Spirometry, Impulse Oscillometry and Capnovolumetry in welders and healthy male subjects

“…Capnographic measurements can be described by various parameters, and a number of investigations have addressed the question, which of these parameters are suited to assess the presence of airway obstruction (e.g. [8, 11, 12]). One study [10] suggested a high diagnostic accuracy especially for the ratio of slopes of phases 3 and 2 that are obtained when the expiratory CO 2 concentration is plotted against volume (capnovolumetry, see Fig.…”

Section: Introductionmentioning

confidence: 99%

Diagnostic accuracy of capnovolumetry for the identification of airway obstruction – results of a diagnostic study in ambulatory care

et al. 2019

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Background One of the known weaknesses of spirometry is its dependence on patients’ cooperation, which can only partially be alleviated by educational efforts. Therefore, procedures less dependent on cooperation might be of value in clinical practice. We investigated the diagnostic accuracy of ultrasound-based capnovolumetry for the identification of airway obstruction. Methods Consecutive patients from a pulmonary outpatient clinic were included in the diagnostic study. As reference standard, the presence of airway obstruction was evaluated via spirometry and bodyplethysmography. Capnovolumetry was performed as index test with an ultrasound spirometer providing a surrogate measure of exhaled carbon dioxide. Receiver operating characteristic (ROC) analysis was performed using the ratio of slopes of expiratory phases 3 and 2 (s3/s2) ≥ 0.10 as primary capnovolumetric parameter for the recognition of airway obstruction. Logistic regression was performed as secondary analysis to identify further useful capnovolumetric parameters. The diagnostic potential of capnovolumetry to identify more severe degrees of airway obstruction was evaluated additionally. Results Of 1400 patients recruited, 1287 patients were included into the analysis. Airway obstruction was present in 29% of patients. The area under the ROC-curve (AUC) of s3/s2 was 0.678 (95% CI 0.645, 0.710); sensitivity of s3/s2 ≥ 0.10 was 47.7 (95% CI 42.7, 52.8)%, specificity 79.0 (95% CI 76.3, 81.6)%. When combining this parameter with three other parameters derived from regression analysis (ratio area/volume phase 3, slope phase 3, volume phase 2), an AUC of 0.772 (95% CI 0.743, 0.801) was obtained. For severe airway obstruction (FEV 1 ≤ 50% predicted) sensitivity of s3/s2 ≥ 0.10 was 75.9 (95% CI 67.1, 83.0)%, specificity 75.8 (95% CI 73.3, 78.1)%; for very severe airway obstruction (FEV 1 ≤ 30% predicted) sensitivity was 86.7 (95% CI 70.3, 94.7)%, specificity 72.8 (95% CI 70.3, 75.2)%. Sensitivities increased and specificities decreased considerably when the combined capnovolumetric score was used as index test. Conclusions Capnovolumetry by way of an ultrasound spirometer had a statistically significant albeit moderate potential for the recognition of airway obstruction in a heterogeneous population of patients typically found in clinical practice. Diagnostic accuracy of the capnovolumetric device increased with the severity of airway obstruction. Trial registration The study is registered under DRKS00013935 at German Clinical Trials Register (DRKS).

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“…[2][3][4] The impulse oscillometry system has been successful, particularly in the respiratory assessment of children, because it does not require effort and it is easy to apply. 4,[5][6][7][8] The literature presents some studies using the impulse oscillometry system as a complementary method of evaluation in children with respiratory disorders, with emphasis on asthma and cystic fibrosis. [8][9][10][11][12] Investigations carried out with healthy children show a growing trend toward determining equations/reference values for new methods of respiratory assessment.…”

Section: Introductionmentioning

confidence: 99%

Reference Equations for Impulse Oscillometry System Parameters in Healthy Brazilian Children and Adolescents

et al. 2016

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BACKGROUND:The impulse oscillometry system is a noninvasive method of evaluating respiratory mechanics that is being increasingly used in the pediatric population. To date, no reference equations have been developed for healthy Brazilian children and adolescents. The purpose of the study was to determine the reference equations for impulse oscillometry system parameters in healthy children and adolescents. METHODS: We undertook an observational cross-sectional analytical study with healthy students age 6 -14 y from educational institutions in the Greater Florianópolis area. Biometric data were evaluated (weight, height, body mass index, and body surface area) as predictors and for sample characterization. All participants were submitted to evaluation of respiratory mechanics using an oscillometry system following American Thoracic Society standards. Three tests were recorded, with data acquisition for >20 s. For data normality verification, the Kolmogorov-Smirnov test was applied, and Pearson's correlation test identified the relationship between the predicted values of height, age, and weight and the oscillometric variables of resistance at 5 and 20 Hz reactance; respiratory impedance at 5 Hz resonant frequency; and reactance area. Models were developed using simple linear regression and multiple analyses. RESULTS: After the recruitment of 864 children, 123 subjects with an average age of 10.0 ؎ 2.4 y for boys and 9.9 ؎ 2.4 y for girls (P ‫؍‬ .94) were considered for final analysis. Correlations were identified between the dependent and predictor oscillometric variables, with height identified as having the greatest predictive power in the equations developed for boys in all oscillometric parameters, with a mean adjusted R 2 of 46.51%. Age had greater influence on resonant frequency (adjusted R 2 ‫؍‬ 40.1%) and reactance area (adjusted R 2 ‫؍‬ 48.8%) for girls. CONCLUSIONS: Reference equations were developed for males and females, and height was the most influential predictor variable for most impulse oscillometry system parameters in the population studied.

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Spirometry, Impulse Oscillometry and Capnovolumetry in welders and healthy male subjects

Cited by 11 publications

References 33 publications

Biological effect markers in exhaled breath condensate and biomonitoring in welders: impact of smoking and protection equipment

Biological effect markers in exhaled breath condensate and biomonitoring in welders: impact of smoking and protection equipment

Diagnostic accuracy of capnovolumetry for the identification of airway obstruction – results of a diagnostic study in ambulatory care

Reference Equations for Impulse Oscillometry System Parameters in Healthy Brazilian Children and Adolescents

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