Respiratory Tract, Ventilation, and Pulmonary Functions Tests

Breathing is considered the common factor that links studying,sleeping,and activities.It is one of the primary indicators that is frequently considered when determining whether or not an unconscious individual is still alive.The evolution and development process of the respiratory system that occurs in a foetus is primarily from head to tail(cephalocaudal).Many changes occur throughout this period until the 28th week of pregnancy at which the foetus^respiratory system will attain adequate development for the rest of his or her life.The respiratory system comprises of the lungs and the encompassing thoracic wall,which includes the thoracic cages,midriff(diaphragm),and the abdominal wall.Spirometry is a procedure used for estimating air volumes that enter and exit the pulmonary system with the aid of a spirometer.The various pulmonary parameters that reflect pulmonary ventilation are of great significance in diagnosing respiratory diseases.The respiratory system will be discussed in more detail in this article.

Effects of left ventricular assist device on pulmonary functions and pulmonary hemodynamics:A meta-analysis

BACKGROUND Given current evidence,the effect of left ventricular assist device(LVAD)implantation on pulmonary function tests remains controversial.AIM To better understand the factors contributing to the changes seen on pulmonary function testing and the correlation with pulmonary hemodynamics after LVAD implantation.METHODS Electronic databases were queried to identify relevant articles.The summary effect size was estimated as a difference of overall means and standard deviation on a random-effects model.RESULTS A total of four studies comprising 219 patients were included.The overall mean forced expiratory volume in one second(FEV1),forced vital capacity(FVC)and diffusion lung capacity of carbon monoxide(DLCO)after LVAD implantation were significantly lower by 0.23 L(95%CI:0.11-0.34,P=00002),0.18 L(95%CI:0.03-0.34,P=0.02),and 3.16 mmol/min(95%CI:2.17-4.14,P<0.00001),respectively.The net post-LVAD mean value of the cardiac index was significantly higher by 0.49 L/min/m2(95%CI:0.31-0.66,P<0.00001)compared to pre-LVAD value.The pulmonary capillary wedge pressure and pulmonary vascular resistance were significantly reduced after LVAD implantation by 8.56 mmHg(95%CI:3.78-13.35,P=0.0004),and 0.83 Woods U(95%CI:0.11-1.55,P=0.02),respectively.There was no significant difference observed in the right atrial pressure after LVAD implantation(0.61 mmHg,95%CI:-2.00 to 3.32,P=0.65).Overall findings appear to be driven by studies using HeartMateII devices.CONCLUSION LVAD implantation might be associated with a significant reduction of the spirometric measures,including FEV1,FVC,and DLCO,and an overall improvement of pulmonary hemodynamics.

Immediate effect of fomentation on pulmonary function in patient with bronchial asthma:a case series

Background:Asthma is a major non-communicable disease affecting both children and adult populations,characterized by inflammation and narrowing of airways.Hydrotherapy is a naturopathy treatment modality effectively used to manage bronchial asthma.This case series presents the immediate effect of one such hydrotherapy treatment hot fomentation on pulmonary function in bronchial asthma.Case presentation:Three women who had chief complaints of wheezing,sneeze and breathlessness due to chronic bronchial asthma.Hot fomentation over the inter-scapular region was given to the patient for a duration of 20 minutes.Pulmonary function test was performed using Recorders&Medicine Systems Pvt Ltd.Helios 401 before and immediately after the intervention to assess the efficacy of hot fomentation.Result:When compared to baseline,the pulmonary function’s parameters,such as forced vital capacity,forced expiratory volume in the first second,forced expiratory volume in the first second/forced vital capacity ratio,forced expiratory flow(25–75%)and peak expiratory flow showed significant improvement immediately after the fomentation.Conclusion:After 20 minutes of hot fomentation,significant improvement in pulmonary function was observed.Hot fomentation over the interscapular region,could thus be used to improve clinical outcomes in the management of bronchial asthma by improving pulmonary function and relieving acute symptoms.

Occupational Health Surveillance: Pulmonary Function Test in Proppant Exposures

Workers involved in hydraulic fracking processes are exposed to various types of chemicals and dusts in their workplaces, such as proppants, which hold open the fissures created in the fracking process. Recently, ceramic proppants have been developed that may be less hazardous to workers than traditional proppants. Pulmonary function testing of workers producing ceramic proppant was used to assess the potential inhalation hazards of ceramic proppant. 100 male workers from a producer of ceramic proppant were evaluated with pulmonary function test data collected and evaluated using The American Thoracic Society (ATS) acceptability criteria. A comparison group was selected from the Third National Health and Nutrition Examination Survey (NHANES III) spirometry laboratory subset. No pulmonary function deficits were found in the worker group in comparison to the NHANES III population. Mean FEV1 and FVC values in workers were 3.8 and 4.8 liters respectively, and were greater as compared to the NHANES III population of similar demographics. An FEV1/FVC ratio of less than 0.8, when compared to the NHANES III group, produced an odds ratio of 0.44 in worker group, indicating less risk of preclinical pulmonary dysfunction. Overall, exposure to ceramic proppant was not found to produce an adverse impact on pulmonary function in workers engaged in the manufacture of ceramic proppant.

Is forced oscillation technique the next respiratory function test of choice in childhood asthma

Respiratory diseases, especially asthma, are common in children. While spirometry contributes to asthma diagnosis and management in older children, it has a limited role in younger children whom are often unable to perform forced expiratory manoeuvre. The development of novel diagnostic methods which require minimal effort, such as forced oscillation technique(FOT) is, therefore, a welcome and promising addition. FOT involves applying external, small amplitude oscillations to the respiratory system during tidal breathing. Therefore, it requires minimal effort and cooperation. The FOT has the potential to facilitate asthma diagnosis and management in preschool children by faciliting the objective measurement of baseline lung function and airway reactivity in children unable to successfully perform spirometry. Traditionally the use of FOT was limited to specialised centres. However, the availability of commercial equipment resulted in its use both in research and in clinical practice. In this article, we review the available literature on the use of FOT in childhood asthma. The technical aspects of FOT are described followed by a discussion of its practical aspects in the clinical field including the measurement of baseline lung function and associated reference ranges, bronchodilator responsiveness and bronchial hyperresponsiveness. We also highlight the difficulties and limitations that might be encountered and future research directions.

Forced Inspiratory Flow Volume Curve in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome

Objective: Obstructive sleep apnea-hypopnea syndrome (OSA) is a disease of obstructive apnea or hypopnea caused by a repeated partial or complete collapse of the upper airway during sleep. The inspiratory part of the flow-volume curve (F-V curve) can be used as an auxiliary means to evaluate upper airway obstruction in adults. This study is to evaluate the ability of the F-V curve to predict the OSA and explore inspiratory indicators related to airway obstruction during sleep. Methods: There were 332 patients included in this cross-sectional study, who were accompanied by snoring, daytime sleepiness and other symptoms, with suspicion of OSA. According to the nocturnal polysomnography, the subjects were distributed into mild to moderate OSA group, severe OSA group and non-OSA group. A pulmonary function test was used to collect the subjects’ spirometry and F-V curves. Results: There was no significant difference in a variety of indices derived from the F-V curve between OSA and normal subjects, including 25% inspiratory flow rate, middle inspiratory flow rate, 75% inspiratory flow rate, peak flow rate, and forced inspiratory flow rate in the first second. The pulmonary function parameters were significantly correlated with the weight, age and sex of the subjects. Conclusion: These findings suggest that the inspiratory curve of pulmonary function cannot evaluate the upper airway abnormalities in patients with obstructive apnea-hypopnea syndrome.

Effects of dermatophagoides pteronyssinus allergen-specific immunotherapy on the serum interleukin-13 and pulmonary functions in asthmatic children

Background Airway remodeling is the specific pathological characteristics of asthma, which is related to the clinical symptoms, pulmonary function, and airway hyperreactivity. This study aimed at exploring the effects of dermatophagoides pteronyssinus allergen-specific immunotherapy （SIT） on the serum interleukin （IL）-13 and pulmonary functions in asthmatic children. Methods Fifty-eight pediatric asthma patients allergic to dust mite participated in this study. Thirty-five children received SIT with a standardized dermatophgoides pteronyssinus extract for one year （SIT group）, and the other 23 children treated with inhaled corticosteroids （ICS group） according to the Global Initiative for Asthma （GINA） for one year. Serum levels of IL-13, IL-4 and interferon （IFN）-γ were examined and the pulmonary functions were checked before and after the treatment. Results After the treatment, the number of emergency visiting for asthma attack in SIT group was significantly less than that in ICS group. The serum levels of IL-4 and IL-13 were clearly reduced, IFN-γ and the ratio of IFN-γ/IL-4 were significantly increased, the pulmonary functions （forced vital capacity （FVC）, forced expiratory volume in one second percentage （FEV1%） and peak expiratory flow percentage （PEF%） were significantly improved in the SIT group. Meanwhile, IFN-γ and the ratio of IFN-γ/IL-4 were greatly increased, but serum levels of IL-4 and IL-13 had less changes, the pulmonary functions （FVC, FEV1% and PEF%） were poorly improved in ICS group. The basic pulmonary functions in both groups were at the same level, which had made more improvement in SIT group than in ICS group one year later. Conclusions One year of dermatophagoides pteronyssinus SIT can significantly reduce the frequencies of emergency visiting for asthma attack and improve the pulmonary functions of children with allergic asthma, and that is attributed to SIT, which can reduce the levels of IL-4 and IL-13 and regulate the imbalance of the Th1/Th2 cells in asthmatic children. All of these might be effective in preventing the asthmatic airway from remodeling.

Age-associated changes in pulmonary function： a comparison of pulmonary function parameters in healthy young adults and the elderly living in Shanghai

Background The respiratory system changes with age and a better understanding of the changes contribute to detect and prevent respiratory dysfunctions in old population. The purpose of this study was to observe age-associated changes of pulmonary function parameters in healthy young adults and the elderly. Methods A cross-sectional study was conducted among 600 male and female subjects aged 19 to 92 years. The subjects were divided into three groups by age： young adult （19-39 years）, middle-aged adult （40-59 years）, and the elderly （〉60 years）. The pulmonary function was measured with routine examination methods and 13 parameters including vital capacity （VC）, residual volume （RV）, functional residual capacity （FRC）, total lung capacity （TLC）, RV/TLC, forced vital capacity （FVC）, forced expiratory volume in one second （FEV1）, FEV1/FVC, peak expiratory flow （PEF）, forced expiratory flow at 25% of FVC exhaled （FEF25）, forced expiratory flow at 50% of FVC exhaled （FEF50）, diffusion capacity of the lung for carbon monoxide （DLCO）, and specific diffusion capacity of CO （KCO） were collected and analyzed. Changes in pulmonary function parameters among the influence on FEVJFVC and RV were studied further. Results Ten pulmonary function parameters including VC, FVC, pre-elderly and elderly subjects, especially the aging FEV1, FEV1/FVC, PEF, FEF25, FEF50, TLC, DLCO and KCO decreased significantly with age in both male and female subjects （P 〈0.01）. RV and RV/TLC were increased with age （P 〈0.01）. FRC remained stable during aging. Except FRC, the linear relationship was significant between age and other pulmonary function parameters. In the pre-elderly and elderly subjects, RV had a non-significantly increasing tendency with age （P 〉0.05）, and FEV1/FVC did not change significantly with age （P 〉0.05）. Conclusion Total pulmonary function was declined tendency of RV and decreasing tendency of FEV1/FVC with advancing age, but FRC was stable, and the increasing obviously slowed down in the pre-elderly and elderly subjects.

A cross-sectional study of post-COVID syndrome at a tertiary care center in Turkey

Objective:To investigate long-term symptoms after acute COVID-19,the link between symptoms and respiratory function,radiological changes in the post-COVID period,and risk factors for post-COVID syndrome.Methods:In this cross-sectional study,123 participants who were admitted within the first 3 months were categorized as group 1,and those who applied after 3 months were categorized as group 2.According to thoracic imaging and pulmonary function tests,patients were split into 3 groups as mild,moderate and severe.Results:At least one symptom was present in 91.9%and 61.8%in acute and post-COVID period,respectively.Pulmonary function tests were normal in 60(70.6%)in the first three months,and 30(78.9%)in 91-days to 1-year period after acute COVID-19 infection.After 3 months,22.4%of chest X-rays and 7.9%of computerized tomography revealed progression.Patients who developed acute complications(OR 9.91,95%CI 1.93-50.87),had 2 or more symptoms at admission(OR 7.73,95%CI 2.56-23.33),had 1%to 14%CT involvement(OR 3.05,95%CI 1.06-8.79),or had 50%or more CT involvement(OR 14.68,95%CI 1.24-172.55)had a higher risk of developing post-COVID syndrome.Conclusions:COVID-19 symptoms can last for long time.Severity of symptoms,acute complications,and the extent of radiological involvement may all contribute to elevated risk of post-COVID syndrome.As a result,patients with COVID-19 should be checked for long-term clinical difficulties on regular basis.

Airway obstruction in competitive swimmers

Background: Swimming has been shown to cause beneficial effects on lung function. However, increased adverse effects have been hypothesized due to the air quality of indoor swimming pools. Objectives: To compare competitive swimmers present lung function to swimmers twenty to thirty years ago and examine the associations between lung function and medical history and reported respiratory symptoms in present swimmers. Methods: One hundred swimmers, 47 females and 53 males were studied with flow-volume spirometry. These findings were compared with ones obtained 20 - 30 years ago among 98 swimmers, 40 females and 58 males. Forced expiratory volume in one second (FEV1), forced expiratory volume (FVC) and their ratio (FEV%) were analysed for airways obstruction. Associations between lung function and asthma, allergy, and respiratory symptoms were examined using questionnaire. In addition airways inflammation was measured with exhaled nitric oxide measurement (FENO) in present swimmers. Airborne trichloramine was measured in air of indoor swimming pools. Results: Airway obstruction was found in 15%, 15 out of 100 studied swimmers, which all reported physician diagnosed asthma and/or family history of asthma. Most, 12 out of 15 of swimmers with obstruction finding, were males. Twenty to thirty years ago obstruction was found in 17 of the 98 swimmers. Airborne concentrations of trichloramine in the present swimming pools, were low, less than 0.1 mg/m3. Conclusion: Airway obstruction was associated with asthma and family history of asthma. There was no increase in obstruction findings among competitive swimmers within 2 - 3 decades. Measured concentrations of trichloramine raised no concern on swimmers health.

Interstitial lung disease and diabetes

Diabetes mellitus (DM) is a chronic metabolic disease and its prevalence has beensteadily increasing all over the world. DM and its associated micro andmacrovascular complications result in significant morbidity and mortality. Themicrovascular complications are usually manifested as retinopathy, neuropathy,nephropathy and macrovascular complications generally affect the cardiovascularsystem. In addition to these complications, DM also affects the lungs because of itsrich vascularity and abundance in connective tissue (collagen and elastin). DMhas been found to cause microvascular complications and proliferation ofextracellular connective tissue in the lungs, leading to decline in lung function in arestrictive pattern. Interstitial lung disease (ILD) includes a diverse group ofdisease conditions characterized by different degrees of inflammation and fibrosisin the pulmonary parenchyma. Idiopathic pulmonary fibrosis (IPF) is one of thecommon type of idiopathic interstitial pneumonia with a high mortality rate. IPFis characterized by chronic progressive fibrosis leading to progressive respiratoryfailure. In this review we focus on lung as the target organ in DM and theassociation of DM and ILD with special emphasis on IPF.

Association between body mass index and pulmonary function of patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease （COPD） is a major cause of chronic morbidity and mortality throughout the world. It is a preventable and treatable disease with significant extra pulmonary effects that may contribute to the severity in individual patients. It is characterized by airflow limitation that is not fully reversible. The diagnosis of COPD should be confirmed by spirometry. Body mass index （BMI） is an important indicator that can well reflect nutritional status of patients, and low BMI is an independent risk factor for mortality in patients with COPD.

Relationship between 6-minute walk test and pulmonary function test in stable chronic obstructive pulmonary disease with different severities

Background The relationship between the 6-minute walk test （6MWT） and pulmonary function test in stable chronic obstructive pulmonary disease （COPD） remains unclear. We evaluate the correlation of 6MWT and spirometric parameters in stable COPD with different severities. 6MWT data assessed included three variables： the 6-minute walk distance （6MWD）, 6-minute walk work （6MWORK）, and pulse oxygen desaturation rate （SPO2%）. Methods 6MWT and pulmonary function test were assessed for 150 stable COPD patients with different severities. Means and standard deviations were calculated for the variables of interest. Analysis of variance was performed to compare means. Correlation coefficients were calculated for 6MWT data with the spirometric parameters and dyspnea Borg scale. Multiple stepwise regression analysis was used to screen pulmonary function-related predictors of 6MWT data. Results The three variables of 6MWT all varied as the severities of the disease. The 6MWD and 6MWORK both correlated with some spirometric parameters （positive or negative correlation; the absolute value of r ranging from 0.34 to 0.67; P 〈0.05） in severe and very severe patients, and the SPO2% correlated with the dyspnea Borg scale in four severities （t= -0.33, -0.34, -0.39, -0.53 respectively; P 〈0.05）. The 6MWD was correlated with the 6MWORK in four severities （r=0.56, 0.57, 0.72, 0.81 respectively, P 〈0.05）, and neither of them correlated with the SPO2%. The percent of predicted forced expiratory volume in 1 second （FEV1% predicted） and residual volume to total lung capacity ratio （RV/TLC） were predictors of the 6MWD, and the maximum voluntary ventilation （MW） was the predictor of the 6MWORK. Conclusions 6MWT correlated with the spirometric parameters in severe and very severe COPD patients. 6MWT may be used to monitor changes of pulmonary function in these patients.

The Influence of Allergic Rhinitis Treatment on Asthma

Background: Rhinopathy, a dysfunction or inflammation of the nasal mucosal lining, presents with symptoms of nasal obstruction, posterior and anterior rhinorrhea, sneezing, nasal itching, and hyposmia, with variations in symptom intensity in each subtype. Asthma originates from a combination of genetic and environmental factors. Objective: This study aimed to treat allergic rhinitis in patients with controlled asthma and to verify the behavior of the variables. Methods: In this prospective study, quantitative and qualitative assessment of rhinopathy in asthma was performed. Patients with symptoms of rhinopathy and controlled asthma, who were controlled with treatment at the pulmonology outpatient clinic of the Center for Medical Specialties at [hospital], were included. Patients were treated for 2 months according to the IV Rhinopathy Consensus. They underwent a pulmonary function test and completed a questionnaire before and after treatment for rhinopathy. Results: In total, 47 patients aged 7 - 12 years (9.30 ± 1.70 years;median 9 years) were evaluated, including 29 (61.7%) males and 18 (38.3%) females. Patients were evaluated at two timepoints, with an interval of 12 days to 14 months (3.81 ± 3.21 months;median 3 months), and were evaluated regarding the various characteristics of their allergy. Conclusion: The treatment of allergic rhinitis in patients with asthma resulted in an improvement in variables related to nasal congestion, rhinorrhea, cough, dyspnea, wheezing, and dyspnea on exertion, and maintaining physical activities without dyspnea.

Cardiopulmonary exercise testing in the evaluation of high risk patients with lung cancer

Background It is still unclear whether pulmonary function tests （PFTs） are sufficient for predicting perioperative risk,and whether all patients or only a subset of them need a cardiopulmonary exercise test （CPET） for further assessment.Thus, this study was designed to evaluate the CPET and compare the results of CPET and conventional PFTs to identify which parameters are more reliable and valuable in predicting perioperative risks for high risk patients with lung cancer.Methods From January 2005 to August 2008, 297 consecutive lung cancer patients underwent conventional PFTs （spirometry ＋ single-breath carbon monoxide diffusing capacity of the lungs （DLCOsb） for diffusion capacity） and CPET preoperatively. The correlation of postoperative cardiopulmonary complications with the parameters of PFT and CPET was retrospectively analyzed using the chi-square test, independent sample t test and binary Logistic regression analysis.Results Of the 297 patients, 78 did not receive operation due to advanced disease stage or poor cardiopulmonary function. The remaining 219 underwent different modes of operations. Twenty-one cases were excluded from this study due to exploration alone （15 cases） and operation-related complications （6 cases）. Thus, 198 cases were eligible for evaluation. Fifty of the 198 patients （25.2%） had postoperative cardiopulmonary complications. Three patients （1.5%）died of complications within 30 postoperative days. The patients were stratified into groups based on VO2max/pred respectively. The rate of postoperative cardiopulmonary complications was significantly higher in the group with cardiopulmonary complications were significantly correlated with age, comorbidities, and poor PFT and CPET results.used to stratify the patients＇ cardiopulmonary function status and to predict the risk of postoperative cardiopulmonary predicting perioperative risk. If available, cardiopulmonary exercise testing is strongly suggested for high-risk lung cancer patients in addition to conventional pulmonary function tests, and both should be combined to assess cardiopulmonary function status.

Computed tomography-identified phenotypes of small airway obstructions in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease(COPD)is a heterogeneous disease characteristic of small airway inflammation,obstruction,and emphysema.It is well known that spirometry alone cannot differentiate each separate component.Computed tomography(CT)is widely used to determine the extent of emphysema and small airway involvement in COPD.Compared with the pulmonary function test,small airway CT phenotypes can accurately reflect disease severity in patients with COPD,which is conducive to improving the prognosis of this disease.CT measurement of central airway morphology has been applied in clinical,epidemiologic,and genetic investigations as an inference of the presence and severity of small airway disease.This review will focus on presenting the current knowledge and methodologies in chest CT that aid in identifying discrete COPD phenotypes.

Long-term Follow-up of 5 Survivors after the First Outbreak of Human Infections with Avian Influenza A（H7N9） Virus in Shanghai, China

At the end of March 2013, the first case of human infection with avian influenza A（H7N9） virus was confirmed in Shanghai. From April to May 2013, 18 patients with avian influenza A（H7N9） virus infection were hospitalized in Shanghai Public Health Clinical Center, and finally, 12 of them survived. The short-term prognosis of these patients had been described previously, but the long-term prognosis remained unclear.