Automated oxygen titration and weaning with FreeO2 in patients with acute exacerbation of COPD: a pilot randomized trial

Int J Chron Obstruct Pulmon Dis. 2016 Aug 24;11:1983-90. doi: 10.2147/COPD.S112820. eCollection 2016.


Introduction: We developed a device (FreeO2) that automatically adjusts the oxygen flow rates based on patients' needs, in order to limit hyperoxia and hypoxemia and to automatically wean them from oxygen.

Objective: The aim of this study was to evaluate the feasibility of using FreeO2 in patients hospitalized in the respiratory ward for an acute exacerbation of COPD.

Methods: We conducted a randomized controlled trial comparing FreeO2 vs manual oxygen titration in the respiratory ward of a university hospital. We measured the perception of appropriateness of oxygen titration and monitoring in both groups by nurses and attending physicians using a Likert scale. We evaluated the time in the target range of oxygen saturation (SpO2) as defined for each patient by the attending physician, the time with severe desaturation (SpO2 <85%), and the time with hyperoxia (SpO2 >5% above the target). We also recorded length of stay, intensive care unit admissions, and readmission rate. Fifty patients were randomized (25 patients in both groups; mean age: 72±8 years; mean forced expiratory volume in 1 second: 1.00±0.49 L; and mean initial O2 flow 2.0±1.0 L/min).

Results: Nurses and attending physicians felt that oxygen titration and monitoring were equally appropriate with both O2 administration systems. The percentage of time within the SpO2 target was significantly higher with FreeO2, and the time with severe desaturation and hyperoxia was significantly reduced with FreeO2. Time from study inclusion to hospital discharge was 5.8±4.4 days with FreeO2 and 8.4±6.0 days with usual oxygen administration (P=0.051).

Conclusion: FreeO2 was deemed as an appropriate oxygen administration system by nurses and physicians of a respiratory unit. This system maintained SpO2 at the target level better than did manual titration and reduced periods of desaturation and hyperoxia. Our results also suggest that FreeO2 has the potential to reduce the hospital length of stay.

Keywords: closed-loop; hyperoxia; hypoxia; oxygen inhalation therapy; technological innovations.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Video-Audio Media

MeSH terms

  • Aged
  • Aged, 80 and over
  • Attitude of Health Personnel
  • Biomarkers / blood
  • Equipment Design
  • Feasibility Studies
  • Female
  • Health Knowledge, Attitudes, Practice
  • Hospitalization
  • Hospitals, University
  • Humans
  • Hyperoxia / etiology
  • Hyperoxia / physiopathology
  • Hyperoxia / prevention & control
  • Hypoxia / etiology
  • Hypoxia / physiopathology
  • Hypoxia / prevention & control
  • Lung / physiopathology*
  • Male
  • Medical Staff, Hospital
  • Middle Aged
  • Nursing Staff, Hospital
  • Oxygen / blood*
  • Oxygen Inhalation Therapy / adverse effects
  • Oxygen Inhalation Therapy / instrumentation*
  • Oxygen Inhalation Therapy / methods
  • Pilot Projects
  • Pulmonary Disease, Chronic Obstructive / blood
  • Pulmonary Disease, Chronic Obstructive / diagnosis
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Pulmonary Disease, Chronic Obstructive / therapy*
  • Quebec
  • Time Factors
  • Treatment Outcome


  • Biomarkers
  • Oxygen