Parent and staff experiences of a feasibility trial evaluating neurally adjusted ventilatory assist in infants with acute viral bronchiolitis: A qualitative study.

There is limited literature regarding family and staff experiences of participating in clinical trials. A qualitative study was embedded in the NAVABronch feasibility trial evaluating the effectiveness of a novel mode of ventilation, neurally adjusted ventilatory assist (NAVA), in infants with acute viral bronchiolitis. The aim of this qualitative study was to explore the experiences of parents and health care practitioners (HCPs) involved in the NAVABronch Trial. Semi-structured interviews were conducted with two parents and two focus groups were held with six HCPs. Four themes were identified from the focus groups: (1) Creating staff engagement, (2) Education to deliver NAVA, (3) Normalizing NAVA in clinical practice (4) Creating meaningful study outcomes and (5) support of parents during the trial, this theme was generated from the parent interviews. The findings indicated the need for education regarding NAVA for HCPs which would lead to increased confidence, better guidance around the use of NAVA and the need for NAVA to be normalized and embedded into the unit culture. Parents identified the need for further support around preparation for what may happen as a result of the interventions, particularly the weaning of sedation. Our study indicates that staff and parents had no concerns regarding the trial methods and procedures. Conducting clinical trials in Paediatric Intensive Care Units (PICUs) is challenging and complex. There is limited literature regarding family and staff experiences of participating in clinical trials. Understanding their experiences is crucial in ensuring trial success. [Abstract copyright: © 2024 The Authors. Nursing in Critical Care published by John Wiley & Sons Ltd on behalf of British Association of Critical Care Nurses.

Inferring Environmental Change in Estuaries from Plant Macrofossils

Aquatic plants are critical components of estuarine ecosystems supporting biodiversity and a range of ecosystem services such as sediment stabilisation and denitrification. However, estuarine plants, similar to their freshwater counterparts, are in decline and under threat. The examination of remains of aquatic plants in sediment records can document the fate of the plants themselves, along with numerous natural and anthropogenic changes in estuaries, including those associated with relative sea level change, pollution and habitat degradation. In comparison with other proxies, the use of macrofossils in estuaries is in its relative infancy. However, many approaches to the examination of plant macrofossils can be utilised from the freshwater domain where a number of advances have been made, particularly in the past decade

Mid-infrared spectroscopy as a potential tool for reconstructing lake salinity

Many aquatic ecosystems in Australia are impacted or threatened by salinisation; however, there is a paucity of records detailing the changes in salinity of individual water bodies that extend beyond a few decades. One way to overcome this issue is the use of inference models, which have typically been based on biological proxies. This pilot project investigates the potential for mid-infrared spectroscopy (MIRS) to provide an alternative method of reconstructing past salinity levels in Australian lakes. A small (19 lakes) calibration dataset was used to develop a MIRS-based lake water salinity inference model (measured vs. inferred salinity, based on leave-one-out cross-validation, R2 = 0.64). This model and a previously published diatom–salinity model were both used to infer salinity levels in Tower Hill Lake in south-eastern Australia, over the last 60 years. Comparisons between these reconstructions and measured salinity data from Tower Hill Lake indicate that salinities inferred by the MIRS model more closely resembled the measured values than those produced using the diatom model, predominantly in terms of the actual values inferred, but also with regard to the trends observed. This supports the hypothesis that MIRS can provide a valuable new tool for reconstructing lake salinity.Laura Cunningham, John Tibby, Sean Forrester, Cameron Barr and Jan Skjemsta

Late Quaternary vegetation history of North Stradbroke Island, Queensland, eastern Australia

Currently there is a paucity of records of late Quaternary palaeoenvironmental variability available from the subtropics of Australia. The three continuous palaeoecological records presented here, from North Stradbroke Island, subtropical Queensland, assist in bridging this large spatial gap in the current state of knowledge. The dominance of arboreal taxa in the pollen records throughout the past >40,000 years is in contrast with the majority of records from temperate Australia, and indicates a positive moisture balance for North Stradbroke Island. The charcoal records show considerable inter-site variability indicating the importance of local-scale events on individual records, and highlighting the caution that needs to be applied when interpreting a single site as a regional record. The variability in the burning regimes is interpreted as being influenced by both climatic and human factors. Despite this inter-site variability, broad environmental trends are identifiable, with changes in the three records comparable with the OZ-INTIMATE climate synthesis for the last 35,000 years. © 2013 Elsevier Ltd.Patrick T. Moss, John Tibby, Lynda Petherick, Hamish McGowan, Cameron Bar

Evaluating the Impact of Cardiopulmonary Bypass Priming Fluids on Bleeding After Pediatric Cardiac Surgery:A Systematic Review and Meta-Analysis

OBJECTIVES: Cardiopulmonary bypass (CPB) predisposes young children to coagulopathy. The authors evaluated possible effects of CPB priming fluids on perioperative bleeding in pediatric cardiac surgery.DESIGN: Meta-analysis and systematic review of previously published studies.SETTING: Each study was conducted in a surgical center or intensive care unit.PARTICIPANTS: Studies investigating patients &lt;18 years without underlying hematologic disorders were included.INTERVENTIONS: The authors evaluated randomized controlled trials (RCTs) published between 1980 and 2020 on MEDLINE, EMBASE, PubMed, and CENTRAL databases. The primary outcome was postoperative bleeding; secondary endpoints included blood product transfusion, mortality, and safety.MEASUREMENTS AND MAIN RESULTS: Twenty eligible RCTs were analyzed, with a total of 1,550 patients and a median of 66 patients per study (range 20-200). The most frequently assessed intervention was adding fresh frozen plasma (FFP) to the prime (8/20), followed by albumin (5/20), artificial colloids (5/20), and blood-based priming solutions (3/20). Ten studies with 771 patients evaluated blood loss at 24 hours in mL/kg and were included in a meta-analysis. Most of them investigated the addition of FFP to the priming fluid (7/10). No significant difference was found between intervention and control groups, with a mean difference of -0.13 (-2.61 to 2.34), p = 0.92, I2 = 69%. Further study endpoints were described but their reporting was too heterogeneous to be quantitatively analyzed.CONCLUSIONS: This systematic review of current evidence did not show an effect of different CPB priming solutions on 24-hour blood loss. The analysis was limited by heterogeneity within the dataset regarding population, type of intervention, dosing, and the chosen comparator, compromising any conclusions.</p

Incorporating comorbidity within risk adjustment for UK pediatric cardiac surgery

INTRODUCTION: When considering early survival rates after pediatric cardiac surgery it is essential to adjust for risk linked to case complexity. An important but previously less well understood component of case mix complexity is comorbidity. METHODS: National congenital heart diseases audit (NCHDA) data representing all pediatric cardiac surgery procedures undertaken in the United Kingdom and Ireland between 2009 and 2014 was used to develop and test groupings for comorbidity and additional non procedure based risk factors within a risk adjustment model for 30-day mortality. A mixture of expert consensus based opinion and empiric statistical analyses were used to define and test the new comorbidity groups. RESULTS: The study dataset consisted of 21,838 pediatric cardiac surgical procedure episodes in 18,834 patients with 539 deaths (raw 30-day mortality rate 2.5%). In addition to surgical procedure type, primary cardiac diagnosis, univentricular status, age, weight, procedure type (bypass, non-bypass or hybrid) and era, the new risk factor groups of: non Downs congenital anomalies, acquired comorbidities, increased severity of illness indicators (such as pre-operative mechanical ventilation or circulatory support) and additional cardiac risk factors (such as heart muscle conditions and raised pulmonary arterial pressure) all independently increased the risk of operative mortality. DISCUSSION: In an era of low mortality rates across a wide range of operations, non-procedure based risk factors form a vital element of risk adjustment and their presence leads to wide variations in the predicted risk of a given operation

A 1500 year record of river discharge inferred from fluvial-marine sediments in the Australian subtropics

Available online 19 May 2018In Australia, there is a scarcity of high resolution hyrdoclimate reconstructions for the last several millennia. Fluvial-marine sediments offer a potential avenue for examining trends in freshwater input to coastal settings and, by inference, past hydroclimates. Here, major elemental geochemistry, δ¹³C and C:N ratios of organic matter, grain size and diatom species abundance, measured in a 4.4m long sediment core collected from Moreton Bay, in east coast Australia, are used to infer the relative freshwater discharge of the adjacent catchment over the last ~1500 years. Reduced freshwater discharge into the Bay occurred from 630 to 1200 CE, especially between 1100 and 1200 CE. A broad increase in discharge is indicated after 1300 CE, extending to the present. The initial shift to the prolonged wet period coincides with both a decrease in the frequency of ‘dry’ El Niño events based on regional records from the austral Pacific, and a broad hemispheric-scale cooling trend. This record provides further insight into low amplitude climate variability in the Australian subtropics over the last 1000 years, supporting efforts in both forecasting current and future climates, and managing regional water resources. Importantly, instrumental records do not cover the full range of natural climate variability experienced in the region over the last 1000 years.J. Coates-Marnane, J. Olley, J. Tibby, J. Burton, D. Haynes, J. Kem

Evaluation of PMIP2 and PMIP3 simulations of mid-Holocene climate in the Indo-Pacific, Australasian and Southern Ocean regions

This study uses the simplified patterns of temperature and effective precipitation approach from the Australian component of the international palaeoclimate synthesis effort (INTegration of Ice core, MArine and TErrestrial records - OZ-INTIMATE) to compare atmosphere–ocean general circulation model (AOGCM) simulations and proxy reconstructions. The approach is used in order to identify important properties (e.g. circulation and precipitation) of past climatic states from the models and proxies, which is a primary objective of the Southern Hemisphere Assessment of PalaeoEnvironment (SHAPE) initiative. The AOGCM data are taken from the Paleoclimate Modelling Intercomparison Project (PMIP) mid-Holocene (ca. 6000 years before present, 6 ka) and pre-industrial control (ca. 1750 CE, 0 ka) experiments. The synthesis presented here shows that the models and proxies agree on the differences in climate state for 6 ka relative to 0 ka, when they are insolation driven. The largest uncertainty between the models and the proxies occurs over the Indo-Pacific Warm Pool (IPWP). The analysis shows that the lower temperatures in the Pacific at around 6 ka in the models may be the result of an enhancement of an existing systematic error. It is therefore difficult to decipher which one of the proxies and/or the models is correct. This study also shows that a reduction in the Equator-to-pole temperature difference in the Southern Hemisphere causes the mid-latitude westerly wind strength to reduce in the models; however, the simulated rainfall actually increases over the southern temperate zone of Australia as a result of higher convective precipitation. Such a mechanism (increased convection) may be useful for resolving disparities between different regional proxy records and model simulations. Finally, after assessing the available datasets (model and proxy), opportunities for better model–proxy integrated research are discussed.Duncan Ackerley, Jessica Reeves, Cameron Barr, Helen Bostock, Kathryn Fitzsimmons, Michael-Shawn Fletcher, Chris Gouramanis, Helen McGregor, Scott Mooney, Steven J. Phipps, John Tibby and Jonathan Tyle

Carbon isotope discrimination in leaves of the common paperbark tree, Melaleuca quinquenervia, as a tool for quantifying past tropical and subtropical rainfall

Quantitative reconstructions of terrestrial climate are highly sought after but rare, particularly in Australia. Carbon isotope discrimination in plant leaves (Δleaf) is an established indicator of past hydroclimate because the fractionation of carbon isotopes during photosynthesis is strongly influenced by water stress. Leaves of the evergreen tree Melaleuca quinquenervia have been recovered from the sediments of some perched lakes on North Stradbroke and Fraser Islands, south-east Queensland, eastern Australia. Here, we examine the potential for using M. quinquenervia ∆leaf as a tracer of past rainfall by analysing carbon isotope ratios (δ13C) of modern leaves. We firstly assess Δleaf variation at the leaf and stand scale and find no systematic pattern within leaves or between leaves due to their position on the tree. We then examine the relationships between climate and Δleaf for an 11 year timeseries of leaves collected in a litter tray. M. quinquenervia retains its leaves for 1-4 years; thus cumulative average climate data are used. There is a significant relationship between annual mean ∆leaf and mean annual rainfall of the hydrological year for 1-4 years (i.e. 365-1460 days) prior to leaf fall (r2=0.64, p=0.003, n=11). This relationship is marginally improved by accounting for the effect of pCO2 on discrimination (r2=0.67, p=0.002, n=11). The correlation between rainfall and Δleaf, and the natural distribution of Melaleuca quinquenervia around wetlands of eastern Australia, Papua New Guinea and New Caledonia offers significant potential to infer past rainfall on a wide range of spatial and temporal scales