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G Viegi

Publications and source records attributed to G Viegi.

At least 91 records · Page 5Linked to original sources
PubMed1988

Ventilation-perfusion heterogeneity and gas exchange variables in acute pulmonary embolism evaluated by two different computerized techniques.

The mechanisms by which the disturbances of gas exchange develop in human pulmonary embolism are unknown. We investigated whether the inequality of ventilation-perfusion ratio is associated with the abnormalities of pulmonary gas exchange as evaluated by two different computerized techniques. We measured the alveolar to arterial gradients of oxygen and carbon dioxide by means of a computer based system with a mass spectrometer and the ventilation-perfusion distributions by the multiple inert gas technique in 5 patients with acute pulmonary embolism. In these subjects there was a marked ventilation-perfusion inhomogeneity, as detected from inert gases and this finding was in agreement with the impairment of the alveolar to arterial gradients and of their derived indexes. Consideration on the responsible mechanisms for the disturbances of gas exchange are also reported. In conclusion these two computerized techniques provide a useful assessment of the ventilation-perfusion relationships in order to explain the disturbances of gas exchange in critically ill patients.

Acute Disease↗
PubMed1988

Variability of maximal expiratory flow-volume curve in young volley players.

In order to assess the variability of forced expiratory flows, 15 male players (age 16-19 years, height 182-201 cm) of the Italian National Junior Volley team were studied twice with the pneumotachygraph of the computerized Hewlett-Packard Pulmonary System. The first time (April), but not the second (July), all the subjects were physically trained. Each subject performed at least three acceptable forced vital capacity (FVC) maneuvers, following the standard of the American Thoracic Society, with the exception of the criterion for determining the FVC end point. Mean values of forced mid- and end-expiratory flows were significantly higher in April than in July. Inter- and intrasubject coefficients of variation were lower for FVC and forced expiratory volume in 1 s (FEV1) than for the flows. However, the within-subject variability of expiratory flows is lower in our athletes than in the subjects described by other authors. Our findings indicate the importance of forced expiratory flows in detecting even minor intra-subject variations related to physical training and suggest that flow in the terminal portion of the FVC curve may be at least moderately dependent upon effort.

Adolescent↗
PubMed1988

Single breath nitrogen test in an epidemiologic survey in North Italy. Reliability, reference values and relationships with symptoms.

The usefulness of single breath nitrogen test (SBN2) was evaluated in a cross-sectional epidemiologic survey on a general population sample (n = 3,289) of North Italy. Each subject was submitted to CNR standardized questionnaire and to lung function testing using automated equipment (Hewlett-Packard 47804S). Acceptable closing volume (CV) and slope of alveolar plateau (DN2%/L) tracings were performed by only 1,370 and 1,982 subjects respectively, in comparison with the 2,638 diffusing capacity and the 3,079 forced vital capacity acceptable maneuvers. Prediction equations were computed on normal subjects for CV indices, with the exception of DN2%/L: they were similar to those found in other studies. Significant differences among smoking categories were found for all the SBN2 parameters in males, but only for DN2%/L in females. The latter was also able to distinguish either subjects with airway obstruction from those without it or symptomatic from asymptomatic individuals, but DN2%/L did not give more information than Vmax75, a sensitive index of flow volume curve. Our results suggest that the place of SBN2 in large scale epidemiologic testing has not been justified.

Adolescent↗
PubMed1988

Prevalence of respiratory symptoms in an unpolluted area of northern Italy.

Using a multistage stratified geographic cluster sample of households living in an unpolluted area of Northern Italy (near Venice), we enrolled 3289 inhabitants (aged 8-64 yr) for a longitudinal respiratory study. During the first cross-sectional survey, before the start of operation of a large oil-burning thermoelectric power plant, they completed a standardized administered questionnaire and performed several lung function tests. In the whole sample, dyspnoea grade 1 (11%), chronic cough and chronic phlegm (9%) were the most frequent respiratory symptoms; all the symptoms except dyspnoea were more prevalent in males than in females. Smokers (S) showed higher prevalence rates than ex-smokers (ES) and nonsmokers (NS), especially in males. In both sexes, the frequency of respiratory symptoms increased with increasing smoking as assessed by pack-years. An inverse relationship between prevalence of symptoms and socio-economic status was also observed. All tests of lung function were significantly impaired in S compared with NS in males; single-breath CO diffusing capacity and slope of alveolar plateau but not spirometric indices were significantly impaired in female S compared to female ES and NS. Finally, our prevalence rates were lower than in other epidemiological surveys: this result may be ascribed to the low levels of air pollution measured in the area.

Age Factors↗
PubMed1987

Comparison of algorithms for determining the end-point of the forced vital capacity maneuver.

The criteria of the American Thoracic Society (ATS) for determining the end-point of the forced vital capacity (FVC) maneuver were compared with an algorithm employed by a computer system (Hewlett-Packard), which yields a later end-point. The 150 subjects tested were divided into five groups of 30 on the basis of the following spirometric diagnoses: normal; small airways' obstruction (SAO); mild airways' obstruction (MAO); severe chronic obstructive pulmonary disease (COPD); or restrictive disease. The subjects performed a minimum of three maneuvers according to ATS standards, and the flow-volume curves with the greatest sum of FVC and forced expiratory volume in one second (FEV) were chosen for analysis by the two algorithms. Hewlett-Packard (HP) values for FVC and FVC time were always higher than the corresponding ATS values, and the HP values for flows were always lower than the corresponding ATS values. The higher differences were observed in the SAO group. In the group with severe COPD, high FVC differences and low flow differences were observed; on the contrary, in the restrictive group, low FVC differences and high flow differences were present. These results, in addition to the different location of the FVC end point, may be explained by the different morphology of the flow-volume curves. In conclusion, the ATS algorithm caused a systematic underevaluation of FVC and a systematic overevaluation of flows, which cause practical consequences only in the SAO group. In fact, 28 percent (17/60) of the subjects with SAO characteristics were considered "normal" using ATS criteria for the end-point.

Adult↗
PubMed1986

Lung function abnormalities in different connective tissue diseases.

Lung volumes, forced expiratory flow-volume curves, diffusing capacity indexes, and arterial blood gases were measured in 72 non-smoking patients with various connective tissue diseases (13 with rheumatoid arthritis, 17 with systemic lupus erythematosus, 25 with progressive systemic sclerosis, 10 with primary Sjögren's syndrome, 4 with polymyositis, and 3 with mixed connective tissue disease). Small airways disease and a diffusion capacity impairment were the most frequent and marked functional abnormalities in the whole group, and were often present in asymptomatic patients. Different lung function defects seemed to be present in each disease group. In fact, large airway obstruction was prevalent in progressive systemic sclerosis, diffusion capacity impairment in systemic lupus erythematosus, and small airways disease in rheumatoid arthritis. In contrast, primary Sjögren's syndrome appeared to be the connective tissue disease in which lung function abnormalities were less frequent and less pronounced.

Adolescent↗
PubMed1986

Respiratory effects of occupational exposure to tobacco dust.

Few investigations of the respiratory effects of occupational exposure to tobacco dust have been carried out and the threshold limit value has not well been established. A cross sectional survey on a sample of 223 male and female workers at a cigar and cigarette factory in Lucca (Tuscany) showed a significantly higher prevalence of wheezing, attacks of shortness of breath with wheezing, dyspnoea, and rhinitis than in a reference population. A trend towards a decrease in forced end expiratory flows according to smoking habit and work duration was evident. Positive skin prick tests were observed in 26% of men and 23% of women and were positively associated with duration of work and negatively with cigarette smoking. Thin interstitial space involvement was observed on chest x ray examination in almost half the female workers with more than 35 years exposure. These findings suggest that prolonged exposure to tobacco dust may have negative health effects and that it is advisable to establish a threshold limit value for tobacco dust different from that of inert dust.

Adult↗
PubMed1985

Noninvasive evaluation of cardiac dysrhythmias, and their relationship with multisystemic symptoms, in progressive systemic sclerosis patients.

Fifty-three patients (34 who had diffuse scleroderma, and 19 who had CREST syndrome [calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias]) were studied by noninvasive procedures, including resting electrocardiogram (ECG), continuous 24-hour Holter ECG monitoring, M-mode echocardiography, and 2-dimensional echocardiography. Only 22 patients (42%) had abnormalities such as conduction defects, supraventricular or ventricular arrhythmias, or ST-T changes detected on resting ECG. In contrast, using Holter monitoring, the number of conduction abnormalities seen increased from 10 to 16 patients and transient ST-T changes increased from 2 to 18 patients. Forty-eight patients had ventricular arrhythmias, with multiform ventricular premature beats in 21 (40%), pairs of runs of ventricular tachycardia in 15 patients (28%), and 1 or more runs of ventricular tachycardia in 7 (13%). Echocardiography detected asymmetric septal hypertrophy in 10 patients, impaired ventricular function in 9 patients, congestive cardiomyopathy in 2, mitral prolapse in 4, and pericardial effusion in 3 patients. Multiform and/or repetitive ventricular premature beats occurred more frequently in patients with echocardiographic abnormalities, but were also present in patients who had normal findings on echocardiographic examination. Cardiac involvement was not correlated with clinical variants of scleroderma (CREST syndrome or diffuse scleroderma), nor with other signs and symptoms of the disease. Thus, cardiac involvement is found much more frequently than would be expected from clinical symptoms or from results of resting ECG alone; therefore, Holter monitoring and echocardiography should be included in the routine workup of patients who have scleroderma.

Adolescent↗
PubMed1985

Lung involvement in Sjögren's syndrome: a comparison between patients with primary and with secondary syndrome.

Lung function was assessed in 20 patients with primary Sjögren's syndrome (SS) and in a group of patients with SS associated with a variety of connective tissue diseases. Signs of small airway disease and of altered diffusion capacity, together with chest x-ray features of mild interstitial involvement, were the most common findings in primary SS. On the whole, lung involvement was more frequent and severe in patients with the secondary form of the syndrome. In both primary and secondary SS lung function changes did not correlate with the other clinical and serological parameters, except for a more severe impairment of diffusion capacity in patients with Raynaud's phenomenon.

Adult↗
PubMed1985

Reference equations for the single-breath diffusing capacity. A cross-sectional analysis and effect of body size and age.

A longitudinal study was implemented in an unpolluted rural area of northern Italy (near Venice), before the start of the operation of a large oil-burning thermoelectric power plant, in order to investigate the effects of the future exposure to air pollution and to elucidate the natural history of obstructive airways diseases. During the first cross-sectional survey, a sample of the general population (n=3,300, 8 to 64 yr of age) performed several lung function tests, and information on risk factors and on the presence of respiratory symptoms were obtained by a standardized questionnaire. There were 712 subjects who were classified as normal on the basis of rigid criteria and who were able to perform satisfactorily a single-breath CO diffusing capacity (DLCOsb) test. The DLCOsb values showed an increase with height and age early in life and a later decrease with age. Two age groups were selected to determine an age at which DLCOsb stopped increasing and began to decline. Reference equations were computed (using age and height) in these 2 different age groups in each of the sexes. Similar equations were calculated for the total lung capacity derived from single-breath helium dilution measurements. The DLCOsb values in this study were higher than reported by other investigators. The method of selection of the study population, the strict criteria for normal, as well as technical, differences probably explain this finding. Reference equations for diffusing capacity corrected to lung volume (DL/VA) were computed only for adults (much greater than 20) in both sexes, because age and height coefficients in young subjects were insignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Respiratory function in chemical workers].

The authors have evaluated the trend of the forced expiratory flows at low lung volumes and of the diffusing capacity for CO in a group of chemical workers of a dye factory, exposed to mineral dusts, organic pigments and solvents. Prevalences of chronic bronchitis and dyspnea, as evaluated by CNR questionnaire, were 15 and 32%. FEF25-75, MEF50 and MEF75 showed statistically significant differences with reference values. The reduction of KCO% was almost completely accounted for by smoking habit. During exercise, DLCOSS2 did not reach the expected values. 71% of the subjects with a diagnosis of COLD had worked more than 15 years in the dye factory. These results suggest a negative effect of the working environment, together with cigarette smoking, on lung function of subjects with a medium-long-term exposure.

Carbon Monoxide↗
PubMed1984

[Role of tobacco smoking in the determination of CO diffusion impairment in silicotic patients].

Alveolar-capillary diffusion of CO was evaluated in 48 silicotics with predominantly small irregular opacities at low profusion. The mean value of CO diffusion lay between 82 and 87% of the reference values, except for DLCOSS2 which was slightly reduced (74% of theoretical). There was no correlation between the functional data and duration of work but there was a significant reduction of the CO diffusion values according to smoking, which was greatest in those smoking more than 15 pack-years. Subjects with small irregular opacities presented lower values than those with small "p" or "q" opacities, but this difference was not apparent when only non-smokers were considered.

Adult↗
PubMedDate not supplied

Effects of the home environment on respiratory symptoms of a general population sample in middle Italy.

The effects of home environment characteristics were evaluated in a multistage, stratified, cluster sample (N = 3,866) of the general population who lived in the district of Pisa (middle Italy). Each subject completed a standardized interviewer-administered questionnaire that contained questions about respiratory symptoms/diseases and risk factors (e.g., type of heating, fuels used for cooking and heating). Cough and asthma were significantly more frequent in men who did not smoke and who did not use natural gas for cooking and heating. Attacks of shortness of breath accompanied by wheeze, dyspnea, and cardiovascular conditions in female nonsmokers were associated with use of a stove or forced-air circulation for heating; the type of fuel used did not affect this result. Multiple logistic models, which accounted for independent effects of age, smoking status, pack-years, childhood respiratory illness, education, zone of residence, and work exposure to dusts, chemicals, or fumes, showed significantly increased odds ratios for (a) cough and phlegm in males (associated with bottled gas for cooking), (b) wheeze and shortness of breath with wheeze in females (associated with the use of a stove or forced-air circulation). These results, which confirm our previous observations in an unpolluted rural area of north Italy, indicate that characteristics of the home environment, as assessed by questionnaire, may be linked to mild adverse health effects, i.e., respiratory symptoms, in the general population. The results also identify the need to better characterize the dose-response relationship in indoor air pollution monitoring studies that include subsamples of this population.

Adolescent↗
PubMedDate not supplied

Respiratory effects of environmental pollution: epidemiological data.

A recent document of the American Thoracic Society and two previous reports of the International Union Against Tuberculosis and Lung Disease have summarized the negative health effects due to air pollution in a list ranging from the increase of mortality to the perception of bad odors. A significant attempt to estimate, on an annual basis, the negative effects of air pollution from particulate matter less than 10 microns in aerodynamic diameter (PM10) has been carried out on data from Austria, France, and Switzerland: e.g. in France, air pollution from PM10 is responsible annually for 31,700 deaths, 36,700 new cases of chronic bronchitis and 577,000 attacks of asthma in adults, 450,000 cases of acute bronchitis and 243,000 attacks of asthma in children. Recently, a study on the long-term effects of air pollution on about 500,000 residents in metropolitan US areas evidenced that each 10 micrograms/m3 elevation in fine particulate air pollution is associated with approximately a 4%, 6% and 8% increased risk of all-cause, cardiopulmonary and lung cancer mortality, respectively. Some Italian experiences have also confirmed respiratory health damages from air pollution, namely the prospective epidemiologic studies on general population samples of the Po Delta and Pisa areas; the cross-sectional study on schoolchildren of the 'Italian study on respiratory disorders in childhood and environment' (SIDRIA); and a meta-analysis of the Italian studies on short-term effects of air pollution. In conclusion, epidemiologic studies suggest that air pollution plays an important role in the exacerbation and in the pathogenesis of chronic respiratory diseases. Thus, respiratory physicians, as well as public health professionals, should advocate for a cleaner environment.

Adult↗
PubMedDate not supplied

[Epidemiology of the chronic obstructive pulmonary disease: environmental and occupational risk].

FACTORS. Chronic Obstructive Pulmonary Disease (COPD) is a very important cause of morbidity and mortality in industrialized and developing countries. According to the World Health Organization (WHO), in 2020 COPD will become the third leading cause of death all over the world. To date, several risk factors for developing COPD have been studied. They can act either singly or interacting among themselves in a synergistic way. Smoking habits and aging are the most important factor for development and exacerbation of COPD, but environmental conditions, such as air pollution and work exposure, can be relevant factors. Recommendations for the prevention of COPD, beside the promotion of smoking cessation, may be air pollution abatement and control of professional exposure. In view of historical trend of risk factors exposure, further epidemiological studies are necessary for a better knowledge of COPD natural history.

Environmental Exposure↗