title: Influence of lightweight ambulatory oxygen on oxygen use and activity patterns of COPD patients receiving long-term oxygen therapy.
abstract: Lightweight ambulatory oxygen devices are provided on the assumptions that they enhance compliance and increase activity, but data to support these assumptions are lacking. We studied 22 patients with severe chronic obstructive pulmonary disease receiving long-term oxygen therapy (14 men, average age = 66.9 y, FEV(1) = 33.6%pred, PaO(2) at rest = 51.7 torr) who were using E-cylinders as their portable oxygen. Subjects were recruited at 5 sites and studied over a 2-week baseline period and for 6 months after randomizing them to either continuing to use 22-lb E-cylinders towed on a cart or to carrying 3.6-lb aluminum cylinders. Utilizing novel electronic devices, ambulatory and stationary oxygen use was monitored continuously over the 2 weeks prior to and the 6 months following randomization. Subjects wore tri-axial accelerometers to monitor physical activity during waking hours for 2-3 weeks prior to, and at 3 and 6 months after, randomization. Seventeen subjects completed the study. At baseline, subjects used 17.2 hours of stationary and 2.5 hours of ambulatory oxygen daily. At 6 months, ambulatory oxygen use was 1.4 ± 1.0 hrs in those randomized to E-cylinders and 1.9 ± 2.4 hrs in those using lightweight oxygen (P = NS). Activity monitoring revealed low activity levels prior to randomization and no significant increase over time in either group. In this group of severe chronic obstructive pulmonary disease patients, providing lightweight ambulatory oxygen did not increase either oxygen use or activity. Future efforts might focus on strategies to encourage oxygen use and enhance activity in this patient group. This trial is registered at ClinicalTrials.gov (NCT003257540).
authors.affiliation: Rehabilitation Clinical Trials Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA. casaburi@ucla.edu
authors.forename: Richard
authors.initials: R
authors.lastname: Casaburi
authors.forename: Janos
authors.initials: J
authors.lastname: Porszasz
authors.forename: Ariel
authors.initials: A
authors.lastname: Hecht
authors.forename: Brian
authors.initials: B
authors.lastname: Tiep
authors.forename: Richard K
authors.initials: RK
authors.lastname: Albert
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Anthonisen
authors.forename: William C
authors.initials: WC
authors.lastname: Bailey
authors.forename: John E
authors.initials: JE
authors.lastname: Connett
authors.forename: J Allen
authors.initials: JA
authors.lastname: Cooper
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: Criner
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Curtis
authors.forename: Mark
authors.initials: M
authors.lastname: Dransfield
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Lazarus
authors.forename: Barry
authors.initials: B
authors.lastname: Make
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Martinez
authors.forename: Charlene
authors.initials: C
authors.lastname: McEvoy
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Niewoehner
authors.forename: John J
authors.initials: JJ
authors.lastname: Reilly
authors.forename: Paul
authors.initials: P
authors.lastname: Scanlon
authors.forename: Steven M
authors.initials: SM
authors.lastname: Scharf
authors.forename: Frank C
authors.initials: FC
authors.lastname: Sciurba
authors.forename: Prescott
authors.initials: P
authors.lastname: Woodruff
mesh_terms: D000368:Aged; D000553:Ambulatory Care; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory; D009043:Motor Activity; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation*; D010349:Patient Compliance; D029424:Pulmonary Disease, Chronic Obstructive / Q000628:therapy*