Single Portable Pulse-dose-conserving Device vs. Combined Use of Stationary and Portable.
Single Portable Pulse-dose-conserving Device vs. Combined Use of Stationary and Portable.
Introduction: Portable oxygen devices simplify and facilitate patient therapy. This study was
 designed to compare oxygen saturation and patient satisfaction with a portable oxygen
 concentrator or with a combined system consisting of a fixed device with continuous flow
 oxygen dispensation and a portable device with pulse dispensation for ambulation.

 Methods: This cross-over trial assessed 25 patients with COPD (92% men; mean age 72.2 ± 7.4
 years; mean FEV 34.14 ± 12.51%) at four hospitals in Madrid. All patients had previously used
 the combined system, consisting of a fixed oxygenation system and a portable system for
 ambulation, with 16 (64%) using stationary and portable concentrators and 9 (36%) using a
 stationary reservoir and portable liquid oxygen bag. Oxygenation settings at rest and while
 walking were determined at baseline. Patients were maintained on the previous combined system
 for one week and then switched to the portable oxygen concentrator for one week. Mean SpO2
 over 24 hours was calculated by the software in the oximeter, and compliance was monitored
Inclusion Criteria:

 -  aged 40-80 years

 -  had been diagnosed with COPD following the GOLD criteria

 -  were receiving oxygen therapy using a fixed oxygenation system and a portable system
 for ambulation

 -  without exacerbation during the previous month

 -  agreed to participate

 Exclusion Criteria:

 -  terminally ill

 -  unable to understand Spanish

 -  had high oxygen flow at rest (> 3 lpm)

 -  high respiratory frequency at rest (> 32 rpm)

 -  were not achieving adequate O2 saturation levels during titration with the portable
 oxygen source

 -  had previously been diagnosed with obstructive sleep apnea hypopnea syndrome (SAHS)

 -  were receiving mechanical ventilation.