T T Bauer1, G Schultze-Werninghaus, J Kollmeier, A Weber, R Eibel, B Lemke, E W Schmidt. 1. Berufsgenossen- schaftliche Kliniken Bergmannsheil, Abteilung für Pneumologie, Allergologie und Schlafmedizin, Medizinische Klinik und Poliklinik, Bürkle-de-la-Camp- Platz 1, D-44789 Bochum, Germany. torsten.bauer@ruhr-uni-bochum.de
Abstract
OBJECTIVES: Dyspnoea is a common symptom in coal miners with pneumoconiosis. Among others, gas exchange disturbances due to airway obstruction or mismatch between ventilation and perfusion may be underlying mechanisms. The validation of dyspnoea by the degree of airway obstruction is controversial, because the extent of airway obstruction often does not correlate with the clinical grade of breathlessness. METHODS: The association was investigated between breathlessness (self reported, on a six point scale) and indices of submaximal spiroergometry in 66 coal workers with radiographically confirmed pneumoconiosis (International Labour Organisation (ILO) grade of profusion > or =1/0, mean (SD) age 64 (5.5) years, mean (SD) forced expired volume in 1 second (FEV(1)) 77.5 (22.9) % predicted). RESULTS: The clinical degree of breathlessness was independently associated with minute ventilation/oxygen consumption (VE/VO(2)) ratio (beta 0.423, 95% confidence interval (95% CI) 0.18 to 0.67, p=0.001) and smoking (beta 0.318, 95% CI 0.21 to 1.79, p=0.014) in a multiple linear regression analysis. The VE/VO(2) ratio (beta 0.556, 95% CI 0.20 to 0.90, p=0.003) was also the best predictor of breathlessness when only coal miners with airway obstruction (FEV(1) < 80% predicted) were analyzed. CONCLUSION: The VE/VO(2) ratio as a measurement of mismatch between ventilation and perfusion predicted the clinical grade of breathlessness better than measurements of bronchial obstruction at rest in coal workers with pneumoconiosis.
OBJECTIVES:Dyspnoea is a common symptom in coal miners with pneumoconiosis. Among others, gas exchange disturbances due to airway obstruction or mismatch between ventilation and perfusion may be underlying mechanisms. The validation of dyspnoea by the degree of airway obstruction is controversial, because the extent of airway obstruction often does not correlate with the clinical grade of breathlessness. METHODS: The association was investigated between breathlessness (self reported, on a six point scale) and indices of submaximal spiroergometry in 66 coal workers with radiographically confirmed pneumoconiosis (International Labour Organisation (ILO) grade of profusion > or =1/0, mean (SD) age 64 (5.5) years, mean (SD) forced expired volume in 1 second (FEV(1)) 77.5 (22.9) % predicted). RESULTS: The clinical degree of breathlessness was independently associated with minute ventilation/oxygen consumption (VE/VO(2)) ratio (beta 0.423, 95% confidence interval (95% CI) 0.18 to 0.67, p=0.001) and smoking (beta 0.318, 95% CI 0.21 to 1.79, p=0.014) in a multiple linear regression analysis. The VE/VO(2) ratio (beta 0.556, 95% CI 0.20 to 0.90, p=0.003) was also the best predictor of breathlessness when only coal miners with airway obstruction (FEV(1) < 80% predicted) were analyzed. CONCLUSION: The VE/VO(2) ratio as a measurement of mismatch between ventilation and perfusion predicted the clinical grade of breathlessness better than measurements of bronchial obstruction at rest in coal workers with pneumoconiosis.
Authors: T P Chao; E F Sperandio; T L V P Ostolin; V R Almeida; M Romiti; A R T Gagliardi; R L Arantes; V Z Dourado Journal: Braz J Med Biol Res Date: 2018-03-26 Impact factor: 2.590