Automated Oxygen Titration in Daily Life in Patients With COPD on Home Oxygen

The patient's ability to perform ADL assessed by the Glittre-ADL test with automatic oxygen titration compared to usual fixed dose will be examined.

The patients will be invited to a visit at one of the participating hospitals. The Glittre-ADL will be performed according to the protocol validated by Skumlien et al. The first test is performed for familiarization in order to avoid a learning effect in the primary tests. The patients will use the fixed-dose oxygen, established after titration to a SpO2 of 90-94 % at rest.

After the familiarization test and gathering of demographics, further two Glittre-ADL tests will be performed on the same day or at another day pending on patient preference. In random order the patients will use A) automated oxygen titration set at an SpO2-target of 90 to 94 % and an oxygen flow of 0 - 8 liters/min and B) their usual fixed dose of oxygen. In both arms O2matic will monitor pulse rate and saturation continuously during the test, but only in the automated oxygen therapy arm O2matic adjusts the oxygen flow. The patients will all use a rollator as walking aid. The oxygen equipment will be placed in the rollator and the tests will be conducted without the steps (due to the use of rollator). The minimum interval between tests will be 20 minutes or until the vital values and symptoms are returned to baseline. Before, and after the Glittre-ADL, the patients will be asked the rate their level of dyspnea using Borg Dyspnea Scale.

Study Analysis Plan

• Paired sample t-test: time used in the Glittre test using AutOx vs Time used using Fixed oxygen (in seconds)
• Paired sample t-test: Borg score after Glittre using Autox vs Borg score after Glittre when using Fixed oxygen (on a scale from 0-10) A test for carryover effect will be performed by comparing the first and the second tests before being divided into the Autox and fixed oxygen groups.

Variables will be examined for normality and analyzed with either a paired t-test (in case of normality) or Wilcoxon-signed-rank test (in case of non-normality). The median of the differences between tests will be used for a value. The number of patients who reach a Minimal Clinically Important Difference (MCID) in either the Dyspnea score or in time used in the Glittre test will be reported.

Difference in time spent within saturation intervals will be extracted from the CSV files and combined using Excel.

IBM SPSS Statistics for Windows, ver. 29.0.1.0 will be used for all statistical analyses.

Inclusion criteria

• Verified history of COPD with FEV1/FVC < 0.70 and FEV1 < 50 %
• Hypoxemic at rest (SpO2≤ 90 %) and fulfilment of general national criteria for LTOT

• Partial pressure of Oxygen (PaO2) (without oxygen supplement) ≤7.3 kPa in clinically stable and optimally treated condition
• Increase in PaO2 after oxygen supplementation (to 8.0-9.0 kPa) without decrease in arterial pH (> 0.03 kPa)
• The oxygen is used at least 15 hours daily (optimally 24 hours daily)
• The treatment is handled by hospital departments with lung medical expertise.
• Able to walk at least 30 meters
• Age >18, Cognitively able to participate in the study and willing to give informed consent

Exclusion criteria

• Pulmonary or cardiac condition other than COPD limiting physical performance
• Unstable heart condition or stenotic aortic valve disease
• A physical condition including paralysis, lower extremity pain, or back problem limiting physical performance
• Exacerbation in COPD treated with either antibiotics or prednisolone within the last 3 weeks