Home Oxygen for patients with Interstitial Lung disease (ILD): A discussion piece

29 November 2021

The BTS Oxygen guideline forms the corner stone of most Home Oxygen services and indeed it provides robust evidence based statements from which our clinical practise is informed. It does however have some limitations as it is primarily based on evidence derived from studies involving patients with COPD.

COPD is the most common disease for which home Oxygen therapy is prescribed, with ILD the second. COPD is 30-40 times more common than ILD. There are key difference in the physiology of COPD and ILDs which make application of the same rules and procedures inappropriate. With the guideline focused heavily on COPD and less frequent day to day experiences with patients with ILD, clinicians may feel unsure how to interpret the current guidance to best meet the needs of our patients.

Most ILDs remain serious, progressive and fatal diseases. In my own experience, I have found many patients with ILD have a unique pattern of disease development, with periods of rapid deterioration, often necessitating more urgent access to assessment and review of Oxygen requirements. I would highlight the following pertinent considerations, but point out the list is not exhaustive;

• Patients with ILD in isolation of any other respiratory disease have a very low likelihood of developing hypercapnia.
• Exertional desaturation is more frequent and more profound than in COPD and is associated with worse prognosis.
• Patients with ILD often require much higher flow rates of ambulatory Oxygen than other patient cohorts.
• It can be difficult to meet high Oxygen requirements within limitations of current equipment.
• Ambulatory Oxygen should be prescribed on “trial” as it is not suitable or effective for all patients.
• ILD “Exacerbations” are less common, but can be more severe most often without a return to baseline.
• Development of type 2 respiratory failure can be associated with terminal stage disease.
• Life expectancy can be extended with the more wide spread use of antifibrotics, but this means patients are living with a high symptom burden.

With this in mind within my own Home Oxygen service we reviewed how we can better serve our patients with ILD to help improve their quality of life. We continue to promote the overarching principles of the BTS guidelines and our patients follow the same clinical pathways as all our Oxygen patients, in terms of administration, safety and assessment processes, but we have initiated some key changes.

• We have a lower threshold for wait time to assessment, aiming for assessment within 4 weeks in ambulatory Oxygen clinic.
• There is a dedicated urgent assessment slot each week for patients with ILD.
• When we are unable to meet our clinic this aim, the patient will have initial assessment in their own home. Assessment is carried out with observation of a relatively high impact activity of daily living such as climbing the stairs. This is then followed up by formal 6 minute walk test assessment in the clinic environment.
• Long term Oxygen therapy (LTOT) continues to be initiated following an initial blood gas, however titration is by pulse oximetry and again where wait time is excessive due to clinical demand and hypoxia is evident on pulse oximetry LTOT is commenced, usually at low levels prior to formal assessment.

Like all clinical services our desires and our resource capabilities sometimes do not synchronise and we continue to explore ways of improving Oxygen assessment and delivery. We would like to offer three monthly Oxygen reviews for this patient group, and are considering options of using telephone or remote monitoring tools as has been successfully used in other cohorts throughout the pandemic.

Patients are often under the care of regional specialist services for their consultant led treatment but a local Home Oxygen service. There can be wide variations in practice, leading to lack of clarity for patients and conflict between professionals. Collaboration is key and North East and North Cumbria HOSAR and ILD consultants are working together developing a guideline to ensure patients across our region receive equitable Oxygen services and key health care professionals involved in their care are able to advise patients appropriately about their expectations around Oxygen therapy.

This article is intended to provoke thought and discussion about how we meet the needs of patients with ILD across widely differing Oxygen services up and down the country. It is not a guideline in itself and only serves to describe how my individual Oxygen service is addressing some of the challenges we all face.

 

Bibliography:

1. Hardinge M, Annandale J, Bourne S et al. ‘BTS guidelines for Home Oxygen Use in Adults’, Thorax, 2015; 70 (1)
2. Zhu Z, Barnette RK, Fussell KM, et al. ‘Continuous oxygen monitoring—a better way to prescribe long-term oxygen therapy’, Respir Med, 2005; 99:1386–92.
3. Sharp C, Adamali H, Millar AB. ‘Ambulatory and short burst oxygen for interstitial lung disease (review)’, Cochrane database of systematic reviews, 2016, 7, CD011716
4. Bell E, Cox N, Goh N et al. ‘Oxygen therapy for interstitial lung disease: a systematic review’, European Respiratory Review, 2017, 26, 160080
5. Schaeffer MR, Ryerson CJ, Ramsook AH, et al. ‘Effects of hyperoxia on dyspnoea and exercise endurance in fibrotic interstitial lung disease’, Eur Respir J, 2017; 49: 1602494.
6. Dowman LM, McDonald CF, Bozinovski S, et al. ‘Greater endurance capacity and improved dyspnoea with acute oxygen supplementation in idiopathic pulmonary fibrosis patients without resting hypoxaemia’, Respirology, 2017; 22: 957–64.
7. Khor Y, Goh N, McDonald C et al. ‘Oxygen therapy for interstitial lung disease: A Mismatch between patient expectations and experiences’, ATS, 2017, 14 (6), 888-895