The OXISITE-ILD study is a prospective, multicenter, observational study designed to evaluate the agreement between finger (digital) and earlobe (auricular) pulse oximetry for measuring oxygen saturation (SpO2) during the six-minute walk test (6MWT) in patients with interstitial lung disease (ILD). In routine clinical practice, exercise SpO2 is usually measured at the finger; however, the finger reading can be unreliable in some patients, and there is currently no recommendation on the best sensor location in ILD. This study compares the two sensor locations, recorded at the same time, and evaluates whether any disagreement changes how exercise desaturation is classified and whether ambulatory oxygen is indicated.
All patients undergoing a 6MWT as part of routine ILD care are included consecutively to ensure a pragmatic, real-world representation of the ILD population. The primary objective is to measure the agreement between the two locations in the lowest SpO2 reached during the test, including the size and direction of any difference. Secondary objectives include the reclassification of patients at the clinical desaturation thresholds, the comparison between autoimmune and non-autoimmune ILD, the rate of invalid readings at each location, and the clinical, vascular and functional factors associated with disagreement.
Adults aged 18 years or older
Confirmed diagnosis of interstitial lung disease (ILD) based on clinical, radiological and/or histological criteria
Newly diagnosed or under follow-up for ILD
Physically and cognitively able to perform the 6-minute walk test (6MWT)
Inability to obtain a reliable, stable baseline pulse oximetry reading at the finger and/or the earlobe, preventing a valid paired baseline measurement and the calculation of agreement
ILD exacerbation, decompensated comorbidity, or acute respiratory infection at the time of the test