Mechanisms of improvement in exercise capacity using a rollator in patients with COPD

Abstract

Study objective: We analyzed the effects of the use of a rollator on walking distance and physiologic variables: pulmonary gas exchange, heart rate, minute ventilation (Ve), oxygen saturation, and symptoms during the 6-min walk test (6MWT) in patients with COPD.

Setting: Outpatient clinic at university hospital.

Patients: Fourteen patients with COPD in stable clinical condition. One patient had mild COPD, five patients had moderate COPD, six patients had severe COPD, and two patients had very severe COPD.

Interventions: Two 6MWTs were performed with a portable metabolic system (VmaxST 1.0; Viasys Healthcare; MEDA; Aartselaar, Belgium) with a rollator and without a rollator, in random order. In addition, maximal voluntary ventilation (MVV) was measured with and without a rollator, randomly.

Results: The median 6MWT distance increased significantly with a rollator: 416 m without a rollator (interquartile range [IQR], 396 to 435 m), vs 462 m with a rollator (IQR, 424 to 477 m) [p = 0.04]. Significant increases were also seen in oxygen uptake (0.04 L/min [IQR, - 0.002 to 0.09 L/min]); tidal volume (0.06 L/min [IQR, - 0.001 to 0.11 L/min]); and Ve (0.95 L/min [IQR, - 0.67 to 7.1 L/min]), recorded in the last minute of the 6MWT; as well as in MVV (3 L/min [IQR, 0 to 12 L/min]) [p < 0.05 for all]. Borg dyspnea scores tended to be lower with a rollator: 6 (IQR, 4 to 7) without a rollator, vs 5 (IQR, 4 to 7) with a rollator (p = 0.10). The variation in the 6MWT was explained by individual changes in walking efficiency (partial R(2) = 0.31) and changes in Ve (partial R(2) = 0.36) [p model < 0.04].

Conclusion: The use of a rollator improves walking distance of patients with COPD through an increased ventilatory capacity and/or better walking efficiency.