Ventilatory problems play progressive role in activity limitations in COPD
MedWire News: Results from a Dutch study show that ventilatory problems play an important and progressive role in limitations to activities of daily life (ADL) in patients with chronic obstructive pulmonary disease (COPD).
"Exertional dyspnea during ADL is the main complaint in patients with moderate-to-severe COPD," explain A Lahaije (Radboud University Nijmegen Medical Centre) and team. "As a consequence, patients adapt or reduce such activities, which in turn leads to a reduced quality of life."
The researchers enrolled 21 stable patients with moderate-to-very-severe COPD, who had a mean FEV1 of 43% of the predicted value, and 10 healthy controls who were matched for age and gender.
All the participants were asked to perform similar household tasks while wearing a device that measured ventilatory demand.
The researchers found that mean duration of ADL was significantly shorter in COPD patients than controls, at 318 s versus 530 s, and resulted in significant levels of dyspnea.
Mean oxygen consumption during ADL was significantly higher in patients than controls, at 957 versus 768 ml/min. Ventilatory demand was also significantly higher in COPD patients than controls during comparable activities.
In addition, more than 80% of COPD patients had ventilatory constraints, such as low ventilatory reserve and inspiratory reserve volume, and dynamic hyperinflation, which were particularly prevalent in patients with very severe COPD.
Lahaije and team conclude: "Patients with COPD experience limitations in the performance of ADL, which lead to reductions in ADL time and dyspnea complaints. There appears to be an important role for ventilatory limitations, which become more prominent as disease progresses."
They add: "Investigating patients with mild and moderate disease might help to understand why and when in the course of the disease physiological limitation begins to have its repercussion in daily life and/or activity level is reduced."
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By Mark Cowen