PT  - JOURNAL ARTICLE
AU  - Iván Caviedes
AU  - Rodrigo Soto
TI  - Influence of ventilatory inefficiency in to limit exercise capacity in COPD patients
DP  - 2012 Sep 01
TA  - European Respiratory Journal
PG  - P857
VI  - 40
IP  - Suppl 56
4099  - http://erj.ersjournals.com/content/40/Suppl_56/P857.short
4100  - http://erj.ersjournals.com/content/40/Suppl_56/P857.full
SO  - Eur Respir J2012 Sep 01; 40
AB  - Background: We recently demonstrated an influence of Ventilatory efficiency (VE/VCO2) over exercise capacity in COPD (Resp Care 2012 in press). Purpose: to demonstrate increase of ventilatory inefficiency depending on the severity of COPD, and its influence into reduce exercise capacity.Methods: 58 Gold I - III patients, mean age 61, mean FEV1: 98, 68.5 and 44.3%, mean DCO: 68, 59.5 and 45%. A cardiopulmonary stress test measuring Power (Wmax), Oxygen consumption (VO2max), VE/VCO2, expiratory flow limitation (EFL) and dynamic end expiratory volume (DEELV) was performed. In patients with hyperinflation correlations and multiple regressions between BMI, EFL, DEELV and VE/VCO2 over Wmax and VO2max were calculated.Results: patients ended the test due to dyspnea with increased VE/VCO2 (mean 34). Depending on the severity of COPD, VE/VCO2 was higher. 36 patients presented hyperinflation (mean DEELV 0.5 L), with a reduction in Wmax and in VO2max(mean: 63 and 76%). Significative correlation was demonstrated between VE/VCO2 over VO2max and Wmax (r: -0.5 and -0.5). In multiple regression the relation between VE/VCO2 and Wmax and VO2max was significative (p< 0.05 and <0.05), but not to BMI, EFL and DEELV. Conclusions: in COPD patients ventilatory inefficiency increases depending on the severity and is related with a reduction in the exercise capacity. Ventilatory inefficiency is an independent factor in to reduce exercise capacity in COPD.