Antenatal corticosteroids for fetal lung maturation in threatened preterm delivery: indications and administration

Introduction: Antenatal maternal administration of corticosteroids has been shown to reduce morbidity and mortality rates in preterm delivery. Threatened spontaneous or medically indicated preterm delivery for maternal or fetal indications between 24 and 34weeks of gestation with unknown fetal lung maturity status are indications for antenatal corticosteroid administration. Recent studies have challenged current practice of antenatal glucocorticoid use. The goal of this expert letter is to provide recommendations based for the clinical use of antenatal glucocorticoids based on the current evidence from published studies. Methods: The published literature (PubMed search), as well as the recommendations of other national societies, has been searched and taken into consideration for these recommendations. Results/conclusions: The standard regimen of antenatal corticosteroids involves a single course of 2×12mg betamethasone administered intramuscularly within 24h. The administration of corticosteroids usually is performed between 24 and 34weeks gestation. However, under particular circumstances it may be beneficial even at 23weeks and at 35-36weeks of gestation. The evidence to date is clearly against the routine administration of multiple antenatal steroid courses. In special clinical situations, a second course of betamethasone ("rescue course”) may be justifiable. Tocolysis during administration of steroids is not routinely indicated in the absence of contractions, cervical shortening or rupture of membrane

Prenatal diagnosis and treatment planning of congenital heart defects—possibilities and limits

Background: Newborns with hypoplastic left heart syndrome (HLHS) or right heart syndrome or other malformations with a single ventricle physiology and associated hypoplasia of the great arteries continue to be a challenge in terms of survival. The vast majority of these forms of congenital heart defects relate to abnormal morphogenesis during early intrauterine development and can be diagnosed accurately by fetal echocardiography. Early knowledge of these conditions not only permits a better understanding of the progression of these malformations but encourages some researchers to explore new minimally invasive therapeutic options with a view to early pre- and postnatal cardiac palliation. Data sources: PubMed database was searched with terms of "congenital heart defects”, "fetal echocardiography” and "neonatal cardiac surgery”. Results: At present, early prenatal detection has been applied for monitoring pregnancy to avoid intrauterine cardiac decompensation. In principle, the majority of congenital heart defects can be diagnosed by prenatal echocardiography and the detection rate is 85%-95% at tertiary perinatal centers. The majority, particularly of complex congenital lesions, show a steadily progressive course including subsequent secondary phenomena such as arrhythmias or myocardial insufficiency. So prenatal treatment of an abnormal fetus is an area of perinatal medicine that is undergoing a very dynamic development. Early postnatal treatment is established for some time, and prenatal intervention or palliation is at its best experimental stage in individual cases. Conclusion: The upcoming expansion of fetal cardiac intervention to ameliorate critically progressive fetal lesions intensifies the need to address issues about the adequacy of technological assessment and patient selection as well as the morbidity of those who undergo these procedure

Lung Volume, Breathing Pattern and Ventilation Inhomogeneity in Preterm and Term Infants

BACKGROUND: Morphological changes in preterm infants with bronchopulmonary dysplasia (BPD) have functional consequences on lung volume, ventilation inhomogeneity and respiratory mechanics. Although some studies have shown lower lung volumes and increased ventilation inhomogeneity in BPD infants, conflicting results exist possibly due to differences in sedation and measurement techniques. METHODOLOGY/PRINCIPAL FINDINGS: We studied 127 infants with BPD, 58 preterm infants without BPD and 239 healthy term-born infants, at a matched post-conceptional age of 44 weeks during quiet natural sleep according to ATS/ERS standards. Lung function parameters measured were functional residual capacity (FRC) and ventilation inhomogeneity by multiple breath washout as well as tidal breathing parameters. Preterm infants with BPD had only marginally lower FRC (21.4 mL/kg) than preterm infants without BPD (23.4 mL/kg) and term-born infants (22.6 mL/kg), though there was no trend with disease severity. They also showed higher respiratory rates and lower ratios of time to peak expiratory flow and expiratory time (t(PTEF)/t(E)) than healthy preterm and term controls. These changes were related to disease severity. No differences were found for ventilation inhomogeneity. CONCLUSIONS: Our results suggest that preterm infants with BPD have a high capacity to maintain functional lung volume during natural sleep. The alterations in breathing pattern with disease severity may reflect presence of adaptive mechanisms to cope with the disease process

Nebulizing poractant alfa versus conventional instillation: Ultrastructural appearance and preservation of surface activity.

BACKGROUND Nebulized surfactant therapy has been proposed as an alternative method of surfactant administration. The use of a perforated vibrating membrane nebulizer provides a variety of advantages over conventional nebulizers. We investigated the molecular structure and integrity of poractant alfa pre- and post-nebulization. METHOD Curosurf® was nebulized using an Investigational eFlow® Nebulizer System. Non-nebulized surfactant ("NN"), recollected surfactant droplets from nebulization through an endotracheal tube ("NT") and nebulization of surfactant directly onto a surface ("ND") were investigated by transmission electron microscopy. Biophysical characteristics were assessed by the Langmuir-Wilhelmy balance and the Captive Bubble Surfactometer. RESULTS Volume densities of lamellar body-like forms (LBL) and multi-lamellar forms (ML) were high for "NN" and "NT" samples (38.8% vs. 47.7% for LBL and 58.2% vs. 47.8% for ML). In the "ND" sample, we found virtually no LBL's, ML's (72.6%) as well as uni-lamellar forms (16.4%) and a new structure, the "garland-like" forms (9.4%). Surface tension for "NN" and "NT" was 23.33 ± 0.29 and 25.77 ± 1.12 mN/m, respectively. Dynamic compression-expansion cycling minimum surface tensions were between 0.91 and 1.77 mN/m. CONCLUSION The similarity of surfactant characteristics of nebulized surfactant via a tube and the non-nebulized surfactant suggests that vibrating membrane nebulizers are suitable for surfactant nebulization. Alterations in surfactant morphology and characteristics after nebulization were transient. A new structural subtype of surfactant was identified. Pediatr Pulmonol. 2014; 49:348-356. © 2013 Wiley Periodicals, Inc

Antenatal corticosteroids for fetal lung maturation in threatened preterm delivery: indications and administration

Antenatal maternal administration of corticosteroids has been shown to reduce morbidity and mortality rates in preterm delivery. Threatened spontaneous or medically indicated preterm delivery for maternal or fetal indications between 24 and 34 weeks of gestation with unknown fetal lung maturity status are indications for antenatal corticosteroid administration. Recent studies have challenged current practice of antenatal glucocorticoid use. The goal of this expert letter is to provide recommendations based for the clinical use of antenatal glucocorticoids based on the current evidence from published studies

Length Normalized Indices for Fat Mass and Fat-Free Mass in Preterm and Term Infants during the First Six Months of Life.

OBJECTIVE Postnatal tissue accretion in preterm infants differs from those in utero, affecting body composition (BC) and lifelong morbidity. Length normalized BC data allows infants with different body lengths to be compared and followed longitudinally. This study aims to analyze BC of preterm and term infants during the first six months of life. METHODS The BC data, measured using dual energy X-ray absorptiometry, of 389 preterm and 132 term infants from four longitudinal studies were combined. Fat-mass/length² (FMI) and fat-free mass/length² (FFMI) for postmenstrual age were calculated after reaching full enteral feeding, at term and two further time points up to six months corrected age. RESULTS Median FMI (preterm) increased from 0.4 kg/m² at 30 weeks to 2.5, 4.3, and 4.8 kg/m² compared to 1.7, 4.7, and 6 kg/m² in term infants at 40, 52, and 64 weeks, respectively. Median FFMI (preterm) increased from 8.5 kg/m² (30 weeks) to 11.4 kg/m² (45 weeks) and remained constant thereafter, whereas term FFMI remained constant at 11 kg/m² throughout the tested time points. CONCLUSION The study provides a large dataset of length normalized BC indices. Followed longitudinally, term and preterm infants differ considerably during early infancy in the pattern of change in FMI and FFMI for age

dd+ - A new dendro software for large data sets and for institutions with archives

Most dendro software packages lack features that are of great importance to long-standing dendro-institutions with large numbers of samples in their archives and with numerous datasets on their hard drives. Among these essential features are (i) context information and metadata for each sample and measurement, (ii) detailed information on the structure and content of every mean curve, (iii) data consistency, (iv) the definition of subsamples as dynamic or static, (v) ability to crossdate using thousands of measurements, (vi) provide output tables for external use such as GIS-systems, (vii) defining roles and rights for different users, (viii) provide flexible vector graphic export options; and several others. The new software dd+ covers all these issues. However, it is not meant as an all-in-one software for dendro studies. Many numeric analyses are better done in R. It rather aims at providing stability, transparency and consistency for large datasets together with high performance crossdating tools. dd+ is a Microsoft server SQL database with in-built dendro features. A SQL querybuilder allows to define subsets and groups based on a wealth of attributes. These groups can be saved either as dynamic or static list and form the base for browser based management, editing, correlation or the production of database-tables for external use such as GIS. There are two browsers for wood samples and two for mean curves, all of which can be used independently by applying SQL queries or manually picking samples and mean curves. Calculation procedures are optimised for large datasets. Crossdating 851 vs 1204 series in all possible synchronous positions takes less than 3 min. Crossdating is assisted by direct visual presentation of individual pairs which can be set to visible or hidden. dd+ enforces data consistency by checking your crossdating decisions. Mean curve construction and dating is only possible if all single crossdating positions are consistent. By now, dd+ uses the Heidelberg-format and excel-files for import and export. Knowing about the weaknesses of these formats, they seem helpful for overcoming the many problems of backward-digitalisation. Once data are entered, the data model opens new 212 possibilities. Future development aims at a xml format for data exchange. The latest version 2.6 covers an csv-export in long format for import into R. Meanwhile, the standardisation of meta data aids in the exchange between labs. Taking part: dd+ is not open source, but it aims at an open data policy and common data standards. It has been programmed by professionals in cooperation with the Zurich lab. It comes without licensing fees, but it is not free of costs: Whoever wants to use dd+, joins the user community "ArGe dd+" by a contract. All users share the costs of support by a fixed amount per year. The community decides by simple majority on further development and improvement projects and the costs are shared. For the moment, dd+ has a focus on managing samples from historical and archaeological contexts. Future versions will add ecological aspects. If you are interested in dd+, please contact [email protected]