Oxygen therapy in ILD: What is the evidence?

1. Oxygen therapy in ILD: What is the evidence? Matt Dickson ST5 NUTH

2. Why do we use oxygen? The hope… • Lengthen life • Alleviate breathlessness • Improve function and QoL Does it do any of the above? Does it simply improve the numbers? Who are we treating?

3. Introduction • BTS guidance for home oxygen in ILD (2017)1 • Evidence for use: • Survival • QoL • Dyspnoea • Exercise capacity • Discussion

4. BTS Guidance (in a nutshell) • LTOTshould be ordered for patients with ILD with a resting PaO2 ≤7.3 kPa/ ≤8 kPa in the presence of peripheral oedema, polycythaemia (haematocrit ≥55%) or evidence of pulmonary hypertension (Grade D) • AOT should not be routinely offered in those not eligible for LTOT (if offered, should be proven improvement in endurance e.g.6MWT) (√)

5. BTS Guidance (in a nutshell) • POT not recommended if not hypoxaemicor have mild levels of hypoxia (SpO2 ≥92%) above LTOT thresholds (trial opiates/non-pharmacologicals) (Grade A) • SBOT not recommended (Grade A) • NOT not recommended for nocturnal hypoxaemia alone who do not fulfill LTOT criteria (Grade B)

6. Does long-term oxygen therapy improve survival in ILD?

7. LTOT and survival in ILD • BTS Guidance Home Oxygen: “… may improve survival and tissue oxygenation, and prevent complications associated with hypoxaemia such as worsening pulmonary hypertension” • Expert opinion only • Extrapolated from evidence in COPD • BTS ILD Guidance2: there is no evidence that oxygen therapy influences quality of life or long-term survival in patients with IPF or other ILD.

8. LTOT and survival in ILD • Cochrane review 20103: Domiciliary oxygen for interstitial lung disease • Only ONE RCT identified (unpublished) • long-term oxygen vs. control group • 37 on LTOT vs 25 controls • No difference in mortality at 12,24 or 36 months (91% at 3 years) • QoL not reported • Patients will gain a benefit in terms of survival if used for >500 days continuously for a minimum of 15hrs per day (chronic bronchitis/emphysema with corpulmonale)4

9. LTOT and survival in ILD • Retrospective analysis 2000: Idiopathic Pulmonary Fibrosis - Impact of Oxygen and Colchicine, Prednisone, or No Therapy on Survival5 • Univariate analysis – increased mortality in oxygen group • Multivariate analysis – no difference in mortality

10. Does long-term oxygen therapy improve quality of life in ILD?

11. LTOT and HRQoL • Longitudinal study of HRQoL in IPF6: • QoL (physical and psychosocial) declined more significantly in those requiring oxygen • Unclear if reflecting disease severity • Not controlled for severity of disease • Providing oxygen did not improve QoL • Self conscious, social withdrawal, trapped

12. Does ambulatory oxygen therapy improve dyspnoea in ILD? NICE guidance (IPF in Adults 2015)7: “Oxygen therapy relieves symptoms of breathlessness”

13. What causes dyspnoea? • Respiratory mechanics • Impaired gas exchange • Cardiovascular abnormalities • Peripheral muscle dysfunction

14. AOT and dyspnoea in ILD • Oxygen therapy for interstitial lung disease: a systematic review (2017)8 • Two studies included in review which showed no benefit in dyspnoea during exercise • Supplemental oxygen users with pulmonary fibrosis perceive greater dyspnea than oxygen non-users (2015)9 • 6MWT on O2 vs. RA • Dyspnoea ratings (BORG score) higher amongst oxygen users

15. Does ambulatory oxygen therapy improve exercise capacity in ILD?

16. AOT and exercise capacity in ILD • Oxygen therapy for interstitial lung disease: a systematic review (2017)8 • Only randomised trial to assess 6MWD – no benefit • Laboratory based trials – some benefit

17. AOT and exercise capacity in ILD

18. AOT and exercise capacity in ILD 6 MWT Distance

19. AOT and exercise capacity in ILD Results: • 23 patients • Average increase in 6 MWT distance of 7.3% • Walked on average 23 metres further on oxygen than RA from 297 to 320

20. AOT and exercise capacity in ILD

21. Controversy • Ethics of performing RCT (giving oxygen vs control group) • Guidelines based on extrapolated data • Patient’s receive oxygen with little justification • Patient expectation • Provider feels better • Can cause harm and poorer outcomes • Many studies of poor quality/small cohorts

22. But watch this space… • AmbOx study: • Prospective, multicentre, randomised controlled crossover UK study • Ambulatory O2 against control over 4 weeks • Does it improve health status? • Does it improve dyspnoea during ADLs? • Secondary outcomes: • QoL • HADS • Economic evaluation

23. Over to you!

24. Any Questions?

25. References • BTS Guidelines for Home Oxygen Use in Adults. BTS Home Oxygen Guideline Group. 2017 • BTS Interstitial Lung Disease Guideline. British Thoracic. BTS ILD Guideline Group. 2008 • Crockett AJ, Cranston JM, Antic N. Domiciliary oxygen for interstitial lung disease. Cochrane Database Syst. Rev. 2001: CD002883. • Long term domiciliary oxygen therapy in chronic hypoxic corpulmonale complicating chronic bronchitis and emphysema. Report of the Medical Research Council Working Party. Lancet. 1981 Mar 28;1(8222):681-6. • Douglas WW, Ryu JH, Schroeder DR. Idiopathic pulmonary fibrosis: Impact of oxygen and colchicine, prednisone, or no therapy on survival. Am J RespirCrit Care Med. 2000 Apr;161(4 Pt 1):1172-8. • TomiokaH, Imanaka K, Hashimoto K, et al. Health-related quality of life in patients with idiopathic pulmonary fibrosis – cross-sectional and longitudinal study. Intern Med 2007; 46: 1533–1542 • NICE Guidance for IPF in Adults (2013) • Emily C. Bell, Narelle S. Cox, Nicole Goh, Ian Glaspole, Glen P. Westall, Alice Watson, Anne E. Holland. Oxygen therapy for interstitial lung disease: a systematic review. European Respiratory Review Mar 2017, 26 (143) • Cao M, Wamboldt FS, Brown KK, et al. Supplemental oxygen users with pulmonary fibrosis perceive greater dyspnea than oxygen non-users. MultidiscipRespir Med 2015; 10: 37