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[Diaphragmatic function during exercise in patients with severe COPD].

J Gea·J Sauleda·M Orozco-Levi·M C Aguar·E Barreiro·J M Broquetas
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Abstract

UNLABELLED: Ventilatory requirements increase during exercise. The respiratory muscles of patients with chronic obstructive pulmonary disease (COPD) are at a particular disadvantage when dealing with such increased demand. The objective of this study was to evaluate the changes in respiratory muscles brought on by exercise in such patients. METHODS: Twelve patients with severe CFOPD (FEV1 < 50% ref., 63 +/- 7 years) were enrolled. Breathing patterns and esophageal (Pes and transdiaphragmatic (Pdi) pressures and SaO2 were measured during submaximal exercise/Ecsbmax, 60% of the maximum tolerated load). A sniff maneuver was performed with the patients breathing ambient air with added oxygen to achieve 99% SaO2. We also measured level of FRC by inductive plethysmograph in a subgroup of five patients. RESULTS: During EXsbmáx, SaO2 decreased (from 95.0 +/- 2.1 to 92.3 +/- 4.0%; p < 0.01); Vt increased (717 +/- 199 to 990 +/- 297 cc, p < 0.01), as did respiratory rate (RR, 17 +/- 6 a 28 +/- 9; p < 0.01). Pes and Pdi were greater at Vt, changing from -12.4 +/- 4.8 to -27.0 +/- 10.1 and 16.6 +/- 6.1 to 30.4 +/- 12.4 cmH2O, respectively (p < 0.01 in both cases), whereas no significant changes were observed for maximal effort (Pesmax, -61.4 +/- 16.5 cersus -65.9 +/- 15.2 cmH2O; Pdimac 89.7 +/- 26.1 versus 81.7 +/- 35.7 cmH2O). Used as a global measure, Pdi/Pdimáx worsened (0.21 +/- 0.12 a 0.42 +/- 0.20; p < 0.01), as dud the diaphragm tension-time (TTdi; 0.07 +/- 0.04 to 0.15 +/- 0.06, p < 0.01). Intrinsic positive end-expiratory pressure (PEEPi) increased an estimated 2.7 +/- 2.1 to 9.4 +/- 5.8 cmH2O (p < 0.001), while FRC (delta 357 +/- 274 ml). Durante el EXsbmáx with oxygen supplementation, SaO2 did not decrease. However supplementation, though Ti/TTOT and maximal pressures remained unchanged. CONCLUSIONS: Respiratory muscle function changes induced by Exsbmáx seem to relate mainly to a worsening of system mechanics.

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Data Interpretation, StatisticalDiaphragmExerciseExercise TestHumansLung Diseases, ObstructiveMaleMiddle AgedModels, BiologicalRespirationRespiratory Function TestsRespiratory MusclesComparative StudyEnglish AbstractJournal ArticleResearch Support, Non-U.S. Gov't

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BibTeXRIS

J Gea, J Sauleda, M Orozco-Levi, M C Aguar, E Barreiro, J M Broquetas. 1999. [Diaphragmatic function during exercise in patients with severe COPD].. https://doi.org/10.1016/s0300-2896(15)30244-1

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