Measurements of pulmonary function among patients stratified by treatment pressure. Circles represent patients treated at 2.0 ATA before (n = 37) hyperbaric oxygen therapy (Pre-HBOT) and after 20 (n = 35), 40 (n = 20), and 60 (n = 6) treatment sessions, and triangles represent patients treated at 2.4 ATA before (n = 49) hyperbaric oxygen therapy (Pre-HBOT) and after 20 (n = 46), 40 (n = 32), and 60 (n = 6) treatment sessions. FEV1% is represented in panel A, FVC% in panel B, and FEF25-75% in panel C. Points represent subgroup means at each timepoint, and bars delineate a confidence limit of 95%. Abbreviations: FEV1% = percentage of predicted forced expiration volume in one second; FVC% = percentage of predicted forced vital capacity; FEF25-75% = percentage of predicted mid-expiratory flow.