Metabolic and ventilatory parameters of four activities of daily living accomplished with arms in COPD patients

Abstract

Study objective: The upper limbs are involved in the activities of daily living (ADLs). Normal subjects usually perform such activities without noticing the energy cost, but patients with COPD report tiredness when performing them. This study was designed to assess the metabolic and ventilatory demands in patients with COPD during the performance of four ADLs involving the upper limbs.

Design: The patients were tested on two different days. Oxygen uptake (O(2)), carbon dioxide output (CO(2)), minute ventilation (E), and heart rate were measured while performing four ADLs for 5 min each: sweeping, erasing a blackboard, lifting pots, and replacing lamps.

Participants: Ten normal, young, male subjects (mean age, 27.9 years) were selected for testing the reproducibility of the methods, and 9 male patients with COPD (FEV(1), 32.5%; mean age, 58.9 years) entered the study.

Measurements and results: The tests were reproducible for both groups. Patients with COPD presented a significant increase (p < 0.05) in O(2) (mean, 50.2% of maximum O(2)) and in E (mean, 55.7% of maximum voluntary ventilation [MVV]) in relation to initial resting conditions for all four activities.

Conclusions: We conclude that when performing these four activities, patients with moderate-to-severe COPD present a high O(2), which may explain the tiredness reported by them during simple activities involving the upper limbs; the high E/MVV may be associated to dyspnea.