Impact of oxygen therapy on quality of life in patients with idiopathic pulmonary fibrosis and hypoxaemia

Abstract

Background

Most of the patients that suffer from Idiopathic Pulmonary Fibrosis (IPF) end up experiencing hypoxaemia at some point of their pathologic progression. That is expressed in desaturation (SpO2) of blood oxygen (O2) in a pulse oximetry, dyspnoea and a worsening of the quality of life with it. All patients with Chronic Respiratory Insufficiency (CRI), with basal blood gasometric levels of less than SpO2 89% or PaO2 60 mmHg, are treated a minimum of 15 hours per day with domiciliary O2 therapy in order to hold these levels up to an acceptable threshold. However, this prescription is based in low quality evidence and most of it is brought by analogy from the evidence reported in patients with Chronic Obstructive Pulmonary Disease (COPD)(1)(2)(3). Even today mildly hypoxic patients are treated with oxygen depending on subjective factors and no statistically significant studies have been conducted in patients with IPF to prove oxygenotherapy’s positive or negative effects(4). Furthermore, since the prognostic of IPF is poor and its course is torpid, to improve the patient’s quality of life, and to report what role oxygen might play in that, has to be a priority. Objective

The main objective of this study is to evaluate the impact of continuous domiciliary oxygen therapy in patients with IPF and with chronic hypoxia but without CRI, and see if their quality of life, their physical and respiratory capacities and their survival expectancy are improved.

Design

This trial will be a prospective, multicentric, controlled and randomized study.

Methods

All subjects (N= 358) will be enrolled consecutively in various sanitary centres and assigned randomly to a group intervention (n1= 179) or a group control (n2= 179). The first ones will receive a minimum of 16 hours of continuous oxygen therapy a day for 2 years, while the second group will not. A third group (n3=97) of patients with basal SpO2< 89% and/or basal PaO2 <60 mmHg (CRI) will be followed with the same O2 prescription to see their progression throughout the disease course. We defined the primary outcome as the punctuation stated by the participants in a quality of life questionnaire called EuroQol-5D-5L (see annex 1). Secondary outcomes will be number of hospitalisations due to any cause, number of acute exacerbations and time to the first one, a comparison of the dyspnoea between two groups through mMRC scale, the evolution in the 6mWT and functional respiratory parameters (measured in RFT) and the survivors rate at 5 years.

Participants

Patients with a certified diagnose of IPF, under 80 years old, with a basal blood SpO2 of <95% and RFT with FVC 50-80% and a DLco >35% will be welcome to participate