[The dosage of hyperbaric oxygen therapy in patients with sudden hearing loss]

Free radical metabolism substances in different stages of hyperbaric oxygen (HBO) therapy in 33 patients with sudden hearing loss were studied. The time of treatment is 40 min each day and the pressure of HBO is 0.2 MPa, with treatment lasting for 20 days. The result indicated that after ten times of HBO therapy, the level of lipid peroxidation (LPO) in plasma increased slightly and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) in erythrocytes decrease was not significant (P > 0.05). Only the levels of glutathione (GSH) in erythrocytes decreased significantly (P < 0.05). After 20 days, HBO therapy, the plasma LPO value increased significantly (P < 0.05), the activities of SOD, GSHPx and the values of GSH in erythrocytes decreased significantly (P < 0.05). The results indicated that continuous therapy for patients with HBO should not be carried out for more than 20 days.