Population based trends in mortality, morbidity and treatment for very preterm- and very low birth weight infants over 12 years

BACKGROUND: Over the last two decades, improvements in medical care have been associated with a significant increase and better outcome of very preterm (VP, < 32 completed gestational weeks) and very low birth weight (VLBW, < 1500 g) infants. Only a few publications analyse changes of their short-term outcome in a geographically defined area over more than 10 years. We therefore aimed to investigate the net change of VP- and VLBW infants leaving the hospital without major complications. METHODS: Our population-based observational cohort study used the Minimal Neonatal Data Set, a database maintained by the Swiss Society of Neonatology including information of all VP- and VLBW infants. Perinatal characteristics, mortality and morbidity rates and the survival free of major complications were analysed and their temporal trends evaluated. RESULTS: In 1996, 2000, 2004, and 2008, a total number of 3090 infants were enrolled in the Network Database. At the same time the rate of VP- and VLBW neonates increased significantly from 0.87% in 1996 to 1.10% in 2008 (p < 0.001). The overall mortality remained stable by 13%, but the survival free of major complications increased from 66.9% to 71.7% (p < 0.01). The percentage of infants getting a full course of antenatal corticosteroids increased from 67.7% in 1996 to 91.4% in 2008 (p < 0.001). Surfactant was given more frequently (24.8% in 1996 compared to 40.1% in 2008, p < 0.001) and the frequency of mechanical ventilation remained stable by about 43%. However, the use of CPAP therapy increased considerably from 43% to 73.2% (p < 0.001). Some of the typical neonatal pathologies like bronchopulmonary dysplasia, necrotising enterocolitis and intraventricular haemorrhage decreased significantly (p ≤ 0.02) whereas others like patent ductus arteriosus and respiratory distress syndrome increased (p < 0.001). CONCLUSIONS: Over the 12-year observation period, the number of VP- and VLBW infants increased significantly. An unchanged overall mortality rate and an increase of survivors free of major complication resulted in a considerable net gain in infants with potentially good outcome

Multimodel assessment of the upper troposphere and lower stratosphere: Tropics and global trends

The performance of 18 coupled Chemistry Climate Models (CCMs) in the Tropical Tropopause Layer (TTL) is evaluated using qualitative and quantitative diagnostics. Trends in tropopause quantities in the tropics and the extratropical Upper Troposphere and Lower Stratosphere (UTLS) are analyzed. A quantitative grading methodology for evaluating CCMs is extended to include variability and used to develop four different grades for tropical tropopause temperature and pressure, water vapor and ozone. Four of the 18 models and the multi-model mean meet quantitative and qualitative standards for reproducing key processes in the TTL. Several diagnostics are performed on a subset of the models analyzing the Tropopause Inversion Layer (TIL), Lagrangian cold point and TTL transit time. Historical decreases in tropical tropopause pressure and decreases in water vapor are simulated, lending confidence to future projections. The models simulate continued decreases in tropopause pressure in the 21st century, along with ∼1K increases per century in cold point tropopause temperature and 0.5–1 ppmv per century increases in water vapor above the tropical tropopause. TTL water vapor increases below the cold point. In two models, these trends are associated with 35% increases in TTL cloud fraction. These changes indicate significant perturbations to TTL processes, specifically to deep convective heating and humidity transport. Ozone in the extratropical lowermost stratosphere has significant and hemispheric asymmetric trends. O3 is projected to increase by nearly 30% due to ozone recovery in the Southern Hemisphere (SH) and due to enhancements in the stratospheric circulation. These UTLS ozone trends may have significant effects in the TTL and the troposphere

Stratospheric ozone and surface ultraviolet

As a result of the Montreal Protocol, ozone is expected to recover from the effect of ozone-depleting substances (ODSs) as their abundances decline in the coming decades. The 2006 Assessment showed that globally averaged column ozone ceased to decline around 1996, meeting the criterion for the first stage of recovery. Ozone is expected to increase as a result of continued decrease in ODSs (second stage of recovery). This chapter discusses recent observations of ozone and ultraviolet radiation in the context of their historical records. Natural variability, observational uncertainty, and stratospheric cooling necessitate a long record in order to attribute an ozone increase to decreases in ODSs. Table S2-1 summarizes ozone changes since 1980. The primary tools used in this Assessment for prediction of ozone are chemistry-climate models (CCMs). These CCMs are designed to represent the processes determining the amount of stratospheric ozone and its response to changes in ODSs and greenhouse gases. Eighteen CCMs have been recently evaluated using a variety of process-based comparisons to measurements. The CCMs are further evaluated here by comparison of trends calculated from measurements with trends calculated from simulations designed to reproduce ozone behavior during an observing period.Fil: Douglass, Anne R.. No especifíca;Fil: Fioletov, Vitali E.. No especifíca;Fil: Godin Beekmann, Sophie. No especifíca;Fil: Müller, Rolf. No especifíca;Fil: Stolarski, Richard S.. No especifíca;Fil: Webb, Ann R.. No especifíca;Fil: Arola, Antti. No especifíca;Fil: Burkholder, James B.. No especifíca;Fil: Burrows, John P.. No especifíca;Fil: Chipperfield, Martyn P.. No especifíca;Fil: Cordero, Raul. No especifíca;Fil: David, Christine. No especifíca;Fil: den Outer, Peter N.. No especifíca;Fil: Diaz, Susana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Flynn, Lawrence E.. No especifíca;Fil: Hegglin,Michaela I.. No especifíca;Fil: Herman, Jay R. No especifíca;Fil: Huck, Petra. No especifíca;Fil: Janjai, Serm. No especifíca;Fil: Jánosi, Imre M. No especifíca;Fil: Krzyścin, Janusz W. No especifíca;Fil: Liu, Yi. No especifíca;Fil: Logan, Jennifer. No especifíca;Fil: Matthes, Katja. No especifíca;Fil: McKenzie, Richard L.. No especifíca;Fil: Muthama, Nzioka John. No especifíca;Fil: Petropavlovskikh, Irina. No especifíca;Fil: Pitts, Michael. No especifíca;Fil: Ramachandran, S.. No especifíca;Fil: Rex, Markus. No especifíca;Fil: Salawitch, Ross J.. No especifíca;Fil: Sinnhuber, Björn Martin. No especifíca;Fil: Staehelin, Johannes. No especifíca;Fil: Strahan, Susan. No especifíca;Fil: Tourpali, Kleareti. No especifíca;Fil: Valverde Canossa, Jéssica. No especifíca;Fil: Vigouroux, Corinne. No especifíca