title: Small Airway Obstruction in Chronic Obstructive Pulmonary Disease: Potential Parameters for Early Detection.
abstract: The impulse oscillometry (IOS) is recognized as a complementary method to spirometry in the diagnostics of obstructive pulmonary disorders. The IOS enables to measure total respiratory resistance (R5) and proximal respiratory resistance (R20), with the R5-R20 difference reflecting small airway resistance. This study seeks to evaluate the usefulness of R5-R20, maximal mid-expiratory flow (MMEF),and forced expiratory volume in 3 s/forced vital capacity ratio (FEV3/FVC), in the assessment of small airway obstruction in chronic obstructive pulmonary disease (COPD). One hundred and six COPD patients and 43 control subjects, aged over 55, were investigated. Spirometry and IOS were used to assess pulmonary function. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were evaluated. The findings demonstrate significant reductions in FEV3/FVC and MMEF, and an increase in R5-R20 difference in COPD patients; the changes that depended on the severity of airway obstruction. The sensitivity of R5-R20 in reflecting the MMEF was 84%, specificity 44.2%, PPV 72.4%, and NPV 61.3%. We conclude that the R5-R20 difference is superior to spirometry in the assessment of small bronchi obstruction. A high sensitivity of R5-R20 in reflecting the MMEF makes the IOS method particularly useful for detection of mild lung injury, while a high specificity of the spirometric FEV3/FVC ratio makes it useful to exclude obstruction of small airways. Both methods are thus complimentary.
authors.affiliation: Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 84 Szamarzewskiego Street, 60-569, Poznan, Poland. t_piorun@op.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Piorunek
authors.affiliation: Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 84 Szamarzewskiego Street, 60-569, Poznan, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kostrzewska
authors.affiliation: Department of Epidemiology, German Institute of Human Nutrition Potsdam-Rehbruecke, 114-116 Arthurt-Scheunert Alee, Nuthetal, Germany.|Department of Pediatric Gastroenterology and Metabolic Diseases, Poznan University of Medical Sciences, 27/33 Szpitalna Street, 60-572, Poznan, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Stelmach-Mardas
authors.affiliation: Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, 31 Wojska Polskiego Street, 60-624, Poznan, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Mardas
authors.affiliation: Department of Neurochemistry and Neuropathology, Poznan University of Medical Sciences, 49 Przybyszewskiego Street, 60-355, Poznan, Poland.|Neuroimmunological Unit, Polish Academy of Sciences, 49 Przybyszewskiego Street, 60-355, Poznan, Poland.
authors.forename: Sławomir
authors.initials: S
authors.lastname: Michalak
authors.affiliation: Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 84 Szamarzewskiego Street, 60-569, Poznan, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Goździk-Spychalska
authors.affiliation: Department of Pulmonology, Allergology and Respiratory Oncology, Poznan University of Medical Sciences, 84 Szamarzewskiego Street, 60-569, Poznan, Poland.
authors.forename: Halina
authors.initials: H
authors.lastname: Batura-Gabryel
mesh_terms: D000368:Aged; D000402:Airway Obstruction / Q000175:diagnosis* / Q000503:physiopathology; D000403:Airway Resistance / Q000502:physiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009991:Oscillometry / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012680:Sensitivity and Specificity; D013147:Spirometry / Q000379:methods; D013990:Tidal Volume / Q000502:physiology
keywords: Airflow Limitation; Airways Obstruction; Chronic Lung Disease; Lung Function; Respiratory Resistance