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Background: The natural history of flock worker's lung (FWL) and longitudinal lung function changes in nylon flock-exposed workers have not been well characterized.Methods: Symptoms, pulmonary function testing, and chest radiographs from five index cases, subsequent case referrals, and screened employees of a flocking plant in Kingston, Ontario, Canada, were compared and analyzed for changes over time (variable follow-up intervals between 1991 and 2011).Results: Nine cases and 30 flock-exposed workers without FWL were identified. Four cases had persistent interstitial lung disease despite three having left the workplace. Two developed hypoxemic respiratory failure and secondary pulmonary hypertension and died of complications 18 and 20 years after diagnosis, respectively. Five cases resolved after leaving the workplace. Compared with resolved cases, persistent cases had lower diffusing capacity of the lung for carbon monoxide at presentation (P < .05) and follow-up (P < .05). Among exposed workers employed for 14.5 ± 4.7 years, five had abnormal chest radiographs vs none at baseline (P = .001) over 14.8 ± 4.6 years of follow-up. The prevalence of wheeze increased (P = .001), and FEV₁/FVC decreased (P < .001). FEV₁% predicted was significantly lower at follow-up (P = .05). Average FEV₁ decline was 46 mL/year (range, -27 to 151 mL/y). Seventy-seven percent of exposed workers were current or former smokers.Conclusions: The natural history of FWL includes the following patterns: complete resolution of symptoms; radiographic and pulmonary function abnormalities; permanent, but stable symptoms and restrictive pulmonary function deficits; and progressive decline in pulmonary function, causing death from respiratory failure and secondary pulmonary hypertension. A low baseline diffusing capacity of the lung for carbon monoxide is associated with the persistence and progression of FWL. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the impact of increasing body mass index (BMI) on static lung volumes and airway function in a cohort of 2,265 subjects. The researchers also evaluated the influence of severity of airway obstruction. It was found that subjects with airway obstruction had consistent reductions in lung hyperinflation with increasing BMI.

Objectives: Current criteria use FEV(1) to assess bronchodilator responsiveness, despite its insensitivity and inability to predict improvement in symptoms or exercise tolerance. Response in lung volumes remains largely unexplored even though volume parameters, such as inspiratory capacity (IC), closely correlate with functional improvements. Therefore, we assessed the response of lung volumes (i.e., by IC, total lung capacity [TLC], functional residual capacity [FRC], residual volume [RV], and FVC) to salbutamol and the relationship of these changes to improvements in the spirometry in these patients.Design: A retrospective review of data extracted from a large database of patients who were undergoing spirometry and static lung volume measurements before and after the administration of 200 microg salbutamol.Patients: Patients with an FEV(1)/FVC ratio of < 85% of predicted values were defined as being severely hyperinflated (SH) if TLC was > 133% of predicted and as being moderately hyperinflated (MH) if TLC was 115 to 133% of predicted.Results: Two hundred eighty-one SH patients and 676 MH patients were identified. Salbutamol significantly reduced the mean (+/- SEM) TLC (SH patients, 222 +/- 23 mL; MH patients, 150 +/- 10 mL; p < 0.001), FRC (SH patients, 442 +/- 26 mL; MH patients, 260 +/- 39 mL; p < 0.001), and RV (SH patients, 510 +/- 28 mL; MH patients, 300 +/- 14 mL; p < 0.001) and increased both the IC (SH patients, 220 +/- 15 mL; MH patients, 110 +/- 11 mL; p < 0.001) and FVC (SH patients, 336 +/- 21 mL; MH patients, 204 +/- 13 mL; p < 0.001). FEV(1) improved in a minority of patients (SH patients, 33%; MH patients, 26%), but if lung volume measurements are also considered, the overall bronchodilator response may improve to up to 76% of the SH group and up to 62% of the MH group. Changes in volumes correlated poorly with changes in maximal airflows.Conclusions: Bronchodilators reduce hyperinflation. Measurements of lung volumes before and after bronchodilators add sensitivity when examining for bronchodilator responsiveness. [ABSTRACT FROM AUTHOR]

Objectives: Current criteria use FEV[sub 1] to assess bronchodilator responsiveness, despite its insensitivity and inability to predict improvement in symptoms or exercise tolerance. Response in lung volumes remains largely unexplored even though volume parameters, such as inspiratory capacity (IC), closely correlate with functional improvements. Therefore, we assessed the response of lung volumes (ie, by IC, total lung capacity [TLC], functional residual capacity [FRC], residual volume [RV], and FVC) to salbutamol and the relationship of these changes to improvements in the spirometry in these patients. Design: A retrospective review of data extracted from a large database of patients who were undergoing spirometry and static lung volume measurements before and after the administration of 200 µg salbutamol. Patients: Patients with an FEV[sub 1]/FVC ratio of < 85% of predicted values were defined as being severely hyperinflated (SH) if TLC was > 133% of predicted and as being moderately hyperinflated (MH) if TLC was 115 to 133% of predicted. Results: Two hundred eighty-one SH patients and 676 MH patients were identified. Salbutamol significantly reduced the mean (± SEM) TLC (SH patients, 222 ± 23 mL; MH patients, 150 ± 10 mL; p < 0.001), FRC (SH patients, 442 ± 26 mL; MH patients, 260 ± 39 mL; p < 0.001), and RV (SH patients, 510 ± 28 mL; MH patients, 300 ± 14 mL; p < 0.001) and increased both the 1C (SH patients, 220 ± 15 mL; MH patients, 110 ± 11 mL; p < 0.001) and FVC (SH patients, 336 ± 21 mL; MH patients, 204 ± 13 mL; p < 0.001). FEV[sub 1] improved in a minority of patients (SH patients, 33%; MH patients, 26%), but if lung volume measurements are also considered, the overall bronchodilator response may improve to up to 76% of the SH group and up to 62% of the MH group. Changes in volumes correlated poorly with changes in maximal airflows. Conclusions: Bronchodilators reduce... [ABSTRACT FROM AUTHOR]

A response from the authors of the article concerning the cases and history of interstitial lung disease in nylon flock worker in Canada is presented.

Presents a letter to the editor of the journal 'Chest,' commenting on the paper 'Response of lung volumes to inhaled salbutamol in a large population of patients with severe hyperinflation,' by M.F. Newton and colleagues. Criteria for bronchodilator response in FVC; Use of functional criteria to exclude asthmatic patients from the analysis; Explanation for postbronchodilator lung volume increase.

Presents a response by Lutz Forkert to a letter to the editor about his article on bronchodilator response which appeared in the April 2002 issue.

An abstract of the study "Description of Lung Function During the Initial Evaluation of Patients With Idiopathic Pulmonary Fibrosis," by Onofre Moran and Arturo Cortes-Telles is presented.