The Walking Capacity Assessment in the Respiratory Patient

Abstract

Exercise testing is commonly used in respiratory patients to assess their degree of disability, prognosis for survival, presence of exercise-induced hypoxemia and response to treatment. Recently, simple exercise tests, which are based on walking, have been developed and are increasingly being used both for clinical and research purposes. The 6-min walk test (6-MWT) is the most widely used and simply consists in the measurement of the distance walked in 6 min. The 6-MWT is self-paced and differs from the shuttle walking test, which is externally paced via a recorded metronome and entails incrementally faster speeds. Although the field walking tests do not require complex equipment, they can provide reliable and useful clinical information. This review deals with the validity, reliability and interpretation of these walking tests in the assessment of patients with chronic respiratory disease.

Reference Equation for the 2-Minute Walk Test in Adults and the Elderly

“…19,23,30,31 The influence of gender on DW has been demonstrated previously in the 6MWT by either of these conditions: prediction equation specific for gender 30 or gender as a predictor variable in the prediction equation. 19,20,22,[32][33][34] Aerobic capacity, represented by maximum oxygen uptake, is ϳ30% lower in women compared with men. 35,36 Consequently, women exhibit lower performances in tests of physical capacity, including the 2MWT.…”

A Multicenter Pilot Study of a Bronchial Valve for the Treatment of Severe Emphysema

“…When the 6MWT test is severely reduced it becomes a reliable predictor of mortality in COPD, but this may be due to loss of muscle mass and peripheral muscle dysfunction [31,32] rather than solely a decrement in respiratory function. In addition, the 6MWT results can be confounded by the use of supplemental oxygen, effort, and practice, and the results can be affected by the function of non-respiratory issues [33], including psychological factors [34]. Even studies of the 6MWT for predicted values vary by up to 30% [33], and >50% of patients with surgery in the NETT had no improvement in the 6MWT [5].…”

“…In addition, the 6MWT results can be confounded by the use of supplemental oxygen, effort, and practice, and the results can be affected by the function of non-respiratory issues [33], including psychological factors [34]. Even studies of the 6MWT for predicted values vary by up to 30% [33], and >50% of patients with surgery in the NETT had no improvement in the 6MWT [5]. Cycle ergometry is less studied in this patient population because of complexity, expense, and technologist training [33] and, like 6MWT, may be confounded in this severe patient population.…”

“…Even studies of the 6MWT for predicted values vary by up to 30% [33], and >50% of patients with surgery in the NETT had no improvement in the 6MWT [5]. Cycle ergometry is less studied in this patient population because of complexity, expense, and technologist training [33] and, like 6MWT, may be confounded in this severe patient population. Therefore, the lack of a measured bronchial valve treatment effect on these exercise tests may be due to the inherent limitations of these tests.…”

Flying with Respiratory Disease

“…Moreover, the potential travellers do not even perform the test, instead they are simply asked if they are able to walk 50 m [25]. Unlike the 50-metre walking test, the 6-min walking test (6MWT) has been standardized and validated [53,54]. The 6MWT is widely used in lung function laboratories and the British Thoracic Society [1] recommends its use to evaluate the fitness to fly.…”