Dynamic hyperinflation during activities of daily living in COPD patients.

The objective of this study was to investigate whether some activities of daily living (ADLs) usually related to dyspnea sensation in patients with chronic obstructive pulmonary disease (COPD) are associated with dynamic lung hyperinflation (DH) and whether the use of simple energy conservation techniques (ECTs) might reduce this possible hyperinflation. Eighteen patients (mean age: 65.8 ± 9.8 years) with moderate-to-severe COPD performed six ADLs (walking on a treadmill, storing pots, walking 56 meters carrying a 5-kilogram weight, climbing stairs, simulating taking a shower, and putting on shoes) and had their inspiratory capacity (IC) measured before and after each task. The patients were moderately obstructed with forced expiratory volume in 1 second (FEV1): 1.4 ± 0.4 L (50% ± 12.4); FEV1/forced vital capacity: 0.4 ± 8.1; residual volume/total lung capacity: 52.7 ± 10.2, and a reduction in IC was seen after all six activities (p < 0.05): (1) going upstairs, 170 mL; (2) walking 56 meters carrying 5 kilogram weight, 150 mL; (3) walking on a treadmill without and with ECT, respectively, 230 mL and 235 mL; (4) storing pots without and with ECT, respectively, 170 mL and 128 mL; (5) taking a shower without and with ECT, respectively, 172 mL and 118 mL; and (6) putting on shoes without and with ECT, respectively, 210 mL and 78 mL). Patients with moderate to severe COPD develop DH after performing common ADLs involving the upper and lower limbs. Simple ECTs may avoid DH in some of these ADLs.