Effects of Pulmonary Rehabilitation on Distance-Saturation Product and Clinical Outcomes in IPF Patients With and Without Exercise-Induced Desaturation

Exercise-induced dyspnea and desaturation are distinguishing features of patients with idiopathic pulmonary fibrosis (IPF); these symptoms are associated with disease severity and poorer prognosis. The distance-saturation product, which combines the distance walked and oxygen saturation by multiplying the two measures, has been identified as a predictor of mortality.

Patients with IPF who completed the pulmonary rehabilitation (PR) program were included in the study. Pre- and post-program assessments included spirometric measurements, arterial blood gas values, perception of dyspnea using the Modified Medical Research Council (mMRC) dyspnea scale, exercise capacity via the six-minute walk test (6MWT), health-related quality of life using the St. George's Respiratory Questionnaire (SGRQ) and the Short Form-36 (SF-36), and psychological symptoms assessed with the Hospital Anxiety and Depression Scale (HADS). Additionally, the distance-saturation product was calculated by multiplying the distance walked by the oxygen saturation at the end of the 6MWT. Patients whose oxygen saturation dropped to 88% or below during the pre-rehabilitation 6MWT were classified as the desaturation group, while those with oxygen saturation of 89% or above were classified as the non-desaturation group. The obtained data were compared between these two groups.