This Article Full Text Full Text (PDF) All Versions of this Article: chest.07-0732v1 132/5/1500    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Benzo, R. P. Articles by Sciurba, F. C. Search for Related Content PubMed PubMed Citation Articles by Benzo, R. P. Articles by Sciurba, F. C.

Optimal Protocol Selection for Cardiopulmonary Exercise Testing in Severe COPD^*

^* From the Division of Pulmonary & Critical Care Medicine (Drs. Benzo, Patel, and Sciurba, and Mr. Slivka), University of Pittsburgh, Pittsburgh, PA; and Georgia Lung Associates (Dr. Paramesh), Austell, GA.

Correspondence to: Roberto P. Benzo, MD, MSc, FCCP, Division of Pulmonary and Critical Care Medicine, University of Pittsburgh, Suite 1211 Kaufmann Building, 3471 Fifth Ave, Pittsburgh, PA 15213; e-mail: benzorp{at}upmc.edu

Abstract

Background: The current recommendations of 8 to 12 min for the optimal targeted duration of symptom-limited maximal cardiopulmonary exercise testing (CPET) to attain maximal oxygen consumption are based on results from healthy individuals and may not be applicable to patients with severe COPD. We aimed to determine the optimal duration for a CPET to attain the peak oxygen consumption (O₂peak) in a group of patients with severe COPD using different carefully conducted workload protocols.

Methods: We studied 11 subjects with severe COPD (mean FEV₁, 32% predicted; 95% confidence interval [CI], 27 to 38% predicted). They completed four incremental, symptom-limited exercise tests on a cycle ergometer using four protocols (4, 8, and 16 W/min continuous ramp protocols, and 8 W/min step protocol) using a randomized double-blind design.

Results: The mean duration of these 44 tests was 6.3 min (95% CI, 5.0 to 9.0 min). The duration of the exercise tests differed significantly for the protocols used, as follows: 16-W ramp protocol, 4.0 min (95% CI, 3.0 to 5.1 min); 8-W ramp protocol, 6.6 min (95% CI, 5.0 to 9.0 min); 8-W step protocol, 6.0 min (95% CI, 4.0 to 8.0 min); and 4-W ramp protocol, 8.7 min (95% CI, 4.4 to 13.0 min; p < 0.001). The maximal workload significantly increased as the ramp slope increased from 4 to 8 to 16 W/min (maximal workload, 35.6 vs 50.7 vs 64.3 W, respectively; p < 0.001). Maximal minute ventilation, heart rate, Borg ratings, and O₂ peak_, were not different among the four protocols. No differences were found between the ramp and step protocols.

Conclusions: In patients with severe COPD (Global Initiative for Chronic Obstructive Lung Disease stages III–IV), 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. Maximal workload, in contrast to O₂peak, is highly dependent on the ramp incrementation rate.

Key Words: COPD • emphysema • exercise test • health outcomes