Atmospheric Carbon and Transport - America (ACT-America) Data Sets: Description, Management, and Delivery

The ACT-America project is a NASA Earth Venture Suborbital-2 mission designed to study the transport and fluxes of greenhouse gases. The open and freely available ACT-America data sets provide airborne in situ measurements of atmospheric carbon dioxide, methane, trace gases, aerosols, clouds, and meteorological properties, airborne remote sensing measurements of aerosol backscatter, atmospheric boundary layer height and columnar content of atmospheric carbon dioxide, tower-based measurements, and modeled atmospheric mole fractions and regional carbon fluxes of greenhouse gases over the Central and Eastern United States. We conducted 121 research flights during five campaigns in four seasons during 2016-2019 over three regions of the US (Mid-Atlantic, Midwest and South) using two NASA research aircraft (B-200 and C-130). We performed three flight patterns (fair weather, frontal crossings, and OCO-2 underflights) and collected more than 1,140 h of airborne measurements via level-leg flights in the atmospheric boundary layer, lower, and upper free troposphere and vertical profiles spanning these altitudes. We also merged various airborne in situ measurements onto a common standard sampling interval, which brings coherence to the data, creates geolocated data products, and makes it much easier for the users to perform holistic analysis of the ACT-America data products. Here, we report on detailed information of data sets collected, the workflow for data sets including storage and processing of the quality controlled and quality assured harmonized observations, and their archival and formatting for users. Finally, we provide some important information on the dissemination of data products including metadata and highlights of applications of ACT-America data sets.

Treatment of asphyxiated newborns with moderate hypothermia in routine clinical practice: how cooling is managed in the UK outside a clinical trial

BACKGROUND

This is a phase 4 study of infants registered with the UK TOBY Cooling Register from December 2006 to February 2008. The registry was established on completion of enrolLment to the TOBY randomised trial of treatment with whole body hypothermia following perinatal asphyxia at the end of November 2006.

METHODS

We collected information about patient characteristics, condition at birth, resuscitation details, severity of encephalopathy, hourly temperature record, clinical complications and outcomes before hospital discharge.

RESULTS

120 infants born at a median of 40 (IQR 38-41) weeks' gestation and weighing a median of 3287 (IQR 2895-3710) g at birth were studied. Cooling was started at a median of 3 h 54 min (IQR 2 h-5 h 32 min) after birth. All but three infants underwent whole body cooling. The mean (SD) rectal temperature from 6 to 72 h of the cooling period was 33.57 degrees C (0.51 degrees C). The daily encephalopathy score fell: median (IQR) 11 (6-15), 9.7 (5-14), 8 (5-13) and 7 (2-12) on days 1-4 after birth, respectively. 51% of the infants established full oral feeding at a median (range) of 9 (4-24) days. 26% of the study infants died. MRI was consistent with hypoxia-ischaemia in most cases. Clinical complications were not considered to be due to hypothermia.

CONCLUSION

In the UK, therapeutic hypothermia following perinatal asphyxia is increasingly being provided. The target body temperature is successfully achieved and the clinical complications observed were not attributed to hypothermia. Treatment with hypothermia may have prevented the worsening of the encephalopathy that is commonly observed following asphyxia.

Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a serious and common problem among very low birth weight infants despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Due to their anti-inflammatory properties, corticosteroids have been widely used to treat or prevent CLD. However, the use of systemic steroids has been associated with serious short and long-term adverse effects. Administration of corticosteroids topically through the respiratory tract might result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To determine the effect of inhaled versus systemic corticosteroids administered to ventilator dependent preterm neonates with birth weight < 1500 g or gestational age < 32 weeks after two weeks of life for the treatment of evolving CLD.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2007), MEDLINE (1966 - June 2007), EMBASE (1980 - June 2007), CINAHL (1982 - June 2007), reference lists of published trials and abstracts published in Pediatric Research or electronically on the Pediatric Academic Societies website (1990 - April 2007).

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing inhaled versus systemic corticosteroid therapy (irrespective of the dose and duration of therapy) starting after the first two weeks of life in ventilator dependent very low birth weight preterm infants.

DATA COLLECTION AND ANALYSIS

Data were extracted regarding clinical outcomes including CLD at 28 days or 36 weeks postmenstrual age (PMA), mortality, combined outcome of death or CLD at 28 days of age or 36 weeks PMA, other pulmonary outcomes and adverse effects. All data were analyzed using RevMan 4.2.10. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was statistically significant, the number needed to treat (NNT) was calculated.

MAIN RESULTS

Data from one additional trial were available for inclusion in this update. Thus, five trials comparing inhaled versus systemic corticosteroids in the treatment of CLD were identified. Two trials were excluded as both included non-ventilator dependent patients and three trials qualified for inclusion in this review. Halliday et al (Halliday 2001) randomized infants at < 72 hours, while Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) randomized at 12 - 21 days. The data from the two trials of Rozycki et al and Suchmoski et al are combined using meta-analytic techniques. The data from the trial by Halliday et al are reported separately, as outcomes were measured over different time periods from the age at randomization. In none of the trials was there a statistically significant difference between the groups in the incidence of CLD at 36 weeks PMA among all randomized infants. The estimates for the trial by Halliday et al (Halliday 2001) were RR 1.10 (95% CI 0.82, 1.47), RD 0.03 (95% CI -0.08, 0.15); number of infants (n = 292). For the trials by Rozycki et al (Rozycki 2003) and Suchomski et al (Suchomski 2002) the typical RR was 1.02 (95% CI 0.83, 1.25) and the typical RD 0.01 (95% CI -0.11, 0.14); (number of infants = 139 ). There were no statistically significant differences between the groups in either trial for oxygen dependency at 28 days of age, death by 28 days or 36 weeks PMA, the combined outcome of death by or CLD at 28 days or 36 weeks PMA, duration of intubation, duration of oxygen dependence, or adverse effects. Information on the long-term neurodevelopmental outcomes was not available.

AUTHORS' CONCLUSIONS

This review found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator dependent preterm infants. Neither inhaled steroids nor systemic steroids can be recommended as standard treatment for ventilated preterm infants. There was no evidence of difference in effectiveness or side-effect profiles for inhaled versus systemic steroids. A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing side-effects. To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. The long-term effects of inhaled steroids, with particular attention to neurodevelopmental outcome, should be addressed in future studies.

Inhaled versus systemic corticosteroids for preventing chronic lung disease in ventilated very low birth weight preterm neonates

BACKGROUND

Chronic lung disease (CLD) remains an important cause of mortality and morbidity in preterm infants despite the administration of antenatal corticosteroids, surfactant replacement therapy and other advances in neonatal intensive care. There is increasing evidence from cellular and biochemical research that inflammation plays an important role in the pathogenesis of CLD. Thus, interventions aimed at reducing or modulating the inflammatory process may reduce the incidence or severity of CLD. Theoretically, the use of inhaled corticosteroids may allow for beneficial effects on the pulmonary system without concomitant high systemic concentrations and less risk of adverse effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids, started within the first two weeks of life, in preventing CLD in ventilated very low birth weight infants.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1980 - September 2002), CINAHL (1982 - September 2002), reference lists of published trials and abstracts published in Pediatric Research (1990 - April 2002) from the Society of Pediatric Research/ Pediatric Academic Society's annual meetings.

SELECTION CRITERIA

Randomized or quasi-randomized clinical trials comparing inhaled versus systemic corticosteroid therapy (regardless of the dose and duration of therapy), started in first two weeks of life in very low birth weight preterm infants receiving assisted ventilation.

DATA COLLECTION AND ANALYSIS

Data regarding clinical outcomes including CLD at 28 days or 36 weeks corrected gestational age (CGA), mortality, combined outcome of death or CLD at 28 days or 36 weeks CGA, other pulmonary outcomes and adverse effects were evaluated. All data were analyzed using RevMan 4.1. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was significant, number needed to treat (NNT) or number needed to harm (NNH) was calculated.

MAIN RESULTS

Two trials qualified for inclusion in this review. There was an increase in the incidence of CLD at 36 weeks CGA in the inhaled steroid group amongst all randomized infants, which was of borderline statistical significance: [RR 1.45 (95% CI 0.99, 2.11); RD 0.11 (95% CI 0.00, 0.21), p = 0.05, 1 trial and n = 278]. There was no statistically significant difference in the incidence of CLD at 36 weeks amongst all survivors [RR 1.34 (95% CI 0.94, 1.90); RD 0.11(95% CI -0.02, 0.24), 1 trial and n = 206]. There were no statistically significant differences for oxygen dependency at 28 days (2 trials and n = 294), death by 28 days (2 trials and n = 294) or 36 weeks (2 trials and n = 294) and the combined outcome of death or CLD by 28 days (2 trials and n = 294) or 36 weeks CGA (1 trial and n = 278). The duration of mechanical ventilation was statistically significantly longer in the inhaled as compared to the systemic steroid group (WMD 3.89 days, 95% CI 0.24, 7.55; 2 trials and n = 294). The duration of supplemental oxygen was statistically significantly longer in the inhaled as compared to the systemic steroid group (WMD 11.10 days, 95% CI 1.97, 20.22; 2 trials and n = 294). There was a significantly lower incidence of hyperglycemia in the group receiving inhaled steroids (RR 0.52, 95% CI 0.39,0.71; RD -0.25, 95% CI -0.37, -0.14; 1 trial and n = 278). The NNT was 4.0 (95% CI 2.7, 7.14) to avoid one infant experiencing hyperglycemia. There was a statistically significant increase in the rate of patent ductus arteriosus (RR 1.64, 95% CI 1.23, 2.17; RD 0.21, 95% CI 0.10, 0.33; 1 trial and n = 278) in the group receiving inhaled steroids. The NNH was 4.8, 95% CI 3, 10. There were decreases of borderline statistical significance in the incidences of gastrointestinal hemorrhage and gastrointestinal perforation in the inhaled as compared to systemic steroid group: for gastrointestinal hemorrhage, RR 0.40, 95% CI 0.16, 1.02; RD -0.06, 95% CI -0.12, 0.00, p = 0.05 (1 trial and n = 278); for gastrointestinal perforation, RR 0.16, 95% CI 0.02, 1.29; RD -0.04, 95% CI -0.07, 0.00, p = 0.05 (1 trial and n = 278). The incidence of other side effects was not statistically significantly different in the two groups. No information was available on long term neurodevelopmental outcomes.

REVIEWER'S CONCLUSIONS

This review found no evidence that early inhaled steroids confer important advantages over systemic steroids in the management of ventilator dependent preterm infants. Neither inhaled steroids, nor systemic steroids, can be recommended as a part of standard practice for ventilated preterm infants. Because they might have fewer adverse effects than systemic steroids, further randomized controlled trials of inhaled steroids are needed which address risk/benefit ratio of different delivery techniques, dosing schedules and long term effects, with particular attention to neurodevelopmental outcome.

Inhaled versus systemic corticosteroids for the treatment of chronic lung disease in ventilated very low birth weight preterm infants

BACKGROUND

Chronic lung disease (CLD) remains a serious and common problem among very low birth weight infants despite the use of antenatal steroids and postnatal surfactant therapy to decrease the incidence and severity of respiratory distress syndrome. Corticosteroids have been widely used to treat or prevent CLD due to their anti-inflammatory properties. However, the use of systemic steroids has been associated with serious short and long term adverse effects. Administration of corticosteroids topically through the respiratory tract might result in beneficial effects on the pulmonary system with fewer undesirable systemic side effects.

OBJECTIVES

To compare the effectiveness of inhaled versus systemic corticosteroids administered to ventilator dependent preterm neonates with birth weight </= 1500 grams or gestational age </= 32 weeks after two weeks of life for the treatment of evolving CLD.

SEARCH STRATEGY

Randomized and quasi-randomized trials were identified by searching the Cochrane Controlled Trials Register (The Cochrane Library, Issue 3, 2002), MEDLINE (1966 - September 2002), EMBASE (1980 - September 2002), CINAHL (1982 - September 2002), reference lists of published trials and abstracts published in Pediatric Research (1990 - April 2002) from the Society for Pediatric Research/Pediatric Academic Societies' Annual Meetings.

SELECTION CRITERIA

Randomized or quasi-randomized trials comparing inhaled versus systemic corticosteroid therapy (irrespective of the dose and duration of therapy) starting after the first two weeks of life in ventilator dependent very low birth weight preterm neonates.

DATA COLLECTION AND ANALYSIS

Data were extracted regarding clinical outcomes including CLD at 28 days or 36 weeks corrected gestational age (CGA), mortality, combined outcome of death or CLD at 28 days or 36 weeks CGA, other pulmonary outcomes and adverse effects. All data were analyzed using RevMan 4.1. When appropriate, meta-analysis was performed using relative risk (RR), risk difference (RD), and weighted mean difference (WMD) along with their 95% confidence intervals (CI). If RD was statistically significant, number needed to treat (NNT) was calculated.

MAIN RESULTS

Five trials comparing inhaled versus systemic corticosteroids in the treatment of CLD were identified. Two trials were excluded as both included non ventilator dependent patients. One trial is awaiting assessment and clarification of published data. Two trials qualified for inclusion in this review. Halliday et al (Halliday 2001a) randomized infants < 72 hours, while Suchomski et al (Suchomski 2002) randomized at 12-21 days. Although the steroids were commenced after the first 2 weeks of life in both the trials, the outcomes were measured over different time periods, from the age at randomization in each trial, making it inappropriate to combine results. In neither trial was there a statistically significant difference between the groups in the incidence of CLD at 36 weeks CGA amongst all randomized infants. The estimates for the trial by Halliday et al (Halliday 2001a) were RR 1.10 (95% CI 0.82, 1.47), RD 0.03 (95% CI -0.08, 0.15); number of infants (n) = 292 and for the trial by Suchomski et al (Suchomski 2002) RR 0.90 (95% CI 0.79, 1.02), RD -0.10 (95% CI -0.22, 0.02; n = 78 ). There were no statistically significant differences between the groups in either trial for oxygen dependency at 28 days, death by 28 days or 36 weeks, the combined outcome of death or CLD by 28 days or 36 weeks CGA, duration of intubation, duration of oxygen dependence, or adverse effects. Information on the long term neurodevelopmental outcomes was not available.

REVIEWER'S CONCLUSIONS

This review found no evidence that inhaled corticosteroids confer net advantages over systemic corticosteroids in the management of ventilator dependent preterm infants. Neither inhaled steroids, nor systemic steroids, can be recommended as standard treatment for ventilated preterm infants. There was no evidence of difference in effectiveness or side-effect profiles for inhaled versus systemic steroids. A better delivery system guaranteeing selective delivery of inhaled steroids to the alveoli might result in beneficial clinical effects without increasing side-effects. To resolve this issue, studies are needed to identify the risk/benefit ratio of different delivery techniques and dosing schedules for the administration of these medications. The long term effects of inhaled steroids, with particular attention to neurodevelopmental outcome, should be addressed in future studies.

[Evaluation of surfactant administration in neonates with respiratory distress syndrome. III. The role of intra-uterine stimulation on lung maturity]

Prenatal corticosteroids and exogenous surfactant therapy independently reduce the adds of neonatal death by about 40%. It is not clear however if babies who develop RDS despite prenatal corticosteroid therapy behave differently when later given exogenous surfactant. This paper presents an evaluation of the outcome of babies treated with Curosurf (a porcine surfactant) for RDS depending upon whether they received prenatal corticosteroids (16 babies) or not (11 babies). Although not randomised these two groups of babies appear to be similar in respect of gestational age. However, lower mortality was found in the group treated with prenatal corticosteroids (12.5% vs. 27.2%).

Randomized multicentre trial of treatment with porcine natural surfactant for moderately severe neonatal respiratory distress syndrome. The Collaborative European Multicentre Study Group

A randomized trial comparing outcome of babies treated with a natural surfactant (Curosurf) for moderately severe respiratory distress syndrome (RDS) with corresponding data from babies treated at a more advanced stage of the disease is reported. A total of 182 newborn babies (mean gestational age 29.8 weeks) requiring mechanical ventilation and a fraction of inspired oxygen (FiO2) in the range of 0.40-0.59 for RDS were randomized to immediate ("early") treatment (No = 86) with surfactant (200 mg/kg), or to a control group (No = 96). According to the protocol 49 controls (51%) qualified for a "late" surfactant treatment at an FiO2 requirement of > or = 0.60. In both groups of treated patients administration of surfactant led to a rapid improvement of oxygenation, but the peak value for PaO2 and the variability of the response tended to be lower in babies given immediate treatment. In comparison with the total control group, babies treated immediately had lower incidence of grade III-IV intraventricular hemorrhage (7% vs 18%; p < 0.05), lower mortality (9% vs 23%; p < 0.05), and lower incidence of unfavourable outcome--defined as death or bronchopulmonary dysplasia--(18% vs 34%; p < 0.05) at 28 days. Also significant reductions of time in oxygen > 21% and time on mechanical ventilation were observed. Our data suggest that treatment with surfactant when RDS is moderately severe prevents or reverses the natural progression of the disease in at least 50% of the cases and lowers the risk of serious complications.

[Effects of surfactant administration in neonates with respiratory distress syndrome. II. Radiographic changes]

The effect of treatment of severe respiratory distress syndrome with a natural porcine surfactant (Curosurf) on the radiographic appearances and degree of aeration is described. Separate assessment of each lung of 22 preterm babies was made before and after surfactant administration. The beneficial effect of Curosurf treatment on the aeration of the lungs was seen in 19 (86%) of the babies.

A 2-year follow up of babies enrolled in a European multicentre trial of porcine surfactant replacement for severe neonatal respiratory distress syndrome. Collaborative European Multicentre Study Group

The postnatal growth, respiratory status and neurodevelopmental outcome of surviving babies enrolled in the first European multicentre trial of porcine surfactant (Curosurf) replacement for severe neonatal respiratory distress syndrome, were assessed at corrected ages of 1 and 2 years. Follow up rates of survivors were 93% at 1 year and 89% at 2 years. Treated and control groups were similar at both 1 and 2 years in terms of physical growth, the prevalence of persistent respiratory symptoms and the occurrence of major and minor disability. Serum antibodies recognising Curosurf and surfactant-anti-surfactant immune complexes were detected in both treated and control babies, the titres showing no difference between groups. Examination of histological lung sections from non-survivors revealed a higher incidence of severe pulmonary interstitial emphysema in control babies than in those treated with surfactant. Surfactant treatment for severe respiratory distress syndrome reduces neonatal mortality and air leaks and is not associated with an increase in disability 2 years later.

Systemic neonatal candidiasis

Forty-five cases of systemic neonatal candidiasis were diagnosed over a 9-year period in a neonatal intensive care unit; 42 infants weighted less than 1.5 kg. All had been very ill with preceding bacterial sepsis and other complications of low birthweight. Where treatment was instituted the mortality was low (4 out of 39 dying) and complications of treatment were transitory. We therefore recommend diligent examination for the presence of this infection, and treatment with a combination of amphotericin B and 5-flucytosine.

Automated image analysis of alveolar expansion patterns in immature newborn rabbits treated with natural or artificial surfactant

Automated image analysis of histological lung sections was used to compare the efficacy of an artificial surfactant (dipalmitoylphosphatidylcholine + high-density lipoprotein, 10:1) and a natural surfactant (the phospholipid fraction of porcine surfactant, isolated by liquid-gel chromatography in ventilated immature newborn rabbits delivered after 27 days' gestation. Tidal volumes were significantly improved in each group treated with surfactant when compared with controls, but natural surfactant-treated rabbits had significantly higher tidal volumes than those receiving artificial surfactant. There were no statistically significant differences in alveolar expansion between the artificial surfactant group and the controls, but alveolar volume density and a shape factor (assessing the 'circularity' of terminal airspaces) were significantly higher in animals receiving natural surfactant. These animals also had a lower coefficient of variation of alveolar volume density and a lower alveolar average integral mean surface curvature, indicating a uniform pattern of alveoli with a smooth profile. We conclude that automated image analysis is useful for the quantitation of alveolar expansion patterns in immature neonatal lungs and that natural surfactant is superior to the artificial surfactant tested in the present study.

Controlled trial of new formulae for feeding low birth weight infants

Over a 13-month period 85 babies were randomly allocated to one of three groups at birth. Babies in Group A were fed SMA Low Birth Weight, Group B Prematalac and Group C Preaptamil. A fourth group, the control group was fed expressed breast milk (EBM). The babies were studied when they were on full enteral feeds until weight was greater than 2.0 kg. Weight gain was greatest in Group B compared to the other three groups but there was no significant difference in gain of length or occipito-frontal circumference. The babies in Group B had a lower volume of feeds and lower energy intake than the other groups but had a significantly higher sodium intake which was reflected in higher mean sodium levels. This may have accounted for the increased weight gain. There was no significant difference in serum calcium, osmolality, total protein or haematocrit.

Echographic ventricular systolic time intervals in normal term and preterm neonates

Right ventricular and left ventricular systolic time intervals (RVSTIs and LVSTIs) were measured in normal term and preterm infants from 1 hour to 90 days of life. LVSTIs in both term and preterm infants were similar in the first five days of life. The ratio of left pre-ejection period (LPEP) to left ventricular ejection time (LVET) was lower in preterm infants older than age 5 days. Estimated gestational age had no influence on LVSTI. The ratio of right pre-ejection period (RPEP) to right ventricular ejection time (RVET) was lower in preterm infants (0.32) than in term newborns (0.37). The preterm RPEP/RVET ratio decreased with age, but at a slower rate than in term babies. This was consistent with the lower pulmonary vascular resistance present in preterm infants.

Respiratory distress syndrome: echocardiographic assessment of cardiovascular function and pulmonary vascular resistance

Echocardiograms were performed for 82 preterm infants comprising 22 normal infants, 29 with mild respiratory distress syndrome (RDS), and 31 with severe RDS. Left ventricular systolic time intervals were measured from aortic valve echograms and right ventricular systolic time intervals from pulmonic valve echograms. Left ventricular performance seemed to be altered early in postnatal adaptation of preterm infants, but played no demonstrable role in the outcome of RDS. The right ventricular preejection period/right ventricular ejection time (RPEP/RVET) ratio was prolonged in 17 out of 31 patients with severe RDS, consistent with increased pulmonary vascular resistance or right ventricular dysfunction. Prolonged RPEP/RVET identified a subgroup with increased mortality and morbidity.