title: Clinical Roles of Lung Volumes Detected by Body Plethysmography and Helium Dilution in Asthmatic Patients: A Correlation and Diagnosis Analysis.
abstract: Roles of lung volumes in asthma remain controversial. We aimed to evaluate the efficacy of lung volumes in differentiating asthma severity levels. Consecutive outpatients with chronic persistent asthma were enrolled, and body plethysmography (BP) and helium dilution (HD) were performed simultaneously to extract RV%pred, TLC%pred, and RV/TLC. Significant negative correlations were found between FEV1%pred and RV%pred (r = -0.557, P < 0.001), TLC%pred (r = -0.387, P < 0.001), and RV/TLC (r = -0.485, P < 0.001) measured by BP, as well as difference in volumes between these two techniques (ΔRV%pred, ΔTLC%pred and ΔRV/TLC). In mild and moderate asthma, AUC of RV%pred detected by BP and ΔTLC%pred was 0.723 (95%CI 0.571-0.874, P = 0.005) and 0.739 (95%CI 0.607-0.872, P = 0.002) with sensitivity and specificity being 79.41% and 88.24%, and 65.22% and 56.52% at cut-off of 145.40% and 14.23%, respectively. In moderate and severe asthma, AUC of RV%pred detected by BP and ΔTLC%pred was 0.782 (95%CI 0.671-0.893, P < 0.001) and 0.788 (95%CI 0.681-0.894, P < 0.002) with sensitivity and specificity being 77.78% and 97.22%, and 73.53% and 52.94% at cut-off of 179.85% and 20.22%, respectively. In conclusion, lung volumes are reliable complement of FEV1in identifying asthma severity levels.
authors.affiliation: Department of Respiratory Diseases, West China School of Medicine and West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Critical Care Medicine, West China School of Medicine and West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Gerontology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China.
authors.forename: Guo
authors.initials: G
authors.lastname: Chen
authors.affiliation: Department of Respiratory Diseases, West China School of Medicine and West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Binmiao
authors.initials: B
authors.lastname: Liang
authors.affiliation: Department of Respiratory Diseases, West China School of Medicine and West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Chuntao
authors.initials: C
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001249:Asthma / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D005541:Forced Expiratory Volume; D006371:Helium / Q000737:chemistry*; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D012372:ROC Curve; D012129:Respiratory Function Tests; D012720:Severity of Illness Index
chemical_list: D006371:Helium