The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Compared with measurements of forced vital capacity (FVC), using the forced expiratory volume in six seconds (FEV(6)) reduces test time and frustration. It was hypothesised that using FEV(6) in the workplace setting would result in an acceptably low misclassification rate for detecting airways obstruction and spirometry-defined restriction when compared with using the traditional FVC. Experienced technicians from the National Institute for Occupational Safety and Health performed spirometry using dry rolling-seal spirometers as per American Thoracic Society guidelines in four workplace investigations. ⋯ The median (range) age of the 1,139 workers was 37 yrs (18-71 yrs) and 51.4% were male. A significantly high overall agreement was obtained between the two definitions. In conclusion, the current results confirm that forced expiratory volume in six seconds can be used as a surrogate for forced vital capacity in detecting airways obstruction and restriction in workers, although with some misclassification when compared to obtaining American Thoracic Society-acceptable manoeuvres of longer duration.
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The cuff-leak test was widely used for the prediction of post-extubation stridor, but controversial results limit its clinical application. The current study used real-time ultrasonography to evaluate the air-leak and hypothesised that the air-column width, measured by ultrasonography, may be correlated to the development of post-extubation stridor. From June 1, 2001 to March 1, 2002, a total of 51 planned extubations in 51 consecutively intubated patients were included. ⋯ They were found to be statistically significant. In conclusion, the authors demonstrated that laryngeal ultrasonography could be a reliable, noninvasive method, in the evaluation of vocal cords, laryngeal morphology and the ease of airflow, which passed through vocal cords or subglottic area due to laryngeal oedema. The air-column width during cuff deflation was a potential predictor of post-extubation stridor.
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The purpose of this study was to determine fixed cut-off points for forced expiratory volume in one second (FEV(1))/FEV(6) and FEV(6) as an alternative for FEV(1)/forced vital capacity (FVC) and FVC in the detection of obstructive and restrictive spirometric patterns, respectively. For the study, a total of 11,676 spirometric examinations, which took place on Caucasian subjects aged between 20-80 yrs, were analysed. Receiver-operator characteristic curves were used to determine the FEV(1)/FEV(6) ratio and FEV(6) value that corresponded to the optimal combination of sensitivity and specificity, compared with the commonly used fixed cut-off term for FEV(1)/FVC and FVC. ⋯ For the spirometric diagnosis of airway obstruction (prevalence of 45.9%), FEV(1)/FEV(6) sensitivity and specificity were 94.4 and 93.3%, respectively; the positive and negative predictive values were 92.2 and 95.2%, respectively. For the spirometric detection of a restrictive pattern (prevalence of 14.9%), FEV(6) sensitivity and specificity were 95.9 and 98.6%, respectively; the positive and negative predictive values were 92.2 and 99.3%, respectively. This study demonstrates that forced expiratory volume in one second/forced expiratory volume in six seconds <73% and forced expiratory volume in six seconds <82% predicted, can be used as valid alternatives to forced expiratory volume in one second/forced vital capacity <70% and forced vital capacity <80% predicted, as fixed cut-off terms for the detection of an obstructive or restrictive spirometric pattern in adults.