Ambulatory oxygen in fibrotic lung disease (AmbOx): study protocol for a randomised controlled trial

Abstract

BackgroundFibrotic interstitial lung diseases (ILDs) are chronic and often progressive conditions resulting in substantial morbidity and mortality. Shortness of breath, a symptom often linked to oxygen desaturation on exertion, is tightly linked to worsening quality of life in these patients. Although ambulatory oxygen is used empirically in their treatment, there are no ILD-specific guidelines on its use. To our knowledge, no studies are available on the effects of ambulatory oxygen on day-to-day life in patients with ILD.Methods/designAmbulatory oxygen in fibrotic lung disease (AmbOx) is a multicentre, randomised controlled crossover trial (RCT) funded by the Research for Patient Benefit Programme of the National Institute for Health Research. The trial will compare ambulatory oxygen used during daily activities with no ambulatory oxygen in patients with fibrotic lung disease whose oxygen saturation (SaO2) is ≥94% at rest, but drops to ≤88% on a 6-min Walk Test. The randomised controlled trial (RCT) will evaluate the effects on health status (measured by the King’s Brief ILD Questionnaire: K-BILD) of ambulatory oxygen used at home, at an optimal flow rate determined by titration at screening visit, and administered for a 2-week period, compared to 2 weeks off oxygen. Key secondary outcomes will include breathlessness on activity scores, as measured by the University of California San Diego Shortness of Breath Questionnaire, global patient assessment of change scores, as well as quality of life scores (St George’s Respiratory Questionnaire), anxiety and depression scores (Hospital Anxiety and Depression Scale), activity markers measured by SenseWear Armbands, pulse oximetry measurements, patient-reported daily activities, patient- and oxygen company-reported oxygen cylinder use. The study also includes a qualitative component and will explore in interviews patients’ experiences of the use of a portable oxygen supply and trial participation in a subgroup of 20 patients and carers.DiscussionThis is the first RCT of the effects of ambulatory oxygen during daily life on health status and breathlessness in fibrotic lung disease. The results generated should provide the basis for setting up ILD-specific guidelines for the use of ambulatory oxygen.Trial registrationNational Clinical Trials Registry, identifier: NCT02286063. Registered on 8 October 2014 (retrospectively registered).Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-017-1912-9) contains supplementary material, which is available to authorized users.

Effect of ambulatory oxygen on quality of life for patients with fibrotic lung disease (AmbOx): a prospective, open-label, mixed-method, crossover randomised controlled trial

“…In a two period crossover, it is impossible to separate carryover (be it pharmacological or psychological) from treatment by period interaction (32). Given these uncertainties, we took the a priori decision to adjust for order of treatment (18), as this takes into account the possibility of a difference in effect according to treatment sequence. However, the unadjusted analysis of the primary outcome, where sequence is omitted, can be found in the supplementary file (supplementary table 4, p5).…”

“…The AmbOx trial is a UK multi-centre, prospective, randomised, open label, mixed-method, controlled cross-over trial of portable ambulatory oxygen for two weeks, against no intervention for two weeks, to evaluate whether ambulatory oxygen is associated with improved HRQoL compared to no intervention in patients with fibrotic ILD. Approval of the final clinical protocol (18) was provided by the appropriate independent Ethics Committee (NRES Ref: 14/LO/0258).…”

Year in review 2017: Interstitial lung disease, pulmonary vascular disease and sleep

“…A crossover trial comparing the efficacy of two portable oxygen concentrators with traditionally used compressed oxygen cylinders showed no significant differences in either the desaturation rate or 6‐min walk test (6MWT) distance . The complete results of the AmbOx study, a multicentre, prospective, randomized controlled crossover trial of ambulatory oxygen in patients with ILD, are eagerly anticipated (NCT02286063) …”

Improving Home Oxygen Therapy In Patients With Interstitial Lung Diseases (ILDs): Application Of A Portable Non-Invasive Ventilation (NIV) Device

“…A retrospective study of patients with different ILDs showed that home oxygen increased exercise tolerance and decreased dyspnea [8,9]. Recently, a clinical trial (the AmbOx study) has demonstrated that ambulatory oxygen could improve health-related quality of life [10] Moreover, given the multifactorial nature of the low exercise tolerance in patients with ILDs, the standard use of home supplemental oxygen therapy could not solve the whole problem. In COPD patients, multiple therapies have been described to solve this aspect.…”