The effect of walking aids on exercise capacity and oxygenation in elderly patients with chronic obstructive pulmonary disease

Age and Ageing, Nov, 1998 by Jamal Roomi, Abebaw M. Yohannes, Martin J. Connolly

Abstract

Background: high walking frames may improve exercise capacity in young patients with chronic obstructive pulmonary disease (COPD). We have assessed the effect of Zimmer, rollator and gutter frames on 6-min walking distance and on arterial oxygenation during exercise in elderly patients with COPD.

Methods: 27 out-patients (15 men) aged 70-82 (mean 75) years were recruited. Exclusions comprised: COPD exacerbation or oral steroid use within 6 weeks, confusional state, participation in a pulmonary rehabilitation programme and exercise limitation by other diseases. Subjects completed 6-min walk tests unaided and with the three frames on four separate days in random order 30 min after nebulized salbutamol (5 mg) and ipratropium (0.5 mg) and were accompanied by an investigator blinded to results of all other walk tests undertaken. Oxygen saturation (Sa[O.sub.2]) was monitored by finger probe during exercise. Grouped t-tests were used to compare distances and reductions in Sa[O.sub.2].

Results: Unaided, the mean (SEM) 6-min walk distance was 210 (16) m and fall in oxygen saturation was 6.0 (1.1)%. Use of a rollator frame did not significantly affect either of these values. Using the Zimmer frame reduced the mean distance to 165 (13) m (t=5.2, P [is less than] 0.001 vs unaided walk) with an Sa[O.sub.2] fall similar to that recorded during the unaided walk. Using the gutter frame increased the mean distance to 234 (150) m (t = 3.1, P = 0.004 vs unaided walk) and reduced the fall in Sa[O.sub.2] to 3.7 (0.8)% (t= 2.3, P = 0.03 vs unaided walk).

Conclusions: gutter frames improve exercise capacity and Sa[O.sub.2] during exercise in elderly COPD patients who remain symptomatic on optimal therapy, whereas unwheeled Zimmer frames have a deleterious effect in such patients.

Keywords: chronic obstructive pulmonary disease, exercise capacity, gutter frame, oxygen saturation, walking aids

Introduction

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and disability in elderly people [1]. The main disabling symptoms are breathlessness and fatigue, both of which lead to reduced exercise capacity and difficulties in performing activities of daily living.

Walking aids improve walking distance [2, 3] and breathlessness [4] in relatively young patients with COPD. These studies [2-4] included only a small number of patients and did not evaluate the effect of different frames (wheeled or non-wheeled) on walk distance in a blinded manner.

We hypothesized that if walking frames were beneficial to patients with a respiratory disability, much of the benefit would arise from the ability of the patient to lean on the frame during walking, thus bracing the accessory muscles of respiration and allowing them to be engaged in respiratory activities. Such an action would be facilitated by wheeled walking frames which should therefore have an advantage over non-wheeled frames. Indeed, we thought it possible that non-wheeled frames would have a disadvantage because of the necessary extra muscular activity involved in repeatedly lifting such frames. The aim of the present study was to assess the effect of an unwheeled walking aid (Zimmer frame) and wheeled frames (rollator frame and gutter frame) on the 6-min walking distance and on oxygen saturation during exercise.

Methods

Elderly COPD patients were referred to the pulmonary rehabilitation clinic at the geriatric day hospital because of dyspnoea, fatigue, reduced exercise tolerance and difficulty performing activities of daily living despite optimum medical therapy. The diagnosis of COPD was made by history, physical examination and pulmonary function testing. Spirometric criteria for inclusion were forced expiratory volume in 1 s ([FEV.sub.1]) of [is less than] 60% of predicted, [FEV.sub.1]/forced vital capacity (FVC) ratio of [is less than] 60%, and a rise in [FEV.sub.1] of [is less than] 15% following nebulized salbutamol (5 mg) and ipratropium (0.5 mg). Patients with COPD who were aged 70 or older were recruited to the study if they were clinically stable with no change in medication in the previous month and no hospital admission for respiratory illness in the previous 6 weeks. Exclusion criteria comprised: acute or chronic confusion (Hodkinson Abbreviated Mental Test Score [is less than or equal to] 7/10 [5]), previous experience of the walk test or current involvement in a pulmonary rehabilitation programme, uncontrolled cardiac arrhythmia, severe cardiac failure or uncontrolled ischaemic heart disease or exercise limitation by factors other than dyspnoea and fatigue (such as visual impairment, musculoskeletal problems, neurological impairment and peripheral vascular disease). However, subjects with other disabilities were included if the subjects themselves considered their respiratory problems to be the chief cause of their exercise limitation.

The study was approved by ethical committees of Central Manchester Healthcare Trust and Bury Health Authority, and informed, witnessed, written consent was obtained from all subjects.