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A2184 - Effects of Respiratory Rate and Dynamic Hyperinflation on Respiratory System Resistance in Patients with Bronchiectasis
Author Block: R. Moroli1, D. O. Santos1, L. Perossi1, M. Holtz1, J. A. Baddini-Martinez2, A. Gastaldi3; 1Department of Physioterapy, University of São Paulo, Ribeirao Preto, Brazil, 2Medical Sch of Ribeirao Preto, Ribeirao Preto 14048-900, Brazil, 3Ribeirao Preto Medical School, Ribeirao Preto, Brazil.
Normal 0 21 false false false PT-BR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:""Tabela normal""; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:7.35pt; mso-para-margin-bottom:auto; mso-para-margin-left:0cm; line-height:15.0pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:""Calibri"",""sans-serif""; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:""Times New Roman""; mso-bidi-theme-font:minor-bidi; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} Background: Bronchiectasis is characterized by a chronic inflammatory condition that causes permanent dilation of the bronchi and bronchioles, and thus symptoms such as dyspnea, chronic productive cough, and consequent reduction of exercise capacity. The main limitations to the exercises are increased dyspnea due to increased respiratory rate and dynamic hyperinflation. Objective: The aim of the present study was to evaluate the effects of dynamic hyperinflation and increased respiratory rate on respiratory system resistance in patients with bronchiectasis, simulating what happens to these patients during exercise. Methods: The study involved 18 patients with non-cystic fibrosis bronchiectasis, clinically stable, of both genders with mean age of 50.33±14.48 years. Was evaluated by ventilometry, vital capacity (VC) and inspiratory capacity (IC), tidal volume (TV) and respiratory rate (r). They were also evaluated by Impulse Oscillometry System (IOS), which analyzed, resistance at 5 Hz and 20 Hz (R5 and R20), reactance at 5 Hz (X5), frequency of resonance (Fres) and reactance area (Ax). Measurements with IOS were performed in seated position, under the following conditions, in a random order: a) basal TV and r= 30 breaths per minute (bpm); b) basal TV and r= 40bpm; c) hyperinflation and basal r; d) hyperinflation and r= 30 bpm; and e) hyperinflation and r= 40bpm. A metronome was used to control the r. To simulate hyperinflation, respirations were performed at about 50% of IC. Results: Basal values were compared with those obtained under conditions from “a” to “e”, with a significance level of 0.05. Statistical analysis showed an increase of R5 in relation to the basal (0.51±0.17 kPa/L/s) for r=40bpm (0.75±0.34 kPa/L/s), p=0.0045. An increase of R5-20 in relation to baseline (0.16±0.11 kPa/L/s) for r=30bpm (0.31±0.19 kPa/L/s), p=0.0008; for r=40bpm (0.39±0.26 kPa/L/s), p=0.0001, and in hyperinflation with r=40bpm (0.37±0.28 kPa/L/s, p=0.0001. For the other conditions and variables (R20, X5, AX and Fres), no significant differences were found. Conclusions: The results suggest that increased respiratory rate, increases the resistance of the respiratory system, mainly peripheral, and this increase can be attenuated by dynamic hyperinflation.