ORCID Profile
0000-0002-4895-0975
Current Organisation
Telethon Kids Institute
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JCF.2017.01.013
Abstract: We assessed the effect of posture on ventilation distribution and the impact on associations with structural lung disease. Multiple breath washout (MBW) was performed in seated and supine postures in 25 healthy children and 21 children with CF. Children with CF also underwent a chest CT scan. Functional residual capacity (FRC), lung clearance index (LCI) and moment ratios were calculated from the MBW test. CT scans were evaluated for CF-related structural lung disease. FRC was lower in the supine than in the seated posture, whereas LCI was higher in the supine than in the seated posture. In children with CF, associations between LCI and the extent of structural lung disease were stronger when performed in the supine posture. Body posture influences lung volumes and ventilation distribution in both healthy children and children with CF. MBW testing in the supine posture strengthened associations with structural lung damage.
Publisher: Wiley
Date: 05-10-2016
DOI: 10.1002/PPUL.23326
Abstract: Multiple breath washout (MBW) testing with SF6 gas mixture is routinely used to assess ventilation distribution in infants. It is currently unknown whether SF6 changes tidal breathing parameters during MBW in infants. We investigated if SF6 does change tidal breathing parameters in infants and whether a separate tidal breathing trace prior to MBW testing is necessary. Tidal breathing during MBW was compared to standard tidal breathing in room air in healthy infants (n = 38), preterm infants (n = 41), and infants with cystic fibrosis (n = 41). Outcomes included inspiratory and expiratory times (TI and TE ), time to peak tidal inspiratory and expiratory flow (tPTIF and tPTEF), tidal volume (VT ), respiratory rate (f), and minute ventilation (VE ). Breath times were all significantly increased for both healthy (TE : -0.0790 [-0.10566, -0.05217] mean difference [95% confidence intervals]) and CF (-0.109 [-0.15235, -0.06607]) infants during the MBW wash-in (P < 0.001). Healthy infants and those with CF showed decreased f during MBW wash-in (P < 0.001) however, no change in VT, resulting in a decreased VE (0.154 (0.086, 0.222) and 0.128 (0.069, 0.186) for healthy and CF infants, respectively, P < 0.001). Preterm infants experienced a decreased VE during both wash-in (0.134 [0.061, 0.207] P < 0.001) and wash-out phases of MBW (P < 0.05). There are differences in tidal breathing parameters during MBW testing with SF6 in infants. It is, therefore, important to measure a separate tidal breathing trace in room air, prior to MBW testing to ensure rigour of tidal breath indices derived from analysis.
Publisher: European Respiratory Society (ERS)
Date: 04-2021
Publisher: BMJ
Date: 24-01-2017
DOI: 10.1136/THORAXJNL-2016-208985
Abstract: Survivors of preterm birth are at risk of chronic and lifelong pulmonary disease. Follow-up data describing lung structure and function are scarce in children born preterm during the surfactant era. To obtain comprehensive data on lung structure and function in mid-childhood from survivors of preterm birth. We aimed to explore relationships between lung structure, lung function and respiratory morbidity as well as early life contributors to poorer childhood respiratory outcomes. Lung function was tested at 9-11 years in children born at term (controls) and at ≤32 weeks gestation. Tests included spirometry, oscillatory mechanics, multiple breath nitrogen washout and diffusing capacity of the lung for carbon monoxide. Preterm children had CT of the chest and completed a respiratory symptoms questionnaire. 58 controls and 163 preterm children (99 with bronchopulmonary dysplasia) participated. Preterm children exhibited pulmonary obstruction and hyperinflation as well as abnormal peripheral lung mechanics compared with term controls. FEV Abnormal lung structure in mid-childhood resulting from preterm birth in the contemporary era has important functional consequences.
Publisher: Wiley
Date: 20-11-2013
DOI: 10.1002/PPUL.22699
Abstract: The forced oscillation technique (FOT) can be used in children as young as 2 years of age and in those unable to perform routine spirometry. There is limited information on changes in FOT outcomes in healthy children beyond the preschool years and the level of bronchodilator responsiveness (BDR) in healthy children. We aimed to create reference ranges for respiratory impedance outcomes collated from multiple centers. Outcomes included respiratory system resistance (R(rs)) and reactance (X(rs)), resonant frequency (Fres), frequency dependence of R(rs) (Fdep), and the area under the reactance curve (AX). We also aimed to define the physiological effects of bronchodilators in a large population of healthy children using the FOT. Respiratory impedance was measured in 760 healthy children, aged 2-13 years, from Australia and Italy. Stepwise linear regression identified anthropometric predictors of transformed R(rs) and X(rs) at 6, 8, and 10 Hz, Fres, Fdep, and AX. Bronchodilator response (BDR) was assessed in 508 children after 200 µg of inhaled salbutamol. Regression analysis showed that R(rs), X(rs), and AX outcomes were dependent on height and sex. The BDR cut-offs by absolute change in R(rs8), X(rs8), and AX were -2.74 hPa s L(-1), 1.93 hPa s L(-1), and -33 hPa s L(-1), respectively. These corresponded to relative and Z-score changes of -32% -1.85 for R(rs8), 65% 1.95 for X(rs8), and -82% -2.04 for AX. We have established generalizable reference ranges for respiratory impedance and defined cut-offs for a positive bronchodilator response using the FOT in healthy children.
Publisher: Informa UK Limited
Date: 2018
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.PRRV.2018.04.001
Abstract: Preterm birth accounts for approximately 11% of births globally, with rates increasing across many countries. Concurrent advances in neonatal care have led to increased survival of infants of lower gestational age (GA). However, infants born <32 weeks of GA experience adverse respiratory outcomes, manifesting with increased respiratory symptoms, hospitalisation and health care utilisation into early childhood. The development of bronchopulmonary dysplasia (BPD) - the chronic lung disease of prematurity - further increases the risk of poor respiratory outcomes throughout childhood, into adolescence and adulthood. Indeed, survivors of preterm birth have shown increased respiratory symptoms, altered lung structure, persistent and even declining lung function throughout childhood. The mechanisms behind this persistent and sometimes progressive lung disease are unclear, and the implications place those born preterm at increased risk of respiratory morbidity into adulthood. This review aims to summarise what is known about the long-term pulmonary outcomes of contemporary preterm birth, examine the possible mechanisms of long-term respiratory morbidity in those born preterm and discuss addressing the unknowns and potentials for targeted treatments.
Publisher: The Company of Biologists
Date: 2012
DOI: 10.1242/JEB.072413
Abstract: At birth, the newborn fat-tailed dunnart relies on cutaneous gas exchange to meet metabolic demands, with continuous lung ventilation emerging several days later. We hypothesized that the delayed expression of lung ventilation (VE) in these animals is in part owing to a low responsiveness of the respiratory control system to blood gas perturbations. To address this hypothesis we assessed the ventilatory and metabolic response to hypoxia (10% O2) and hypercapnia (5% CO2) using closed-system respirometry from birth to 23 days postpartum (P). Neonatal fat-tailed dunnarts displayed no significant hypoxic or hypercapnic ventilatory responses at any age. Regardless, significant hyperventilation through a suppression of metabolic rate (Vo2) was observed at birth in response to hypercapnia and in response to hypoxia at all ages, except P12. Therefore, reliance on cutaneous gas exchange during early life may be partially attributed to reduced chemosensitivity or a lack of central integration of chemosensitive afferent information. This may be in part due to the relative immaturity of this species at birth, compared to other mammals.
Publisher: Wiley
Date: 27-02-2015
DOI: 10.1111/RESP.12503
Abstract: One of the most significant complications of preterm birth is bronchopulmonary dysplasia (BPD). The pathophysiology of BPD has changed in recent years as advances in neonatal care have led to increased survival of smaller, more preterm, infants who display alterations to alveolar and pulmonary microvascular development. It is becoming clear that infants with 'new' BPD experience lung disease that persists into later childhood, however, the oldest of these children are just now entering young adulthood and therefore the longer term pulmonary implications remain unknown. The role of lung function testing in the identification and subsequent management of patients with lung disease resulting from a neonatal classification of BPD is reviewed based on the underlying pathophysiology of the disease.
Publisher: Elsevier BV
Date: 10-2019
DOI: 10.1016/J.JPEDS.2019.06.048
Abstract: To evaluate the role of upper airway dysfunction, indicated by altered vocal quality (dysphonia), on the respiratory symptoms of children surviving very preterm birth. Children born .05), except for the oscillatory mechanics measures, which were all at least 0.5 z score lower in the dysphonic group (Xrs The upper airway may play a role in the respiratory symptoms experienced by some very preterm children and should be considered by clinicians, especially when symptoms are in the presence of normal lung function and are refractory to treatment.
Publisher: European Respiratory Society (ERS)
Date: 17-09-2015
DOI: 10.1183/13993003.00622-2015
Abstract: Measures of ventilation distribution are promising for monitoring early lung disease in cystic fibrosis (CF). This study describes the cross-sectional and longitudinal impacts of pulmonary inflammation and infection on ventilation homogeneity in infants with CF. Infants diagnosed with CF underwent multiple breath washout (MBW) testing and bronchoalveolar lavage at three time points during the first 2 years of life. Measures were obtained for 108 infants on 156 occasions. Infants with a significant pulmonary infection at the time of MBW showed increases in lung clearance index (LCI) of 0.400 units (95% CI 0.150–0.648 p=0.002). The impact was long lasting, with previous pulmonary infection leading to increased ventilation inhomogeneity over time compared to those who remained free of infection (p .05). Infection with Haemophilus influenzae was particularly detrimental to the longitudinal lung function in young children with CF where LCI was increased by 1.069 units for each year of life (95% CI 0.484–1.612 p .001). Pulmonary infection during the first year of life is detrimental to later lung function. Therefore, strategies aimed at prevention, surveillance and eradication of pulmonary pathogens are paramount to preserve lung function in infants with CF.
Publisher: American Thoracic Society
Date: 2016
Publisher: Wiley
Date: 09-08-2012
DOI: 10.1002/PPUL.21515
Abstract: The upper airway shunt attenuates measurements of respiratory system impedance (Zrs), with greater impact in young children. Changes in respiratory system admittance, Ars (or Zrs(-1)), are theoretically independent of the shunt. This study compared the ability of Ars, to standard oscillatory outcomes, to determine respiratory disease and differentiate responses to inhaled bronchial challenges in the clinical setting. The forced oscillation technique (FOT) was used to establish reference equations for Ars in healthy preschool children, compare the change in Ars to standard oscillatory outcomes during bronchial challenge with inhaled adenosine-5'-monophosphate (AMP) and to inhaled bronchodilator in healthy children and those with respiratory disease. Children with respiratory disease had lower baseline Ars than healthy children (P < 0.05). However, there was no improved ability for Ars to differentiate between bronchodilator responses in healthy and disease populations. In contrast, the response to inhaled AMP occurred at a lower concentration, [25 (3.12-400) mg ml(-1) median (10th-90th centile)], as measured by Ars when compared to respiratory system resistance [225 (6.25-400) mg ml(-1) P = 0.016]. This study supports the use of Ars during inhaled challenges, but not in response to bronchodilation.
Publisher: European Respiratory Society (ERS)
Date: 26-11-2019
DOI: 10.1183/13993003.00753-2019
Abstract: Oscillometry (also known as the forced oscillation technique) measures the mechanical properties of the respiratory system (upper and intrathoracic airways, lung tissue and chest wall) during quiet tidal breathing, by the application of an oscillating pressure signal (input or forcing signal), most commonly at the mouth. With increased clinical and research use, it is critical that all technical details of the hardware design, signal processing and analyses, and testing protocols are transparent and clearly reported to allow standardisation, comparison and replication of clinical and research studies. Because of this need, an update of the 2003 European Respiratory Society (ERS) technical standards document was produced by an ERS task force of experts who are active in clinical oscillometry research. The aim of the task force was to provide technical recommendations regarding oscillometry measurement including hardware, software, testing protocols and quality control. The main changes in this update, compared with the 2003 ERS task force document are 1) new quality control procedures which reflect use of “within-breath” analysis, and methods of handling artefacts 2) recommendation to disclose signal processing, quality control, artefact handling and breathing protocols ( e.g. number and duration of acquisitions) in reports and publications to allow comparability and replication between devices and laboratories 3) a summary review of new data to support threshold values for bronchodilator and bronchial challenge tests and 4) updated list of predicted impedance values in adults and children.
Publisher: Wiley
Date: 11-12-2015
DOI: 10.1002/PPUL.22965
Publisher: Informa UK Limited
Date: 06-2013
DOI: 10.1586/ERS.13.25
Publisher: Public Library of Science (PLoS)
Date: 18-01-2013
Publisher: European Respiratory Society (ERS)
Date: 10-2018
DOI: 10.1183/23120541.00048-2018
Abstract: Evidence regarding the prevalence of expiratory flow limitation (EFL) during exercise and the ventilatory response to exercise in children born preterm is limited. This study aimed to determine the prevalence of EFL as well as contributing factors to EFL and the ventilatory response to exercise in preterm children with and without bronchopulmonary dysplasia (BPD). Preterm children (≤32 weeks gestational age) aged 9–12 years with (n=64) and without (n=42) BPD and term controls (n=43), performed an incremental treadmill exercise test with exercise tidal flow–volume loops. More preterm children with BPD (53%) had EFL compared with preterm children without BPD (26%) or term controls (28%) (p .05). The presence of EFL was independently associated with decreased forced expiratory volume in 1 s/forced vital capacity z-score and lower gestational age (p .05). There was no difference in peak oxygen uptake between preterm children with BPD and term controls (48.0 versus 48.4 mL·kg −1 ·min −1 p=0.063) however, children with BPD had a lower tidal volume at peak exercise (mean difference −27 mL·kg −1 , 95% CI −49– −5 p .05). Children born preterm without BPD had ventilatory responses to exercise similar to term controls. Expiratory flow limitation is more prevalent in children born preterm with BPD and is associated with airway obstruction and a lower gestational age.
Publisher: Wiley
Date: 19-10-2018
DOI: 10.1111/RESP.13201
Publisher: University of Chicago Press
Date: 11-2011
DOI: 10.1086/662557
Abstract: Marsupials are born with structurally immature lungs and rely, to varying degrees, on cutaneous gas exchange. With a gestation of 13 d and a birth weight of 13 mg, the fat-tailed dunnart (Sminthopsis crassicaudata) is one of the smallest and most immature marsupial newborns. We determined that the skin is almost solely responsible for gas exchange in the early neonatal period. Indeed, fewer than 35% of newborn dunnarts were observed to make any respiratory effort on the day of birth, with pulmonary ventilation alone not meeting the demand for oxygen until approximately 35 d postpartum. Despite the lack of pulmonary ventilation, the phrenic nerve had made contact with the diaphragm, and the respiratory epithelium was sufficiently developed to support gas exchange on the day of birth. Both type I and type II (surfactant-producing) alveolar epithelial cells were present, with fewer than 7% of the cells resembling undifferentiated alveolar epithelial precursor cells. The type I epithelial cells did, however, display thickened cytoplasmic extensions, leading to a high diffusion distance for oxygen. In addition, the architecture of the lung was immature, resembling the early canalicular stage, with alveolarization not commencing until 45 d postpartum. The pulmonary vasculature was also immature, with a centrally positioned single-capillary layer not evident until 100 d postbirth. These structural limitations may impede efficient pulmonary gas exchange, forcing the neonatal fat-tailed dunnart to rely predominately on its skin, a phenomenon supported by a low metabolic rate and small size.
Publisher: Wiley
Date: 06-06-2017
DOI: 10.1002/PPUL.23499
Abstract: A refined software algorithm was recently proposed for the analysis of infant multiple breath washout (MBW) measurements. The proposed algorithm uses the change in end-inspiratory molar mass between the wash-in and wash-out curves (EIMM-step) to define the required step response correction of the MM signal and is assumed to provide an accurate evaluation of complete washout of the tracer gas, in comparison to the current software algorithm which applies the change in end-expiratory molar mass (EEMM)-step. We aimed to evaluate the use of the EIMM-step method in a broad range of infants. We performed retrospective analyses comparing the EIMM- and EEMM-step change methods in MBW data collected from infants with cystic fibrosis (CF), infants born preterm, and healthy infants using an ultrasonic flowmeter. We found that the EIMM-step correction significantly increased LCI and functional residual capacity (FRC) in infants with CF, preterm infants, and healthy infants compared with the EEMM-step method. In addition, more than half the measurements that were technically acceptable and repeatable using the EEMM-step correction in healthy infants were excluded after using the EIMM-step correction. We found a large difference between the EIMM- and EEMM-steps in healthy infants indicating incomplete washout, suggesting the need for a longer washout time with using the EIMM-step analysis method. The data indicates that the EIMM-step analysis method may have the potential to generate false abnormal LCI values in in iduals without lung disease. Revised normative data may be required if this method is universally adopted. Pediatr Pulmonol. 2017 :10-13. © 2016 Wiley Periodicals, Inc.
Publisher: European Respiratory Society (ERS)
Date: 29-08-2013
Publisher: European Respiratory Society (ERS)
Date: 06-04-2023
DOI: 10.1183/23120541.00046-2023
Abstract: Few studies exist investigating lung function trajectories of those born preterm however growing evidence suggests some in iduals experience increasing airway obstruction throughout life. Here we use the studies identified in a recent systematic review to provide the first meta-analysis investigating the impact of preterm birth on airway obstruction measured by the forced expiratory volume in 1 s (FEV 1 ) to forced vital capacity (FVC) ratio. Cohorts were included for analysis if they reported FEV 1 /FVC in survivors of preterm birth ( weeks’ gestation) and control populations born at term. Meta-analysis was performed using a random effect model, expressed as standardised mean difference (SMD). Meta-regression was conducted using age and birth year as moderators. 55 cohorts were eligible, 35 of which defined groups with bronchopulmonary dysplasia (BPD). Compared to control populations born at term, lower values of FEV 1 /FVC were seen in all in iduals born preterm (SMD −0.56), with greater differences seen in those with BPD (SMD −0.87) than those without BPD (SMD −0.45). Meta-regression identified age as a significant predictor of FEV 1 /FVC in those with BPD with the FEV 1 /FVC ratio moving −0.04 sd s away from the term control population for every year of increased age. Survivors of preterm birth have significantly increased airway obstruction compared to those born at term with larger differences in those with BPD. Increased age is associated with a decline in FEV 1 /FVC values suggesting increased airway obstruction over the life course.
Publisher: Wiley
Date: 25-07-2023
DOI: 10.1111/DMCN.15714
Abstract: To establish the burden of respiratory illness in cerebral palsy (CP) on the Western Australian health care system by quantifying the costs of respiratory hospitalizations in children with CP, compared with non‐respiratory hospitalizations. A 2‐year (2014–2015) retrospective study using linked hospital data (excluding emergency department visits), in a population of children with CP in Western Australia aged 18 years and under (median age at hospitalization 7 years interquartile range 5–12 years). In 671 in iduals (57% male) there were 726 emergency hospitalizations, and 1631 elective hospitalizations. Although there were more elective hospitalizations, emergency hospitalizations were associated with longer stays in hospital, and more days in an intensive care unit, resulting in a higher total cost of emergency hospitalizations than elective hospitalizations (total costs: emergency AU$7 748 718 vs elective AU$6 738 187). ‘Respiratory’ was the leading cause of emergency hospitalizations, contributing to 36% of all emergency admission costs. For a group of high‐cost inpatient users (top 5% of in iduals with the highest total inpatient costs) the most common reason for hospitalization was ‘respiratory’. Where non‐respiratory admissions were complicated by an additional respiratory diagnosis, length of stay was greater. Respiratory hospitalizations in CP are a significant driver of health care costs. In the paediatric group, they are a burden for a subgroup of children with CP.
Publisher: Wiley
Date: 18-03-2019
DOI: 10.1002/PPUL.24286
Abstract: Increasing evidence suggests the forced oscillation technique (FOT) has the capacity to provide non-invasive monitoring and diagnosis of respiratory disease in young children. However, which FOT outcomes provide the most pertinent clinical information is currently unknown. The aim of this study was to determine which FOT outcomes were most sensitive for differentiating between health and specific childhood respiratory disease. Respiratory impedance was measured using a commercial device (i2M, Chess Medical, Belgium) in children aged between 3 and 7 years, who had been diagnosed with either cystic fibrosis (N = 84), asthma (N = 99) or were born very preterm (N = 114). Z-scores were calculated for respiratory system resistance (Rrs) and reactance (Xrs) at 6, 8, and 10 Hz, the resonance frequency (Fres), frequency dependence (Fdep The FOT outcomes best able to discern between health and disease were Fres (P < 0.0001) in cystic fibrosis, Fres (P < 0.0001) in asthma and Xrs
Publisher: Public Library of Science (PLoS)
Date: 19-08-2011
Publisher: American Thoracic Society
Date: 15-11-2014
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.PRRV.2018.11.003
Abstract: Birth prior to term interrupts the normal development of the respiratory system and consequently results in poor respiratory outcomes that persist throughout childhood. The mechanisms underpinning these poor respiratory outcomes are not well understood, but intrinsic abnormalities within the airway epithelium may be a contributing factor. Current evidence suggests that the airway epithelium is both structurally and functionally abnormal after preterm birth, with reports of epithelial thickening and goblet cell hyperplasia in addition to increased inflammation and apoptosis in the neonatal intensive care unit. However, studies focusing on the airway epithelium are limited and many questions remain unanswered including whether abnormalities are a direct result of interrupted development, a consequence of exposure to inflammatory stimuli in the perinatal period or a combination of the two. In addition, the difficulty of accessing airway tissue has resulted in the majority of evidence being collected in the pre-surfactant era which may not reflect contemporary preterm birth. This review examines the consequences of preterm birth on the airway epithelium and explores the clinical relevance of currently available models whilst highlighting the need to develop a clinically relevant in vitro model to help further our understanding of the airway epithelium in preterm birth.
Publisher: Informa UK Limited
Date: 13-12-2017
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.PRRV.2018.12.002
Abstract: Bronchopulmonary dysplasia (BPD), also known as Chronic Lung Disease (CLD), is a chronic respiratory condition of prematurity with potential life-long consequences for respiratory well-being. BPD was first described by Northway in 1967, when the mean gestation of preterm infants with BPD was 34 weeks' postmenstrual age (PMA). Survival of preterm infants at lower gestational ages has increased steadily since 1967 associated with marked improvements in respiratory management of respiratory distress syndrome. Currently, BPD develops in approximately 45 % of all infants born extremely preterm (Stoll et al., 2015). These smaller and more immature babies are born during the late canalicular or early saccular period of lung development. Not surprisingly, the pathophysiology of BPD also evolved since classical BPD was described. As the nature and our understanding of BPD evolved, so too the definitions and classification of BPD changed over time. These differing and ever-changing definitions h er clinical benchmarking as they are interpreted and applied inconsistently, and define BPD and its severity by non-standardised treatments rather than independent evaluations of structure or function. A standardised, unambiguous definition and classification of BPD is essential for evaluation and improvement in clinical practice, both within an in idual unit, as well as across and between neonatal networks. The determination and implementation of diagnostic criteria and severity classification that is standardised, globally applicable, and that has prognostic utility for clinical outcomes and guidance of ongoing respiratory management remain of utmost importance. This review describes the evolution of BPD definitions, evaluates the benefits and limitations of each approach, and discusses alternative approaches that may improve the functional assessment of BPD severity.
Start Date: 2014
End Date: 2017
Funder: National Health and Medical Research Council
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: National Health and Medical Research Council
View Funded ActivityStart Date: 2018
End Date: 2020
Funder: National Health and Medical Research Council
View Funded Activity