Exercise testing as a screening measure for ability to walk with aprosthesis after transfemoral amputation due to peripheral vascular disease.

PURPOSE: To establish at which exercise-power level is the vascular response, as measured by oxygen uptake, closest to the response during the 6-min walk test (6 MWT) in people after lower-limb amputation due to peripheral vascular disease (PVD). METHOD: A prospective exploratory cohort study was conducted. 6 MWT and exercise testing using a hand-wheel ergometer (starting at 10 W and increasing the workload by 10 W) were performed in 101 consecutively recruited participants after transfemoral amputation due to PVD. Agreement of oxygen uptake during 6 MWT and exercise testing was compared between the groups defined by the exercise-power level reached. RESULTS: Linear regression through origin with Chow test for comparing slopes indicated that oxygen uptake at 30 W agreed more with 6 MWT than at 20, 40 or 50 W. Analyses of observed differences (one-way ANOVA with post-hoc tests, Jonckheere-Terpstra test) confirmed 30 W to be the recommendable threshold. CONCLUSIONS: At the level of 30 W, the oxygen uptake during the exercise was the closest to the 6 MWT, so we estimated that to be the minimum required level for walking using a prosthesis after transfemoral amputation due to PVD. Implications for Rehabilitation Exercise testing after transfemoral amputation. Walking with a prosthesis causes notable strain to the person's vascular system: after the 6-min walk test, the participants' heart rate reached 75% of the maximum predicted heart rate on average. The study shows that persons after transfemoral amputation due to peripheral vascular disease who reach the level of 30 W or more in exercise testing with an arm ergometer at admission to rehabilitation are likely to be able to walk in-doors using a prosthesis.

Postocclusive reactive hyperemia in healthy volunteers and patients with peripheral vascular disease measured by three noninvasive methods.

Postocclusive reactive hyperemia (PORH) was evaluated in three healthy volunteers and in three patients with different etiologies and suffering from peripheral arterial occlusive disease (PAOD). Three noninvasive methods were used: transcutaneous oximetry (TcPO2), near-infrared spectroscopy (NIRS), and laser Doppler flowmetry (LDF). Changes in perfusion and oxygenation of tissue were measured on foot before, during, and after arterial occlusion on thigh. Numerical parameters were derived from measured signals for quantification of the PORH response. Results of all three methods provided distinction between healthy volunteers and patients. The experimental optical techniques of NIRS and LDF demonstrated more clearly than the well-established TcPO2 method the difference between healthy volunteers and patients. The dynamics of the PORH response proved to be a better indicator of peripheral vascular disorder than the amplitude of responses.