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Talaat M, Si XA, Kitaoka H, Xi J. Septal destruction enhances chaotic mixing and increases cellular doses of nanoparticles in emphysematous acinus. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/abe0f8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
One hallmark of emphysema is the breakdown of inter-alveolar septal walls in pulmonary acini. How the acinar dosimetry of environmental aerosols varies at different stages of emphysema remains unclear; this is specifically pertinent to users of tobacco products, which is the leading cause of emphysema. The objective of this study is to systematically assess the impacts of septal destruction on the behavior and fate of nanoparticles (1–800 nm) in a pyramid-shaped sub-acinar model consisting of 496 alveoli. Four diseased geometry variants were created by gradually removing the septal walls from the base model. Particle motions within the acinar region were tracked for particles raging 1–800 nm at four emphysema stages using a well-tested Lagrangian tracking model. Both spatial profile and temporal variation of particle deposition were predicted in healthy and diseased sub-acinar geometries on both a total and regional basis. Results show large differences in airflow and particle dynamics among different emphysema stages. Large differences in particle dynamics are also observed among different particle sizes, with one order of magnitude’s variation in the speeds of particles of 1, 10, and 200 nm. The destruction of septal walls also changed the deposition mechanisms, shifting from connective diffusion to chaotic mixing with emphysema progression. The sub-acinar dosimetry became less sensitive to particle size variation with more septal destructions. The lowest retention rate was found at 200–500 nm in the healthy sub-acinar geometry, but at 800 nm in all emphysematous models considered. The acinus-averaged dose for nanoparticles (1–800 nm) increases with aggravating septal destructions, indicating an even higher risk to the acinus at later emphysema stages.
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Hoesterey D, Das N, Janssens W, Buhr RG, Martinez FJ, Cooper CB, Tashkin DP, Barjaktarevic I. Spirometric indices of early airflow impairment in individuals at risk of developing COPD: Spirometry beyond FEV 1/FVC. Respir Med 2019; 156:58-68. [PMID: 31437649 DOI: 10.1016/j.rmed.2019.08.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 07/08/2019] [Accepted: 08/07/2019] [Indexed: 01/24/2023]
Abstract
Spirometry is the current gold standard for diagnosing and monitoring the progression of Chronic Obstructive Pulmonary Disease (COPD). However, many current and former smokers who do not meet established spirometric criteria for the diagnosis of this disease have symptoms and clinical courses similar to those with diagnosed COPD. Large longitudinal observational studies following individuals at risk of developing COPD offer us additional insight into spirometric patterns of disease development and progression. Analysis of forced expiratory maneuver changes over time may allow us to better understand early changes predictive of progressive disease. This review discusses the theoretical ability of spirometry to capture fine pathophysiologic changes in early airway disease, highlights the shortcomings of current diagnostic criteria, and reviews existing evidence for spirometric measures which may be used to better detect early airflow impairment.
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Affiliation(s)
- Daniel Hoesterey
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Nilakash Das
- Laboratory of Respiratory Diseases, Department of Chronic Diseases, Metabolism and Ageing, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Wim Janssens
- Laboratory of Respiratory Diseases, Department of Chronic Diseases, Metabolism and Ageing, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Russell G Buhr
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA; Department of Health Policy and Management, Fielding School of Public Health, University of California, Los Angeles, USA; Medical Service, Greater Los Angeles Veterans Affairs Healthcare System, Los Angeles, USA
| | | | - Christopher B Cooper
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA; Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Donald P Tashkin
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Igor Barjaktarevic
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, USA.
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Classification of Tidal Breathing Airflow Profiles Using Statistical Hierarchal Cluster Analysis in Idiopathic Pulmonary Fibrosis. Med Sci (Basel) 2018; 6:medsci6030075. [PMID: 30213144 PMCID: PMC6165053 DOI: 10.3390/medsci6030075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 09/03/2018] [Indexed: 12/13/2022] Open
Abstract
In idiopathic pulmonary fibrosis (IPF) breathing pattern changes with disease progress. This study aims to determine if unsupervised hierarchal cluster analysis (HCA) can be used to define airflow profile differences in people with and without IPF. This was tested using 31 patients with IPF and 17 matched healthy controls, all of whom had their lung function assessed using spirometry and carbon monoxide CO transfer. A resting tidal breathing (RTB) trace of two minutes duration was collected at the same time. A Euclidian distance technique was used to perform HCA on the airflow data. Four distinct clusters were found, with the majority (18 of 21, 86%) of the severest IPF participants (Stage 2 and 3) being in two clusters. The participants in these clusters exhibited a distinct minute ventilation (p < 0.05), compared to the other two clusters. The respiratory drive was greatest in Cluster 1, which contained many of the IPF participants. Unstructured HCA was successful in recognising different airflow profiles, clustering according to differences in flow rather than time. HCA showed that there is an overlap in tidal airflow profiles between healthy RTB and those with IPF. The further application of HCA in recognising other respiratory disease is discussed.
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Motamedi-Fakhr S, Iles R, Barney A, de Boer W, Conlon J, Khalid A, Wilson RC. Evaluation of the agreement of tidal breathing parameters measured simultaneously using pneumotachography and structured light plethysmography. Physiol Rep 2018; 5:5/3/e13124. [PMID: 28193785 PMCID: PMC5309576 DOI: 10.14814/phy2.13124] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 12/12/2016] [Accepted: 12/18/2016] [Indexed: 11/24/2022] Open
Abstract
Structured light plethysmography (SLP) is a noncontact, noninvasive, respiratory measurement technique, which uses a structured pattern of light and two cameras to track displacement of the thoraco–abdominal wall during tidal breathing. The primary objective of this study was to examine agreement between tidal breathing parameters measured simultaneously for 45 sec using pneumotachography and SLP in a group of 20 participants with a range of respiratory patterns (“primary cohort”). To examine repeatability of the agreement, an additional 21 healthy subjects (“repeatability cohort”) were measured twice during resting breathing and once during increased respiratory rate (RR). Breath‐by‐breath and averaged RR, inspiratory time (tI), expiratory time (tE), total breath time (tTot), tI/tE, tI/tTot, and IE50 (inspiratory to expiratory flow measured at 50% of tidal volume) were calculated. Bland–Altman plots were used to assess the agreement. In the primary cohort, breath‐by‐breath agreement for RR was ±1.44 breaths per minute (brpm). tI, tE, and tTot agreed to ±0.22, ±0.29, and ±0.32 sec, respectively, and tI/tE, tI/tTot, and IE50/IE50SLP to ±0.16, ±0.05, and ±0.55, respectively. When averaged, agreement for RR was ±0.19 brpm. tI, tE, and tTot were within ±0.16, ±0.16, and ±0.07 sec, respectively, and tI/tE, tI/tTot, and IE50 were within ±0.09, ±0.03, and ±0.25, respectively. A comparison of resting breathing demonstrated that breath‐by‐breath and averaged agreements for all seven parameters were repeatable (P > 0.05). With increased RR, agreement improved for tI, tE, and tTot (P ≤ 0.01), did not differ for tI/tE, tI/tTot, and IE50 (P > 0.05) and reduced for breath‐by‐breath (P < 0.05) but not averaged RR (P > 0.05).
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Affiliation(s)
| | - Richard Iles
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Anna Barney
- ISVR, Faculty of Engineering and Environment, University of Southampton, Southampton, UK
| | | | - Jenny Conlon
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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A Novel Approach to the Identification of Compromised Pulmonary Systems in Smokers by Exploiting Tidal Breathing Patterns. SENSORS 2018; 18:s18051322. [PMID: 29693559 PMCID: PMC5981858 DOI: 10.3390/s18051322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 11/16/2022]
Abstract
Smoking causes unalterable physiological abnormalities in the pulmonary system. This is emerging as a serious threat worldwide. Unlike spirometry, tidal breathing does not require subjects to undergo forceful breathing maneuvers and is progressing as a new direction towards pulmonary health assessment. The aim of the paper is to evaluate whether tidal breathing signatures can indicate deteriorating adult lung condition in an otherwise healthy person. If successful, such a system can be used as a pre-screening tool for all people before some of them need to undergo a thorough clinical checkup. This work presents a novel systematic approach to identify compromised pulmonary systems in smokers from acquired tidal breathing patterns. Tidal breathing patterns are acquired during restful breathing of adult participants. Thereafter, physiological attributes are extracted from the acquired tidal breathing signals. Finally, a unique classification approach of locally weighted learning with ridge regression (LWL-ridge) is implemented, which handles the subjective variations in tidal breathing data without performing feature normalization. The LWL-ridge classifier recognized compromised pulmonary systems in smokers with an average classification accuracy of 86.17% along with a sensitivity of 80% and a specificity of 92%. The implemented approach outperformed other variants of LWL as well as other standard classifiers and generated comparable results when applied on an external cohort. This end-to-end automated system is suitable for pre-screening people routinely for early detection of lung ailments as a preventive measure in an infrastructure-agnostic way.
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Sun JJ, Ray RS. Tg(Th-Cre)FI172Gsat ( Th-Cre) defines neurons that are required for full hypercapnic and hypoxic reflexes. Biol Open 2017; 6:1200-1208. [PMID: 28684394 PMCID: PMC5576086 DOI: 10.1242/bio.026823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The catecholaminergic (CA) system has been implicated in many facets of breathing control and offers an important target to better comprehend the underlying etiologies of both developmental and adult respiratory pathophysiologies. Here, we used a noninvasive DREADD-based pharmacogenetic approach to acutely perturb Tg(Th-Cre)FI172Gsat (Th-Cre)-defined neurons in awake and unrestrained mice in an attempt to characterize CA function in breathing. We report that clozapine-N-oxide (CNO)-DREADD-mediated inhibition of Th-Cre-defined neurons results in blunted ventilatory responses under respiratory challenge. Under a hypercapnic challenge (5% CO2/21% O2/74% N2), perturbation of Th-Cre neurons results in reduced fR, and . Under a hypoxic challenge (10% O2/90% N2), we saw reduced fR, and , in addition to instability in both interbreath interval and tidal volume, resulting in a Cheyne-Stokes-like respiratory pattern. These findings demonstrate the necessity of Th-Cre-defined neurons for the hypercapnic and hypoxic ventilatory responses and breathing stability during hypoxia. However, given the expanded non-CA expression domains of the Tg(Th-Cre)FI172Gsat mouse line found in the brainstem, full phenotypic effect cannot be assigned solely to CA neurons. Nonetheless, this work identifies a key respiratory population that may lead to further insights into the circuitry that maintains respiratory stability in the face of homeostatic challenges. Summary: DREADD-mediated silencing of Tg(Th-Cre)FI172Gsat-defined neurons in adult mice results in reduced O2 and CO2 breathing reflexes and respiratory rhythm destabilization under hypoxic challenge, resembling Cheyne-Stokes respiration.
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Affiliation(s)
- Jenny J Sun
- Baylor College of Medicine, Department of Neuroscience, 1 Baylor Plaza, T707, Houston, TX 77030, USA
| | - Russell S Ray
- Baylor College of Medicine, Department of Neuroscience, 1 Baylor Plaza, T707, Houston, TX 77030, USA
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Sinharay A, Rakshit R, Khasnobish A, Chakravarty T, Ghosh D, Pal A. The Ultrasonic Directional Tidal Breathing Pattern Sensor: Equitable Design Realization Based on Phase Information. SENSORS (BASEL, SWITZERLAND) 2017; 17:E1853. [PMID: 28800103 PMCID: PMC5579868 DOI: 10.3390/s17081853] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 12/03/2022]
Abstract
Pulmonary ailments are conventionally diagnosed by spirometry. The complex forceful breathing maneuver as well as the extreme cost of spirometry renders it unsuitable in many situations. This work is aimed to facilitate an emerging direction of tidal breathing-based pulmonary evaluation by designing a novel, equitable, precise and portable device for acquisition and analysis of directional tidal breathing patterns, in real time. The proposed system primarily uses an in-house designed blow pipe, 40-kHz air-coupled ultrasound transreceivers, and a radio frequency (RF) phase-gain integrated circuit (IC). Moreover, in order to achieve high sensitivity in a cost-effective design philosophy, we have exploited the phase measurement technique, instead of selecting the contemporary time-of-flight (TOF) measurement; since application of the TOF principle in tidal breathing assessments requires sub-micro to nanosecond time resolution. This approach, which depends on accurate phase measurement, contributed to enhanced sensitivity using a simple electronics design. The developed system has been calibrated using a standard 3-L calibration syringe. The parameters of this system are validated against a standard spirometer, with maximum percentage error below 16%. Further, the extracted respiratory parameters related to tidal breathing have been found to be comparable with relevant prior works. The error in detecting respiration rate only is 3.9% compared to manual evaluation. These encouraging insights reveal the definite potential of our tidal breathing pattern (TBP) prototype for measuring tidal breathing parameters in order to extend the reach of affordable healthcare in rural regions and developing areas.
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Affiliation(s)
| | - Raj Rakshit
- TCS Research and Innovation, Kolkata 700156, India.
| | | | | | - Deb Ghosh
- TCS Research and Innovation, Kolkata 700156, India.
| | - Arpan Pal
- TCS Research and Innovation, Kolkata 700156, India.
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Motamedi-Fakhr S, Wilson RC, Iles R. Tidal breathing patterns derived from structured light plethysmography in COPD patients compared with healthy subjects. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2016; 10:1-9. [PMID: 28096696 PMCID: PMC5214700 DOI: 10.2147/mder.s119868] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Differences in tidal breathing patterns have been reported between patients with chronic obstructive pulmonary disease (COPD) and healthy individuals using traditional measurement techniques. This feasibility study examined whether structured light plethysmography (SLP) - a noncontact, light-based technique - could also detect differences in tidal breathing patterns between patients with COPD and healthy subjects. PATIENTS AND METHODS A 5 min period of tidal (quiet) breathing was recorded in each patient with COPD (n=31) and each healthy subject (n=31), matched for age, body mass index, and sex. For every participant, the median and interquartile range (IQR; denoting within-subject variability) of 12 tidal breathing parameters were calculated. Individual data were then combined by cohort and summarized by its median and IQR. RESULTS After correction for multiple comparisons, inspiratory time (median tI) and its variability (IQR of tI) were lower in patients with COPD (p<0.001 and p<0.01, respectively) as were ratios derived from tI (tI/tE and tI/tTot, both p<0.01) and their variability (p<0.01 and p<0.05, respectively). IE50SLP (the ratio of inspiratory to expiratory flow at 50% tidal volume calculated from the SLP signal) was higher (p<0.001) in COPD while SLP-derived time to reach peak tidal expiratory flow over expiratory time (median tPTEFSLP/tE) was shorter (p<0.01) and considerably less variable (p<0.001). Thoraco-abdominal asynchrony was increased (p<0.05) in COPD. CONCLUSION These early observations suggest that, like traditional techniques, SLP is able to detect different breathing patterns in COPD patients compared with subjects with no respiratory disease. This provides support for further investigation into the potential uses of SLP in assessing clinical conditions and interventions.
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Affiliation(s)
| | | | - Richard Iles
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
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Lee J, Lee CT, Lee JH, Cho YJ, Park JS, Oh YM, Lee SD, Yoon HI. Graphic analysis of flow-volume curves: a pilot study. BMC Pulm Med 2016; 16:18. [PMID: 26801632 PMCID: PMC4724104 DOI: 10.1186/s12890-016-0182-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 01/15/2016] [Indexed: 12/02/2022] Open
Abstract
Background Conventional spirometric parameters have shown poor correlation with symptoms and health status of chronic obstructive pulmonary disease (COPD). While it is well-known that the pattern of the expiratory flow-volume curve (EFVC) represents ventilatory dysfunction, little attempts have been made to derive quantitative parameters by analyzing the curve. In this study, we aimed to derive useful parameters from EFVC via graphic analysis and tried to validate them in patients with COPD. Methods Using Graphical Analysis 3.4 Vernier Software, we derived from the EFVC such parameters as area of obstruction (Ao), area of triangle (AT), area of rectangle (AR) and ratio of volume at 75 and 25 % peak expiratory flow (PEF) (0.25/0.75 V). For validation, we reviewed clinical and spirometric data of 61 COPD patients from Seoul National University Airway Registry (SNUAR) and Korean obstructive Lung Disease (KOLD) cohorts. Results Of all parameters, only RV/TLC significantly correlated with scores from St. George’s Respiratory Questionnaire (SGRQ) (r = 0.447, p = 0.037). Six-minute walking distance (6MWD) highly correlated with Ao/AR (r = −0.618, p = 0.005) and Ao/PEF (r = −0.581, p = 0.009) whereas neither FEV1 nor FEV1/FVC had significant correlation with 6MWD. Conclusions Ao/AR and Ao/PEF are promising parameters which correlate well with the exercising capacity of COPD patients. Electronic supplementary material The online version of this article (doi:10.1186/s12890-016-0182-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jungsil Lee
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
| | - Choon-Taek Lee
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
| | - Jae Ho Lee
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
| | - Young-Jae Cho
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
| | - Jong Sun Park
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
| | - Yeon-Mok Oh
- Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
| | - Sang-Do Lee
- Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
| | - Ho Il Yoon
- Department of Internal Medicine, Seoul National University College of Medicine, Division of Pulmonary and Critical Care Medicine, Seoul National University Bundang Hospital, 166, Gumi-ro, Bundang-gu, 463-707, Seongnam-si, Gyeonggi-do, Republic of Korea.
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Olukogbon KL, Thomas P, Colasanti R, Hope-Gill B, Williams EM. Breathing pattern and breathlessness in idiopathic pulmonary fibrosis: An observational study. Respirology 2015; 21:344-9. [PMID: 26597757 DOI: 10.1111/resp.12686] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/10/2015] [Accepted: 08/25/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Idiopathic pulmonary fibrosis (IPF) is characterized by progressive decline in lung function and increasing dyspnoea. The aim of this study was to investigate the relationship among IPF, pulmonary function, resting tidal breathing patterns and level of breathlessness. METHODS Thirty-one participants with IPF and 17 matched healthy controls underwent lung function testing, followed by a 2-min period of resting tidal breathing. The IPF cohort was stratified according to disease severity, based on their forced vital capacity and diffusion capacity for carbon monoxide. RESULTS In comparison to the healthy controls, the IPF cohort showed a higher tidal volume, VT , of 0.22 L (P = 0.026) and a raised minute ventilation in the severest IPF group, while no differences in the timing of inspiration or expiration were observed. In the IPF cohort, the ratio of VT to forced vital capacity was around 15% higher. These changes corresponded with an increase in the self-reported sensation of breathlessness. CONCLUSION Those with IPF increased their depth of breathing with worsening disease severity, with IPF-induced changes in pulmonary function and breathlessness associated with an altered tidal breathing pattern.
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Affiliation(s)
| | - Paul Thomas
- Lung Function Laboratory, University Hospital Llandough, Cardiff, UK
| | - Ricardo Colasanti
- Computation Institute, University of Chicago, Chicago, Illinois, USA
| | - Ben Hope-Gill
- Department of Respiratory Medicine, University Hospital Llandough, Cardiff, UK
| | - Edgar Mark Williams
- Faculty of Life Sciences and Education, University of South Wales, Cardiff, UK
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Bentsen MHL, Haaland ØA, Lønning LB, Gudmundsdottir HK, Markestad T, Halvorsen T. A new non-invasive method of infant spirometry demonstrates a level of repeatability that is comparable to traditional methods. Acta Paediatr 2015; 104:1130-7. [PMID: 26287280 DOI: 10.1111/apa.13155] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 04/09/2015] [Accepted: 08/13/2015] [Indexed: 01/19/2023]
Abstract
AIM The FloRight system provides novel non-invasive infant spirometry based on electromagnetic inductance plethysmography. We investigated the consistency of repeated measurements carried out in a Norwegian neonatal intensive care unit (NICU) using the system and how well these were tolerated. METHODS Tidal flow-volume loops were obtained from 10 preterm infants at discharge, 10 stable growing preterm infants weighing about 1500 g and 10 term-born infants. A nurse experienced with the system measured all patients before and after meals, and these measurements were repeated by nurses new to the system. RESULTS The measurements were well tolerated by the infants. The repeatability for the two parameters 'tidal volume' (Vt) and 'time to peak tidal expiratory flow to total expiratory time' (Tptef/Te) were relatively poor, similar to previous methods. However, the repeatability was good for the new 'flow-volume gravity mid-point' (FVg) parameter. Repeatability was better for term than preterm infants, when measurements were obtained by the experienced nurse and for measurements carried out before meals. CONCLUSION The FloRight system proved feasible in a NICU setting. The repeatability of the lung function measurements was similar to those reported for traditional infant spirometry. The nurse's experience and the relationship to meals appeared to be important.
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Affiliation(s)
- Mariann H. L. Bentsen
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
- Department of Clinical Science, Faculty of Medicine and Odontology; University of Bergen; Bergen Norway
| | - Øystein A. Haaland
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
- Department of Global Public Health and Primary Care; University of Bergen; Bergen Norway
| | - Lise B. Lønning
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
| | | | - Trond Markestad
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
- Department of Clinical Science, Faculty of Medicine and Odontology; University of Bergen; Bergen Norway
| | - Thomas Halvorsen
- Department of Pediatrics; Haukeland University Hospital; Bergen Norway
- Department of Clinical Science, Faculty of Medicine and Odontology; University of Bergen; Bergen Norway
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