Development of a Non-Invasive Dynamic Pulmonary Function Monitor

2012 ◽  
Vol 6 (2) ◽  
Author(s):  
Michael D. Sokoloff ◽  
Larry Bortner ◽  
Ralph J. Panos
Keyword(s):  
Pulmonary Function ◽  
Respiratory Diseases ◽  
Inert Gas ◽  
Airflow Limitation ◽  
Small Airways ◽  
Specific Measure ◽  
Gas Concentration ◽  
Non Invasive ◽  
Ventilation Inhomogeneity ◽  
Mass Spectrometer Sampling

Characterizing the complexity of airflow limitation in diagnosing and assessing disease severity in asthma, COPD, cystic fibrosis, and other respiratory diseases can help guide clinicians toward the most appropriate treatments. Current technologies allow obstructive lung disease to be measured with about 5%−10% precision. A noninvasive dynamic pulmonary function monitor (DPFM) can quantify ventilation inhomogeneities, such as those originating in partially blocked or constricted small airways, with 1% precision if inert gas concentrations can be measured accurately and precisely over three to four decades of sensitivity. We have studied the precision and linearity of a commercially available mass spectrometer, sampling the gas exhaled by a mechanical lung analog, mimicking a multibreath inert gas washout measurement. The root mean square deviation of the inert gas concentration measured for each “breath,” compared to the expected value for a purely exponential decay, is found to be about 1.1% over three decades of concentration. The corresponding overall impairment, a specific measure of ventilation inhomogeneity, is found to be about 0.2%, which indicates that were inhomogeneities observed, the corresponding impairment could be measured with 1% precision.

scholarly journals Airflow obstruction in sarcoidosis

2013 ◽  
Vol 66 (suppl. 1) ◽  
pp. 39-41
Author(s):  
Aleksandra Dudvarski-Ilic ◽  
Spasoje Popevic ◽  
Mihailo Stjepanovic ◽  
Branislav Gvozdenovic ◽  
Branislava Milenkovic ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Pulmonary Function ◽  
Airflow Obstruction ◽  
Lung Parenchyma ◽  
Forced Expiratory Volume ◽  
Airflow Limitation ◽  
Small Airways ◽  
Lung Capacity ◽  
Late Stages ◽  
Expiratory Flow Rates

Introduction. Aberrations in pulmonary function test are present in about 20% of patients with radiographic stage I sarcoidosis, whereas the pulmonary function is damaged in 40-80% of patients with parenchymal infiltrates (stages II, III or IV). Discussion and Review of Literature. Reductions in lung volumes (vital capacity and total lung capacity) are characteristic. The diffusing capacity of lungs is often reduced, but it is less pronounced in sarcoidosis than in idiopathic pulmonary fibrosis. Oxygenation is usually preserved until late in the course of sarcoidosis. Airflow obstruction (reduced forced expiratory volume in one second and expiratory flow rates) and bronchial hyper-reactivity occur in 30-50% of sarcoidosis patients with pulmonary parenchymal involvement. Conclusion. While restrictive spirometry pattern could easily be explained by fibrous changes in lung parenchyma, especially in late stages of the lung disease, pathogenesis of airflow limitation can be attributed mostly to endobronchial involvement (intraluminal granuloma or fibrous scars formation), airway compression due to enlarged lymph nodes and to distortion of small airways due to established pulmonary fibrosis.

scholarly journals Detection of Peripheral Ventilation Inhomogeneity in Smokers

1997 ◽  
Vol 4 (1) ◽  
pp. 27-33
Author(s):  
DJ Cotton ◽  
JT Mink ◽  
BL Graham
Keyword(s):  
Predictive Value ◽  
Vital Capacity ◽  
Phase Iii ◽  
Airflow Limitation ◽  
Mixing Efficiency ◽  
Breath Holding ◽  
Small Airways ◽  
Test Gas ◽  
Ventilation Inhomogeneity ◽  
Lung Periphery

BACKGROUND: In smokers, ‘small airways’ narrowing alters the conventional, vital capacity single breath washout (SBWVC). Although, in some studies, the test predicts smokers at risk of developing chronic airflow limitation, its wide variability partly explains its poor positive predictive value. An alternative explanation for the test’s poor predictive value is that it may not accurately reflect small airway narrowing in the lung periphery.OBJECTIVE: To determine whether smoke-induced increases in ventilation inhomogeneity differ between SBWVCmanoeuvres, which augment topographical (apex-to-base) ventilation inhomogeneity, and submaximal manoeuvres (SBWSM), which enhance peripheral ventilation inhomogeneity.STUDY GROUP AND DESIGN: Cross-sectional study of 21 current smokers and 21 nonsmokers with similar age and forced expiratory volumes in 1 s (FEV1).METHODS: Smokers and nonsmokers performed SBW with either slow vital capacity inhalation and exhalation of test gas without breath holding (SBWVC); or slow inhalation of test gas from functional residual capacity to one-half inspiratory capacity and, after 0 s or 10 s of breath holding, slow exhalation to residual volume (SBWSM). For all SBW the normalized phase III helium slope (Sn), closing capacity (CC) as a percentage of total lung capacity (TLC) and mixing efficiency (Emix) were measured.RESULTS: For SBWVC, smoking had no effect on Snor Emix. However, CC/TLC was increased in smokers (P<0.05), but did not correlate with pack years or age. For SBWSM, smoking had no effect on Emixor CC/TLC, but resulted in a steeper Sn(P <0.05), which decreased more with breath holding (P<0.01) and correlated with pack years (P<0.05) at 0 s but not 10 s of breath holding.CONCLUSIONS: In smokers with normal FEV1, SBWSM manoeuvres reveal increases in breath hold time-dependent ventilation inhomogeneity in the lung periphery, not detected by conventional SBWVC.

Lung clearance index: a new measure of ventilation inhomogeneity in childhood respiratory diseases

2021 ◽  
Vol 17 ◽  
Author(s):  
Giuseppe Fabio Parisi ◽  
Emanuela Pignatone ◽  
Maria Papale ◽  
Enza Mulé ◽  
Sara Manti ◽  
...  
Keyword(s):  
Respiratory Diseases ◽  
Small Airways ◽  
Early Assessment ◽  
Lung Clearance ◽  
Ventilation Inhomogeneity ◽  
Lung Clearance Index ◽  
Multiple Breath Washout ◽  
Primary Test ◽  
Forced Breathing

: Conventional spirometry has long been considered the primary test for assessing respiratory function deficits in children and adults. However, the need to perform forced breathing maneuvers can make it challenging to perform these examinations in an uncooperative child. For these reasons, techniques such as gas dilutions and the multiple-breath-washout (MBW) method have been implemented because they allow for early assessment of damage to the small airways. These methods permit the determination of the possible presence of ventilatory inhomogeneity in the lungs by analyzing the clearance of an inert gas used as a tracer. The equipment consists of a mass spectrometer combined with a flow meter. The Lung Clearance Index (LCI) is most often used to evaluate ventilatory inhomogeneity. This narrative review aimed to review the literature on technical and practical aspects of the MBW test and evaluate the clinical implications of the LCI in pediatric respiratory disease.

scholarly journals Exercise tolerance and dyspnea in patients with chronic obstructive pulmonary disease

2010 ◽  
Vol 67 (1) ◽  
pp. 36-41
Author(s):  
Ivan Cekerevac ◽  
Zorica Lazic ◽  
Ljiljana Novkovic ◽  
Marina Petrovic ◽  
Vojislav Cupurdija ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Function ◽  
Exercise Tolerance ◽  
Airflow Limitation ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Diffusion Capacity ◽  
Tolerance Level ◽  
Lung Hyperinflation ◽  
Copd Patients

Background/Aim. Peripheral muscle weakness and nutritional disorders, firstly loss of body weight, are common findings in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to analyse the impact of pulmonary function parameters, nutritional status and state of peripheral skeletal muscles on exercise tolerance and development of dyspnea in COPD patients. Methods. Thirty COPD patients in stable state of disease were analyzed. Standard pulmonary function tests, including spirometry, body pletysmography, and measurements of diffusion capacity were performed. The 6-minute walking distance test (6MWD) was done in order to assess exercise tolerance. Level of dyspnea was measured with Borg scale. In all patients midthigh muscle cross-sectional area (MTCSA) was measured by computerized tomography scan. Nutritional status of patients was estimated according to body mass index (BMI). Results. Statistically significant correlations were found between parameters of pulmonary function and exercise tolerance. Level of airflow limitation and lung hyperinflation had significant impact on development of dyspnea at rest and especially after exercise. Significant positive correlation was found between MTCSA and exercise tolerance. Patients with more severe airflow limitation, lung hyperinflation and reduced diffusion capacity had significantly lower MTCSA. Conclusion. Exercise tolerance in COPD patients depends on severity of bronchoobstruction, lung hyperinflation and MTCSA. Severity of bronchoobstruction and lung hyperinflation have significant impact on dyspnea level.

scholarly journals Pulmonary involvement in Fabry disease: effect of plasma globotriaosylsphingosine and time to initiation of enzyme replacement therapy

2018 ◽  
Vol 5 (1) ◽  
pp. e000277 ◽  
Author(s):  
Daniel Franzen ◽  
Sarah R Haile ◽  
David C Kasper ◽  
Thomas P Mechtler ◽  
Andreas J Flammer ◽  
...  
Keyword(s):  
Lung Function ◽  
Enzyme Replacement Therapy ◽  
Pulmonary Function ◽  
Fabry Disease ◽  
Replacement Therapy ◽  
Pulmonary Function Tests ◽  
Airflow Limitation ◽  
Z Score ◽  
Lung Function Decline ◽  
Enzyme Replacement

IntroductionAnderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by mutations of GLA gene leading to reduced α-galactosidase activity and resulting in a progressive accumulation of globotriaosylceramide (Gb3) and its deacylated derivative, globotriaosyl-sphingosine (Lyso-Gb3). Plasma Lyso-Gb3 levels serve as a disease severity and treatment monitoring marker during enzyme replacement therapy (ERT).MethodsAdult patients with AFD who had yearly pulmonary function tests between 1999 and 2015 were eligible for this observational study. Primary outcome measures were the change in z-score of forced expiratory volume in the first second (FEV1) and FEV1/FVC over time. Plasma Lyso-Gb3 levels and the age of ERT initiation were investigated for their association with lung function decline.ResultsFifty-three patients (42% male, median (range) age at diagnosis of AFD 34 (6–61) years in men, 34 (13–67) in women) were included. The greatest decrease of FEV1/FVC z-scores was observed in Classic men (−0.048 per year, 95% CI −0.081 to –0.014), compared with the Later-Onset men (+0.013,95% CI −0.055 to 0.082), Classic women (−0.008, 95% CI −0.035 to +0.020) and Later-Onset women (−0.013, 95% CI −0.084 to +0.058). Cigarette smoking (P=0.022) and late ERT initiation (P=0.041) were independently associated with faster FEV1 decline. FEV1/FVC z-score decrease was significantly reduced after initiation of ERT initiation (−0.045 compared with −0.015, P=0.014). Furthermore, there was a trend towards a relevant influence of Lyso-Gb3 (P=0.098) on airflow limitation with age.ConclusionEarly ERT initiation seems to preserve pulmonary function. Plasma Lyso-Gb3 is maybe a useful predictor for airflow limitation. Classic men need a closer monitoring of the lung function.

scholarly journals Characterisation of pulmonary function trajectories: results from a Brazilian cohort

2020 ◽  
Vol 6 (3) ◽  
pp. 00065-2020
Author(s):  
Priscila Weber ◽  
Ana Maria Baptista Menezes ◽  
Helen Gonçalves ◽  
Rogelio Perez-Padilla ◽  
Deborah Jarvis ◽  
...  
Keyword(s):  
Birth Weight ◽  
Family History ◽  
Pulmonary Function ◽  
Birth Cohort ◽  
Respiratory Diseases ◽  
Smoking Status ◽  
Forced Expiratory Volume ◽  
Birth Cohort Study ◽  
History Of ◽  
Brazilian Cohort

BackgroundPulmonary function (PF) trajectories are determined by different exposures throughout the life course. The aim of this study was to investigate characteristics related to PF trajectories from 15 to 22 years in a Brazilian cohort.MethodsA birth cohort study (1993 Pelotas Birth Cohort) was conducted with spirometry at 15, 18 and 22 years. PF trajectories were built based on z-score of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and their ratio using a group-based trajectory model. Associations with exposures reported from perinatal to 22 years were described.ResultsThree trajectories, low (LT), average (AT) and high (HT) were identified in 2917 individuals. Wealthiest individuals belonged to the HT of FEV1 (p=0.023). Lower maternal pregestational body mass index (BMI) (22.4±0.2; p<0.001 and 22.1±0.14; p<0.001) and lower birth weight (3164.8±25.4; p=0.029 and 3132.3±19.4; p=0.005) were related to the LT of FEV1 and FVC. Mother's smoking exposure during pregnancy (37.7%; p=0.002), active smoking at ages 18 and 22 years (20.1% and 25.8%; p<0.001) and family history of asthma (44.8%; p<0.001) were related to the LT of FEV1/FVC. Wheezing, asthma and hospitalisations due to respiratory diseases in childhood were related to the LT of both FEV1 and FEV1/FVC. Higher BMIs were related to the HT of FEV1 and FVC at all ages.ConclusionsPF trajectories were mainly related to income, pregestational BMI, birth weight, hospitalisation due to respiratory diseases in childhood, participant's BMI, report of wheezing, medical diagnosis and family history of asthma, gestational exposure to tobacco and current smoking status in adolescence and young adult age.

scholarly journals Effects of Sublingual Duster Mite Drops on Lung Function and Exhaled Nitric Oxide in Children with Multiple and Single Allergic Respiratory Diseases

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Li Wang ◽  
Tao Ai ◽  
Ronghua Luo ◽  
Yinghong Fan ◽  
Huiling Liao ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Symptom Score ◽  
Respiratory Diseases ◽  
Allergic Diseases ◽  
Dermatophagoides Farinae ◽  
Vas Score ◽  
Significant Difference ◽  
Before And After ◽  
Drug Score ◽  
One Year

Objective. To evaluate the efficiency of sublingual immunotherapy with Dermatophagoides Farinae Drops in children with single and multiple respiratory allergic diseases. Methods. Seventy-one children with allergic respiratory diseases who had been treated with Dermatophagoides Farinae Drops for one year or more were divided into a single allergic group (12 cases) and multiple allergic group (59 cases). The rhinitis score, daytime and night symptom score of asthma, VAS score, drug score, pulmonary function, and FeNO level before and after treatment were evaluated and compared between the two groups. Results. The rhinitis score, night symptom score, VAS score, and drug score in the single allergic group after treatment were significantly lower than those before treatment ( p < 0.05 ), but there was no significant difference in the daytime symptom score before and after treatment ( p > 0.05 ). The rhinitis score, VAS score, and drug score in the multiple allergic group after treatment were significantly lower than those before treatment ( p < 0.05 ), but there was no significant difference in the scores of daytime symptoms and nighttime symptoms before and after treatment ( p > 0.05 ). In both the single allergic group and multiple allergic group, the pulmonary function indexes of the patients were significantly improved after treatment, and the FeNO after treatment was significantly lower than that before treatment ( p < 0.05 ). There was no significant difference in scores, pulmonary function, and FeNO between the two groups ( p > 0.05 ). Conclusion. Sublingual specific immunotherapy is effective in treating multiple and single allergic respiratory diseases in children.

scholarly journals Regional ventilation characteristics during non-invasive respiratory support in preterm infants

2020 ◽  
pp. fetalneonatal-2020-320449
Author(s):  
Jessica Thomson ◽  
Christoph M Rüegger ◽  
Elizabeth J Perkins ◽  
Prue M Pereira-Fantini ◽  
Olivia Farrell ◽  
...  
Keyword(s):  
Oxygen Saturation ◽  
Preterm Infants ◽  
Neonatal Intensive Care ◽  
Repeated Measure ◽  
Regional Ventilation ◽  
Quiet Breathing ◽  
Impedance Tomography ◽  
Non Invasive ◽  
Ventilation Inhomogeneity ◽  
The Right

ObjectivesTo determine the regional ventilation characteristics during non-invasive ventilation (NIV) in stable preterm infants. The secondary aim was to explore the relationship between indicators of ventilation homogeneity and other clinical measures of respiratory status.DesignProspective observational study.SettingTwo tertiary neonatal intensive care units.PatientsForty stable preterm infants born <30 weeks of gestation receiving either continuous positive airway pressure (n=32) or high-flow nasal cannulae (n=8) at least 24 hours after extubation at time of study.InterventionsContinuous electrical impedance tomography imaging of regional ventilation during 60 min of quiet breathing on clinician-determined non-invasive settings.Main outcome measuresGravity-dependent and right–left centre of ventilation (CoV), percentage of whole lung tidal volume (VT) by lung region and percentage of lung unventilated were determined for 120 artefact-free breaths/infant (4770 breaths included). Oxygen saturation, heart and respiratory rates were also measured.ResultsVentilation was greater in the right lung (mean 69.1 (SD 14.9)%) total VT and the gravity-non-dependent (ND) lung; ideal–actual CoV 1.4 (4.5)%. The central third of the lung received the most VT, followed by the non-dependent and dependent regions (p<0.0001 repeated-measure analysis of variance). Ventilation inhomogeneity was associated with worse peripheral capillary oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) (p=0.031, r2 0.12; linear regression). In those infants that later developed bronchopulmonary dysplasia (n=25), SpO2/FiO2 was worse and non-dependent ventilation inhomogeneity was greater than in those that did not (both p<0.05, t-test Welch correction).ConclusionsThere is high breath-by-breath variability in regional ventilation patterns during NIV in preterm infants. Ventilation favoured the ND lung, with ventilation inhomogeneity associated with worse oxygenation.

scholarly journals Short- and long-term effects of diving on pulmonary function

2017 ◽  
Vol 26 (143) ◽  
pp. 160097 ◽  
Author(s):  
Kay Tetzlaff ◽  
Paul S. Thomas
Keyword(s):  
Lung Function ◽  
Pulmonary Function ◽  
Ambient Pressure ◽  
Small Airways ◽  
Long Term Effects ◽  
Cold Temperatures ◽  
Factors Associated ◽  
Stress Changes ◽  
The Impact

The diving environment provides a challenge to the lung, including exposure to high ambient pressure, altered gas characteristics and cardiovascular effects on the pulmonary circulation. Several factors associated with diving affect pulmonary function acutely and can potentially cause prolonged effects that may accumulate gradually with repeated diving exposure. Evidence from experimental deep dives and longitudinal studies suggests long-term adverse effects of diving on the lungs in commercial deep divers, such as the development of small airways disease and accelerated loss of lung function. In addition, there is an accumulating body of evidence that diving with self-contained underwater breathing apparatus (scuba) may not be associated with deleterious effects on pulmonary function. Although changes in pulmonary function after single scuba dives have been found to be associated with immersion, ambient cold temperatures and decompression stress, changes in lung function were small and suggest a low likelihood of clinical significance. Recent evidence points to no accelerated loss of lung function in military or recreational scuba divers over time. Thus, the impact of diving on pulmonary function largely depends on factors associated with the individual diving exposure. However, in susceptible subjects clinically relevant worsening of lung function may occur even after single shallow-water scuba dives.

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