The Journal of asthma : official journal of the Association for the Care of Asthma
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Multicenter Study
Influence of season and temperature on the relationship of elemental carbon air pollution to pediatric asthma emergency room visits.
Previous studies have demonstrated an association between air pollution and asthma exacerbation. Less understood is the effect of elemental carbon (EC), and the interaction of EC with temperature, on increases in pediatric asthma emergency department visits and how these relationships change across the seasons in a metropolitan area with several industries and relatively low air pollution. Measurements of EC, ozone (O(3)), sulfur dioxide (SO(2)), and total oxides of nitrogen (NO(x)) were available from the St. ⋯ During the winter, a 0.10 microg/m(3) increase in EC resulted in 2.80% increase in asthma ED visits among 11-17-year-olds (95%CI = 1.01,1.05) at the median seasonal temperature (43.3 degrees F). This risk increased with decreasing temperature. Among 11-17-year-olds, daily number of asthma ED visits is associated with increased levels of EC at higher temperatures in the summer and lower temperatures in the winter.
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Comparative Study
Validation of automatic wheeze detection in patients with obstructed airways and in healthy subjects.
Computerized lung-sound analysis is a sensitive and quantitative method to identify wheezing by its typical pattern on spectral analysis. We evaluated the accuracy of the VRI, a multi-sensor, computer-based device with an automated technique of wheeze detection. The method was validated in 100 sound files from seven subjects with asthma or chronic obstructive pulmonary disease and seven healthy subjects by comparison of auscultation findings, examination of audio files, and computer detection of wheezes. ⋯ The present findings demonstrate that the wheeze detection algorithm has good accuracy, sensitivity, specificity, negative predictive value and positive predictive value for wheeze detection in regional analyses with a single sensor and multiple sensors. Results are similar to those reported in the literature. The device is user-friendly, requires minimal patient effort, and, distinct from other devices, it provides a dynamic image of breath sound distribution with wheeze detection output in less than 1 minute.
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As optimal treatment and prognosis differ between asthma and COPD, a new diagnostic approach to differentiating between the two disorders would be clinically desirable. We evaluated the utility of vibration response imaging in differentiating between asthma and COPD. Sixty-six subjects with asthma or COPD were recorded, before and after the administration of a short-acting bronchodilator, using a computerized lung sound analysis device. ⋯ Combined analyses based on qualitative image evaluation and quantitative data demonstrated an overall 85% accuracy (84% for asthma, 86% for COPD) in differentiating between asthma and COPD. Combined qualitative and quantitative evaluations of lung sounds are quite sensitive in distinguishing between lung sound recordings of COPD and asthma individuals. Lung sound features of synchronization in timing and intensity provide objective data that may further differentiate these two airway disorders.