December 2024: Long-Term Oxygen Therapy for 24 or 15 Hours per Day
The issue
A recent trial in patients with severe resting hypoxemia showed that prescribing long‑term oxygen therapy (LTOT) for 24 hours a day did not reduce the combined risk of hospitalization or death within one year compared with 15 hours a day.
What do I need to know?
Ekström et al.’s multicenter study found no short‑term disadvantage to limiting LTOT to 15 hours daily, challenging the assumption that “more hours are always better.” Earlier landmark trials (the 1980 NOTT study and the 1981 MRC study) did report lower mortality after two‑to‑five years with longer oxygen exposure, suggesting benefits may take longer to appear. Today’s LTOT population is older and sicker, with a median survival of only 1.9 years; observational data show similar mortality whether patients are prescribed 24 or 15 hours per day. Current evidence therefore supports prescribing at least 15 hours a day while tailoring the schedule to reduce burden and improve adherence.
Potential risk of oxygen dependence
Chronic lung disease with exertional or nocturnal desaturation but daytime SpO₂ ≥ 89 %.
Recommended Actions
Recheck oxygen saturation at every visit and during sleep.
Optimize inhalers, vaccinations, and pulmonary‑rehab participation.
Discuss smoking cessation and home safety (fire hazards).
Imminent risk of oxygen dependence
Resting SpO₂ ≤ 88 % at two separate checks or PaO₂ ≤ 55 mm Hg; patient being evaluated for LTOT.
Recommended Actions
Order arterial blood gas and overnight oximetry to confirm eligibility.
Review equipment options (portable concentrator vs. tanks) and insurance coverage.
Decide with the clinician whether to start 15 h/d or 24 h/d based on lifestyle and symptom relief; schedule follow‑up in four weeks.
Confirmed oxygen dependence
Patient already on LTOT for severe hypoxemia.
Recommended Actions
Ensure adherence to at least 15 h/d; adjust hours if symptoms worsen.
Check cannula fit, humidification, and skin integrity; replace supplies regularly.
Reassess need annually—some may improve and discontinue therapy; others may require palliative support.
What can I do?
Ask the respiratory team: “Am I at potential, imminent, or confirmed risk that warrants long‑term oxygen, and for how many hours?” Keep a daily log of wear‑time and oxygen saturation. Secure tubing to prevent trips, avoid open flames while using oxygen, and arrange portable devices for outings so social life stays active. If 24‑hour use feels overwhelming, discuss a 15‑hour schedule—evidence shows it is often just as safe, and a regimen you can live with is the one you are most likely to follow.
