A 6MWT index to predict O2 flow correcting exercise induced SpO2 desaturation in ILD

Summary Introduction Ambulatory oxygen (O 2 ) is prescribed to interstitial lung disease (ILD) patients with mild hypoxemia, breathlessness and dyspnea on exertion. Oxygen titration is generally done with the 6 minute walk test (6MWT) to determine the O 2 flow preventing oxygen saturation by pulse oximetry (SpO 2 ) from falling below 88%. His study was designed to generate a 6MWT index predicting the O 2 flow allowing completion of the 6MWT without oxygen desaturation. Methods Oxygen titration data from a group of 66 ILD patients and 30 controls, were used to generate the algorithm determining an index (O 2 -GAP) predicting oxygen flow required to complete a 6MWT without desaturation below 88%. This index was validated in a group of 93 ILD patients. Results The O 2 -GAP index, as obtained from the derivation population, ( r 2  = 0.97, p 2 falling below 88% validated in the validation population ( r 2  = 0.842; p Conclusions The O 2 -GAP index appears to be a useful tool to titrate ambulatory O 2 with a single 6MWT on room air in ILD patients with breathlessness and dyspnea on exertion.