Ventilatory limitations are not associated with dyspnea on exertion or reduced aerobic fitness in pectus excavatum: a critical information that must be highlighted to prevent inappropriate interventions.

Cover letter Pediatric Pulmonology Dear Editor, Enclosed is a manuscript to be considered in Pediatric Pulmonology that does not require an abstract , usually. This letter to the editor entitled “Ventilatory limitations are not associated with dyspnea on exertion or reduced aerobic fitness in pectus excavatum: a critical information that must be highlighted to prevent inappropriate interventions” comments the reports by Hardie and al. which tested the hypothesis that PEX deformities are associated with a pulmonary impairment during exercise and concluded that resting lung volume measurements were associated with the anatomic degree of PEX severity.

Reproducibility of Lung and Liver Volume Measurements on Fetal Magnetic Resonance Imaging in Left-Sided Congenital Diaphragmatic Hernia

<b><i>Introduction:</i></b> Congenital diaphragmatic hernia (CDH) affects 1 in 3,000 live births and is associated with significant morbidity and mortality. <b><i>Methods:</i></b> A review of fetal magnetic resonance imaging (MRI) examinations was performed for fetuses with left CDH and normal lung controls. Image review and manual tracings were performed by 4 pediatric radiologists; right and left lung volumes in the coronal and axial planes as well as liver volume above and below the diaphragm in the coronal plane were measured. Intra- and interreviewer reproducibility was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. <b><i>Results:</i></b> Excellent intra- and interreviewer reproducibility of the right and left lung volume measurements was observed in both axial planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95–0.99; left lung: 0.97, 95% CI: 0.95–0.98) and coronal planes (interreviewer ICC: right lung: 0.97, 95% CI: 0.95–0.98; left lung: 0.96, 95% CI: 0.93–0.98). Moderate-to-good interreviewer reproducibility was observed for liver volume above the diaphragm (ICC 0.7, 95% CI: 0.59–0.81). Liver volume below the diaphragm had a good-to-excellent interreviewer reproducibility (ICC 0.88, 95% CI: 9.82–0.93). <b><i>Conclusions:</i></b> The present study demonstrated an excellent intra- and interreviewer reproducibility of MRI lung volume measurements and good-to-moderate inter- and intrareviewer reproducibility of liver volume measurements after standardization of the methods at our fetal center.

The physiological basis and clinical significance of lung volume measurements

From a physiological standpoint, the lung volumes are either dynamic or static. Both subclasses are measured at different degrees of inspiration or expiration; however, dynamic lung volumes are characteristically dependent on the rate of air flow. The static lung volumes/capacities are further subdivided into four standard volumes (tidal, inspiratory reserve, expiratory reserve, and residual volumes) and four standard capacities (inspiratory, functional residual, vital and total lung capacities). The dynamic lung volumes are mostly derived from vital capacity. While dynamic lung volumes are essential for diagnosis and follow up of obstructive lung diseases, static lung volumes are equally important for evaluation of obstructive as well as restrictive ventilatory defects. This review intends to update the reader with the physiological basis, clinical significance and interpretative approaches of the standard static lung volumes and capacities.

Investigating the relationships among lung function variables in chronic obstructive pulmonary disease in men

Background In patients with chronic obstructive pulmonary disease (COPD), the independent contributions of individual lung function variables to outcomes may be lower when they are modelled together if they are collinear. In addition, lung volume measurements may not be necessary after spirometry data have been obtained. However, these hypotheses depend on whether forced vital capacity (FVC) can predict total lung capacity (TLC). Moreover, the definitions of hyperinflation and air trapping according to lung function variables overlap and need be clarified. Therefore, the aim of this study was to evaluate the relationships among various lung function parameters to elucidate these issues. Methods Demographic data and 26 parameters of full lung function were measured in 94 men with COPD and analyzed using factor and correlation analyses. Results Factor analysis revealed five latent factors. Inspiratory capacity (IC)/TLC and residual volume (RV)/TLC were most strongly correlated with all other lung volumes. IC/TLC, RV/TLC, and functional residual capacity (FRC)/TLC were collinear and were potential markers of air trapping, whereas TLC%, FRC%, and RV% were collinear and were potential markers of hyperinflation. RV/TLC >0.4 (or IC/TLC <0.4) was comparable with the ratio of forced expiratory volume in one second (FEV1) and FVC <0.7. FVC% and FEV1% were poorly correlated with TLC%. The correlation study showed that TLC%, RV/TLC, and FEV1% could be used to represent individual latent factors for hyperinflation, air trapping, inspiration, expiration, and obstruction. Combined with diffusion capacity%, these four factors could be used to represent comprehensive lung function. Conclusions This study identified collinear relationships among individual lung function variables and thus selecting variables with close relationships for correlation studies should be performed with caution. This study also differentiated variables for air trapping and lung hyperinflation. Lung volume measurements are still required even when spirometry data are available. Four out of 26 lung function variables from individual latent factors could be used to concisely represent lung function.

Portable Spirometer for Measuring Lung Function Health (FVC and FEV1)

Extreme climate change and air pollution caused by dust, smoke, vehicle exhaust gases and industry can increase the chances of contracting various infectious diseases caused by viruses, especially respiratory infections. Lung volume measurements obtained from air that is inhaled and exhaled by someone can help doctors diagnose abnormalities in the lungs. The purpose of this study was to develop an affordable pulmonary function measurement system, which is a spirometer. The main board consists of a non-inverting amplifier, Arduino microcontroller, LCD and SD Card memory. FVC and FEV1 volume measurements are carried out when the breath blew through the MPX5100DP gas pressure sensor. The sensor’s output is a voltage, which is converted to a volume unit using the venturimeter method. The SD card memory is used to store data. The results of measurement data on respondents with a spirometer comparison device then there is an FVC error of 0.98% 5, FEV1 3.83% and FEVI / FVC 2.50%. This value is still below the error tolerance limit of 5%. The design of this spirometer is portable and low cost to be made for mass production to help people to measure the health of lung function in humans.