Pediatric admissions that include intensive care: a population-based study

Background Pediatric admissions to intensive care outside children’s hospitals are generally excluded from registry-based studies. This study compares pediatric admission to specialist pediatric intensive care units (PICU) with pediatric admissions to intensive care units (ICU) in general hospitals in an Australian population. Methods We undertook a population-based record linkage cohort study utilizing longitudinally-linked hospital and death data for pediatric hospitalization from New South Wales, Australia, 2010-2013. The study population included all new pediatric, post-neonatal hospital admissions that included time in ICU (excluding neonatal ICU). Results Of 498,466 pediatric hospitalizations, 7,525 (1.5%) included time in an intensive care unit – 93.7% to PICU and 6.3% to ICU in a general (non-PICU) hospital. Non-PICU admissions were of older children, in rural areas, with shorter stays in ICU, more likely admitted for acute conditions such as asthma, injury or diabetes, and less likely to have chronic conditions, receive continuous ventilatory support, blood transfusion, parenteral nutrition or die. Conclusions A substantial proportion of children are admitted to ICUs in general hospitals. A comprehensive overview of pediatric ICU admissions includes these admissions and the context of the total hospitalization.NHMRC, NSW Mo

Modeling Oxygen Uptake during V1 Treadmill Roller Skiing

The use of regression equations to predict oxygen uptake in relation to speed, grade, power output, and anthropometric characteristics is common in cardiac rehabilitation and athlete fitness testing. Research has suggested that sport specific testing improves the reliability of the test methodology and is appropriate for the development of effective training programs. This study focused on the development of a cross-country skiing specific predictor of maximal oxygen uptake based on treadmill speed, treadmill grade, gender, and body mass. This project simulated snow skiing on a large research treadmill using roller skis. A small sample size (N = 34) warranted the use of bootstrapping techniques and multiple regression analysis to develop a cross-country skiing specific model of oxygen uptake. The stability of each bootstrapped sample was confirmed via a cross-validation procedure. The equation of best resolve was: VO2 = -4.534 + 0.223(G) + 0.061(BM) + 0.139(TG) + 0.016(TS) in which G = Gender, BM = Body Mass, TG = Treadmill Grade, TS = Treadmill Speed. The resultant model can be used to design training programs, develop athlete fitness testing or research protocols, and to predict maximal oxygen uptake when sophisticated metabolic measurement equipment is unavailable

Nitrogen substrate–dependent nitrous oxide cycling in salt marsh sediments

Nitrous oxide (N2O) is important to Earth\u27s climate because it is a strong absorber of radiation and an important ozone depletion agent. Increasing anthropogenic nitrogen input into the marine environment, especially to coastal waters, has led to increasing N2O emissions. Identifying the nitrogen compounds that serve as substrates for N2O production in coastal waters reveals important pathways and helps us understand their control by environmental factors. In this study, sediments were collected from a long-term fertilization site in Great Sippewissett Marsh, Falmouth, Massachusetts. The 15N tracer incubation time course experiments were conducted and analyzed for potential N2O production and consumption rates. The two nitrogen substrates of N2O production, ammonium and nitrate, correspond to the two production pathways, nitrification and denitrification, respectively. When measurable nitrate was present, despite ambient high ammonium concentrations, denitrification was the major N2O production pathway. When nitrate was absent, ammonium became the dominant substrate for N2O production, via nitrification and coupled nitrification-denitrification. Net N2O consumption was enhanced under low oxygen and nitrate conditions. N2O production and consumption rates increased with increasing levels of nitrogen fertilization in long-term experimental plots. These results indicate that increasing anthropogenic nitrogen input to salt marshes can stimulate sedimentary N2O production via both nitrification and denitrification, whereas episodic oxygen depletion results in net N2O consumption

Trends in use of neonatal CPAP: a population-based study

<p>Abstract</p> <p>Background</p> <p>Continuous positive airway pressure (CPAP) is used widely to provide respiratory support for neonates, and is often the first treatment choice in tertiary centres. Recent trials have demonstrated that CPAP reduces need for intubation and ventilation for infants born at 25-28 weeks gestation, and at > 32weeks, in non-tertiary hospitals, CPAP reduces need for transfer to NICU. The aim of this study was to examine recent population trends in the use of neonatal continuous positive airway pressure.</p> <p>Methods</p> <p>We undertook a population-based cohort study of all 696,816 liveborn neonates ≥24 weeks gestation in New South Wales (NSW) Australia, 2001-2008. Data were obtained from linked birth and hospitalizations records, including neonatal transfers. The primary outcome was CPAP without mechanical ventilation (via endotracheal intubation) between birth and discharge from the hospital system. Analyses were stratified by age ≤32 and > 32 weeks gestation.</p> <p>Results</p> <p>Neonates receiving any ventilatory support increased from 1,480 (17.9/1000) in 2001 to 2,486 (26.9/1000) in 2008, including 461 (5.6/1000) to 1,465 (15.8/1000) neonates who received CPAP alone. There was a concurrent decrease in mechanical ventilation use from 12.3 to 11.0/1000. The increase in CPAP use was greater among neonates > 32 weeks (from 3.2 to 11.8/1000) compared with neonates ≤32 weeks (from 18.1 to 32.7/1000). The proportion of CPAP > 32 weeks initiated in non-tertiary hospitals increased from 6% to 30%.</p> <p>Conclusions</p> <p>The use of neonatal CPAP is increasing, especially > 32 weeks gestation and among non-tertiary hospitals. Recommendations are required regarding which infants should be considered for CPAP, resources necessary for a unit to offer CPAP and monitoring of longer term outcomes.</p

Prelabor cesarean delivery for twin pregnancies close to term is associated with reduced mortality

Objectives: To examine short and longer term outcomes for twins born at or near term, comparing prelabor cesarean delivery (CD) to birth after trial of labor. Methods: A retrospective cohort of twin pregnancies delivered ≥ 36 weeks gestation from 2000 to 2009. Pregnancies with an antenatal death, lethal anomaly, birthweight discordance ≥25% or birthweight 4000 grams were excluded. Outcomes included severe hypoxia, stillbirth and neonatal death, and hospital admissions or death during the first 5 years of life. Results: 45.3% of 7099 twin pregnancies were delivered by prelabor CD. Compared to delivery after labor, prelabor CD was associated with significantly reduced risks of adverse infant outcomes including severe birth hypoxia (0.08% vs. 0.75%, RR 0.10, 95% CI 0.04-0.26), neonatal death (0.00% vs. 0.15%, RR 0.05, 95% CI 0.00-0.82), and death up to 5 years of age (0.16% vs. 0.40%, RR 0.41, 95% CI 0.20-0.85). Whereas total mortality for first twins was similar after labor (0.15%) compared to prelabor CD (0.16%), total mortality was four times more common in second twins born after labor (0.64%) compared to second twins born after prelabor CD (0.16%). Conclusions: Twin pregnancies at and beyond 36 weeks who are delivered after labor have increased risks for birth outcomes associated with hypoxia. These risks do not result in increased mortality in the first twin, but second twins have significantly increased mortality up to 5 years of age. However, the absolute mortality rate for relatively uncomplicated twin pregnancies born at or near term is low.The New South Wales (NSW) Ministry of Health provided access to the population health data and the NSW Centre for Health Record Linkage linked the data sets. This work was supported by an Australian National Health and Medical Research Council (NHMRC) Centre for Research Excellence Grant (1001066). CLR is supported by a NHMRC Senior Research Fellowship (#APP1021025)

Hospitalisations from one to six years of age: Effects of Gestational Age and Severe Neonatal Morbidity

Background: To investigate whether the adverse infant health outcomes associated with early birth and severe neonatal morbidity (SNM) persist beyond the first year of life and impact on paediatric hospitalisations for children up to six years of age. Methods: The study population included all singleton live births, >32 weeks gestation in New South Wales, Australia in 2001-2005, with follow-up to six years of age. Birth data were probabilistically linked to hospitalisation data (n=392,964). The odds of hospitalisation, mean hospital length of stay (LOS) and costs, and cumulative LOS were evaluated by gestational age and SNM using multivariable analyses. Results: A total of 74,341 (18.9%) and 41,404 (10.5%) infants were hospitalized once and more than once, respectively. SNM was associated with increased odds of hospitalisation once (adjusted odds ratio (aOR) 1.16 [95% CI 1.10, 1.22]), and more than once (aOR 1.51 [1.42, 1.60]). Decreasing gestational age was associated with increasing odds of hospitalisation more than once from aOR 1.19 at 37-38 weeks to 1.49 at 33-34 weeks. Average LOS and costs per hospital admission were increased with SNM but not with decreasing gestational age. Cumulative LOS was significantly increased with SNM and decreasing gestational age. Conclusions: Adverse effects of SNM and early birth persist between one and six years of age. Strategies to prevent early birth and reduce SNM, and to increase health monitoring of vulnerable infants throughout childhood may help reduce paediatric hospitalisations.NHMRC, NSW Health Population Health and Health Services Gran

Red cell and platelet transfusions in neonates: a population based study

Objectives: Reports of neonatal transfusion practices have focused predominantly on premature neonates admitted to neonatal intensive care units (NICU), however little is known about transfusion among other neonates. This study aimed to describe the use of blood products among all neonates. Design: Linked population-based birth and hospital discharge data from New South Wales (NSW), Australia was used to determine rates of blood product transfusion in the first 28 days of life. The study included all livebirths ≥23 weeks’ gestation in NSW between 2001 and 2011. Results: Between 2001-2011, 5326 of 989,491 live born neonates received a blood product transfusion (5.4 per 1000 births). Transfusion rates were 4.8 per 1000 for red cells, 1.3 per 1000 for platelets and 0.3 per 1000 for exchange transfusion. High transfusion rates were seen in neonates with prior in-utero transfusion (631/1000), congenital anomaly requiring surgery (440/1000) or haemolytic disorder (106/1000). Among transfused infants, 7% received transfusions in a hospital without a NICU. Of those transfused, 64% were born ≤32 weeks gestation (n=3384, 255/1000 births), with 96% of these receiving red cells. 36% were born >32 weeks gestation (n= 1942, 1.98/1000 births), with 76% receiving red cells and 38% receiving platelets. Conclusions: In this population based study, high transfusion rates were seen in neonates with haemolytic disorders or requiring surgery, as well as in those born preterm. Thirty-six percent of neonates who received blood products were born >32 weeks gestation and 7% were transfused in hospitals without a NICU.NHMRC, AR

Long-term fertilization alters the relative importance of nitrate reduction pathways in salt marsh sediments

Salt marshes provide numerous valuable ecological services. In particular, nitrogen (N) removal in salt marsh sediments alleviates N loading to the coastal ocean. N removal reduces the threat of eutrophication caused by increased N inputs from anthropogenic sources. It is unclear, however, whether chronic nutrient over-enrichment alters the capacity of salt marshes to remove anthropogenic N. To assess the effect of nutrient enrichment on N cycling in salt marsh sediments, we examined important N cycle pathways in experimental fertilization plots in a New England salt marsh. We determined rates of nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA) using sediment slurry incubations with 15 N labeled ammonium or nitrate tracers under oxic headspace (20% oxygen / 80% helium). Nitrification and denitrification rates were more than ten-fold higher in fertilized plots compared to control plots. By contrast, DNRA, which retains N in the system, was high in control plots but not detected in fertilized plots. The relative contribution of DNRA to total nitrate reduction largely depends on the carbon/nitrate ratio in the sediment. These results suggest that long-term fertilization shifts N cycling in salt marsh sediments from predominantly retention to removal. Long-term fertilization alters the relative importance of nitrate reduction pathways in salt marsh sediments: NO 3 - reduction in salt marsh sediments (PDF Download Available). Available from: https://www.researchgate.net/publication/305480944_Long-term_fertilization_alters_the_relative_importance_of_nitrate_reduction_pathways_in_salt_marsh_sediments_NO_3_-_reduction_in_salt_marsh_sediments [accessed Jun 6, 2017]

Nutrient enrichment induces dormancy and decreases diversity of active bacteria in salt marsh sediments

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 7 (2016): 12881, doi:10.1038/ncomms12881.Microorganisms control key biogeochemical pathways, thus changes in microbial diversity, community structure and activity can affect ecosystem response to environmental drivers. Understanding factors that control the proportion of active microbes in the environment and how they vary when perturbed is critical to anticipating ecosystem response to global change. Increasing supplies of anthropogenic nitrogen to ecosystems globally makes it imperative that we understand how nutrient supply alters active microbial communities. Here we show that nitrogen additions to salt marshes cause a shift in the active microbial community despite no change in the total community. The active community shift causes the proportion of dormant microbial taxa to double, from 45 to 90%, and induces diversity loss in the active portion of the community. Our results suggest that perturbations to salt marshes can drastically alter active microbial communities, however these communities may remain resilient by protecting total diversity through increased dormancy

NLOAD: An interactive, web-based modelling tool for nitrogen management in estuaries

Abstract. Eutrophication of estuaries is an increasing global concern that requires development of new tools to identify causes, quantify conditions, and propose management options that address this environmental problem. Since eutrophication is often associated with increased inputs of land-derived nitrogen to estuaries, we developed NLOAD, a user-friendly, web-based tool that brings together six different published models that predict nitrogen loading to estuaries and two models that estimate nitrogen concentrations in coastal waters. Here we describe each of the models, demonstrate how NLOAD is designed to function, and then use the models in NLOAD to predict nitrogen loads to Barnegat Bay, New Jersey (USA). The four models that we used to estimate nitrogen loads to Barnegat Bay, when adjusted, all had similar results that matched well with measured values and indicated that Barnegat Bay receives roughly 26 kg NÁha . Atmospheric deposition was the dominant source of nitrogen to Barnegat Bay, followed by fertilizer nitrogen. Wastewater in Barnegat Bay is diverted to an offshore outfall and contributes no nitrogen to the system. The NLOAD tool has an additional feature that allows managers to assess the effectiveness of a variety of management options to reduce nitrogen loads. We demonstrate this feature of NLOAD through simulations in which fertilizer inputs to the Barnegat Bay watershed are reduced. Even modest cutbacks in the use of fertilizers on agricultural fields and lawns can be shown to reduce the amount of N entering Barnegat Bay