Till Örebro universitet

Introduction: Automated oxygen titration (AutOx) is a new technology which could give patients with chronic respiratory failure the opportunity of personalized oxygen treatment. AutOx has been tested in a safe environment but never in a real life setting for several days in the patient's home.

Aim: To investigate the setup of automated oxygen in the home of patients with chronic respiratory failure in a pilot study.

Methods: A new device, O2matic HOT, was connected to a high-flow concentrator which could provide for up to 10 l/min. Patients wore a Nonin WristOx pulse oximeter, connected via bluetooth to the O2matic HOT. In a closed-loop circuit oxygen flow was titrated based on oxygen saturation (SpO2). Patients were encouraged to wear the pulse oximeter as much as possible, also during activity. Data was sent to a cloud solution.

Results: Two patients tested the setup for each 4 days. Pulse oximeter signal was achieved for 78.3 to 78.9 % of the time, with 272,399 paired observations of SpO2 and oxygen flow for patient 1 and 262,568 observations for patient 2. SpO2 was in target interval (90-94 %) in 94.8 % of the time for patient 1 and 84.7 % of the time for patient 2. Oxygen flow was median 1.3 l/min (2.5-97.5 % percentile: 1.0-5.9 l/min) for patient 1 and median 0.6 l/min (2.5-97.5 % percentile: 0.5-6.7 l/min) for patient 2.

Discussion: It is possible to titrate oxygen flow in a home setting and achieve almost perfect control of SpO2, but it requires major adjustments in oxygen flow. The clinical importance of controlling SpO2 is not clear, but dyspnea and endurance has been shown to improve with titrated oxygen. Further studies will be needed to examine the feasibility of automated oxygen titration at home.