Prospective analysis included patients, 18 years or older, scheduled for 60 daily HBOT sessions between 2016-2018. Each session was 90 min of 100% oxygen at 2 ATA with 5 minutes air breaks every 20 min, five days per week. Pulmonary functions,measured at baseline and after HBOT,included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEF).

After signing an informed consent form, the participants underwent a pulmonary function baseline evaluation. Participants were treated in a multiplace chamber (HAUX-Life-Support GmbH) for 60 daily sessions, 5 days a week. Each session consisted of 90 minutes of exposure to 100% oxygen at 2 ATA with 5 minute air breaks every 20 minutes. Participants repeated their pulmonary function evaluation after the last HBOT session.

Pulmonary function Measurements of pulmonary functions were performed using the MiniSpir testing apparatus (MIR- Medical International Research, USA). The equipment was calibrated using a 3-liter syringe before performing measurements according to the manufacturer's instructions. Measurements were performed by a trained technician. The forced expiratory maneuvers were performed as recommended by the guidelines[13].

The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow rate (PEF) were taken as the highest readings obtained from at least three satisfactory forced expiratory maneuvers. Mean forced mid-expiratory flow rate (FEF25-75%) and forced expiratory flow rates at 25, 50 and 75% of FVC expired (FEF25%, FEF50% and FEF75%) were taken as the best values from flow-volume loops not differing by >5% from the highest FVC.

Inclusion Criteria:

• 18 and older patients
• scheduled for 60 HBOT sessions for any indication

Exclusion Criteria:

• Active smokers were excluded but patients who quit smoking more than six months prior to inclusion were allowed in the study.
• active smoking
• severe known pulmonary disease
• chest pathology incompatible with HBOT
• inner ear disease
• claustrophobia
• other neurological conditions
• pregnancy
• previous HBOT within six months prior to inclusion
• the inability to sign informed consent.

The study included participants 18 years or older, scheduled for 60 HBOT sessions for any indication