical significance of punctate lesions

OBJECTIVE

To describe the magnetic resonance imaging (MRI) characteristics of punctate brain lesions in neonates (number, appearance, distribution, and association with other brain abnormalities) and to relate them to neurodevelopmental outcome.

METHODS

A retrospective analysis was performed of 110 MRI brain scans from 92 infants admitted in 1998 to the neonatal intensive care unit. Results of routine neurodevelopmental follow up (1998-2001) in those infants with punctate brain lesions were analysed.

RESULTS

Punctate lesions were observed in 15/50 preterm and 2/42 term infants. In the preterm group, the number of lesions was < 3 in 20%, 3-10 in 27%, and > 10 in 53%. In 14/15 the lesions were linearly organised and located in the centrum semiovale. Other brain abnormalities were absent or minor--that is, "isolated" punctate lesions--in 8/15 and major in 7/15. In the term group, punctate lesions were organised in clusters and no other brain abnormalities were observed. Isolated punctate lesions were observed in 10/17 infants, and a normal neurodevelopmental outcome was seen in 9/10 (mean follow up 29.5 months). One infant showed a slight delay in language development. In the infants with associated brain lesions (7/17, mean follow up 27.5 months), outcome was normal in only two subjects.

CONCLUSIONS

Punctate lesions are predominantly seen in preterm infants, are usually linearly organised, and border the lateral ventricles. Isolated punctate lesions may imply a good prognosis, because most of these subjects have a normal neurodevelopmental outcome so far.

[Terminal and pre-terminal chronic renal insufficiency in newborns in French neonatal intensive care units: survey of the French pediatric nephrologic society of resuscitation and emergency]

OBJECTIVES

The aim of this study was to describe the intensive care unit neonatologists' attitudes about a neonate with terminal or pre-terminal renal failure.

METHODS

A questionnaire was sent to all French neonatal intensive care units. Physicians were asked to describe their attitude about neonatal chronic renal failure (Would you agree with dialysis and graft for these children?). Physicians were also presented with two clinical observations involving neonates with varying degrees of renal insufficiency and a complicating comorbidity, including neurological abnormality or socioeconomic circumstances.

RESULTS

Responses were obtained from 92% of the university neonatal care units. The will to take care of a neonate with end-stage renal failure till the renal graft, varied greatly from a centre to another one. Three (9%) university-teams said they had a strong will to bring the baby from the neonatal period to the time of renal graft. Eleven other centres (32%) did not have any will for accompanying the baby till the renal graft. Eight centres (24%) would be rather favourable to the idea of dialysis and graft, and 12 others (35%) would be rather unfavourable.

CONCLUSION

The results of this study show great differences between French neonatologists when they are faced to newborns with end stage renal failure. Ethical, medical and organisational difficulties are matters of controversy. The epidemiological impact of the perinatal discussion could be a 20% variation of all the renal grafts in children.

[Etiologies of cerebral palsy and classical treatment possibilities]

Cerebral palsy is a non-progressive disorder of the developing brain with different etiologies in the pre-, peri- or postnatal period. The most important of these diseases is cystic periventricular leukomalacia (PVL), followed by intra- and periventricular hemorrhage, hypoxic-ischemic encephalopathy, vascular disorders, infections or brain malformations. The underlying cause is always a damage of the first motor neuron. Prevalence of cerebral palsy in Europe is 2-3 per 1000 live births with a broad spectrum in different birth weight groups. Our own data concerning only pre-term infants in the NICU with birth weight below 1500 g (VLBW) are between 10%-20%. Established classical treatment methods include physiotherapy (Bobath, Vojta, Hippotherapy), methods of speech and occupational therapists (Castillo-Morales, Sensory Integration) and other therapeutical concepts (Petö, Affolter, Frostig).

Neonatal cholestasis

Neonatal cholestasis must always be considered in a newborn who is jaundiced for more than 14-21 days and a measurement of the serum total and conjugated bilirubin in these infants is mandatory. Conjugated hyperbilirubinaemia, dark urine and pale stools are pathognomic of the neonatal hepatitis syndrome which should be investigated urgently. The neonatal hepatitis syndrome has many causes and should be investigated using a structured protocol. The most important condition in the differential diagnosis is biliary atresia and affected infants require a Kasai portoenterostomy performed by an experienced surgeon, ideally before the infant is 60 days old. A modified evaluation schedule should be used for preterm infants who have required neonatal intensive care. Genetic causes of the neonatal hepatitis syndrome are increasingly recognized and early diagnosis facilitates genetic counselling and, in some situations, specific treatment. The management of cholestasis is largely supportive, consisting of aggressive nutritional support with particular attention to fat-soluble vitamin status. The use of ursodeoxycholic acid is associated with improvement in biochemical measures of cholestasis and may improve the natural history of cholestasis in some circumstances. Outcome is dependent on aetiology. In idiopathic neonatal hepatitis more than 90% make a complete biochemical and d clinical recovery.

Recent advances in neonatology

This update focuses on recent neonatal research of potential interest to obstetricians. Accurate information on outcomes for infants born at the edges of viability is critical to informing management decisions. New research, population based, gives guidance on short-term survival and long-term neurodevelopmental outcome. Recent research has also highlighted the variation in attitudes to end-of-life decision-making and important influences on this that cross different boundaries. Although research is dominated by issues related to prematurity, some important developments relevant to term infants will be covered. There is accumulating evidence that challenges the traditional approach of using 100% O2 in resuscitation. For infants suffering intrapartum asphyxia there are new approaches to neuroprotection actively being explored. Therapeutic interventions such as extracorporeal membrane oxygenation and inhaled nitric oxide, available for some time, are having their place in neonatal intensive care more clearly defined.

Risk factors for early death among extremely low-birth-weight infants

OBJECTIVE

The purposes of this study were to compare the clinical characteristics of extremely low birth-weight infants (501-1000 g birth weight) who die early (<12 hours of age) with those of infants who die >12 hours after birth and infants who survive to neonatal intensive care unit discharge and to develop a model of risk for early death.

STUDY DESIGN

Perinatal data were prospectively collected on 5986 infants in the 12 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network from March 1993 through December 1997. Maternal and neonatal characteristics of infants who died early were compared with infants who survived and infants who died beyond 12 hours of age. A model for risk for early death was developed by logistic regression analysis, with results expressed as odds ratio with 95% CI.

RESULTS

Mothers of infants who died early were more likely to be delivered in an inborn setting and experience labor and were less likely to have hypertension or preeclampsia, to receive antenatal corticosteroids, or to be delivered by cesarean birth than mothers of infants who died >12 hours after birth or infants who survived. Infants who died early were more likely to have lower Apgar scores and lower gestational age/birth weight and were less likely to be intubated at birth and to receive mechanical ventilation and surfactant therapy than infants who died >12 hours after birth or infants who survived. Greater risk for early death versus survival to neonatal intensive care unit discharge was associated with the lack of surfactant administration (odds ratio, 8.6; 95% CI, 6.3-11.9), lack of delivery room intubation (odds ratio, 5.3; 95% CI, 3.5-8.1), lack of antenatal corticosteroid use (odds ratio, 2.3; 95% CI, 1.6-3.2), lower 1-minute Apgar score (odds ratio, 2.0; 95% CI, 1.8-2.2), male sex (odds ratio, 1.7; 95% CI, 1.3-2.3), multiple gestation (odds ratio, 1.7; 95% CI, 1.2-2.5), no tocolytics (odds ratio, 1.7; 95% CI, 1.2-2.3), lower gestational age per week (odds ratio, 1.4; 95% CI, 1.3-1.6), and lower birth weight per 50 g (95% CI, 1.2-1.4).

CONCLUSION

Early death (<12 hours of age) among extremely low-birth-weight infants may reflect an assessment of non-viability by obstetricians and neonatologists.

Neonatal life support during magnetic resonance imaging

Magnetic resonance techniques are required frequently for the assessment of the brain of ill neonates. In the present study, the effects of a 1.5 T MR scanner on devices for life support were assessed. A ventilator (Dräger Babylog 2000) was tested in the 1.5 T magnet, using a neonatal ventilation tester and 1.5-5 m tubes. In a special MR incubator, temperature and humidity were measured at 1-min intervals. Infusion was tested with the pump outside the magnet room: infusion rates and time to alarm were tested with 7-m tubes. The ventilator performed normally at a magnetic field line of 2 mT, although the alarms failed. The incubator created a temperature of 35.9 degrees C and humidity of 40.7%, which was acceptable for examinations of 45 min. The alarm limits of the infusion pump placed outside the magnet at 7 m were within company limits. The study indicates that magnetic resonance examinations can be performed safely in ill preterm neonates who require life-support devices.

Two-year outcome of normal-birth-weight infants admitted to a Singapore neonatal intensive care unit

INTRODUCTION

To describe the characteristics, the immediate and short-term outcome and predictors of mortality in normal-birth-weight (NBW) infants admitted to a tertiary neonatal intensive care unit (NICU) in Singapore.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 137 consecutive NBW infants admitted to the NICU of the Singapore General Hospital from January 1991 to December 1992. Data on the diagnoses, clinical presentation of illness, intervention received, complications and outcome as well as follow-up patterns for the first 2 years of life, were collected and analysed.

RESULTS

NBW NICU infants comprised 1.8% of births in our hospital and 40.8% of all NICU admissions. The main reasons for NICU admissions were respiratory disorders (61.3%), congenital anomalies (15.3%) and asphyxia neonatorum (11.7%). Respiratory support was necessary in 81.8%. Among those ventilated, the only predictive factor contributing to mortality was the mean inspired oxygen concentration. The mortality rate was 11.7%. Causes of death included congenital anomalies (43.75%), asphyxia neonatorum (31.25%) and pulmonary failure secondary to meconium aspiration syndrome (12.5%). The median hospital stay among survivors (88.3%) was 11.0 (range, 4 to 70) days. Of 42 patients (out of 117 survivors) who received follow-up for at least 6 months, 39 infants did not have evidence of any major neurodevelopmental abnormalities at their last follow-up visit, prior to or at 2 years of age.

CONCLUSIONS

Despite their short hospital stay (compared to very-low-birth-weight infants), the high volume of NBW admissions make the care of this population an important area for review to enhance advances in and hence, reduce the cost of NICU care. With improved antenatal diagnostic techniques (allowing earlier and more accurate diagnosis of congenital malformations) and better antenatal and perinatal care (allowing better management of at-risk pregnancies), it is anticipated that there should be a reduction in such admissions with better outcomes. Close follow-up of this high-risk group of infants is also important in order to offer early intervention to those who may possibly have perinatally-related developmental difficulties.

Ethical issues in neonatal intensive care: perspectives for the neurologist

Intensive medical care for neonates may present medically complex and ethically challenging issues affecting not only patients but also their families and the professionals caring for them. The consulting neurologist working with these infants and their families is frequently a key figure in determining diagnoses and prognoses. This places the neurology specialist at the center of the process by which the treating team provides parents with appropriate information, collaborates with them in making medical and ethical decisions, and supports them through immeasurably difficult times.

The role of bacterial vaginosis in preterm labor and preterm birth: a case-control study

OBJECTIVE

To study the association between preterm labor and bacterial vaginosis; in women with preterm labor, to determine whether vaginosis modifies the risk of preterm delivery.

STUDY DESIGN

Case-control study. We used Amsel's clinical criteria to test 102 patients hospitalized for preterm labor and 102 control patients for bacterial vaginosis.

RESULTS

Patients with preterm labor were diagnosed with bacterial vaginosis significantly more often (13.8%, 95% confidence interval (CI) (7.7-22.0) than control patients (0.0%, 95% CI (0.0-3.6)) (P<0.001). Among the former, the time elapsed to delivery was identical regardless of the patient's bacterial vaginosis status (elapsed time: 35.9 versus 37.1 days, rate of spontaneous preterm birth 42.9 versus 43.2%, not significant).

CONCLUSION

Bacterial vaginosis is associated with preterm labor. Nonetheless, it does not appear to predict preterm birth among these patients.

Bedside functional imaging of the premature infant brain during passive motor activation

BACKGROUND

Changes in regional brain blood flow and hemoglobin oxygen saturation occur in the human cortex in response to neural activation. Traditional functional radiologic methods cannot provide continuous, portable measurements. Imaging methods, which use near-infrared light allow for non-invasive measurements by taking advantage of the fact that hemoglobin is a strong absorber at these wavelengths.

AIMS

To test the feasibility of a new optical functional imaging system in premature infants, and to obtain preliminary brain imaging of passive motor activation in this population.

METHODS

A new optical imaging system, the Diffuse Optical Tomography System (DOTS), was used to provide real-time, bedside assessments. Custom-made soft flexible fiberoptic probes were placed on two extremely ill, mechanically ventilated 24 week premature infants, and three healthier 32 week premature infants. Passive motor stimulation protocols were used during imaging.

RESULTS

Specific movement of the arm resulted in reproducible focal, contralateral changes in cerebral absorption. The data suggest an overall increase in blood volume to the imaged area, as well as an increase in deoxyhemoglobin concentration. These findings in premature infants differ from those expected in adults.

CONCLUSIONS

In the intensive care setting, continuous non-invasive optical functional imaging could be critically important and, with further study, may provide a bedside monitoring tool for prospectively identifying patients at high risk for brain injury.

Patent ductus arteriosus in very low birthweight infants: complications of pharmacological and surgical treatment

AIMS

To evaluate complications of surgical and pharmacological treatment of symptomatic patent ductus arteriosus (PDA) in very low birthweight (VLBW) infants.

PATIENTS AND METHODS

Of 931 VLBW infants consecutively admitted 1987-1998, a significant PDA prompted first-choice treatment by indomethacin in 101 infants, and surgery in 55 infants. PDA closed or became asymptomatic after indomethacin in 64 patients (63%), while 34 went on to surgery. PDA closure was achieved in all 61 infants after ligation and in 26 of 28 infants after clipping.

RESULTS

Transient renal impairment after indomethacin treatment was recorded in 40 of 101 infants (40%), compared to renal impairment in 9 of 55 infants (16%) undergoing surgery without prior indomethacin. No differences in necrotizing enterocolitis and intracranial hemorrhage rates were seen. Air leak occurred in 6 of 89 infants after surgery, two of which had fatal tension pneumothorax. Intraoperative hemorrhage requiring emergency transfusion occurred in 2 infants, wound infection occurred in 2 infants and phrenic palsy in one infant. Based on an intention-to-treat analysis, the overall fatality rates were 16 of 101 (16%) for indomethacin and 14 of 55 (25%) for surgery.

CONCLUSIONS

Despite the short-comings inherent to retrospective analyses, we propose that surgery should be reserved for infants not responding to pharmacological PDA closure.

[Limitation of intensive care and infant death during the postnatal period]

The primary goal of neonatal intensive care is to save the life of all newborns, recognized as a complete human being despite their life-threatening situation. There are situations however where extensive and irreversible brain damage leading to major handicaps is the cost of saving the infant's life. In these extreme situations, where the infant may or may not yet depend totally on life support systems, the physicians in charge are faced with the question of whether medical interruption of the infant's life could be an ethical option. We recall here the main phases of the discussions conducted by french neonatologists faced with these dilemmas and the fundamental principles of current recommendations. Interruption of infant's life in the neonatal unit could be a possible alternative to feticide performed during third trimester termination of pregnancy: in an ethic and coherent medical and human approach, it would be possible to envisage termination of life during the postnatal period in certain specific cases at the request of the parents.

Use of individualized versus standard criteria to identify abnormal levels of heart rate or oxygen saturation in preterm infants

Preterm infants' physiological indicators, such as heart rate, respiratory rate, and oxygen saturation levels, are routinely monitored by devices that can alert nurses to threatening changes in condition. Most Neonatal Intensive Care Units use standard criteria as alerting algorithms to determine when an alert should be issued, and these standard criteria have been adopted uncritically in studies of preterm infants. This article presents results from a study examining preterm infants' physiological responses to a gentle human touch (GHT) intervention in which we compared the use of standard and individualized criteria to define the percentages of abnormally low and high heart rates (HRs) and abnormally low oxygen saturation (O2 sat) levels before, during, and after periods of GHT. Results indicated that there were no differences in the percentages of abnormal HRs or O2 sat values between periods using standard criteria. However, using individualized criteria, there were significantly greater percentages of abnormally low heart rates and O2 sat levels during and after GHT periods as compared to baseline periods. The findings suggest that standard criteria may not be sensitive enough to detect subtle physiological responses to environmental stimuli such as touch. Moreover, consistent with the recognition of the value of individualized developmental care, these results suggest that the clinical effectiveness of individualized criteria for setting monitor alert limits merits further investigation.

[Exposure of nursing personnel to electromagnetic fields in neonatal intensive care]

Electromagnetic fields (EMF) are recognised as a source of environmental pollution for workers and people resident in exposed areas. The level of exposure to EMFs of the nurses working in the Siena Neonatal Intensive Care Unit, during two workdays was recorded and peak levels > 10 mG (1 microT) were registered well above an almost permanence exposure at > 2 mg G. The application of existing standard, cautionary criteria and rules would suggest protective or restrictive measures against EMF exposure for these workers.

Basement membrane biomarkers in very low birth weight premature infants. Association with length of NICU stay and bronchopulmonary dysplasia

Basement membranes, critical for vital organs like the lungs, consist of two interwoven homopolymers, one assembled by type IV collagens and one by laminins. We hypothesized their serum antigens C-IV and P1, respectively, to be global measures for the maturity of these organs. In 39 very low birth weight premature neonates (means: gestational age, 25.8 weeks; birth weight, 779 g) requiring intensive care, we analyzed these biomarkers during the first two months post partum. Median C-IV and P1 exceeded adult levels by one order of magnitude. The individuals with the lowest first week C-IV values (mean: 667 ng/ml) required significantly longer neonatal intensive care unit stays than those with the highest values (mean: 2,467 ng/ml), on average 109 vs. 80 days (p = 0.008) irrespective of gestational age. Patients diagnosed with bronchopulmonary dysplasia (BPD) at 36 weeks postconceptional age, already in their first week of life displayed C-IV levels lower than in controls, suggesting a defect in pulmonary basement membrane remodeling. This is the first identification by a matrix biomarker of a BPD-antecedent state.