A follow-up study of post infectious obliterative bronchiolitis in adults and comparative analysis with chronic obstructive pulmonary disease

Objectives: The objective is (1) To evaluate the change in forced expiratory volume in one second (FEV1), forced vital capacity (FVC), dyspnea grading, body mass index, and oxygen saturation (SpO(2)) in adults with postinfectious obliterative bronchiolitis (PIOB) over a period of time (2) To evaluate the same parameters in chronic obstructive pulmonary disease (COPD) patients and compare with PIOB. Materials and Methods: It was a retrospective observational study involving appropriately managed patients of PIOB and COPD with minimum 3 years of follow-up. Out of a total of 106 patients who followed up from January 2019 to December 2019 and had a follow-up data of more than 3 years, 61 (31 COPD and 30 PIOB) patients were included in the final analysis after applying the inclusion and exclusion criteria. Results: The baseline FEV1 and FVC was significantly worse in PIOB group compared to COPD group. In PIOB group, there was nonsignificant increment in both the parameters (FVC by 18.79 ml and FEV1 by 12.2 ml per year). There was a significant decline in FVC and FEV1 in the COPD group by 106.8 ml and 63.25 ml per year, respectively. There was a significant difference between PIOB and COPD for the yearly change in FVC and FEV1 (P value being 0.000083 and 0.000033, respectively). In PIOB group, there was increment in modified Medical Research Council (mMRC) score and nonsignificant change in SpO(2) whereas the SpO(2) and mMRC score had a yearly decline in the COPD group. Conclusion: The PIOB is characterized by a nonsignificant increase in lung function whereas COPD shows a significant progressive decline.