Ventilatory Function Measurements Research Articles

Respiratory Findings in Herd Dairy Farmworkers from the Nile Delta Region.

Dairy farmworkers are exposed to a variety of respiratory hazards, including organic and inorganic dust, allergens, disinfectants, and gases emitted by cows and their wastes resulting in a range of adverse health effects. In Egypt, large herd dairy farms (>1000 cattle) are growing in both size and number and thereby more workers are employed. However, there is a lack of studies on the respiratory health status of these workers. Accordingly, the present study aimed to determine the prevalence of respiratory problems, assess ventilatory functions, and highlight the predictors of abnormal spirometry patterns among Egyptian dairy farmworkers. A cross-sectional study was carried out on 282 male workers, of whom 141 were dairy farmworkers and the other 141, not involved in livestock handling, were enrolled as controls. Full history, clinical examination, and ventilatory function measurements were done for both groups. Dairy farmworkers had a significantly higher prevalence of respiratory symptoms (throat irritation and/or sore throat, cough, sputum production, and difficulty breathing) than controls as well as bronchitis, wheezes on chest auscultation, and obstructive ventilatory patterns. Older age (>37 years), longer smoking duration (>10 years), and longer working duration (>4 years) were independent predictors of abnormal spirometry patterns, particularly obstructive patterns, in dairy farmworkers. Large herd dairy farms, despite being open and naturally ventilated, are hazardous to workers' respiratory health. Hence, the provision of personal protective equipment, periodic spirometry examinations as well as mandatory breaks and days off, are highly urged.

End-tidal capnography provides reliable ventilatory monitoring for non-intubated patients presenting after sedative overdose to the emergency department.

To assess the ability of end-tidal capnography to provide continuous ventilatory monitoring in sedated, non-intubated ED patients following sedative overdose. Observational study undertaken in a tertiary hospital ED. Patient ventilation was assessed using capnography over 60 min. Capnography provided uninterrupted monitoring for 99% of total study time. Capnography detected all episodes of hypoxia detected by SpO2 monitoring. Changes in capnography preceded 70% of hypoxic episodes detected by SpO2 . There were no major adverse events or incidents of device failure. Capnography provided reliable measurement of ventilatory function in sedated non-intubated, poisoned ED patients.

Relationship between pulmonary function and indoor air pollution from coal combustion among adult residents in an inner-city area of southwest China.

Few studies evaluate the amount of particulate matter less than 2.5 mm in diameter (PM2.5) in relation to a change in lung function among adults in a population. The aim of this study was to assess the association of coal as a domestic energy source to pulmonary function in an adult population in inner-city areas of Zunyi city in China where coal use is common. In a cross-sectional study of 104 households, pulmonary function measurements were assessed and compared in 110 coal users and 121 non-coal users (≥18 years old) who were all nonsmokers. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), the FEV1/FVC ratio, and peak expiratory flow rate (PEFR) were compared between the 2 groups. The amount of PM2.5 was also measured in all residences. There was a significant increase in the relative concentration of PM2.5 in the indoor kitchens and living rooms of the coal-exposed group compared to the non-coal-exposed group. In multivariate analysis, current exposure to coal smoke was associated with a 31.7% decrease in FVC, a 42.0% decrease in FEV1, a 7.46% decrease in the FEV1/FVC ratio, and a 23.1% decrease in PEFR in adult residents. The slope of lung function decrease for Chinese adults is approximately a 2-L decrease in FVC, a 3-L decrease in FEV1, and an 8 L/s decrease in PEFR per count per minute of PM2.5 exposure. These results demonstrate the harmful effects of indoor air pollution from coal smoke on the lung function of adult residents and emphasize the need for public health efforts to decrease exposure to coal smoke.

Phenotyping of COPD: challenges and next steps

That FEV1 alone does not account for the complexity and heterogeneity of chronic obstructive pulmonary disease (COPD) is now well recognised. 1 Agusti A Calverley PM Celli B et al. Characterisation of COPD heterogeneity in the ECLIPSE cohort. Respir Res. 2010; 11: 122 Crossref PubMed Scopus (864) Google Scholar The Global Initiative for Chronic Obstructive Lung Disease (GOLD) global strategy has recently moved away from the recommendation of stratification of the severity of COPD, and choice of treatment by FEV1 alone. 2 Vestbo J Hurd SS Agusti AG et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Resp Crit Care Med. 2013; 187: 347-365 Crossref PubMed Scopus (3791) Google Scholar A new approach to risk assessment has been proposed, including the assessment of symptoms, health status, exacerbation rate, and severity. 2 Vestbo J Hurd SS Agusti AG et al. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. Am J Resp Crit Care Med. 2013; 187: 347-365 Crossref PubMed Scopus (3791) Google Scholar This approach is a tentative move towards personalised treatment for patients with COPD, matching therapy more closely to a multidimensional assessment of specific patient attributes—the patient's phenotype. Coming off the GOLD standardThe one second forced expiratory volume (FEV1), as Sir Winston Churchill once remarked of the unfortunately named Mr Bossom, is neither one thing nor the other. FEV1 is a measure of air flow but, because it is highly correlated with the forced vital capacity (FVC), is a poor indicator of airflow obstruction. Identification of two basic spirometric measures of ventilatory function is therefore useful—the vital capacity (VC, more usually the FVC), which gives a rough indication of lung size and assesses restriction, and the FEV1/FVC ratio, which assesses airflow obstruction adjusted for lung size. Full-Text PDF

Respiratory Diseases Due to Occupational Exposure to Nickel and Chromium among Factory Workers in Kenya

Inhalation of airborne nickel (Ni) and chromium (Cr) in workplaces causes a variety of respiratory ailments which adversely affects the productivity of employees. A study was therefore conducted on production workers (N=233) from six different types industrial plants, to investigate the influence of Ni and Cr exposure on their respiratory systems. Breathing zone air and urinary samples were collected, and analyzed for total Ni and Cr using atomic absorption spectroscopy. The medical history of the workers was obtained using questionnaires. Their lung functions were further examined using a spirometer. Mean (± standard deviation) breathing zone air of 23.4 ± 11.6 μg/m3 Cr and 10.3 ± 4.3 μg/ m3 Ni was highest among the tanners and welders, respectively. The mean level of 35.2 ± 12.1 Cr and 28.4 ± 7.8 Ni in μg/g creatinine were also highest in the urine of corresponding workers. A significant (P<0.01) correlation of r=0.86 Cr and r=0.89 Ni was observed between airborne and urinary levels in all production workers. Approximately 26.6% of the workers had respiratory diseases that were associated with wheezing, shortness of breath, sneezing attacks among other related symptoms. Most of these workers were welders, tanners and, to lesser extent, paint manufacturers. The breathing zone air of the afflicted workers had significantly (P<0.05) high mean levels of 6.4 ± 4.4 μg/m3 Ni and 9.6 ± 5.3 μg/m3 Cr than those who were not affected (3.9 ± 3.2 μg/m3 Ni and 4.4 ± 3.8 μg/m3 Cr). A high proportion of the workers had reduced ventilatory function measurements. We recommend comprehensive assessment of Cr and Ni in related industries with significant exposures. Designing and developing of training programs and educative manuals on safety and health procedures, and regular medical surveillance is also recommended.

Forced vital capacity, airway obstruction and survival in a general population sample from the USA

BackgroundMany studies show a link between forced expiratory volume in 1 s (FEV1) and survival in the general population and this has been interpreted as a link between airway obstruction...

The Influence of Living Near Roadways on Spirometry and Exhaled Nitric Oxide in Elementary Schoolchildren

BackgroundLiving near major roadways has been associated with an increase in respiratory symptoms, but little is known about how this relates to airway inflammation.ObjectiveWe assessed the effects of living near local residential roadways based on objective indicators of ventilatory function and airway inflammation.MethodsWe estimated ambient air pollution, resolved to the level of the child’s neighborhood, using a land-use regression model for children 9–11 years of age. We also summed the length of roadways found within a 200-m radius of each child’s neighborhood. We had measurements of both air pollution exposure and spirometry for 2,328 children, and also had measurements of exhaled nitric oxide (eNO) for 1,613 of these children.ResultsEach kilometer of local roadway within a 200-m radius of the home was associated with a 6.8% increase in eNO (p = 0.045). Each kilometer of any type of roadway (local, major, highway) was also associated with an increase in eNO of 10.1% (p = 0.002). Each microgram per cubic meter increase in PM2.5 was associated with a 3.9% increase in eNO (p = 0.058) and 0.70% decrease in forced vital capacity (FVC) expressed as a percentage of predicted (p = 0.39). Associations between roadway density and both forced expired volume in 1 sec and FVC were negative but not statistically significant at p < 0.05.ConclusionTraffic from local neighborhood roadways may cause airway inflammation as indicated by eNO. This may be a more sensitive indicator of adverse air pollution effects than traditional measures of ventilatory function.

Effects of Nebivolol versus Carvedilol on Left Ventricular Function in Patients with Chronic Heart Failure and Reduced Left Ventricular Systolic Function

Beta-adrenoceptor antagonist (beta-blocker) therapy results in a significant improvement in left ventricular (LV) systolic function and prognosis in patients with chronic heart failure. Both carvedilol and nebivolol produce hemodynamic and clinical benefits in chronic heart failure, but it is unknown whether their peculiar pharmacologic properties produce different effects on LV function. To assess the effects on LV function of nebivolol compared with carvedilol in patients with chronic heart failure and reduced LV systolic function. Seventy patients with a LV ejection fraction <or=40% and in New York Heart Association (NYHA) functional class II or III were randomly assigned to receive carvedilol or nebivolol therapy for 6 months. At baseline and after 6 months of treatment, all patients were assessed clinically and by biochemical and hematological investigation, ECG, 24-hour Holter monitoring, echocardiogram, measurement of ventilatory function, and a 6-minute walk test. Compared with baseline values LV end-systolic volume decreased and LV ejection fraction increased in both the carvedilol (from 79 +/- 38mL to 73 +/- 43mL and from 33% +/- 6% to 37% +/- 11%) and the nebivolol group (from 72 +/- 35mL to 66 +/- 32mL and from 34% +/- 7% to 38% +/- 10%), although the between-group differences were not statistically significant. ECG data showed a decrease in resting HR in both groups (from 83 +/- 20 bpm to 66 +/- 11 bpm for carvedilol and from 81 +/- 15 bpm to 65 +/- 11 bpm for nebivolol; p < 0.001 vs baseline for both groups) but no difference in the PQ, QRS, and QT intervals. Hematologic (in particular, N-terminal pro-brain natriuretic peptide), Holter monitoring (with the exception of HR), and respiratory functional data did not show any significant variation in either group after 6 months' therapy. SBP and DBP decreased in both groups. A small reduction in mean NYHA functional class from baseline was seen in both groups (from 2.5 +/- 0.5 to 2.2 +/- 0.5 for carvedilol [p < 0.05] and from 2.3 +/- 0.4 to 2.2 +/- 0.5 for nebivolol [not significant]). The 6-minute walk test showed a trend toward an increase in the walking distance in both groups. During 6 months of treatment no significant differences in adverse events were observed between the groups. Nebivolol is as effective as carvedilol in patients with symptomatic chronic heart failure and reduced LV systolic function.

The association of biomass fuel combustion on pulmonary function tests in the adult population of Mid-Anatolia.

To assess the association of biomass as domestic energy source on respiratory function in rural areas of Mid-Anatolia in Turkey where biomass use is frequent. In a cross-sectional study, pulmonary functions measurements of 112 cow-dung users and 153 modern energy source users, all non-smokers, were assessed and compared. Several sociodemographic factors were assessed by questionnaire, and ventilatory function measurements included forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio and the flow between the first 25 and 75 of forced expiratory flow (FEF(25-75)), and were compared, deploying univariate and multivariate methods, between the two groups. The individuals in the biomass exposed and unexposed group were similar regarding demographic characteristics: 67.0% were female (exposed) vs 60.1% (unexposed) with an age range of 17 to 64 (exposed) and 18 to 70 years (unexposed), and with 36% of biomass users having had pulmonary tract infections (20% in non-users). For all pulmonary function test parameters FEV1, FVC, FEV1/FVC, and FEF(25-75) a highly significant (p < 0.0001) reduction was observed in biomass users. A 12.4% (95% confidence interval: 7.0% to 17.7%) reduction in forced vital capacity was observed in multivariate linear regression. It is well known that biomass combustion is a relevant public health problem. The substantial differences in pulmonary functions associated with biomass use as an energy source observed in this cross-sectional study in non-smokers support that also in rural Turkey measures may be in need to reduce this public health problem.

Effect of breathing circuit resistance on the measurement of ventilatory function

BACKGROUNDThe American Thoracic Society (ATS) has set the acceptable resistance for spirometers at less than 1.5 cm H2O/l/s over the flow range 0–14 l/s and for monitoring devices at less...

Effects of body fat on ventilatory function in children and adolescents: cross-sectional findings from a random population sample of school children.

Childhood obesity is associated with a range of adverse consequences, and the prevalence is increasing in developed nations. Most of the literature on obesity and ventilatory function in children concerns samples selected for gross obesity with relatively little detail available from random population samples. This report examines the effect of total body fat as a percentage of weight (TBF%) on ventilatory function in a nationally representative sample of 2,464 Australian school children aged 9, 12, and 15 years. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were used as measures of ventilatory function. TBF% was estimated from skinfold thickness measurements. Ventilatory function was adjusted (for height and then for both height and weight) using linear regression on a logarithmic scale. Adjustment was performed within separate strata of age and gender. Analysis of covariance was used for hypothesis testing. Height-adjusted FVC and FEV1 values increased significantly with increasing weight within each age and gender group and for all subjects combined (P < 0.0001). The effect of TBF% independent of lean tissue was examined using FVC and FEV1 values adjusted for both height and weight, because body weight measures both lean and fat mass. Adjusted FVC and FEV1 values decreased significantly with increasing TBF% within each age and gender group and for all subjects combined (P < 0.0001). Ventilatory function decreased with increasing proportions of body fat. This is consistent with previous findings on lean tissue mass and ventilatory function. Although the magnitude of the effect was relatively small in clinical terms, from a public health perspective our findings indicate yet another adverse consequence of childhood obesity.

Effect of a Microaerosol Barrier Filter on the Measurement of Lung Function

A disposable barrier filter (Pall Biomedical, United Kingdom) was developed to prevent the contamination of lung function equipment in clinical use. The aims of this study were to examine its resistance characteristics and to determine the effect of the filter on clinical measurements of lung function. Twenty-one randomly selected patients and four normal subjects had lung function measured with and without the filter between the mouth and measuring equipment. Measurements of ventilatory function were made with a pneumotachograph (Lilly; Hoechberg, Germany), total lung capacity and airway resistance by constant volume plethysmography, and diffusing capacity for carbon monoxide by the single breath method. Resistance was determined in five unused filters over the flow range 1 to 12 L/s and at a single flow rate (12 L/s) just after a normal subject expired 20 forced vital capacity (FVC) breaths through each of them. The resistance (mean +/- SD) of unused filters was 0.19 +/- 0.02 cm H2O/L/s at 1 L/s and increased linearly to 0.56 +/- 0.02 cm H2O/L/s at 12 L/s. There was no significant increase in resistance after use. The addition of the filter to the breathing circuit caused statistically significant decreases in forced expiratory volume in 1 s (FEV1) (0.044 +/- 0.08 L, p = 0.014) and peak expiratory flow rate (PEFR) (0.47 +/- 0.073 L/s, p = 0.004). The filter did not affect other indices of lung function. The filter caused a statistically significant reduction in FEV1 and PEFR; however, this difference was believed not to affect the clinical utility of routine lung function testing.

The effect of controlled-release salbutamol on sleep and nocturnal oxygenation in patients with asthma and chronic obstructive pulmonary disease

Patients with asthma or chronic obstructive pulmonary disease (COPD) may have falls in oxygen saturation at night. We have investigated the effect of a long acting beta agonist (salbutamol CR) on nocturnal oxygen saturation ( SaO 2) in asthma and COPD. Eleven asthmatic and 14 COPD patients in stable condition were randomly allocated to 8 mg salbutamol CR or placebo twice daily in a double-blind, cross-over study. FEV 1 at entry was 71·5% predicted in the asthmatic patients and 36% predicted in the COPD group. Each treatment period lasted 7 days, at the end of which measurements of ventilatory function and detailed sleep studies were performed. There was a significant improvement in morning FEV 1 in the asthmatic patients when on active treatment and a small, but non-significant improvement in the COPD group. Sleep architecture and oxygenation were similar on placebo and on active treatment in both groups. We conclude that salbutamol CR has no significant effect on nocturnal oxygenation or sleep pattern in patients with mild asthma or moderately severe COPD.

The value of questionnaires and spirometry in asthma surveillance programmes in the workplace.

Shipyard workers and job applicants (n = 1126) completed an asthma questionnaire, and underwent measurements of ventilatory lung function (FEV1, FEV1/FVC and PEFR) and airway responsiveness. Airway responsiveness (to inhaled methacholine) was expressed as the dose calculated to provoke a 20 per cent fall in FEV1, ie the PD20. Results were categorized into four levels: high (PD20 < 200 micrograms), medium (200-1000 micrograms), low (1001-6400 micrograms) and unquantifiable (> 6400 micrograms), which correspond with definite, possible, doubtful and no asthmatic activity. These categories agreed closely with diagnoses of asthma by general practitioners and the use of bronchodilator medication. The sensitivity and specificity of the questionnaire and the measurements of ventilatory function for detecting asthmatic activity were then determined. The questionnaire symptoms (wheeze, chest tightness, undue coughing or abnormal breathlessness) had a low (28 per cent) sensitivity for detecting definite or possible asthmatic activity and a specificity of only 73 per cent. The sensitivity of the ventilatory function tests (any one abnormal) was also low at 21 per cent with a specificity of 92 per cent. When the FEV1 < 80 per cent predicted criterion was considered separately, its sensitivity was 11 per cent and its specificity was 98 per cent. These results illustrate that caution is needed when interpreting the results of questionnaires and measurements of ventilatory lung function in the diagnosis of asthma among working populations.

The effect of ozone inhalation on metabolic functioning of vascular endothelium and on ventilatory function

The primary purpose of this research was to determine the effect of ozone inhalation on pulmonary vascular endothelium. Male Fischer-344 rats were exposed to 0.5 or 0.7 ppm ozone, 20 hr/day for 7 days. Lungs were excised and perfused with Krebs medium containing [ 14C]serotonin or [ 14C]hippurylhistidylleucine (HHL). When compared to controls, the animals exposed to the lower ozone concentration showed no statistically significant changes in serotonin removal. In contrast, the higher ozone concentration resulted in a 32% decrease ( p < 0.0001) in serotonin removal, but had no effect on HHL. Rats similarly exposed to 0.7 ppm ozone but allowed to recover for 14 days in clean air showed no decrease in serotonin removal compared to their controls. Animals exposed sequentially to 0.5 ppm ozone for 7 days and then to 0.7 ppm for 7 days showed no alteration in serotonin metabolism, suggesting the development of tolerance initiated by the lower dose. After 7 days exposure to 0.7 ppm ozone, lung ventilatory function measurements revealed small though significant decreases in several parameters. Electron microscopic evaluation of lung capillary endothelium from animals exposed to the 0.7 ppm ozone showed no changes. Positive control animals exposed to >95% oxygen, 20 hr/day for 2 days showed a 23% decrease in serotonin removal ( p < 0.03) and a 12% decrease in HHL removal ( p < 0.017). These studies indicate that inhalation of ozone can induce functional alterations in the lung endothelium, and that this effect occurs at a dosage of ozone that produces minimal ventilatory changes and no observable endothelial ultrastructural changes.

Repeatability of ventilatory function measurements in a population survey of 7 year old children.

The within subject variability of forced vital capacity (FVC), forced expiratory volumes in one second (FEV1) and half a second (FEV0.5), peak expiratory flow (PEF), and flow rates at 25-75%, 75-85%, 25%, 50%, and 75% of expired FVC were assessed among 7 year old children from the general population. Within occasion variability in 232 children was lowest for FVC (coefficient of variation (CV) 5%) and FEV1 (CV 4%), and greatest for end expiratory flow rates. The precision of measurement for FEV1 supports its use for bronchial provocation tests, particularly those using a graded challenge. In this context the value of PEF (CV 7%) and mid expiratory flow rates (CV 11%) is limited by their poorer repeatability. Between occasion variability was assessed in 171 children tested at an interval of one to four weeks. The difference between the variances between occasions and within occasions was attributed to biological variation; this accounted for a substantial component of the between occasion variance in all indices, particularly FEV1 (73%) and PEF (66%). Together, within subject variability, sex, and height accounted for about half of the measured variance between subjects for all indices except FVC (68%). These results have implications for epidemiological studies.

Spirometric findings and mortality in never-smokers

The relation of ventilatory function to overall mortality has been studied in 662 male and 2048 female never-smokers who during the period 1976–1978 participated in the Copenhagen City Heart Study, a prospective community study of more than 14,000 men and women randomly selected from the general population of the City of Copenhagen. Until the end of 1986, 195 subjects who said they were never-smokers died. Mortality was analyzed using the proportional hazards model of Cox. In addition to measures of ventilatory function, the mortality analysis included age, sex, body-mass index, alcohol consumption, school education, diabetes mellitus, heart disease and bronchial asthma as confounding factors. Forced expiratory volume in 1 second (FEV 1) as a percentage of that predicted, forced vital capacity (FVC) as a percentage of that predicted and the ratio of FEV 1 to FVC were significant risk factors for mortality among both sexes. The relative risk of death associated with a 50% decrease in FEV 1 and FVC as a percentage of a predicted value was 1.65 and 1.81, respectively. This study confirms that lowered ventilatory function is a strong risk factor for mortality among never-smokers of both sexes.

Repeatability of ventilatory function measurements in a population survey of 7 year old children.

The within subject variability of forced vital capacity (FVC), forced expiratory volumes in one second (FEV1) and half a second (FEV0.5), peak expiratory flow (PEF), and flow rates at 25-75%, 75-85%, 25%, 50%, and 75% of expired FVC were assessed among 7 year old children from the general population. Within occasion variability in 232 children was lowest for FVC (coefficient of variation (CV) 5%) and FEV1 (CV 4%), and greatest for end expiratory flow rates. The precision of measurement for FEV1 supports its use for bronchial provocation tests, particularly those using a graded challenge. In this context the value of PEF (CV 7%) and mid expiratory flow rates (CV 11%) is limited by their poorer repeatability. Between occasion variability was assessed in 171 children tested at an interval of one to four weeks. The difference between the variances between occasions and within occasions was attributed to biological variation; this accounted for a substantial component of the between occasion variance in all indices, particularly FEV1 (73%) and PEF (66%). Together, within subject variability, sex, and height accounted for about half of the measured variance between subjects for all indices except FVC (68%). These results have implications for epidemiological studies.

Subclinical Effects of Cigarette Smoking: A Five-Year Follow-Up of Physiologic Comparisons of Healthy Middle-aged Smokers and Nonsmokers

Measurements of ventilatory function, lung elastic recoil, diffusing capacity, and distribution of ventilation were obtained on healthy middle-aged cigarette smokers and nonsmokers on two occasions five years apart in order to assess the effects of smoking and the change which may occur over this five-year interval. Subjects were drawn from a randomly selected sample of the population of Tucson, AZ. Exactly the same protocol, methods, and equipment were employed in both studies. Although very few of these healthy subjects had abnormal function, there were significant differences in most indices of function between smokers and nonsmokers. However, we could discern no difference between smokers and nonsmokers in change in function over five years. It appears that, in smokers who remain free of serious respiratory trouble, there are subtle changes which accumulate over the years and which are too gradual to detect over a five-year interval.

Longitudinal decline in FEV1 in United States coalminers.

Changes in ventilatory function measurements of United States miners who had participated in two surveys held nine years apart were analysed in relation to smoking habits, dust exposure, and other factors. The results showed trends similar to those reported among British miners. Loss of FEV1 over time and found to be related to smoking (0.1 litre excess decline in current smokers compared with those who had never smoked over 11 years) and to occupational exposure (0.036-0.084 litres over 11 years, depending on the index used). The results offer confirmation of the relationship between work in coal mines and loss in ventilatory function observed in British miners, and also seen in cross sectional studies.