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COPD with post-exacerbation home oxygen reassessment — SCE Respiratory MCQ

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HardStopping CriteriaCOPD with post-exacerbation home oxygen reassessmentSCE Respiratory

A 69-year-old woman with severe smoking-related COPD was discharged after an infective exacerbation 4 months ago. At discharge she remained breathless and unable to mobilise safely without oxygen; while breathing air, SpO₂ was 86% and PaO₂ was 6.7 kPa. Long-term oxygen therapy (LTOT) at 1 L/min for at least 15 hours daily was arranged, with counselling that it might be withdrawn after reassessment. She stopped smoking 5 years ago. She has now been clinically stable for 10 weeks on optimised inhaled therapy. At specialist home-oxygen review, room-air arterial blood gases on two visits 3 weeks apart show PaO₂ values of 8.2 and 8.3 kPa, with normal pH and PaCO₂. Resting SpO₂ is 94%. Haemoglobin is 146 g/L, and there is no peripheral oedema or echocardiographic pulmonary hypertension. During a 6-minute walk test on air, SpO₂ falls to 82% and she stops after 240 metres because of breathlessness. With titrated portable oxygen, SpO₂ remains at least 90%, walking distance increases to 335 metres and Borg breathlessness score improves by 3 points. She wishes to remain active outside her home and is willing to use portable equipment. Which home-oxygen plan is most appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Withdraw LTOT in a planned manner and prescribe ambulatory oxygen at the assessed exertional flow rate

Explanation lettering: C = shown as A · A = shown as B · D = shown as C · E = shown as D · B = shown as E

LTOT should be withdrawn because reassessment during sustained clinical stability shows that its physiological indication is no longer present. Her repeated room-air PaO₂ measurements exceed 8.0 kPa, and she has none of the modifiers that support LTOT at PaO₂ 7.3–8.0 kPa: secondary polycythaemia, peripheral oedema or pulmonary hypertension. Oxygen started around hospital discharge must not be continued merely because severe hypoxaemia was documented during an exacerbation; BTS standards require blood-gas reassessment within 3 months and planned withdrawal when home oxygen is no longer required. This does not mean that every oxygen modality should be withdrawn. She has substantial exertional desaturation, and specialist testing demonstrates a clinically relevant improvement in exercise capacity, oxygenation and breathlessness with supplemental oxygen. She is also motivated to use it. These features support ambulatory oxygen independently of LTOT eligibility. A incorrectly retains LTOT despite loss of its resting indication. C delays action even though the required reassessment has established that LTOT is unnecessary. D recognises the LTOT stopping criterion but ignores the separately demonstrated benefit from ambulatory oxygen. E is inappropriate because isolated nocturnal oxygen has not been indicated, whereas exertional benefit has been objectively demonstrated.

Reference: British Thoracic Society guidelines for home oxygen use in adults: accredited by NICE (2015) — https://thorax.bmj.com/content/70/Suppl_1/i1 Chronic obstructive pulmonary disease in over 16s: diagnosis and management (2018, updated 2019) — https://www.nice.org.uk/guidance/ng115/chapter/Recommendations Chronic obstructive pulmonary disease in over 16s: diagnosis and management (2018, updated 2019) — https://www.nice.org.uk/guidance/ng115/chapter/Recommendations