Complications and side effects of hyperbaric oxygen therapy

Background: Despite ongoing controversy, hyperbaric oxygen (HBO) therapy is frequently administered in various clinical situations. Probably because o f the unique atmospheric conditions to which the patient is exposed, there are concerns about the safety aspects of this therapy. Possible complicatio ns during HBO therapy include barotraumatic lesions (middle ear, nasal sinu ses, inner ear, lung, teeth), oxygen toxicity (central nervous system, lung ), confinement anxiety, and ocular effects (myopia, cataract growth). Metho ds: To analyze the medical safety of HBO therapy, this report reviewed comp lications and side effects of 782 patients treated for various indications with a total of 11,376 HBO therapy sessions within a multiplace chamber. Th e absolute treatment pressure was 240 or 250 kPa (14 or 15 msw). The compre ssion was performed in a linear manner with 14 to 15 kPa (1.4 to 1.5 msw).m in(-1) AII data were gathered prospectively within a special database. Resu lts: More than 17% of all patients experienced ear pain or discomfort as an expression of problems in equalizing the middle ear pressure. Most episode s were not related to a persistent eustachian tube dysfunction since they o nly occurred once. Barotraumatic lesions on visual otological examinations tear microscopy) were verified in 3.8% of all patients. Patients with senso ry deficits involving the ear region need special attention, because they s eem to be at risk for rupture of the tympanic membrane (three cases documen ted). A barotrauma of the nasal sinuses occurred rarely and no barotraumati c lesions of the inner ear, lung, or teeth were noted. Oxygen toxicity of t he CNS manifested by generalized seizures affected four patients without an y recognizable risk factors or prodromes. None of the patients suffered rec urrences or sequelae. Regular checks of the blood glucose in diabetics fail ed to reveal episodes of hypoglycemia as a cause for seizures. Lung functio n tests of patients undergoing prolonged treatment (average 52.8 sessions) did not deteriorate. Conclusion: Patients scheduled for HBO therapy need a careful pre-examination and monitoring. If safety guidelines are strictly f ollowed, HBO therapy is a modality with an acceptable rate of complications . The predominant complication is represented by pressure equalization prob lems within the middle ear. Serious complications rarely occur.