The effect of expiratory flow limitation on supine persistent hyperinflation in COPD: a prospective observational study.

Introduction: COPD is characterised by airflow obstruction, expiratory airway collapse and closure causing expiratory flow limitation (EFL) and hyperinflation. Supine posture may worsen ventilatory function in COPD, which may cause hyperinflation to persist and contribute to symptoms of orthopnoea and sleep disturbance. Our aim was to determine the impact of supine posture on hyperinflation, dynamic elastance and EFL in COPD and healthy subjects.

Outcomes of extracardiac Fontan operation: A single institution experience with 398 patients.

Objective: The study objective was to evaluate the outcomes of the extracardiac Fontan operation at a single institution.

Methods: We conducted a retrospective study of 398 patients from a single institution who underwent their initial extracardiac Fontan operation between 1997 and 2020. We determined the incidence of and risk factors for failure of the Fontan circulation, which includes death, Fontan takedown, heart transplantation, protein-losing enteropathy, plastic bronchitis, and functional status at the last follow-up.

Surgeon Upper Extremity Kinematics During Error and Error-Free Retropubic Trocar Passage.

Introduction And Hypothesis: Surgeon kinematics play a significant role in the prevention of patient injury. We hypothesized that elbow extension and ulnar wrist deviation are associated with bladder injury during simulated midurethral sling (MUS) procedures.

Methods: We used motion capture technology to measure surgeons' flexion/extension, abduction/adduction, and internal/external rotation angular time series for shoulder, elbow, and wrist joints.

High preseason temperature variability drives convergence of xylem phenology in the Northern Hemisphere conifers.

Wood growth is key to understanding the feedback of forest ecosystems to the ongoing climate warming. An increase in spatial synchrony (i.e.

Cognitive models for mentally visualizing a sharp instrument in a blind procedure.

Purpose: Our objective was to understand the cognitive strategies used by surgeons to mentally visualize navigation of a surgical instrument through blind space.

Methods: We conducted semi-structured interviews with 15 expert and novice surgeons following simulated retropubic trocar passage on 3D-printed models of pelvises segmented from preop MRIs. Midurethral sling surgery involves blind passage of a trocar among the urethra, bladder, iliac vessels, and bowel while relying primarily on haptic feedback from the suprapubic bone (SPB) for guidance.

Surgeon estimation of retropubic trocar position in blind 3D space.

Introduction And Hypothesis: Retropubic midurethral sling surgery involves the blind passage of trocars near vital organs. We quantified the proximity of surgeons' mental representation of trocar position relative to actual position using a pelvis simulation platform. We hypothesized that novice surgeons, compared with experts, would estimate the trocar's location to be further from the actual location.

Physical activity, balance, and bicycling in older adults.

Falls are a critical public health issue among older adults. One notable factor contributing to falls in older adults is a deterioration of the structures supporting balance and overall balance control. Preliminary evidence suggests older adults who ride a bicycle have better balance than those who do not.

Impact of Aortic Atresia After Fontan Operation in Patients With Hypoplastic Left Heart Syndrome.

Background: Patients with aortic atresia have the worst prognosis in the spectrum of hypoplastic left heart syndrome. It remains unknown whether patients with aortic atresia continue to do poorly after Fontan operation. This study aimed to determine the association between aortic atresia and atrioventricular valve (AVV) function and clinical outcomes after Fontan operation in patients with hypoplastic left heart syndrome.

Model analysis of multiple breath nitrogen washout data: robustness to variations in breathing pattern.

We recently developed a model-based method for analyzing multiple breath nitrogen washout data that does not require identification of Phase-III. In the present study, we assessed the effect of irregular breathing patterns on the intra-subject variabilities of the model parameters. Nitrogen fraction at the mouth was measured in 18 healthy and 20 asthmatic subjects during triplicate performances of multiple breath nitrogen washout, during controlled (target tidal volume 1 L at 8-12 breaths per minute) and free (unrestricted) breathing.

Atrioventricular septal defect in Fontan circulation: Right ventricular dominance, not valve surgery, adversely affects survival.

Objective: The effect of ventricular dominance and previous atrioventricular valve (AVV) surgery on patient outcomes after Fontan operation remains unclear. We sought to determine the effect of ventricular dominance and previous AVV surgery on transplantation-free survival and long-term AVV competency in patients with atrioventricular septal defect (AVSD) and Fontan circulation.

Methods: We conducted a retrospective study of 1703 patients in the Australia and New Zealand Fontan Registry, who survived Fontan operation between 1987 and 2021.

Small airways dysfunction is associated with increased exacerbations in patients with asthma.

There is a poor understanding of why some patients with asthma experience recurrent exacerbations despite high levels of treatment. We compared measurements of peripheral ventilation heterogeneity and respiratory system mechanics in participants with asthma who were differentiated according to exacerbation history, to ascertain whether peripheral airway dysfunction was related to exacerbations. Three asthmatic groups: "stable" (no exacerbations for >12 mo, = 18), "exacerbation-prone" (≥1 exacerbation requiring systemic corticosteroids within the last 12 mo, but stable for ≥1-mo, = 9), and "treated-exacerbation" (exacerbation requiring systemic corticosteroids within the last 1 mo, = 12) were studied.

The effect of oxygen and carbon dioxide cross-sensitivity sensor error in the Eco Medics Exhalyzer D device on measures of conductive and acinar airway function.

Introduction: The multiple breath nitrogen washout (MBNW) test provides important clinical information in obstructive airways diseases. Recently, a significant cross-sensitivity error in the O and CO sensors of a widely used commercial MBNW device (Exhalyzer D, Eco Medics AG, Duernten, Switzerland) was detected, which leads to overestimation of N concentrations. Significant errors in functional residual capacity (FRC) and lung clearance index (LCI) have been reported in infants and children.

Detection of IgG Antibodies to SARS-CoV-2 and Neutralizing Capabilities Using the Luminex xMAP SARS-CoV-2 Multi-Antigen IgG Assay.

Serological assays have been a useful tool for detection of antibodies to SARS-CoV-2 during the COVID-19 pandemic. These assays are used for epidemiology and serosurveillance to monitor the progression of the pandemic, to identify and differentiate individuals who have developed antibodies from natural infection versus vaccine-induced immunity, and to identify potential donors of convalescent plasma for therapeutic purposes. In this chapter, we describe a commercially available bead-based serological assay, the Luminex xMAP SARS-CoV-2 Multi-Antigen IgG Assay, that detects and identifies antibodies against three SARS-CoV-2 antigens.

Retropubic trocar modified with a load cell to verify contact with pubic bone.

Background: Vital injuries during midurethral sling surgery are avoided by maintaining constant trocar contact with bone, and yet this is challenging for a teaching surgeon to monitor during this blind procedure. We modified a retropubic trocar with a load cell to distinguish on-bone and off-bone movement and tested it on a midurethral sling surgery 3-dimensional surgery simulator.

Methods: Two experts and 3 novice surgeons performed retropubic trocar passage on the physical pelvic floor model using the modified trocar.

Ultrafine particle exposure and biomarkers of effect on small airways in children.

The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH) cross-sectional study was conducted in 8-11-year-old schoolchildren attending 25 primary (elementary) schools, randomly selected from the Brisbane Metropolitan Area, Queensland, Australia. Main study findings outlined indirect evidence of distal airway deposition (raised C reactive protein) but as yet, there is no direct evidence in the literature of effects of UFP exposure on peripheral airway function.

Fixed Airflow Obstruction in Asthma: A Problem of the Whole Lung Not of Just the Airways.

Asthma with irreversible or fixed airflow obstruction (FAO) is a severe clinical phenotype that is difficult to treat and is associated with an accelerated decline in lung function and excess morbidity. There are no current treatments to reverse or prevent this excessive decline in lung function in these patients, due to a lack of understanding of the underlying pathophysiology. The current paradigm is that FAO in asthma is due to airway remodeling driven by chronic inflammation.

Relationship between concavity of the flow-volume loop and small airway measures in smokers with normal spirometry.

Background: There is increasing evidence of small airway abnormalities in smokers despite normal spirometry. The concavity in the descending limb of the maximum expiratory flow curve (MEFV) is a recognised feature of obstruction and can provide information beyond FEV, and potentially early smoking-related damage. We aimed to evaluate concavity measures compared to known small airway measurements.

Impact of Fontan Fenestration on Long-Term Outcomes: A Propensity Score-Matched Analysis.

Background The long-term impact of fenestration at the time of Fontan operation remains unclear. We aimed to review the early and long-term impact of Fontan fenestration in the Australia and New Zealand cohort. Methods and Results We reviewed 1443 patients (621 fenestrated, 822 nonfenestrated) from the Australia and New Zealand Fontan registry.