Longitudinal study of changes in pulmonary function among inside attendants of hyperbaric oxygen therapy.

Hyperbaric oxygen therapy (HBOT) administers 100% oxygen in a pressurised chamber at pressures above 1 atmosphere absolute. Inside hyperbaric personnel accompany patients during sessions and breathe compressed air, exposing them to risks like decompression illness and respiratory changes. This study investigated whether hyperbaric exposure affects the long-term lung function of inside hyperbaric personnel. An analysis was conducted on spirometry data from 14 personnel working between 2012 and 2023. Lung function tests measured forced vital capacity (FVC), forced expiratory volume in one second (FEV1), mid breath forced expiratory flow (FEF25-75), and peak expiratory flow (PEF) before and after hyperbaric exposure. Participants were categorised based on age, body mass index, number of HBOT sessions, and duration of employment. No clinically or statistically significant differences were found in FVC, FEV1, or PEF measurements before and after hyperbaric exposures (P > 0.05). However, FEF25-75, an indicator of small airway function, showed a (mean) 16% reduction in personnel with more than 150 HBOT sessions (P = 0.038). A post-hoc analysis confirmed a significant difference in FEF25-75 between personnel with fewer than 74 sessions and those with 150 or more sessions (P = 0.015). No clinically significant symptoms such as dyspnoea were reported during the study period. The FEF25-75 reduction, without changes in FEV1, FVC, or PEF, could be due to improper performance of the FVC manoeuvre. Maintaining pulmonary health in inside hyperbaric personnel is essential, emphasising the importance of accurate FVC execution in assessments. Further studies are recommended to explore the long-term implications of these findings and the effects of repeated hyperbaric exposure on respiratory health.