The shuttle walk exercise test in idiopathic pulmonary fibrosis

Abstract

The shuttle walk test (SWT) is a validated, incremental walking test for chronic obstructive pulmonary disease, but not for idiopathic pulmonary fibrosis (IPF). The measurement of maximal oxygen consumption (VO2 max) is considered to be the gold standard measurement of functional capacity. This study examines the relationship between IPF patients' performance on the SWT and VO2 max. Twenty patients were recruited for the study, which consisted of two separate experiments. Firstly, the relationship between SWT performance on a conventional corridor SWT, with that on a programmable treadmill SWT designed to reproduce the corridor SWT was examined (n=10). In the second experiment, the relationship between performance on the treadmill equivalent SWT and VO2 max measurements was studied (n=10). There was a significant correlation between distance walked on the corridor SWT, and that walked on the treadmill equivalent SWT without VO2 max measurements (367 m vs. 410 m) (r=0.91, P=0.0003). There was a significant correlation between distance walked on the treadmill equivalent SWT (277 m), and the directly determined VO2 max (14.87 ml/kg/min) (r=0.74, P=0.01). During both experiments, a significant correlation was also observed between baseline PaO2 and SWT performance, and between DLCO and SWT performance. The shuttle walk test is a simple objective measure of functional capacity in IPF patients, which should facilitate the evaluation of new therapeutic compounds for IPF.

A step test to assess exercise-related oxygen desaturation in interstitial lung disease

“…As mentioned, the rate of stepping was remarkably constant in all patients (table 2), suggesting that a 2-3-min test would also provide a reasonable estimate of exercise capacity [7]. Nevertheless, it is possible that peak V9O 2 was underestimated in these patients, especially considering ILD patients may present with very slow V9O 2 kinetics during exercise [20]. In addition, the nadir of Sp,O 2 could not be reached in a test shorter than 6 min in duration, as ERD was significantly related to V9O 2 at exercise cessation, which has been found to increase progressively during the test (data not shown).…”

“…In addition, ERD has been associated with health-related quality of life [21], pulmonary hypertension [22] and survival [23]. More recently, ERD during field tests, such as the 6MWT and the shuttle walk test, has been shown to be significantly related to survival in idiopathic interstitial pneumonia [20,24,25].…”

Review series: Aspects of interstitial lung disease: Exercise limitation in interstitial lung disease - mechanisms, significance and therapeutic options

“…The 6-minute walk test is a meaningful alternative but has substantial space requirements due to the need for a 30-m corridor. 60 Other exercise tests whose use has been reported in ILD include the incremental shuttle walk test, 61 4-min and 6-min step tests 34,62 and the 6-min treadmill test. 40 Distance walked on the incremental shuttle walk test has a strong relationship to VO 2 peak in patients with IPF 61 and this test may also be responsive to therapy.…”

“…60 Other exercise tests whose use has been reported in ILD include the incremental shuttle walk test, 61 4-min and 6-min step tests 34,62 and the 6-min treadmill test. 40 Distance walked on the incremental shuttle walk test has a strong relationship to VO 2 peak in patients with IPF 61 and this test may also be responsive to therapy. 45 However, the relationship of incremental shuttle walk distance to clinical progression and mortality has not been tested.…”

The 15-Step Oximetry Test: a Reliable Tool to Identify Candidates for Lung Transplantation Among Patients With Idiopathic Pulmonary Fibrosis

“…22,23 The CPET provides the best index of functional capacity and global oxygen transport (VO 2 max), 7 also estimates cardiac and pulmonary reserves, information that is not provided by other modalities. 24,25 However, VO 2 max cannot be measured in patients with advanced cardiac and lung disease, 26,27 and the use of the CPET requires complicated and expensive equipment and trained staff. 17 In addition, the test may be intimidating to frail, elderly or severely disabled patients because the rate of exercise is not under their control.…”