comparative study of 3 portable oxygen concentrators during a 6-minute walk test in patients with chronic lung disease

Conditions: Chronic Obstructive Lung Disease; Pulmonary Fibrosis

Summary: background: portable oxygen concentrators (pocs) featuring the latest integrated oxygen conserving devices (ocds) provide greater patient accessibility and mobility during ambulation and travel. recent pocs are compact, lightweight, battery-operated, and require no refill-time, thus meeting patients' clinical and lifestyle needs. there is, however, a lack of research on the clinical performance of the latest pocs that could help to determine their ability to maintain patients' oxygen saturations ≥ 90 % during exercise. aim: the purpose of this study is to compare the ability of three pocs, with maximum oxygen production capabilities of 950 to 3000 ml per minute, to maintain oxygen saturations ≥ 90 % in patients with chronic lung disease during exercise. method: six minute walk tests (6-mwts) will be administered in order to measure oxygen saturations by pulse oximetry (spo2) in up to 20 patients with a diagnosis of either chronic obstructive pulmonary disease (copd), or pulmonary fibrosis (pf) with documented exertional oxygen desaturations of ≤ 85% on room air. all participants will participate in 4 different 6-minute walk tests: the first will be a control walk performed with the participants' current oxygen system set at their prescribed exertional flow rate. then, the participants will perform a walk test with each of the three pocs set at the units' maximum pulse dose setting. the order in which the participants use the pocs will be randomly assigned using a sequence generator. hypothesis: it is hypothesized that all three pocs will provide oxygen saturations ≥ 90 % during exercise in patients with chronic lung disease with moderate to severe exertional oxygen desaturation.

participants will attend two study sessions. during the session 1 participants will perform a 6-minute walk test on room air oxygen to assess their suitability for the study. only those participants with documented exertional oxygen desaturations of ≤ 85% as measured by pulse oximetry during this walk will be asked to return for the second session. during session 2 participants will perform a further four 6-minute walk tests spread over a morning and afternoon testing session. all all data for primary and secondary outcomes will be measured at session 2.

Eligibility criteria:
inclusion criteria: * existing diagnosis of chronic obstructive lung disease or pulmonary fibrosis * completed the pulmonary rehabilitation program at the ottawa hospital rehabilitation centre between january 30th 2008 and march 31st 2011 * medically stable * medical prescription for long term oxygen therapy * 18 years or older exclusion criteria: * non-ambulatory * not independent for activities of daily living * not active in the community * show limited improvement with any level of continuous oxygen flow rate * require more than 6 litres per minute of oxygen on continuous flow during exertion * experienced an exacerbation of their respiratory medical condition over the last 6 weeks, or have not fully recovered from a recent exacerbation * have moderate to severe orthopaedic or neurological conditions limiting their ability to walk * have any other impairments that could affect the consistency of the 6-minute walk test * have severe co-morbid conditions * are limited by their cardiac condition or have been diagnosed with a cardiac condition since completion of their pulmonary rehabilitation * severe cognitive or memory deficit * speak neither french nor english

Keywords: portable oxygen concentrator 6-minute walk test chronic obstructive lung disease pulmonary fibrosis long term oxygen therapy