RESUMEN
BACKGROUND: Exposure to pollutants in bakeries and hairdressing salons can cause airway syndromes varying from bronchial irritation to asthma. Workplace respiratory health surveillance aims to identify possible cases requiring further investigation. AIMS: To compare the performance of fractional exhaled nitric oxide (FE(NO)) and spirometry for health surveillance of apprentice bakers (ABs) and apprentice hairdressers (AHDs). Determinants of FE(NO) were also identified. METHODS: Symptoms and physician-diagnosed asthma were evaluated by questionnaire. FE(NO) was measured and spirometry was carried out. Subjects with elevated FE(NO) (FE(NO) > upper limit normal), airway obstruction [forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) < 95th percentile] and atopy (history of allergies) were identified. RESULTS: A total of 126 apprentices (59 ABs and 67 AHDs) participated. Twenty-nine (23%) apprentices had abnormal tests: 4 had associated high FE(NO) and airway obstruction, while 25 had either high FE(NO) (n = 15) or airway obstruction (n = 10) alone. Compared with ABs (n = 16), AHDs (n = 13) had more asthma (38 versus 0%; P < 0.05) and atopy (62 versus 6%; P < 0.05). There was no difference in symptoms, smoking FE(NO) or airways obstruction. Among 97 subjects with normal tests, no differences existed between ABs (n = 53) and AHDs (n = 44). Average FE(NO) was increased in atopic non-smokers compared with atopic smokers and non-atopic subjects (P < 0.05). Smoking, a history of allergies, FEV(1)/FVC % observed and respiratory symptoms were the main determinants of FE(NO). CONCLUSIONS: FE(NO) and spirometry were not overlapping dimensions in ABs and hairdressers, each test contributing unique information on the physiological status of the respiratory system. FE(NO) may provide added information on airway inflammation not provided by spirometry.
Asunto(s)
Asma/diagnóstico , Manipulación de Alimentos , Preparaciones para el Cabello/efectos adversos , Enfermedades Profesionales/diagnóstico , Exposición Profesional/efectos adversos , Adolescente , Contaminantes Ocupacionales del Aire/efectos adversos , Asma/inducido químicamente , Pruebas Respiratorias , Femenino , Volumen Espiratorio Forzado/fisiología , Francia , Humanos , Masculino , Óxido Nítrico/análisis , Enfermedades Profesionales/inducido químicamente , Exposición Profesional/análisis , Vigilancia de la Población/métodos , Espirometría , Encuestas y Cuestionarios , Capacidad Vital/fisiologíaRESUMEN
OBJECTIVES: To investigate the relation between levels of cumulative exposure to wood dust and respiratory symptoms and the occurrence of bronchial hyperresponsiveness among beech and oak workers. METHODS: 114 Male woodworkers from five furniture factories and 13 male unexposed controls were examined. The unexposed control group was supplemented by 200 male historical controls. Statistical analyses were performed excluding and including the historical controls. Dust concentration was measured by personal sampling methods. Cumulative exposure to dust was calculated for each woodworker by multiplying the duration of the work by the intensity of exposure (years. mg/m(3)). Bronchial hyperresponsiveness was assessed by the methacholine bronchial challenge test. Subjects were labelled methacholine bronchial challenge positive if forced expiratory volume in 1 second (FEV(1)) fell by >/=20%. The linear dose-response slope was calculated as the last dose divided by the total dose given. RESULTS: 443 Dust samples were collected. The median cumulative exposure to dust was 110 years.mg/m(3) with lower and upper quartiles at 70 and 160 years.mg/m(3) Overall, no declines in FEV(1) and forced vital capacity (FVC) were found with increasing exposures. A dose-response relation was found between intensity of exposure on the one hand, and sore throat, increased prevalence of positive methacholine bronchial challenge tests, and steeper dose-response slope, on the other. CONCLUSION: Exposure to oak and beech dust may lead to the development of sore throat and bronchial hyperresponsiveness.
Asunto(s)
Contaminantes Ocupacionales del Aire/efectos adversos , Hiperreactividad Bronquial/epidemiología , Polvo/efectos adversos , Exposición Profesional/efectos adversos , Faringitis/epidemiología , Hipersensibilidad Respiratoria/epidemiología , Madera , Adulto , Hiperreactividad Bronquial/etiología , Estudios Transversales , Volumen Espiratorio Forzado/fisiología , Francia/epidemiología , Humanos , Masculino , Faringitis/etiología , Hipersensibilidad Respiratoria/etiología , Capacidad Vital/fisiologíaRESUMEN
Because some authors have reported high rates of failure in performing the single breath N2 (SBN2) test in rural areas, the present study aimed at evaluating its acceptability in a female population, unfamiliar with lung function testing, in a rural area of northeastern France. Two hundred ninety-eight women from a rural area volunteered for a preventive medicine examination (91.6% of those invited); four of them were excluded for clinical reasons, and six (2%) were unable to perform spirometry. The protocol included completion of a questionnaire, spirometry with a bronchial reactivity test, skin prick test, and the SBN2 test utilizing a computerized assembly. Although failures caused by the apparatus were few (n = 7, 2.4%) 96 of 281 women (34.1%) were unable to produce two valid SBN2 tests in a series of six attempts. Compared with the group who succeeded in the test (n = 185), women who failed were older and had a higher prevalence of bronchial hyperresponsiveness. Logistic regression confirmed the independent association of these two variables with an inability to perform. We conclude that in a female population completely unfamiliar with lung function testing the SBN2 test has a high rate of failure associated with higher age and the presence of bronchial hyperresponsiveness.
Asunto(s)
Envejecimiento/fisiología , Pruebas Respiratorias , Hiperreactividad Bronquial/fisiopatología , Población Rural , Adolescente , Adulto , Factores de Edad , Femenino , Francia/epidemiología , Humanos , Modelos Logísticos , Persona de Mediana Edad , EspirometríaRESUMEN
There is only limited information on the factors associated with nonspecific bronchial hyperresponsiveness (BHR) in farmers. Our purpose was to examine the relationship between BHR and respiratory symptoms, atopy, and abnormalities of lung function in a sample of French farmers. Farmers scheduled for a preventive medicine check-up in northeastern France were examined. Occupational exposure, respiratory symptoms, and work-related symptoms were assessed by questionnaire, sensitization to 34 common and agricultural allergens by skin prick tests, and BHR by the single-dose (1,200 microg) acetylcholine (ACh) challenge test. Data were obtained from 741 farmers (95% of those invited). Seventy-seven subjects (10.3%) had BHR defined as a fall in forced expiratory volume in 1 s (FEV1) >/= 10% after the inhalation of ACh or, for those with a poor lung function, an increase in FEV1 > 10% and > 200 ml after the inhalation of 200 microg of salbutamol. The proportion of asthmalike symptoms, especially wheeze during work, positive skin tests to acarian (storage mites) and cereal dust allergens, and low levels of lung function was significantly greater among reactors than among nonreactors. Stepwise logistic regression analysis showed a significant and independent association between BHR and wheezing during work (OR = 4.99; 95% CI = 2.29-10.89; p = 0.0001) and baseline FEV1 (OR = 1.49; 95% CI = 1.05-2.20; p = 0.026). In conclusion, hyperreactive farmers had significantly more asthmalike symptoms, positive skin tests, and abnormal lung function than normoreactive farmers. Work-related wheeze and low baseline FEV1 were significantly and independently associated with BHR.
Asunto(s)
Hiperreactividad Bronquial/epidemiología , Agricultura , Pruebas de Provocación Bronquial , Estudios Transversales , Femenino , Francia/epidemiología , Humanos , Hipersensibilidad Inmediata/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Hipersensibilidad Respiratoria/epidemiología , Pruebas Cutáneas , Fumar/epidemiología , EspirometríaRESUMEN
In population studies, the provocative dose (PD) of bronchoconstrictor causing a significant decrement in lung function cannot be calculated for most subjects. Dose-response curves for carbachol were examined to determine whether this relationship can be summarized by means of a continuous index likely to be calculable for all subjects, namely the two-point dose response slope (DRS) of mean resistance (Rm) and resistance at 10 Hz (R10) measured by the forced oscillation technique (FOT). Five doses of carbachol (320 microg each) were inhaled by 71 patients referred for investigation of asthma (n=16), chronic cough (n=15), nasal polyposis (n=8), chronic rhinitis (n=8), dyspnoea (n=8), urticaria (n=5), post-anaphylactic shock (n=4) and miscellaneous conditions (n=7). FOT resistance and forced expiratory volume in one second (FEV1) were measured in close succession. The PD of carbachol leading to a fall in FEV1 > or = 20% (PD20) or a rise in Rm or R10 > or = 47% (PD47,Rm and PD47,R10) were calculated by interpolation. DRS for FEV1 (DRSFEV1), Rm (DRSRm) and R10 (DRSR10) were obtained as the percentage change at last dose divided by the total dose of carbachol. The sensitivity (Se) and specificity (Sp) of DRSRm, DRS10 delta%Rm and delta%R10 in detecting spirometric bronchial hyperresponsiveness (BHR, fall in FEV1 > or = 20%) were assessed by receiver operating characteristic (ROC) curves. There were 23 (32%) "spirometric" reactors. PD20 correlated strongly with DRSFEV1 (r=-0.962; p=0.0001); PD47,Rm correlated significantly with DRSRm (r=-0.648; p=0.0001) and PD47,R10 with DRSR10 (r=-0.552; p=0.0001). DRSFEV1 correlated significantly with both DRSRm (r=0.700; p=0.0001) and DRSR10 (r=0.784; p=0.0001). The Se and Sp of the various FOT indices to correctly detect spirometric BHR were as follows: DRSRm: Se=91.3%, Sp=81.2%; DRSR10: Se=91.3%, Sp=95.8%; delta%Rm: Se=86.9%, Sp=52.1%; and delta%R10: Se=91.3%, Sp=58.3%. Dose-response slopes of indices of forced oscillation technique resistance, especially the dose-response slope of resistance at 10Hz are proposed as simple quantitative indices of bronchial responsiveness which can be calculated for all subjects and that may be useful in occupational epidemiology.
Asunto(s)
Hiperreactividad Bronquial/diagnóstico , Pruebas de Provocación Bronquial/métodos , Adulto , Resistencia de las Vías Respiratorias , Pruebas de Provocación Bronquial/instrumentación , Broncoconstrictores/administración & dosificación , Carbacol/administración & dosificación , Relación Dosis-Respuesta a Droga , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Curva ROC , Sensibilidad y EspecificidadRESUMEN
STUDY OBJECTIVES: To verify that sick building symptoms are present in north-eastern France office workers; to try to identify new confounding factors. METHODS: The design was that of a cross-sectional study with control group. We studied with the same methods the personnel of an air-conditioned building (n=425), and of a naturally ventilated building (n=351). Air temperature and humidity, bacterial and fungal densities were measured by the same technical staff in the two buildings. A standard questionnaire on irritative and respiratory symptoms, personal and family history, and lifestyle was completed by the participants. RESULTS: In univariate analysis, exposure to air-conditioning was associated with an increased prevalence of symptoms (odds ratios-OR-between 1.54 and 2.84). A significant increase in sickness absence was also found among subjects working in air-conditioned offices. As a series of factors were suspected to interfere with these associations, logistic regression was applied. This method confirmed exposure to be an independent determinant of 7 symptoms, and also identified two determinants not previously described: a family history of respiratory diseases and "do-it-yourself' activities. IN CONCLUSION: we found the sick building symptoms to be present in a group of French office workers exposed to air-conditioning. We confirmed the influence of a number of confounding factors and described two further confounders - do-it-yourself activities at home and a history of familial respiratory disease.
Asunto(s)
Contaminación del Aire Interior , Síndrome del Edificio Enfermo/epidemiología , Absentismo , Adulto , Aire Acondicionado , Femenino , Francia/epidemiología , Humanos , Masculino , Proyectos Piloto , Prevalencia , Enfermedades Respiratorias/epidemiología , Enfermedades Respiratorias/etiología , Síndrome del Edificio Enfermo/etiologíaRESUMEN
OBJECTIVES: To measure the levels of exposure to nitrogen trichloride (NCl3) in the atmosphere of indoor swimming pools and to examine how they relate to irritant and chronic respiratory symptoms, indices of pulmonary function, and bronchial hyperresponsiveness to methacholine in lifeguards working in the pools. METHOD: 334 lifeguards (256 men; 78 women) recruited from 46 public swimming pools (n = 228) and 17 leisure centre swimming pools (n = 106) were examined. Concentrations of NCl3 were measured with area samplers. Symptoms were assessed by questionnaire and methacholine bronchial challenge (MBC) test by an abbreviated method. Subjects were labelled MBC+ if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given. RESULTS: 1262 samples were taken in the 63 pools. Mean NCl3 concentrations were greater in leisure than in public pools. A significant concentration-response relation was found between irritant eye, nasal, and throat symptoms-but not chronic respiratory symptoms-and exposure concentrations. Among women, the prevalence of MBC+ was twice as great as in men. Overall, no relation was found between bronchial hyperresponsiveness and exposure. CONCLUSIONS: The data show that lifeguards exposed to NCl3 in indoor swimming pools are at risk of developing irritant eye, nasal, and throat symptoms. Exposure to NCl3 does not seem to carry the risk of developing permanent bronchial hyperresponsiveness, but this association might have been influenced by self selection. The possibility that subjects exposed to NCl3 are at risk of developing transient bronchial hyperresponsiveness cannot be confidently ruled out.
Asunto(s)
Cloruros/efectos adversos , Irritantes/efectos adversos , Compuestos de Nitrógeno/efectos adversos , Exposición Profesional/efectos adversos , Enfermedades Respiratorias/inducido químicamente , Piscinas , Adulto , Pruebas de Provocación Bronquial , Bronquitis/inducido químicamente , Cloruros/análisis , Oftalmopatías/inducido químicamente , Oftalmopatías/epidemiología , Femenino , Volumen Espiratorio Forzado , Francia/epidemiología , Humanos , Irritantes/análisis , Masculino , Compuestos de Nitrógeno/análisis , Enfermedades Nasales/inducido químicamente , Enfermedades Nasales/epidemiología , Exposición Profesional/análisis , Faringitis/inducido químicamente , Faringitis/epidemiología , Análisis de Regresión , Trastornos Respiratorios/inducido químicamente , Trastornos Respiratorios/epidemiología , Enfermedades Respiratorias/epidemiología , Capacidad VitalRESUMEN
OBJECTIVES: To assess the relation between measured levels of exposure to soluble oil mists in a plant manufacturing ball bearings, and both respiratory symptoms and airway responsiveness in the workforce. METHODS: 114 male workers exposed to oil mist and 55 unexposed male controls from nearby factories were studied. Soluble oil mist concentrations were measured with area samplers. Respiratory symptoms were assessed by questionnaire and measurement of airway responsiveness to methacholine with an abbreviated method. Subjects were labelled positive to methacholine airway challenge (MAC+) if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given. RESULTS: Geometric mean concentrations of oil mists ranged from 0.65 mg/m3 (GSD 1.29) to 2.20 mg/m3 (GSD 1.55) based on 92 measurements obtained from 1979-93. The prevalence of chronic cough or phlegm, bouts of bronchitis, and dyspnoea was greater among exposed workers than among controls (odds ratio (OR) 4.64, P = 0.002 for chronic cough and phlegm). After adjustment for smoking and age, dyspnoea was significantly related to an index of cumulative exposure to oil mist (OR 1.44, P = 0.006/10 y.mg/m3). The proportion of MAC+ subjects was similar in the two groups. However, after adjustment for baseline FEV1 and age, the dose-response slope was significantly steeper among exposed workers than among controls (P = 0.01), a finding indicating airway hyperresponsiveness in the exposed workers. Furthermore, the dose-response slope was significantly related to baseline FEV1, age, and, after adjustment for FEV1, the index of cumulative exposure to oil (P = 0.004). CONCLUSION: Subjects with exposure to soluble oil mist in the metal industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.
Asunto(s)
Contaminantes Ocupacionales del Aire/efectos adversos , Contaminantes Ocupacionales del Aire/análisis , Exposición a Riesgos Ambientales/análisis , Aceites Industriales/efectos adversos , Aceites Industriales/análisis , Industrias , Enfermedades Pulmonares/inducido químicamente , Enfermedades Pulmonares/epidemiología , Trastornos Respiratorios/inducido químicamente , Trastornos Respiratorios/epidemiología , Aerosoles/efectos adversos , Aerosoles/análisis , Estudios de Casos y Controles , Estudios Transversales , Humanos , Masculino , Cloruro de Metacolina , Aceite Mineral/efectos adversos , Aceite Mineral/análisis , Oportunidad Relativa , Prevalencia , Pruebas de Función RespiratoriaRESUMEN
Comparative manual and computer measurements of the alveolar N2 slope and closing volumes have indicated systematic differences. When a computerized system is used in field surveys, predicted values are to be obtained under the same conditions. Therefore, we measured the alveolar nitrogen slope (phase III, PIII), closing volume (CV), and closing capacity (CC) from single-breath N2 washout maneuvers in 158 healthy subjects (68 females), ages 21 to 64 years, from a rural community living in a nonpolluted area of northeast France. PIII, the CV to vital capacity ratio (CV:VC, %), and the CC to the total lung capacity ratio (CC:TLC, %) were regressed against age, height, weight, and the body mass index (BMI, kg/m2) and prediction equations with 95% confidence intervals were computed. PIII increased with age in both sexes and tended to decrease with height in males (r = -0.19, p = .08). The CV:VC and CC:TLC ratios depended on age and, in males, increased with the BMI. Despite accepting a 15% difference between the test VC and the spirometric VC, only 46.3% of asymptomatic nonsmokers produced a valid single-breath nitrogen washout (SBN2) test. This high failure rate limits the usefulness of the test for epidemiologic purposes when older populations "naive" to pulmonary function testing are studied under field-survey conditions.
Asunto(s)
Pulmón/fisiología , Nitrógeno , Pruebas de Función Respiratoria/métodos , Adolescente , Adulto , Anciano , Computadores , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Alveolos Pulmonares/fisiología , Estudios Retrospectivos , Factores de Riesgo , Población RuralRESUMEN
Our aim was to investigate the relationship between suspected occupational hazards and airflow obstruction in industrial workers. The study was a cross-sectional survey of 314 male workers from a chalkpowder plant (n = 158) and from a sugar refinery (n = 156). Occupational exposure to chalkpowder and sugar dust was assessed by individual job classification. Outcome variables included respiratory symptoms and routine spirometric parameters. Statistical analysis was done for each industry separately. Overall, mean pulmonary function parameters fell either within or above the normal range in both industries. However, analysis by job classification showed that in the chalkpowder plant, all indices of airway obstruction declined significantly with increasing dustiness. Additionally, workers in the dustiest workplace (chalk sacking) had significantly lower airflow parameters than workers from other workstations. In the sugar refinery, workers exposed to sugar dust in the sugar cube manufacture workstation had significantly lower forced expiratory volume in 1 s (FEV1) (p = 0.02) than the non-exposed ones. For both industries, the proportion of subjects complaining of cough and/or phlegm was greater among the most exposed subgroups than among the remaining workers but the differences were not statistically significant. In conclusion, coupling spirometry to job classification proved useful in disclosing a relationship between airflow obstruction and exposure to either chalkpowder or sugar dust in industrial workers.
Asunto(s)
Carbonato de Calcio , Polvo/efectos adversos , Enfermedades Pulmonares Obstructivas/epidemiología , Enfermedades Profesionales/epidemiología , Sacarosa , Adulto , Estudios Transversales , Volumen Espiratorio Forzado/fisiología , Humanos , Enfermedades Pulmonares Obstructivas/complicaciones , Enfermedades Pulmonares Obstructivas/fisiopatología , Masculino , Persona de Mediana Edad , Enfermedades Profesionales/complicaciones , Enfermedades Profesionales/fisiopatología , Ocupaciones/clasificación , Fumar/epidemiología , Capacidad Vital/fisiologíaRESUMEN
The direct method of chest percussion, first described by Auenbrugger but disseminated by Corvisart, has rapidly been replaced by the indirect or digitodigital method. Chest percussion has not been evaluated by modern acoustic means, so that our present knowledge of the method does not consistently differ from the 19th century approach. Auscultatory percussion is not superior to conventional percussion.
Asunto(s)
Auscultación , Pulmón , Percusión , Enfermedades Respiratorias/diagnóstico , Tórax , Auscultación/historia , Auscultación/instrumentación , Corazón , Historia del Siglo XVIII , Historia del Siglo XIX , Humanos , Percusión/historia , Percusión/instrumentaciónRESUMEN
BACKGROUND: The use of lung sound monitoring during bronchial provocation testing has not been clearly demonstrated. The appearance of wheeze and changes in inspiratory breath sound intensity have been analysed and related to changes in spirometric parameters and to airways hyperresponsiveness. METHODS: Lung sounds were recorded in 38 patients undergoing a routine carbachol airway challenge (CAC) test. Spirometric testing was performed before and after the inhalation of each of five cumulative doses of 320 micrograms carbachol; a fall in forced expiratory volume in one second (FEV1) by 20% or more was considered as significant. Lung sound analysis was carried out using a computerised system. RESULTS: The CAC test was positive (CAC+) in 21 patients and negative (CAC-) in 17. At the final stage of the challenge, wheeze was identified in 10 positive patients (48%) and in one negative patient (6%); in non-wheezers the inspiratory breath sound intensity decreased significantly from baseline in 11 CAC+ patients (mean (SD) change -35 (24%)) but not in 16 CAC- patients (mean (SD) change 5 (24%)). In all non-wheezers a linear relationship was found between breath sound intensity and the squared inspiratory airflow (r = 0.53-0.92) which became looser after the inhalation of carbachol. CONCLUSION: When unertaking bronchial provocation testing the accurate identification of wheeze may prove useful in avoiding or shortening the test because of the presumed relationship between wheeze and airways hyperresponsiveness. Changes in breath sound intensity may also be useful, but further studies are required to define the threshold for significant changes in this index.
Asunto(s)
Pruebas de Provocación Bronquial , Ruidos Respiratorios/efectos de los fármacos , Adulto , Carbacol , Femenino , Volumen Espiratorio Forzado , Humanos , MasculinoRESUMEN
Our goal was to assess the relation between dust exposure levels and the respiratory health status of workers in grain and flour mills in eastern France. We studied 118 male workers from 11 mills and 164 unexposed male controls. Dust concentration was measured by personal sampling methods. Outcome variables included respiratory symptoms, routine pulmonary function tests, and indices of airway responsiveness to methacholine. A great within- and between-area variability of inhalable dust concentration was found in all mills. A dose-response relationship was observed between dust exposure levels and chronic respiratory symptoms, suggesting that exposure to grain and flour dust may lead to chronic bronchitis. A significant relation was found between dust exposure and airway hyper-responsiveness; this finding is important since it has been hypothesized that the latter abnormality may lead to or be a predisposing factor in subsequent chronic, irreversible airflow obstruction.
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Contaminantes Ocupacionales del Aire/efectos adversos , Polvo/efectos adversos , Grano Comestible/efectos adversos , Harina/efectos adversos , Enfermedades Pulmonares Obstructivas/etiología , Enfermedades Profesionales/etiología , Adulto , Pruebas de Provocación Bronquial , Estudios de Casos y Controles , Enfermedad Crónica , Estudios Transversales , Polvo/análisis , Francia/epidemiología , Humanos , Masculino , Cloruro de Metacolina/inmunología , Análisis de Regresión , Trastornos Respiratorios/epidemiología , Trastornos Respiratorios/etiología , Pruebas Cutáneas , FumarRESUMEN
Methacholine airway challenge (MAC) is a simple and useful means to assess bronchial hyperreactivity in workers exposed to various occupational hazards. Recently, wheeze detection by tracheal auscultation has been proposed as an indicator of bronchial responsiveness during bronchial provocation test in children. Our aim was to examine the relationship between the appearance of wheezes and the concurrent changes in forced expiratory volume in one second (FEV1) observed during MAC test in adults. Three cumulative doses of a methacholine solution (100 micrograms, 500 micrograms and 1500 micrograms) were inhaled by 45 workers with occupational exposure to flour dust. Spirometry was done using an electronic spirometer. Tracheal sounds were recorded with an electronic stethoscope placed over the anterior cervical triangle, 2 cm above the sternal notch. The amplified sounds were stored on magnetic tape, band-pass filtered (50-2000 Hz), and digitized at a sampling rate of 4096 Hz into a GenRad Vibration Control System. Wheezes were detected by fast Fourier transform (FFT) analysis and their presence compared to a 20% fall in FEV1. A positive MAC test by spirometry was found in 12 subjects whereas wheezes were identified in 14 subjects. Among the wheezing subjects, nine had a positive MAC test (range of fall in FEV1 = 20.6 to 42.3%) and five had a negative one (range of fall in FEV1 = 3.6 to 16.9%). Moreover, no wheezes were found in the remaining three subjects with a positive MAC test (range of fall in FEV1 = 20.7 to 27.4%). Taking a 20% fall in FEV1 as reference, wheezes were 75% sensitive and 84.8% specific to detect airflow obstruction. In conclusion, since it carries a significant although small false-negative rate, the acoustic technique based upon wheeze detection cannot, at the present time, fully replace spirometry during airway challenge testing in subjects with suspected asthma.
Asunto(s)
Asma/fisiopatología , Hiperreactividad Bronquial/diagnóstico , Pruebas de Provocación Bronquial , Cloruro de Metacolina , Enfermedades Profesionales/diagnóstico , Ruidos Respiratorios/diagnóstico , Enfermedades de la Tráquea/diagnóstico , Adulto , Auscultación , Hiperreactividad Bronquial/fisiopatología , Polvo/efectos adversos , Volumen Espiratorio Forzado/efectos de los fármacos , Humanos , Masculino , Enfermedades Profesionales/fisiopatología , Valor Predictivo de las Pruebas , Ruidos Respiratorios/fisiopatología , Sensibilidad y Especificidad , Espirometría , Enfermedades de la Tráquea/fisiopatologíaRESUMEN
Our aim was to measure the levels of exposure to wheat flour dust in a modern industrial bakery, and to assess the relationship between respiratory symptoms, sensitization to wheat flour antigens and airway responsiveness in the workforce. Forty four flour-exposed male workers and 164 unexposed controls were examined. Inspirable dust concentrations were measured using personal samplers. Respiratory symptoms were assessed by questionnaire, sensitization to wheat flour antigens by skin-prick tests, and methacholine airway challenge (MAC) test using an abbreviated method. Subjects were labelled MAC+ if forced expiratory volume in one second (FEV1) fell by 20% or more. The linear dose-response slope (DRS) was calculated as the percentage fall in FEV1 at last dose divided by the total dose administered. Inspirable dust concentrations were within acceptable limits in all working areas but one. The proportion of subjects with one or more symptoms and with airway hyperresponsiveness was significantly greater among flour-exposed workers than among controls. Using logistic or linear regression analysis, airway responsiveness was found to be strongly related to working at the bakery and to the baseline level of lung function. A positive skin-prick test was found in only 11% of flour-exposed workers and 6% of controls. In conclusion, our data show that despite exposure to relatively low concentration levels of inspirable flour dust, subjects working in the baking industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.
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Contaminantes Ocupacionales del Aire/efectos adversos , Harina/efectos adversos , Hipersensibilidad Respiratoria/epidemiología , Hipersensibilidad Respiratoria/etiología , Adulto , Estudios Transversales , Polvo/efectos adversos , Humanos , Modelos Lineales , Modelos Logísticos , Masculino , Persona de Mediana Edad , Prevalencia , Análisis de Regresión , Pruebas de Función Respiratoria , Hipersensibilidad Respiratoria/fisiopatología , RiesgoRESUMEN
Wheeze detection has been proposed as an indicator of bronchial responsiveness during airway provocation challenge (APC) test. However, there is evidence that wheeze may be occasionally absent in subjects whose APC is positive by spirometry. We tested the hypothesis that, in this case, inspiratory breath sound intensity (BSI) over the chest is noticeably decreased. Six patients (3 asthmatics and 3 patients with atopic rhinitis) were selected, whose forced expiratory volume in 1 s (FEV1) fell by 20% or more at the end point of the challenge in the absence of concurrent wheezing. Lung sounds were recorded at the right posterior lung base and analysed by computer. Inspiratory BSI at the end point of the challenge was markedly decreased in all patients, a change almost completely reverted by the inhalation of 200 micrograms of salbutamol in all of them but one. These results support the view that BSI monitoring is potentially useful as an indicator of bronchoconstriction during bronchial provocation testing. However, further studies are necessary to confirm this hypothesis.
Asunto(s)
Asma/fisiopatología , Pruebas de Provocación Bronquial , Ruidos Respiratorios , Espirometría , Adolescente , Adulto , Asma/diagnóstico , Broncoconstricción , Niño , Femenino , Volumen Espiratorio Forzado , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Auscultatory percussion is a technique that is potentially useful to study the acoustic behaviour of the chest. However, finger percussion, as used in this technique, has not been previously assessed for consistency. We calculated the intrasubject variability and short-term reproducibility of this technique in 10 healthy subjects. We examined several indices of the output sound of two series of sternal percussion manoeuvres performed one hour apart by the same examiner. The results were compared to those obtained during sternal percussion performed by a mechanical thumper. Consistency for both finger and thumper percussion varied from 4.8-20.6 (coefficients of variation) for various acoustic indices. For thumper percussion, the average results were not significantly different from those of finger percussion. We conclude that finger percussion of the sternum is sufficiently consistent to be used as a tool to investigate the acoustic behaviour of the chest.
Asunto(s)
Auscultación/métodos , Esternón , Acústica , Adulto , Auscultación/instrumentación , Dedos , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , TóraxRESUMEN
Auscultatory percussion of the chest is a clinical examination method that has been purported to detect intrapulmonary masses by their effect on transmission of the percussion note to the posterior chest. Recent findings from this laboratory suggested that the sound of sternal percussion may actually travel through the chest cage and not the lung parenchyma. To investigate this possibility further, we recorded the sound produced by sternal percussion at 63 evenly spaced points over the posterior chest wall of 3 healthy subjects and 4 patients with large, discrete intrathoracic lesions in the right upper lobe (2 patients), left lower lobe, and left upper lobe (1 patient each). We constructed 3-dimensional contour maps of the indices of sound amplitude and frequency to view graphically the pattern of distribution of the sound. Examination of the maps revealed areas of increased amplitude in the zones of projection of some osseous structures, especially the scapulae, both in the healthy subjects and patients. No disturbances in the pattern reflecting the presence of mediastinal structures or intrathoracic lesions were found despite the existence of deeply situated lung masses as large as 10 cm in diameter. These findings support the argument that the sound of sternal percussion travels to the posterior chest predominantly through chest wall structures.
Asunto(s)
Auscultación , Neoplasias Pulmonares/patología , Auscultación/métodos , Humanos , Pulmón/diagnóstico por imagen , Pulmón/patología , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Radiografía , Procesamiento de Señales Asistido por ComputadorRESUMEN
We indirectly determined the transmission path of sound generated by sternal percussion in five healthy subjects. We percussed the sternum of each subject while recording the output audio signal at the posterior left and right upper and lower lung zones. Sound measurements were done during apnea at functional residual capacity, total lung capacity, and residual volume both with the lungs filled with air and with an 80% He-20% O2 (heliox) gas mixture. Three acoustic indexes were calculated from the output sound pulse: the peak-to-peak amplitude, the peak frequency, and the mid-power frequency. We found that the average values of all indexes tended to be greater in the upper than in the ipsilateral lower lung zones. In the upper zones, peak-to-peak amplitude was greater at total lung capacity and residual volume than at functional residual capacity. Replacing air with heliox did not change these results. These experiments, together with others performed during Mueller and Valsalva maneuvers, suggest that resonance of the chest cage is the predominant factor determining the transmission of sternal percussion sounds to the posterior chest wall. The transmission seems to be only minimally affected by the acoustic characteristics of the lung parenchyma.