MedWire News: Patients with severe chronic obstructive pulmonary disease (COPD) can attain peak oxygen consumption after 5 to 9 minutes of symptom-limited maximal cardiopulmonary exercise testing (CPET), as opposed to the 8 to 12 minutes proposed in the current guidelines, US research shows.
"These results may have important implications for the clinical application of CPET as it is commonly applied to patients with severe COPD," the authors write in the journal Chest."
CPET is often used in patients with COPD to tailor exercise prescriptions in pulmonary rehabilitation, evaluate responses to an intervention2, and aid in the construction of prediction rules for defining risk.
However, the 8-12 minutes recommended by the American Thoracic Society/American College of Chest Physicians as being the optimal test duration needed to achieve the highest peak oxygen consumption (VO2 peak) is based on data generated from a group of five healthy individuals.
Robert Benzo, from the University of Pittsburgh in Pennsylvania, USA, and colleagues performed a randomized double-blind study in patients with severe COPD to determine the optimal CPET protocol duration resulting in the highest VO2 peak.
They found that in 11 patients with severe COPD who each completed four incremental, symptom-limited exercise tests on a cycle ergometer using four protocols, the mean duration required to attain VO2 peak was 6.3 minutes. There was no significant difference between the VO2 peaks achieved with the four different protocols.
"VO2 peak, in a group of patients with severe COPD, was achieved in a shorter time frame than that proposed in the current exercise guidelines," the authors write.
They conlude: "a targeted duration of 5 to 9 min for a CPET appears to be more appropriate than the 8 to 12 min proposed in the current guidelines."
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