Chronicle obstructive pulmonary disease is a worldwide cause of mortality and morbidity. This
systemic disease progressively leads to dyspnea, muscle wasting and exercise capacity
impairment.
Pulmonary rehabilitation is a cornerstone in the management of these systemic effects.
Unfortunately, access to pulmonary rehabilitation is limited for many people who would
benefit from it, primarily because of a lack of pulmonary rehabilitation and assessment
centers. Optimal assessment should include an incremental cardiopulmonary exercise testing.
This test allows to evaluate the factors contributing to exercise intolerance by linking
performance and physiological parameters to the underlying metabolism. Moreover, it is the
standard test to determine both the optimal training settings as well as any cardiopulmonary
contraindications to pulmonary rehabilitation. However, this test is not available in most
centers and when it is, consultations are limited. Therefore, pulmonary rehabilitation is
often delayed for several weeks and patients can lose motivation.
In order to promote pulmonary rehabilitation, the incremental cardiopulmonary exercise
testing could be replaced by field tests to individualize pulmonary rehabilitation
prescription.
The six-minute stepper test is a new field tool. Its sensitivity and reproducibility have
previously been reported in patients with chronicle obstructive pulmonary disease. It is easy
to set up in the clinical setting and could be used to individualize pulmonary
rehabilitation.
The main drawback when using field test is that they only provide a non specific assessement
of the functional capacity because cardiopulmonary parameters and gaz exchanges are not
monitored.
Although the performance during the 6-minute stepper test is moderately related with the
maximal oxygen consumption during the incremental cardiopulmonary exercise testing performed
on a cycloergometer, a direct comprehensive comparison of cardiopulmonary parameters and gaz
exchanges during these two tests have never been performed.
Moreover, stepping is more closely related with activities of daily life (requiring a
repetitive transition from rest to submaximal exercise intensity) than the maximal
incremental exercise on cycloergometer and could provide further insight on the disability of
patients during their usual activities, such as stair climbing (which is frequently avoided).
Additionally, on-transient phase two oxygen consumption kinetic is particularly relevant
because it evaluation is independent of the patient's motivation or criteria used to
terminate exercise.
Therefore, the aim of this study is to compare the cardiorespiratory parameters, the gaz
exchanges and the maximality between the six-minute stepper test and the incremental
cardiopulmonary exercise testing performed on a cycloergometer.
The secondary objective was to compare the on-transient oxygen consumption phase two kinetic
parameters (time constant, span and steady state) according to the severity of the disease.