Pulmonary rehabilitation improves distance-saturation product in IPF: Greater benefits in patients with exercise-induced desaturation.

BACKGROUND AND AIM: Exercise-induced dyspnea and desaturation are hallmark features of idiopathic pulmonary fibrosis (IPF) and are linked to disease severity and poor outcomes. The distance-saturation product (DSP), calculated by multiplying the walking distance by oxygen saturation, has been proposed as a mortality predictor. This study aimed to investigate the effects of a pulmonary rehabilitation (PR) program on clinical outcomes and DSP in two IPF patient groups: those with and without desaturation during the six-minute walk test (6MWT).

METHODS

IPF patients who completed a standardized PR program were included. Assessments before and after PR included spirometry, arterial blood gas analysis, Medical Research Council (MRC) dyspnea scale, 6MWT, St. George's Respiratory Questionnaire (SGRQ), 36-Item Short Form Survey (SF-36), and Hospital Anxiety and Depression Scale (HADS). DSP was calculated at the end of the 6MWT. Patients with oxygen saturation ≤88% during baseline 6MWT were assigned to the desaturated group; others were assigned to the non-desaturated group.

RESULTS

Fifty patients were enrolled (20 desaturated, 30 non-desaturated). Following PR, only the desaturated group showed significant improvements in forced vital capacity (FVC), oxygen saturation, and SF-36 domains. In both groups, PaO₂, 6MWT distance, and DSP increased significantly, while MRC, SGRQ, and HADS scores decreased. However, the gains in 6MWT distance and DSP were significantly greater in the desaturated group.

CONCLUSION

PR improved functional, psychological, and quality-of-life outcomes in both groups, with more pronounced benefits on sa in desaturated patients. Referral to PR is especially recommended for this subgroup.