TY - JOUR T1 - Comparison of flow-volume measurements with realtime versus fixed temperature BTPS correction JF - European Respiratory Journal JO - Eur Respir J VL - 42 IS - Suppl 57 SP - P1258 AU - Ton Provily AU - Citta Zaat AU - Karin Nietzman AU - Henk Stam AU - Henk Hoogsteden Y1 - 2013/09/01 UR - http://erj.ersjournals.com/content/42/Suppl_57/P1258.abstract N2 - Introduction and aimTraditionally flow-volume measurements are corrected to BTPS conditions assuming a fixed exhalation temperature. With new techniques exhalation temperature is measured continuously, making realtime BTPS correction possible.Because temperature is changing during the forced exhalation, we investigated if there is a difference in results applying a realtime or fixed temperature BTPS correction.MethodsResults of 46 volunteers (19 males and 27 females, age ranging from 20 to 80 years), who performed slow spirometry and flow-volume measurements according to the ATS/ERS criteria, were compared. Measurements were performed randomly with a Lilly type pneumotachometer (fixed exhalation temperature correction) and with an ultrasonic flow sensor (realtime correction).ResultsWe studied the difference between the FVCex and the FVCin for both systems. We observed a significantly smaller difference between the FVCex and the FVCin in the realtime BTPS correction system (ΔFVC(realtime-fixed) = -57ml, 95% CI (-103ml; -10ml) (p = 0.009)).However, FVCin appeared to be not significantly different (P=0.056) in both systems.We also observed significant differences in the FEV1/(F)VC ratio and in other flow volume parameters (0.00 ≤ P ≤ 0.0185), in which volumes with fixed temperature correction appeared to be larger.ConclusionIt is likely, that there is no difference for FVCin, because both systems use the measured ambient temperature for the correction.The fact, that realtime correction leads to a smaller difference between FVCex and FVCin, suggests that the fixed temperature correction during expiration leads to an overestimation of the expiration parameters. ER -