Echocardiographic Screening for Rheumatic Heart Disease: A Brief History and Implications for the Future

Transthoracic echocardiography is the gold standard for early detection of rheumatic heart disease (RHD) in asymptomatic children living in high-risk regions. Advances in technology allowing miniaturisation and increased portability of echocardiography devices have improved the accessibility of this vital diagnostic tool in RHD-endemic locations. Automation of image optimisation techniques and simplified RHD screening protocols permit use by non-experts after a brief period of training. While these changes are welcome advances in the battle to manage RHD, it is important that the sensitivity and specificity of RHD detection be maintained by all echocardiography users on any device to ensure accurate and timely diagnosis of RHD to facilitate initiation of appropriate therapy. This review of the evolution of echocardiography and its use in the detection of rheumatic valve disease may serve as a reminder of the key strengths and potential pitfalls of this increasingly relied-upon diagnostic test.

Characteristics and Determinants of Pulmonary Long COVID

BACKGROUNDPersistent cough and dyspnea are prominent features of post-acute sequelae of SARS-CoV-2 (also termed 'Long COVID'); however, physiologic measures and clinical features associated with these pulmonary symptoms remain poorly defined. Using longitudinal pulmonary function testing (PFTs) and CT imaging, this study aimed to identify the characteristics and determinants of pulmonary Long COVID.METHODSThis single-center retrospective study included 1,097 patients with clinically defined Long COVID characterized by persistent pulmonary symptoms (dyspnea, cough, and chest discomfort) lasting for ≥1 month after resolution of primary COVID infection.RESULTSAfter exclusion, a total of 929 patients with post-COVID pulmonary symptoms and PFTs were stratified diffusion impairment and restriction as measured by percent predicted diffusion capacity for carbon monoxide (DLCO) and total lung capacity (TLC). Dyspnea was the predominant symptom in the cohort (78%) and had similar prevalence regardless of degree of diffusion impairment or restriction. Longitudinal evaluation revealed diffusion impairment (DLCO ≤80%) and pulmonary restriction (TLC ≤80%) in 51% of the cohort overall (n=479). In multivariable logistic regression analysis (adjusted odds ratio; aOR, 95% confidence interval [CI]), invasive mechanical ventilation during primary infection conferred the greatest increased odds of developing pulmonary Long COVID with diffusion impairment and restriction (aOR=10.9 [4.09-28.6]). Finally, a sub-analysis of CT imaging identified radiographic evidence of fibrosis in this patient population.CONCLUSIONSLongitudinal PFT measurements in patients with prolonged pulmonary symptoms after SARS-CoV-2 infection revealed persistent diffusion impaired restriction as a key feature of pulmonary Long COVID. These results emphasize the importance of incorporating PFTs into routine clinical practice for evaluation of patients with prolonged pulmonary symptoms after resolution of SARS-CoV-2. Subsequent clinical trials should leverage combined symptomatic and quantitative PFT measurements for more targeted enrollment of pulmonary Long COVID patients.FUNDINGThis work was supported by the National Institute of Allergy and Infectious Diseases (AI156898, K08AI129705), the National Heart, Lung, and Blood Institute (HL153113, OTA21-015E, HL149944), and the COVID-19 Urgent Research Response Fund established by the Hugh Kaul Precision Medicine Network at the University of Alabama at Birmingham.

The views of parents and carers on managing acute otitis media in urban Aboriginal and Torres Strait Islander children: a qualitative study

OBJECTIVES

To explore the views of parents and carers regarding the management of acute otitis media in urban Aboriginal and Torres Strait Islander children who are at low risk of complications living in urban communities.

STUDY DESIGN

Qualitative study; semi-structured interviews and short telephone survey.

SETTING, PARTICIPANTS

Interviews: purposive sample of parents and carers of urban Aboriginal and Torres Strait Islander children (18 months - 16 years old) screened in Aboriginal medical services in Queensland, New South Wales, and Canberra for the WATCH study, a randomised controlled trial that compared immediate antibiotic therapy with watchful waiting for Aboriginal and Torres Strait Islander children with acute otitis media.

SURVEY

parents and carers recruited for the WATCH trial who had completed week two WATCH surveys.

RESULTS

We interviewed twenty-two parents and carers, including ten who had declined participation in or whose children were ineligible for the WATCH trial. Some interviewees preferred antibiotics for managing acute otitis media, others preferred watchful waiting, expressing concerns about side effects and reduced efficacy with overuse of antibiotics. Factors that influenced this preference included the severity, duration, and recurrence of infection, and knowledge about management gained during the trial and from personal and often multigenerational experience of ear disease. Participants highlighted the importance of shared decision making by parents and carers and their doctors. Parents and carers of 165 of 262 WATCH participants completed telephone surveys (63%); 81 were undecided about whether antibiotics should always be used for treating acute otitis media. Open-ended responses indicated that antibiotic use should be determined by clinical need, support for general practitioners' decisions, and the view that some general practitioners prescribed antibiotics too often.

CONCLUSIONS

Parents and carers are key partners in managing acute otitis media in urban Aboriginal and Torres Strait Islander children. Our findings support shared decision making informed by the experience of parents and carers, which could also lead to reduced antibiotic use for managing acute otitis media.

Panel 1: Epidemiology and global health, including child development, sequelae and complications

OBJECTIVE

To summarise the published research evidence on the epidemiology of otitis media, including the risk factors and sequelae associated with this condition.

DATA SOURCES

Medline (PubMed), Embase, and the Cochrane Library covering the period from 2019 to June 1st, 2023.

REVIEW METHODS

We conducted a broad search strategy using otitis [Medical Subject Heading] combined with text words to identify relevant articles on the prevalence, incidence, risk factors, complications, and sequelae for acute otitis media, otitis media with effusion, and chronic suppurative otitis media. At least one review author independently screened titles and abstracts of the retrieved records for each condition to determine whether the research study was eligible for inclusion. Any discrepancies were resolved by reviewing the full text followed by discussion with a second review author. Studies with more than 100 participants were prioritised.

RESULTS

Over 2,000 papers on otitis media (OM) have been published since 2019. Our review has highlighted around 100 of these publications. While the amount of otitis media research on the Medline database published each year has not increased, there has been an increase in epidemiological studies using routinely collected data and systematic review methodology. Most of the large incidence studies have addressed acute otitis media (AOM) in children. Several studies have described a decrease in incidence of AOM after the introduction of conjugate PCV vaccines. Similarly, a decrease was noted when rates of coronavirus disease of 2019 (COVID-19) were high and there were major public health efforts to reduce the spread of infection. There have been new studies on OM in adults and OM prevalence in a broader range of countries and population subgroups.

CONCLUSION

Overall, the rates of severe and/or suppurative OM appeared to be decreasing. However, there is substantial heterogeneity between populations. While better use of available data is informative, it can be difficult to predict rates of severe disease without accurate examination findings. Most memorably, the COVID-19 pandemic had an enormous impact on the research and clinical services for otitis media for most of the period under review.

IMPLICATIONS FOR PRACTICE

The use of routinely collected data for epidemiological studies will lead to greater variability in the definitions and diagnostic criteria used. The impact of new vaccines will continue to be important. Some of the lessons learned during the COVID-19 pandemic concerning behaviours that reduce spread of respiratory viruses can hopefully be used to decrease the burden of otitis media in the future. There are still many countries in the world where the burden of otitis media is not well described. In countries where otitis media has been studied over many years, new potential risk factors continue to be identified. In addition, a better understanding of the disease in specific subgroups has been achieved.

Characteristics and Determinants of Pulmonary Long COVID

RATIONALE

Persistent cough and dyspnea are prominent features of post-acute sequelae of SARS-CoV-2 (termed 'Long COVID'); however, physiologic measures and clinical features associated with these pulmonary symptoms remain poorly defined.

OBJECTIVES

Using longitudinal pulmonary function testing (PFTs) and CT imaging, this study aimed to identify the characteristics and determinants of pulmonary Long COVID.

METHODS

The University of Alabama at Birmingham Pulmonary Long COVID cohort was utilized to characterize lung defects in patients with persistent pulmonary symptoms after resolution primary COVID infection. Longitudinal PFTs including total lung capacity (TLC) and diffusion limitation of carbon monoxide (DLCO) were used to evaluate restriction and diffusion impairment over time in this cohort. Analysis of chest CT imaging was used to phenotype the pulmonary Long COVID pathology. Risk factors linked to development of pulmonary Long COVID were estimated using univariate and multivariate logistic regression models.

MEASUREMENTS AND MAIN RESULTS

Longitudinal evaluation 929 patients with post-COVID pulmonary symptoms revealed diffusion impairment (DLCO ≤80%) and restriction (TLC ≤80%) in 51% of the cohort (n=479). In multivariable logistic regression analysis (adjusted odds ratio; aOR, 95% confidence interval [CI]), invasive mechanical ventilation during primary infection conferred the greatest increased odds of developing pulmonary Long COVID with diffusion impaired restriction (aOR=10.9 [4.09-28.6]). Finally, a sub-analysis of CT imaging identified evidence of fibrosis in this population.

CONCLUSIONS

Persistent diffusion impaired restriction was identified as a key feature of pulmonary Long COVID. Subsequent clinical trials should leverage combined symptomatic and quantitative PFT measurements for more targeted enrollment of pulmonary Long COVID patients.

AMPK activation improves recovery from pneumonia-induced lung injury via reduction of er-stress and apoptosis in alveolar epithelial cells

BACKGROUND

Bacterial pneumonia and related lung injury are among the most frequent causes of mortality in intensive care units, but also inflict serious and prolonged respiratory complications among survivors. Given that endoplasmic reticulum (ER) stress is a hallmark of sepsis-related alveolar epithelial cell (AEC) dysfunction, we tested if AMP-activated protein kinase (AMPK) affects recovery from ER stress and apoptosis of AECs during post-bacterial infection.

METHODS

In a murine model of lung injury by P. aeruginosa non-lethal infection, therapeutic interventions included AMPK activator metformin or GSK-3β inhibitor Tideglusib for 96 h. Recovery from AEC injury was evidenced by accumulation of soluble T-1α (AEC Type 1 marker) in BAL fluids along with fluorescence analysis of ER-stress (CHOP) and apoptosis (TUNEL) in lung sections. AMPK phosphorylation status and mediators of ER stress were determined via Immunoblot analysis from lung homogenates. Macrophage-dependent clearance of apoptotic cells was determined using flow cytometry assay.

RESULTS

P. aeruginosa-induced lung injury resulted in accumulation of neutrophils and cellular debris in the alveolar space along with persistent (96 h) ER-stress and apoptosis of AECs. While lung infection triggered AMPK inactivation (de-phosphorylation of Thr172-AMPK), metformin and Tideglusib promptly restored the AMPK activation status. In post infected mice, AMPK activation reduced indices of lung injury, ER stress and related apoptosis of AECs, as early as 24 h post administration of AMPK activators. In addition, we demonstrate that the extent of apoptotic cell accumulation is also dependent on AMPK-mediated clearance of apoptotic cells by macrophages.

CONCLUSIONS

Our study provides important insights into AMPK function in the preservation of AEC viability after bacterial infection, in particular due reduction of ER-stress and apoptosis, thereby promoting effective recovery from lung injury after pneumonia.

Transition of pediatric patients with bronchiectasis to adult medical care in the Northern Territory: A retrospective chart audit

Background

Bronchiectasis is increasingly being recognized to exist in all settings with a high burden of disease seen in First Nations populations. With increasing numbers of pediatric patients with chronic illnesses surviving into adulthood, there is more awareness on examining the transition from pediatric to adult medical care services. We undertook a retrospective medical chart audit to describe what processes, timeframes, and supports were in place for the transition of young people (≥14 years) with bronchiectasis from pediatric to adult services in the Northern Territory (NT), Australia.

Methods

Participants were identified from a larger prospective study of children investigated for bronchiectasis at the Royal Darwin Hospital, NT, from 2007 to 2022. Young people were included if they were aged ≥14 years on October 1, 2022, with a radiological diagnosis of bronchiectasis on high-resolution computed tomography scan. Electronic and paper-based hospital medical records and electronic records from NT government health clinics and, where possible, general practitioner and other medical service attendance were reviewed. We recorded any written evidence of transition planning and hospital engagement from age ≥14 to 20 years.

Results

One hundred and two participants were included, 53% were males, and most were First Nations people (95%) and lived in a remote location (90.2%). Nine (8.8%) participants had some form of documented evidence of transition planning or discharge from pediatric services. Twenty-six participants had turned 18 years, yet there was no evidence in the medical records of any young person attending an adult respiratory clinic at the Royal Darwin Hospital or being seen by the adult outreach respiratory clinic.

Conclusion

This study demonstrates an important gap in the documentation of delivery of care, and the need to develop an evidence-based transition framework for the transition of young people with bronchiectasis from pediatric to adult medical care services in the NT.

Temporal Characteristics of CSF-Venous Fistulas on Digital Subtraction Myelography

BACKGROUND AND PURPOSE

CSF-venous fistula can be diagnosed with multiple myelographic techniques; however, no prior work has characterized the time to contrast opacification and the duration of visualization. The purpose of our study was to evaluate the temporal characteristics of CSF-venous fistula on digital subtraction myelography.

MATERIALS AND METHODS

We reviewed the digital subtraction myelography images of 26 patients with CSF-venous fistulas. We evaluated how long the CSF-venous fistula took to opacify after contrast reached the spinal level of interest and how long it remained opacified. Patient demographics, CSF-venous fistula treatment, brain MR imaging findings, CSF-venous fistula spinal level, and CSF-venous fistula laterality were recorded.

RESULTS

Eight of the 26 CSF-venous fistulas were seen on both the upper- and lower-FOV digital subtraction myelography, for a total of 34 CSF-venous fistula views evaluated on digital subtraction myelography. The mean time to appearance was 9.1 seconds (range, 0-30 seconds). Twenty-two (84.6%) of the CSF-venous fistulas were on the right. The highest fistula level was C7, while the lowest was T13 (13 rib-bearing vertebral bodies). The most common CSF-venous fistula levels were T6 (4 patients) followed by T8, T10, and T11 (3 patients each). The mean age was 58.3 years (range, 31.7-87.6 years). Sixteen patients were women (61.5%).

CONCLUSIONS

This is the first study to report the temporal characteristics of CSF-venous fistulas using digital subtraction myelography. We found that on average, the CSF-venous fistula appeared 9.1 seconds (range, 0-30 seconds) after intrathecal contrast reached the spinal level.

Acute otitis media symptoms and symptom scales in research with Aboriginal and Torres Strait Islander children

BACKGROUND

Aboriginal and Torres Strait Islander children experience a high burden of otitis media. We collected data on symptoms associated with acute otitis media (AOM) in a clinical trial involving children receiving primary care at urban Aboriginal Medical Services. Two scales were employed to monitor symptoms over time: the AOM-Severity of Symptoms scale (AOM-SOS) and the AOM-Faces Scale (AOM-FS). This study took place at a mid-point of the un-blinded trial.

METHODS

We examined symptoms at enrolment and day 7, and compared the scales for trends, and bivariate correlation (Spearman's rho) over 14 days. Responsiveness of the scales to clinical change was determined by Friedman's test of trend in two subgroups stratified by day 7 AOM status. We interviewed parents/carers and research officers regarding their experience of the scales and analysed data thematically.

RESULTS

Data derived from 224 children (18 months to 16 years; median 3.6 years). Common symptoms associated with AOM at baseline were runny nose (40%), cough (38%) and irritability (36%). More than one third had no or minimal symptoms at baseline according to AOM-SOS (1-2/10) and AOM-FS scores (1-2/7). The scales performed similarly, and were moderately correlated, at all study points. Although scores decreased from day 0 to 14, trends and mean scores were the same whether AOM was persistent or resolved at day 7. Users preferred the simplicity of the AOM-FS but encountered challenges when interpreting it.

CONCLUSION

We found minimally symptomatic AOM was common among Aboriginal and Torres Strait Islander children in urban settings. The AOM-SOS and AOM-FS functioned similarly. However, it is likely the scales measured concurrent symptoms related to upper respiratory tract infections, given they did not differentiate children with persistent or resolved AOM based on stringent diagnostic criteria. This appears to limit the research and clinical value of the scales in monitoring AOM treatment among Aboriginal and Torres Strait Islander children.

Breathlessness in a virtual world: An experimental paradigm testing how discrepancy between VR visual gradients and pedal resistance during stationary cycling affects breathlessness perception

INTRODUCTION

The sensation of breathlessness is often attributed to perturbations in cardio-pulmonary physiology, leading to changes in afferent signals. New evidence suggests that these signals are interpreted in the light of prior "expectations". A misalignment between afferent signals and expectations may underly unexplained breathlessness. Using a novel immersive virtual reality (VR) exercise paradigm, we investigated whether manipulating an individual's expectation of effort (determined by a virtual hill gradient) may alter their perception of breathlessness, independent from actual effort (the physical effort of cycling).

METHODS

Nineteen healthy volunteers completed a single experimental session where they exercised on a cycle ergometer while wearing a VR headset. We created an immersive virtual cycle ride where participants climbed up 100 m hills with virtual gradients of 4%, 6%, 8%, 10% and 12%. Each virtual hill gradient was completed twice: once with a 4% cycling ergometer resistance and once with a 6% resistance, allowing us to dissociate expected effort (virtual hill gradient) from actual effort (power). At the end of each hill, participants reported their perceived breathlessness. Linear mixed effects models were used to examine the independent contribution of actual effort and expected effort to ratings of breathlessness (0-10 scale).

RESULTS

Expectation of effort (effect estimate ± std. error, 0.63 ± 0.11, P < 0.001) and actual effort (0.81 ± 0.21, P < 0.001) independently explained subjective ratings of breathlessness, with comparable contributions of 19% and 18%, respectively. Additionally, we found that effort expectation accounted for 6% of participants' power and was a significant, independent predictor (0.09 ± 0.03; P = 0.001).

CONCLUSIONS

An individuals' expectation of effort is equally important for forming perceptions of breathlessness as the actual effort required to cycle. A new VR paradigm enables this to be experimentally studied and could be used to re-align breathlessness and enhance training programmes.

Change in health outcomes for First Nations children with chronic wet cough: rationale and study protocol for a multi-centre implementation science study

BACKGROUND

In children, chronic wet cough may be a sign of underlying lung disease, including protracted bacterial bronchitis (PBB) and bronchiectasis. Chronic (> 4 weeks in duration) wet cough (without indicators pointing to alternative causes) that responds to antibiotic treatment is diagnostic of PBB. Timely recognition and management of PBB can prevent disease progression to irreversible bronchiectasis with lifelong consequences. However, detection and management require timely health-seeking by carers and effective management by clinicians. We aim to improve (a) carer health-seeking for chronic wet cough in their child and (b) management of chronic wet cough in children by clinicians. We hypothesise that implementing a culturally integrated program, which is informed by barriers and facilitators identified by carers and health practitioners, will result in improved lung health of First Nations children, and in the future, a reduced the burden of bronchiectasis through the prevention of the progression of protracted bacterial bronchitis to bronchiectasis.

METHODS

This study is a multi-centre, pseudorandomised, stepped wedge design. The intervention is the implementation of a program. The program has two components: a knowledge dissemination component and an implementation component. The implementation is adapted to each study site using a combined Aboriginal Participatory Action Research and an Implementation Science approach, guided by the Consolidated Framework of Implementation Research. There are three categories of outcome measures related to (i) health (ii) cost, and (iii) implementation. We will measure health-seeking as the proportion of parents seeking help for their child in a 6-month period before the intervention and the same 6-month period (i.e., the same six calendar months) thereafter. The parent-proxy, Cough-specific Quality of Life (PC-QoL) will be the primary health-related outcome measure.

DISCUSSION

We hypothesise that a tailored intervention at each site will result in improved health-seeking for carers of children with a chronic wet cough and improved clinician management of chronic wet cough. In addition, we expect this will result in improved lung health outcomes for children with a chronic wet cough.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry; ACTRN12622000430730 , registered 16 March 2022, Retrospectively registered.

Systematic review of the effect of additional doses of oral rotavirus vaccine on immunogenicity and reduction in diarrhoeal disease among young children

BACKGROUND

Oral rotavirus vaccines have lower effectiveness in high child mortality settings. We evaluated the impact of additional dose(s) schedules of rotavirus vaccine on vaccine immunogenicity and reduction in episodes of gastroenteritis.

METHODS

We searched Medline (via PubMed), Cochrane databases and ClinicalTrials.gov for randomised controlled trials from 1973 to February 2022, evaluating the immunological and clinical impact of additional dose vs standard dose oral rotavirus vaccine schedules. We extracted immunogenicity - proportion of children with evidence of anti-rotavirus IgA seroresponse, and clinical - proportion of children with at least one episode of severe rotavirus gastroenteritis, outcome data and used random effects meta-analysis where appropriate. We assessed the methodological quality of the studies using the Cochrane risk of bias tool. The study protocol was registered in PROSPERO (CRD42021261058).

FINDINGS

We screened 536 items and included 7 clinical trials. Our results suggest moderate to high level evidence that an additional dose rotavirus vaccine schedule improves IgA vaccine immune response, including additional doses administered as a booster dose schedule >6 months old; IgA vaccine seroresponse 74·3% additional dose schedule vs 56·1% standard dose schedule RR 1·3 (95%CI, 1·15 - 1·48), and when administered to children who were seronegative at baseline; IgA vaccine seroresponse 48.2% additional dose schedule vs 29.6% standard dose schedule RR 1.86 (95%CI 1.27 to 2.72). Only one study evaluated reduction in gastroenteritis episodes and found little benefit in first year of life, 1·8% vs 2·0% RR 0·88 (95% CI, 0·52 to 1·48), or second year of life, 1·7% vs 2·9% RR 0·62 (95%CI, 0·31 - 1·23).

INTERPRETATION

Administering an additional dose of oral rotavirus vaccines is likely to result in an improved vaccine immune response, including when administered as a booster dose to older children. Evidence of an impact on diarrhoeal disease is needed before additional dose rotavirus vaccine schedules can be recommended as vaccine policy.

FUNDING

BM was funded by the National Health and Medical Research Council, the Royal Australasian College of Physicians Paediatrics and Child Health Division, and the Australian Academy of Science.

INFLATE: a protocol for a randomised controlled trial comparing nasal balloon autoinflation to no nasal balloon autoinflation for otitis media with effusion in Aboriginal and Torres Strait Islander children

BACKGROUND

Otitis media with effusion (OME) is common and occurs at disproportionately higher rates among Indigenous children. Left untreated, OME can negatively affect language, development, learning, and health and wellbeing throughout the life-course. Currently, OME care includes observation for 3 months followed by consideration of surgical ventilation tube insertion. The use of a non-invasive, low-cost nasal balloon autoinflation device has been found beneficial in other populations but has not been investigated among Aboriginal and Torres Strait Islander children.

METHODS/DESIGN

This multi-centre, open-label, randomised controlled trial will determine the effectiveness of nasal balloon autoinflation compared to no nasal balloon autoinflation, for the treatment of OME among Aboriginal and Torres Strait Islander children in Australia. Children aged 3-16 years with unilateral or bilateral OME are being recruited from Aboriginal Health Services and the community. The primary outcome is the proportion of children showing tympanometric improvement of OME at 1 month. Improvement is defined as a change from bilateral type B tympanograms to at least one type A or C1 tympanogram, or from unilateral type B tympanogram to type A or C1 tympanogram in the index ear, without deterioration (type A or C1 to type C2, C3, or B tympanogram) in the contralateral ear. A sample size of 340 children (170 in each group) at 1 month will detect an absolute difference of 15% between groups with 80% power at 5% significance. Anticipating a 15% loss to follow-up, 400 children will be randomised. The primary analysis will be by intention to treat. Secondary outcomes include tympanometric changes at 3 and 6 months, hearing at 3 months, ear health-related quality of life (OMQ-14), and cost-effectiveness. A process evaluation including perspectives of parents or carers, health care providers, and researchers on trial implementation will also be undertaken.

DISCUSSION

INFLATE will answer the important clinical question of whether nasal balloon autoinflation is an effective and acceptable treatment for Aboriginal and Torres Strait Islander children with OME. INFLATE will help fill the evidence gap for safe, low-cost, accessible OME therapies.

TRIAL REGISTRATION

Australia New Zealand Clinical Trials Registry ACTRN12617001652369 . Registered on 22 December 2017. The Australia New Zealand Clinical Trials Registry is a primary registry of the WHO ICTRP network and includes all items from the WHO Trial Registration data set. Retrospective registration.

Hybrid scanning electrochemical cell microscopy-interference reflection microscopy (SECCM-IRM): tracking phase formation on surfaces in small volumes

We describe the combination of scanning electrochemical cell microscopy (SECCM) and interference reflection microscopy (IRM) to produce a compelling technique for the study of interfacial processes and to track the SECCM meniscus status in real-time. SECCM allows reactions to be confined to well defined nm-to-μm-sized regions of a surface, and for experiments to be repeated quickly and easily at multiple locations. IRM is a highly surface-sensitive technique which reveals processes happening (very) close to a substrate with temporal and spatial resolution commensurate with typical electrochemical techniques. By using thin transparent conductive layers on glass as substrates, IRM can be coupled to SECCM, to allow real-time in situ optical monitoring of the SECCM meniscus and of processes that occur within it at the electrode/electrolyte interface. We first use the technique to assess the stability of the SECCM meniscus during voltammetry at an indium tin oxide (ITO) electrode at close to neutral pH, demonstrating that the meniscus contact area is rather stable over a large potential window and reproducible, varying by only ca. 5% over different SECCM approaches. At high cathodic potentials, subtle electrowetting is easily detected and quantified. We also look inside the meniscus to reveal surface changes at extreme cathodic potentials, assigned to the possible formation of indium nanoparticles. Finally, we examine the effect of meniscus size and driving potential on CaCO₃ precipitation at the ITO electrode as a result of electrochemically-generated pH swings. We are able to track the number, spatial distribution and morphology of material with high spatiotemporal resolution and rationalise some of the observed deposition patterns with finite element method modelling of reactive-transport. Growth of solid phases on surfaces from solution is an important pathway to functional materials and SECCM-IRM provides a means for in situ or in operando visualisation and tracking of these processes with improved fidelity. We anticipate that this technique will be particularly powerful for the study of phase formation processes, especially as the high throughput nature of SECCM-IRM (where each spot is a separate experiment) will allow for the creation of large datasets, exploring a wide experimental parameter landscape.

INFERR-Iron infusion in haemodialysis study: INtravenous iron polymaltose for First Nations Australian patients with high FERRitin levels on haemodialysis-a protocol for a prospective open-label blinded endpoint randomised controlled trial

Background

The effectiveness of erythropoiesis-stimulating agents, which are the main stay of managing anaemia of chronic kidney disease (CKD), is largely dependent on adequate body iron stores. The iron stores are determined by the levels of serum ferritin concentration and transferrin saturation. These two surrogate markers of iron stores are used to guide iron replacement therapy. Most Aboriginal and/or Torres Islander Australians of the Northern Territory (herein respectfully referred to as First Nations Australians) with end-stage kidney disease have ferritin levels higher than current guideline recommendations for iron therapy. There is no clear evidence to guide safe and effective treatment with iron in these patients. We aim to assess the impact of intravenous iron treatment on all-cause death and hospitalisation with a principal diagnosis of all-cause infection in First Nations patients on haemodialysis with anaemia, high ferritin levels and low transferrin saturation

Methods

In a prospective open-label blinded endpoint randomised controlled trial, a total of 576 participants on maintenance haemodialysis with high ferritin (> 700 μg/L and ≤ 2000 μg/L) and low transferrin saturation (< 40%) from all the 7 renal units across the Northern Territory of Australia will be randomised 1:1 to receive intravenous iron polymaltose 400 mg once monthly (200 mg during 2 consecutive haemodialysis sessions) (Arm A) or no IV iron treatment (standard treatment) (Arm B). Rescue therapy will be administered when the ferritin levels fall below 700 μg/L or when clinically indicated. The primary outcome will be the differences between the two study arms in the risk of hospitalisation with all-cause infection or death. An economic analysis and several secondary and tertiary outcomes analyses will also be performed.

Discussion

The INFERR clinical trial will address significant uncertainty on the safety and efficacy of iron therapy in First Nations Australians with CKD with hyperferritinaemia and evidence of iron deficiency. This will hopefully lead to the development of evidence-based guidelines. It will also provide the opportunity to explore the causes of hyperferritinaemia in First Nations Australians from the Northern Territory.

Trial registration

This trial is registered with The Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000705987. Registered 29 June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05854-w.

Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

Risk Factors for and Outcomes Associated With Peri-Intubation Hypoxemia: A Multicenter Prospective Cohort Study

BACKGROUND

Little is known about hypoxemia surrounding endotracheal intubation in the critically ill. Thus, we sought to identify risk factors associated with peri-intubation hypoxemia and its effects' on the critically ill.

METHODS

Data from a multicenter, prospective, cohort study enrolling 1,033 critically ill adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 were used to identify risk factors associated with peri-intubation hypoxemia and its effects on patient outcomes. We defined hypoxemia as any pulse oximetry ≤ 88% during and up to 30 minutes following endotracheal intubation.

RESULTS

In the full analysis (n = 1,033), 123 (11.9%) patients experienced the primary outcome. Five risk factors independently associated with our outcome were identified on multiple logistic regression: cardiac related reason for endotracheal intubation (OR 1.67, [95% CI 1.04, 2.69]); pre-intubation noninvasive ventilation (OR 1.66, [95% CI 1.09, 2.54]); emergency intubation (OR 1.65, [95% CI 1.06, 2.55]); moderate-severe difficult bag-mask ventilation (OR 2.68, [95% CI 1.72, 4.19]); and crystalloid administration within the preceding 24 hours (OR 1.24, [95% CI 1.07, 1.45]; per liter up to 4 liters). Higher baseline S_pO₂ was found to be protective (OR 0.93, [95% CI 0.91, 0.96]; per percent up to 97%). Consistent results were seen in a separate analysis on only stable patients (n = 921, 93 [10.1%]) (those without baseline hypoxemia ≤ 88%). Peri-intubation hypoxemia was associated with in-hospital mortality (OR 2.40, [95% CI 1.33, 4.31]; stable patients: OR 2.67, [95% CI 1.38, 5.17]) but not ICU length of stay (point estimate 0.9 days, [95% CI -1.0, 2.8 days]; stable patients: point estimate 1.5 days, [95% CI -0.4, 3.4 days]) after adjusting for age, body mass index, illness severity, airway related reason for intubation (i.e., acute respiratory failure), and baseline S_PO₂.

CONCLUSIONS

Patients with pre-existing noninvasive ventilation and volume loading who were intubated emergently in the setting of hemodynamic compromise with bag-mask ventilation described as moderate-severe were at increased risk for peri-intubation hypoxemia. Higher baseline oxygenation was found to be protective against peri-intubation hypoxemia. Peri-intubation hypoxemia was associated with in-hospital mortality but not ICU length of stay.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101.

Risk factors for and prediction of post-intubation hypotension in critically ill adults: A multicenter prospective cohort study

Objective

Hypotension following endotracheal intubation in the ICU is associated with poor outcomes. There is no formal prediction tool to help estimate the onset of this hemodynamic compromise. Our objective was to derive and validate a prediction model for immediate hypotension following endotracheal intubation.

Methods

A multicenter, prospective, cohort study enrolling 934 adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 was conducted to derive and validate a prediction model for immediate hypotension following endotracheal intubation. We defined hypotension as: 1) mean arterial pressure <65 mmHg; 2) systolic blood pressure <80 mmHg and/or decrease in systolic blood pressure of 40% from baseline; 3) or the initiation or increase in any vasopressor in the 30 minutes following endotracheal intubation.

Results

Post-intubation hypotension developed in 344 (36.8%) patients. In the full cohort, 11 variables were independently associated with hypotension: increasing illness severity; increasing age; sepsis diagnosis; endotracheal intubation in the setting of cardiac arrest, mean arterial pressure <65 mmHg, and acute respiratory failure; diuretic use 24 hours preceding endotracheal intubation; decreasing systolic blood pressure from 130 mmHg; catecholamine and phenylephrine use immediately prior to endotracheal intubation; and use of etomidate during endotracheal intubation. A model excluding unstable patients’ pre-intubation (those receiving catecholamine vasopressors and/or who were intubated in the setting of cardiac arrest) was also developed and included the above variables with the exception of sepsis and etomidate. In the full cohort, the 11 variable model had a C-statistic of 0.75 (95% CI 0.72, 0.78). In the stable cohort, the 7 variable model C-statistic was 0.71 (95% CI 0.67, 0.75). In both cohorts, a clinical risk score was developed stratifying patients’ risk of hypotension.

Conclusions

A novel multivariable risk score predicted post-intubation hypotension with accuracy in both unstable and stable critically ill patients.

Study registration

Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101.

Quantifying the Core Deficit in Classical Schizophrenia

In the classical descriptions of schizophrenia, Kraepelin and Bleuler recognized disorganization and impoverishment of mental activity as fundamental symptoms. Their classical descriptions also included a tendency to persisting disability. The psychopathological processes underlying persisting disability in schizophrenia remain poorly understood. The delineation of a core deficit underlying persisting disability would be of value in predicting outcome and enhancing treatment. We tested the hypothesis that mental disorganization and impoverishment are associated with persisting impairments of cognition and role function, and together reflect a latent core deficit that is discernible in cases diagnosed by modern criteria. We used Confirmatory Factor Analysis to determine whether measures of disorganization, mental impoverishment, impaired cognition, and role functioning in 40 patients with schizophrenia represent a single latent variable. Disorganization scores were computed from the variance shared between disorganization measures from 3 commonly used symptom scales. Mental impoverishment scores were computed similarly. A single factor model exhibited a good fit, supporting the hypothesis that these measures reflect a core deficit. Persisting brain disorders are associated with a reduction in post-movement beta rebound (PMBR), the characteristic increase in electrophysiological beta amplitude that follows a motor response. Patients had significantly reduced PMBR compared with healthy controls. PMBR was negatively correlated with core deficit score. While the symptoms constituting impoverished and disorganized mental activity are dissociable in schizophrenia, nonetheless, the variance that these 2 symptom domains share with impaired cognition and role function, appears to reflect a pathophysiological process that might be described as the core deficit of classical schizophrenia.

Maternal Anaemia in Pregnancy: A Significantly Greater Risk Factor for Anaemia in Australian Aboriginal Children than Low Birth Weight or Prematurity

OBJECTIVES

To identify maternal and perinatal risk factors associated with childhood anaemia.

METHODS

A retrospective cohort study was conducted in three remote Katherine East Aboriginal communities in Northern Territory, Australia. Children born 2004-2014 in Community A and 2010-2014 in Community B and C, and their respective mothers were recruited into the study. Maternal and child data were linked to provide a longitudinal view of each child for the first 1000 days from conception to 2-years of age. Descriptive analyses were used to calculate mean maternal age, and proportions were used to describe other antenatal and perinatal characteristics of the mother/child dyads. The main outcome was the prevalence of maternal anaemia in pregnancy and risk factors associated with childhood anaemia at age 6 months.

RESULTS

Prevalence of maternal anaemia in pregnancy was higher in the third trimester (62%) compared to the first (46%) and second trimesters (48%). There was a strong positive linear association (R² = 0.46, p < 0.001) between maternal haemoglobin (Hb) in third trimester pregnancy and child Hb at age 6 months. Maternal anaemia in pregnancy (OR 4.42 95% CI 2.08-9.36) and low birth weight (LBW, OR 2.62, 95% CI 1.21-5.70) were associated with an increased risk of childhood anaemia at 6 months of age.

CONCLUSIONS FOR PRACTICE

This is the first study to identify the association of maternal anaemia with childhood anaemia in the Australian Aboriginal population. A review of current policies and practices for anaemia screening, prevention and treatment during pregnancy and early childhood would be beneficial to both mother and child. Our findings indicate that administering prophylactic iron supplementation only to children who are born LBW or premature would be of greater benefit if expanded to include children born to anaemic mothers.

10-Valent pneumococcal non-typeable H. influenzae protein D conjugate vaccine (PHiD-CV10) versus 13-valent pneumococcal conjugate vaccine (PCV13) as a booster dose to broaden and strengthen protection from otitis media (PREVIX_BOOST) in Australian Aboriginal children: study protocol for a randomised controlled trial

INTRODUCTION

Streptococcus pneumoniae and non-typeable Haemophilus influenzae (NTHi) are major otitis media pathogens that densely co-colonise the nasopharynx and infect the middle ear of Australian Aboriginal infants from very early in life. Our co-primary hypotheses are that at 18 months of age infants receiving 10-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV10) compared with those receiving 13-valent pneumococcal conjugate vaccine (PCV13) as a booster at 12 months of age will have higher antibody levels to Haemophilus influenzae protein D and that infants receiving PCV13 will have higher antibody levels to PCV13-only serotypes 3, 6A and 19A.

METHODS AND ANALYSES

Our randomised controlled trial will enrol 270 Aboriginal children at 12 months of age to a booster dose of either PHiD-CV10 or PCV13. Children who completed the three-dose primary course schedules of PHiD-CV10 at 2, 4, 6 months of age; PCV13 at 2, 4, 6 months of age; or a combination schedule of PHiD-CV10 at 1, 2, 4 months of age plus PCV13 at 6 months of age are eligible. The co-primary assessor-blinded outcomes when the infants are 18 months of age are as follows: (a) IgG geometric mean concentration (GMC) and proportion with IgG ≥100 EU/mL for protein D, and (b) IgG GMC and the proportion with IgG ≥0.35 µg/mL for pneumococcal serotypes 3, 6A and 19A. Secondary immunogenicity comparisons of six primary and booster dose schedules of 10 shared serotypes at 18 months of age, nasopharyngeal carriage, all forms of otitis media, hearing loss and developmental milestones at 18, 24, 30 and 36 months of age will be reported.

ETHICS AND DISSEMINATION

Ethics committees of NT Department of Health, Menzies, WA Department of Health and WA Aboriginal Health approved the study. Results will be presented to communities, at conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT01735084.

Early Therapeutic Mobility and Changes in Scores for Pain and Fatigue

This report is a secondary analysis of data from a larger study of a nurse-led early therapeutic mobility intervention among patients receiving mechanical ventilation. This analysis evaluated whether intervention frequency or intensity was associated with pain or fatigue. Frequency was defined as once-daily versus twice-daily interventions. Intensity was defined as low (in-bed activities) or moderate (out-of-bed activities). Thirty-nine patients self-reported pain and fatigue immediately before and after the intervention. Neither pain nor fatigue increased significantly (mean increase, <1 [scale of 0-10] for 95% of interventions). Four patients reported decrements in pain; 1 reported a decrease in fatigue. Less than 5% of enrolled patients indicated a score change of +4 to +6 for pain or fatigue, typically with the first intervention that included sitting at the edge of the bed. Future research could examine the distress associated with these symptoms in critically ill adults receiving early therapeutic mobility interventions.

Panel 6: Otitis media and associated hearing loss among disadvantaged populations and low to middle-income countries

OBJECTIVE:

Summarise the published evidence on otitis media and associated hearing loss in low to middle-income countries (LMIC) and disadvantaged populations.

DATA SOURCES:

PubMed and other databases.

REVIEW METHODS:

Firstly, sensitive search strategy using ‘otitis media’, combined with specific key words for each topic of the review, from January 2015 to June 2019. Then, restriction to LMIC and disadvantaged populations. Topics covered included prevention, epidemiology, risk factors, microbiology, prognosis, diagnosis, and treatment.

CONCLUSIONS:

There was a high degree of methodological heterogeneity and high risk of bias. The majority of studies were school-based. In Africa, Asia and Oceania (e.g., Australian Aboriginal populations) the prevalence of OM was respectively 8% (range 3–16%), 14% (range 7–22%) and 50% (4–95%). Prevalence of any hearing loss in these regions was 12% (range 8–17%), 12% (range 3–24%), and 26% (range 25–28%) respectively. Risk factors in LMIC and disadvantaged populations included age, gender, exposure to smoke and pollution. Microbiology was reported for otitis media with effusion at time of surgery or ear discharge (acute otitis media with perforation or chronic suppurative otitis media). Specimen handling and processing in hospital laboratories was associated with low detection of S. pneumoniae and H. influenzae. Case series described complicated cases of OM due to M. tuberculosis, multidrug resistance and HIV. QOL studies identified discrimination of persons with OM and hearing loss. Diagnostic methods varied greatly, from naked eye to tympanometry. Treatment interventions were reported from four RCTs. Non-RCTs included evaluations of guidelines, surgery outcomes, access to ENTs.

IMPLICATIONS FOR CLINICAL PRACTICE:

Chronic suppurative otitis media, otitis media with effusion and conductive hearing loss are common in LMIC and disadvantaged populations. Paucity of research, poor regional representation, non-standardised methods and low-quality reporting preclude accurate assessment of disease burden in LMIC and disadvantaged populations. Awareness and adherence to reporting Guidelines should be promoted.

Mixed Solid and Cystic Mass in an Infant

Desmoplastic infantile tumors are rare supratentorial brain tumors that occur in pediatric patients. Desmoplastic infantile tumors are made up of 2 subtypes: desmoplastic infantile gangliogliomas and desmoplastic infantile astrocytomas. Desmoplastic infantile tumors are often identifiable on imaging on the basis of multiple characteristics. Nevertheless, pathologic analysis is required to confirm the diagnosis, particularly when the imaging features are atypical. Here, the radiology findings, surgical approach and subsequent management, and pathology of a desmoplastic infantile ganglioglioma are described.

The fear and risk of community falls in patients following an intensive care admission: An exploratory cohort study

BACKGROUND

Muscle weakness and impairments in physical functioning are well-recognised sequelae after critical illness. Whether individuals have a higher risk of community falls and a fear of falling has not been examined amongst individuals after critical illness.

OBJECTIVES

The objective of this study was to explore the prevalence of falls, fear of falling, and fall risk in intensive care unit (ICU) survivors over a 6-month period after hospital discharge.

METHODS

This was a nested exploratory study within a medical ICU. Fall prevalence was measured in line with established guidelines over 6 months after ICU discharge. Fear of falling and prediction of fall risk were assessed at 2, 4, and 6 months after discharge.

RESULTS

Twelve individuals were included. Half of the cohort (n = 6) had at least one fall, with one-third sustaining more than one fall. There were 17 falls reported across the six individuals. Injuries requiring medical intervention were reported with five falls. Almost one-third were classified as 'moderate' to 'severe' injurious falls. Loss of balance and fatigue were reported as the main contributors to the falls. All individuals who had a fall reported a severe fear of falling at 2 months. Individuals classified as having 'moderate' to 'high' risk of falls at 2 months were more likely to have at least one fall.

CONCLUSIONS

This study suggests that ICU survivors may have a high fall risk, fear of falling, and fall prevalence, which can result in significant injury.

Povidone-iodine ear wash and oral cotrimoxazole for chronic suppurative otitis media in Australian aboriginal children: study protocol for factorial design randomised controlled trial

Background

Chronic suppurative otitis media (CSOM) is a significant health issue affecting Aboriginal Australians. Long-term hearing loss can cause communication problems, educational disadvantage, and social isolation. Current standard treatment for CSOM in our region is twice daily dry mopping of the pus from the ear canal followed by instillation of ciprofloxacin antibiotic ear drops for up to 16 weeks, or until the discharge resolves for a period of 3 days. The treatment is long, laborious and fails to resolve ear discharge in 70% of cases in remote communities. Bacterial pathogens also persist. Povidone-iodine ear wash is the preferred method of clearing ear discharge in Western Australia. However, evidence of its effectiveness is lacking. In systematic reviews, topical antibiotics (ciprofloxacin) have been shown to be more effective than oral antibiotics or topical antiseptics. Currently, it is unclear whether there are any benefits of combining these treatments.

Methods

This protocol describes a 2 × 2 factorial randomised controlled trial of two different interventions (povidone-iodine ear wash and oral cotrimoxazole), given as adjunctive therapy to standard treatment for CSOM. 280 children, between 2 months and 17 years of age, Indigenous or non-Indigenous, living in participating Northern Territory (NT) communities are randomised to standard treatment (dry mopping and ciprofloxacin drops) plus one of two topical treatments (dilute povidone-iodine ear wash or no wash) and one of two oral medication treatments (16 weeks of cotrimoxazole or placebo).

Discussion

Current treatment of CSOM in our region shows that eradication of bacterial pathogens from the middle ear space and dry ears is often not achieved. This trial will evaluate the efficacy of adjunctive treatments of antiseptic ear washes and oral antibiotics. Clinical, microbiological and hearing outcomes will be reported.

Trial registration

This trial (ACTRN12614000234617) was registered with ANZCTR on 05 April 2014.

Dose of Early Therapeutic Mobility: Does Frequency or Intensity Matter?

OBJECTIVE

Investigate the feasibility of a nurse-led mobility protocol and compare the effects of once- versus twice-daily episodes of early therapeutic mobility (ETM) and low- versus moderate-intensity ETM on serum biomarkers of inflammation and selected outcomes in critically ill adults.

DESIGN

Randomized interventional study with repeated measures and blinded assessment of outcomes.

SETTING

Four adult intensive care units (ICUs) in two academic medical centers.

SUBJECTS

Fifty-four patients with > 48 hr of mechanical ventilation (MV).

INTERVENTION

Patients were assigned to once- or twice-daily ETM via sealed envelope randomization at enrollment. Intensity of (in-bed vs. out-of-bed) ETM was administered according to protocolized patient assessment.

MEASUREMENTS

Interleukins 6, 10, 8, 15, and tumor necrosis factor-α were collected from serum before and after ETM; change scores were used in the analyses. Manual muscle and handgrip strength, delirium onset, duration of MV, and ICU length of stay (LOS) were evaluated as patient outcomes.

MAIN RESULTS

Hypotheses regarding the inflammatory biomarkers were not supported based on confidence intervals. Twice-daily intervention was associated with reduced ICU LOS. Moderate-intensity (out-of-bed) ETM was associated with greater manual muscle test scores and handgrip strength and reduced occurrence of delirium.

CONCLUSION

Findings from this study suggest that nurses can provide twice-daily mobility interventions that include sitting on the edge of the bed once patients have a stable status without altering a pro-inflammatory serum biomarker profile.

Bioelectrical impedance analysis (BIA)-derived phase angle (PA) is a practical aid to nutritional assessment in hospital in-patients

BACKGROUND

Nutritional status can be difficult to assess. Bioelectrical impedance analysis (BIA)-derived phase angle (PA), and the plasma markers citrulline and transthyretin (pre-albumin) have the potential to assist, but the protocol of fasting and resting for BIA renders the investigation impractical for routine use, especially so in populations at high risk of malnutrition.

AIMS

1 To clarify whether starving and resting are necessary for reliable measurement of PA. 2 To identify whether PA, citrulline and transthyretin correlate with nutritional status.

METHODS

Eighty consenting adult in-patients were recruited. Nutritional status was determined by subjective global assessment (SGA) used as gold standard. The Malnutrition Universal Screening Tool (MUST) was used and anthropometric measurements were performed. Serum was analysed for citrulline and transthyretin. PA was measured using Bodystat 4000. The PA was considered to define malnutrition when lower than reference ranges for sex and age, and severe malnutrition if more than 2 integers below the lower limit. Anthropometric measurements were categorised according to WHO reference centiles. Ordinal logistic regression estimated the strength of association of PA, citrulline and transthyretin with SGA. PA values in the different metabolic states were compared using paired t tests.

RESULTS

All 80 subjects completed the BIA and the nutritional assessments in the 3 different states; 14 declined to provide blood samples for the biochemical assays. Malnutrition was identified in 32 cases, severe malnutrition in 14 cases, the remaining 34 cases were deemed not to be malnourished. PA was strongly inversely associated with SGA (Odds Ratio [OR] per unit increase = 0.21, CI 0.12-0.37, p < 0.001). PA was not influenced by exercise (p = 0.134) or food intake (p = 0.184). Transthyretin was inversely associated with malnourished/severely malnourished states (OR = 0.98, 95% CI 0.97-0.99, p = 0.001), but had poorer predictive values than PA. There was no significant association between citrulline concentration and SGA (OR = 1.01, 95% CI 0.99-1.04, p = 0.348).

CONCLUSIONS

The BIA-derived PA reliably identifies malnutrition. It is strongly associated with SGA but requires less skill and experience, and out-performs circulating transthyretin, rendering it a promising and less operator-dependent tool for assessing nutritional status in hospital patients. Our novel demonstration that fasting and bed-rest are unnecessary consolidates that position.

A novel diagnostic algorithm for heparin-induced thrombocytopenia

INTRODUCTION

While diagnostic algorithm using PF4-heparin enzyme-linked immunosorbent assay (ELISA) optical density (OD), and heparin neutralization assay (HNA), or 4T score have been proposed to replace serotonin-release assay (SRA) for heparin-induced thrombocytopenia (HIT), their performance against SRA is unclear. In this study, we proposed and validated the performance of a new algorithm combining PF4-heparin ELISA optical density (OD), HNA and 4T score against SRA for HIT diagnosis.

METHODS

Heparin neutralization assays were performed on specimens submitted for HIT testing with positive PF4-heparin ELISA from December 2015 to September 2017, which were separated into a "training" and a "validation" data set. 4T scores were calculated for ELISA positive cases.

RESULTS

A total of 123 consecutive unique patient samples had positive PF4-heparin ELISA with also HNA data, SRA data, and 4T scores available. Compared to SRA, a "laboratory criteria" (ELISA OD ≥ 1.4 and HNA ≥ 70%) had a sensitivity of 88% (14/16) and specificity of 91% (42/46), and a "combined criteria" (4T score = 8, or 4T score = 6 or 7 and ELISA OD ≥ 1.0, or 4T score = 4 or 5 and ELISA OD ≥ 2.0) had a sensitivity of 75% (12/16) and specificity of 98% (45/46) in the training data set. Laboratory and combined criteria had 90% (56/62) concordance rate. Importantly, for these concordant cases, the diagnostic specificity is 100% (46/46). Based on the data, a novel diagnostic algorithm combining these 2 criteria was proposed and validated prospectively.

CONCLUSION

A novel algorithm has high diagnostic accuracy and potentially could eliminate the need for SRA testing in at least 90% patients with suspected HIT.

The NICE-GUT trial protocol: a randomised, placebo controlled trial of oral nitazoxanide for the empiric treatment of acute gastroenteritis among Australian Aboriginal children

INTRODUCTION

Diarrhoeal disease is the second leading cause of death in children under 5 years globally, killing 525 000 annually. Australian Aboriginal and Torres Strait Islander (hereafter Aboriginal) children suffer a high burden of disease. Randomised trials in other populations suggest nitazoxanide accelerates recovery for children with Giardia, amoebiasis, Cryptosporidium, Rotavirus and Norovirus gastroenteritis, as well as in cases where no enteropathogens are found.

METHODS AND ANALYSIS

This double blind, 1:1 randomised, placebo controlled trial is investigating the impact of oral nitazoxanide on acute gastroenteritis in hospitalised Australian Aboriginal children aged 3 months to <5 years. Dosing is based on age-based dosing. The primary endpoint is the time to resolution of 'significant illness' defined as the time from randomisation to the time of clinical assessment as medically ready for discharge, or to the time of actual discharge from hospital, whichever occurs first. Secondary endpoints include duration of hospitalisation, symptom severity during the period of significant illness and following treatment, duration of rehydration and drug safety. Patients will be followed for medically significant events for 60 days. Analysis is based on Bayesian inference. Subgroup analysis will occur by pathogen type (bacteria, virus or parasite), rotavirus vaccination status, age and illness severity.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Central Australian Human Research Ethics Committee (HREC-14-221) and the Human Research Ethics Committee of the Northern Territory Department of Health and Menzies School of Health Research (HREC2014-2172). Study investigators will ensure that the trial is conducted in accordance with the principles of the Declaration of Helsinki. Individual participant consent will be obtained. Results will be disseminated via peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ACTRN12614000381684.

The Effects of Amount of Processing on Recall and Recognition

Johnson-Laird, Gibbs and de Mowbray (1978) and Ross (1981) have argued that amount of processing, as indexed by the overall number of decisions a subject makes, provides a good predictor of incidental memory performance. Conversely, McClelland, Rawles and Sinclair (1981) have provided evidence that it is normally the number of positive decisions rather than the overall number of decisions per se that determines level of recall. The present study replicated and extended the findings of McClelland and his colleagues. In free recall (Experiment 1 and 3), cued recall (Experiment 3) and recognition in the presence or absence of context cues (Experiments 2 and 3), an account based on number of positive decisions provided by far the better explanation. Experiment 3 also revealed that the experimental manipulations had a somewhat greater effect on recall than recognition. This is explained in terms of Tulving and Pearlstone's (1966) distinction between availability and accessibility. It is suggested that words associated with negative decisions are not only less accessible in memory, there are also fewer of them available for recall and recognition.

Characterizing Hospitalist Practice and Perceptions of Critical Care Delivery

BACKGROUND

Intensivist shortages have led to increasing hospitalist involvement in critical care delivery.

OBJECTIVE

To characterize the practice of hospitalists practicing in the intensive care unit (ICU) setting.

DESIGN

Survey of hospital medicine physicians.

SETTING

This survey was conducted as a needs assessment for the ongoing efforts of the Critical Care Task Force of the Society of Hospital Medicine Education Committee.

PARTICIPANTS

Hospitalists in the United States.

INTERVENTION

An iteratively developed, 25-item, webbased survey.

MEASUREMENTS

Results were compiled from all respondents then analyzed in subgroups. Various items were examined for correlations.

RESULTS

A total of 425 hospitalists completed the survey. Three hundred and twenty-five (77%) provided critical care services, and 280 (66%) served as primary physicians in the ICU. Hospitalists were significantly more likely to serve as primary physicians in rural ICUs (85% of rural respondents vs 62% of nonrural; P < .001 for association). Half of the rural hospitalists who were primary physicians for ICU patients felt obliged to practice beyond their scope, and 90% at least occasionally perceived that they had insufficient support from board-certified intensivists. Among respondents serving as primary physicians for ICU patients, 67% reported at least moderate difficulty transferring patients to higher levels of ICU care. Difficulty transferring patients was the only item significantly correlated with the perception of being expected to practice beyond one's scope (P < .05 for association).

CONCLUSIONS

Hospitalists frequently deliver critical care services without adequate training or support, most prevalently in rural hospitals. Without major changes in intensivist staffi ng or patient distribution, this is unlikely to change.

Patterns of paediatric emergency presentations to a tertiary referral centre in the Northern Territory

OBJECTIVE

To describe epidemiological data concerning paediatric attendances at the ED of Royal Darwin Hospital (RDH).

METHODS

We conducted a retrospective cohort study of paediatric emergency presentations to the RDH ED during 2004 and 2013. Epidemiological data, including demographics, admission rates and diagnostic grouping, were analysed using descriptive and comparative statistical methods. We compared data with findings from a baseline epidemiological study by the Paediatric Research in Emergency Departments International Collaborative (PREDICT) conducted in 2004.

RESULTS

A total of 12 745 and 15 378 paediatric presentations (age 0-18 years) to the RDH ED were analysed for the years 2004 and 2013 respectively. In 2004, the mean age of children presenting to RDH was 7.1 years, and 56.0% were female. Indigenous patients accounted for 31.2% of presentations at RDH and were significantly more likely to be admitted than non-Indigenous patients (31.6% vs 12.8%, OR 3.24, 95% CI 2.95-3.55). Children <5 years old accounted for the highest number of presentations (45.2%) and admissions (51.2%), and there was a high proportion of adolescent presentations (18.0%). Similar to the PREDICT study, viral infectious conditions (bronchiolitis, gastroenteritis, upper respiratory tract infections) were the most common cause for presentations. Key differences included a higher proportion of patients presenting with cellulitis and head injury at RDH and an increasing proportion of adolescent psychiatric presentations at RDH from 2004 to 2013.

CONCLUSION

This study provides important information regarding paediatric presentations to a major referral hospital in the Northern Territory. Overall, there was a disproportionate rate of presentation and admission among Indigenous children. Other key findings were higher proportions of cellulitis, head injury and adolescent presentations. These findings can assist in service planning and in directing future research specific to children in the Northern Territory.