TY - JOUR T1 - Relationship between supramaximal flows and flow-limiting mechanisms JF - European Respiratory Journal JO - Eur Respir J SP - 512 LP - 516 DO - 10.1183/09031936.96.09030512 VL - 9 IS - 3 AU - H Sala AU - F Galindez AU - A Badolati AU - D Rodenstein Y1 - 1996/03/01 UR - http://erj.ersjournals.com/content/9/3/512.abstract N2 - The aim of this study was to evaluate the relationship between supramaximal flows (SF) and indices of airway mechanics. We studied 26 asymptomatic young subjects (13 smokers, mean +/- SD 15.9 +/- 6.6 pack-years. Subjects performed maximal expiratory flow-volume (MEFV) curves, according to the American Thoracic Society (ATS) criteria, on a rolling-seal spirometer and then repeated them through a specially devised valve, which occluded the mouthpiece either 3 or 6 times.s-1 with a ratio of open:closed time of 3:1. Envelope MEFV curves for 3 and 6 Hz occlusions were constructed passing through the SF obtained after each occlusion, and the increment in flow at 50% of vital capacity was measured with respect to the basal curve (delta V' max50). We found that the delta V' max50 at 3 and 6 Hz correlated to the baseline forced mid-expiratory flow (FEF25-75) in % of predicted value (r = -0.73 and r = -0.55, respectively). our results suggest that inhomogeneities within the lung are an important mechanism in the occurrence of supramaximal flow in normal subjects. ER -