Clinical and Experimental Otorhinolaryngology  2015;8(2):161-166

doi:10.3342/ceo.2015.8.2.161

Changes in the Flow-Volume Curve According to the Degree of Stenosis in Patients With Unilateral Main Bronchial Stenosis.

Yousang KO 1 ; Jung Geun YOO ; Chin A YI ; Kyung Soo LEE ; Kyeongman JEON ; Sang Won UM ; Won Jung KOH ; Gee Young SUH ; Man Pyo CHUNG ; O Jung KWON ; Hojoong KIM

Affiliations

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Keywords

Maximal Expiratory Flow-Volume Curves; Spirometry; Bronchi

Country

Republic of Korea

Language

English

Abstract

OBJECTIVES: The shape of the flow-volume (F-V) curve is known to change to showing a prominent plateau as stenosis progresses in patients with tracheal stenosis. However, no study has evaluated changes in the F-V curve according to the degree of bronchial stenosis in patients with unilateral main bronchial stenosis. METHODS: We performed an analysis of F-V curves in 29 patients with unilateral bronchial stenosis with the aid of a graphic digitizer between January 2005 and December 2011. RESULTS: The primary diseases causing unilateral main bronchial stenosis were endobronchial tuberculosis (86%), followed by benign bronchial tumor (10%), and carcinoid (3%). All unilateral main bronchial stenoses were classified into one of five grades (I, < or =25%; II, 26%-50%; III, 51%-75%; IV, 76%-90%; V, >90% to near-complete obstruction without ipsilateral lung collapse). A monophasic F-V curve was observed in patients with grade I stenosis and biphasic curves were observed for grade II-IV stenosis. Both monophasic (81%) and biphasic shapes (18%) were observed in grade V stenosis. After standardization of the biphasic shape of the F-V curve, the breakpoints of the biphasic curve moved in the direction of high volume (x-axis) and low flow (y-axis) according to the progression of stenosis. CONCLUSION: In unilateral bronchial stenosis, a biphasic F-V curve appeared when bronchial stenosis was >25% and disappeared when obstruction was near complete. In addition, the breakpoint moved in the direction of high volume and low flow with the progression of stenosis.