Oxygen and ventilatory output during several activities of daily living performed by COPD patients stratified according to disease severity.

Abstract

OBJECTIVES: To measure the oxygen and ventilatory output across all COPD stages performing 18 common ADL and identify the activities that present the highest metabolic and ventilatory output as well as to compare the energy expenditure within each disease severity. MATERIALS AND METHODS: Metabolic (VO2 and VCO2), ventilatory (f and VE), cardiovascular (HR) and dyspnea (Borg score) variables were assessed in one hundred COPD patients during the completion of eighteen ADL grouped into four activities domains: rest, personal care, labor activities and efforts. RESULTS: The activities with the highest proportional metabolic and ventilatory output (VO2/VO2max and VE/MVV) were walking with 2.5 Kg in each hand and walking with 5.0 Kg in one hand. Very severe patients presented the highest metabolic, ventilatory output and dyspnea than mild patients (p<0.05). CONCLUSIONS: COPD patients present an increased proportion of energy expenditure while performing activities of daily living. The activities that developed the highest metabolic and ventilatory output are the ones associated to upper and lower limbs movements combined. Very severe patients present the highest proportional estimated metabolic and ventilatory output and dyspnea. Activities of daily living are mainly limited by COPD's reduced ventilatory reserve.