RT Journal Article SR Electronic T1 Diagnostics of loss in lung elastic recoil pressure using impulse oscillometry and body plethysmography JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP p1186 VO 38 IS Suppl 55 A1 Larisa Kiryukhina A1 Marina Kameneva YR 2011 UL http://erj.ersjournals.com/content/38/Suppl_55/p1186.abstract AB Respiratory resistance at 20 Hz (R20) by impulse oscillometry (IO) characterizes airways resistance with inextensible walls. Airways resistance (Rtot) by body plethysmography reflects the total resistance of the first 8 - 10 bronchi generations. These indicators by different methods are close physiologically. The airways in patients with an emphysema are deprived of elastic support, so a lung compliance (CL) considerably increases. We have assumed that shunting of R20 increases with loss of lung elastic recoil.Aim of the study is evaluation loss of respiratory resistance by IO with increasing of compliance and decreasing of lung elastic recoil.Materials and methods: We compared Rtot and R20 in 67 healthy volunteers (32F/35M, 47±1 yrs) and in the patients with obstructive disorders - 41 patients with COPD (0F/41M, 56±1 yrs) and 52 patients with bronchial asthma (34F/18M, 47±2 yrs). We have used the relation Rtot/R20. All patients were performed investigation of lung elasticity using esophagus balloon.Results: Rtot/R20 in healthy group was 0,79±0,03 and in patients with obstructive disorders it was 1,72±0,10 (p<0,01). The analysis Rtot/R20 in patients with obstructive disorders showed considerable difference of Rtot/R20 value in patients with normal lung elastic recoil and in patients with loss lung elastic recoil (1,24 and 2,08 accordingly, p<0,01). The correlation analysis showed moderate dependence Rtot/R20 with CL and coefficient of retraction (CR) (r=0,57 and –0,38 accordingly, p < 0,01).Conclusion: The relation Rtot/R20 reflects loss in parenchymal elastic recoil pressure. In healthy and patients with obstructive disorders with normal lung elastic recoil it is less 1,24.