Steroids, carbogen or placebo for sudden hearing loss: a prospective double-blind study

There is no consensus regarding treatment modalities for idiopathic sudden sensorineural hearing loss (SNHL). In order to evaluate the effectiveness of steroid or carbogen inhalation therapies, a prospective double-blind placebo controlled study was designed. All 41 patients enrolled in the study had unilateral SNHL with no prior history of SNHL, otological pathological history or otoscopic findings. Patients were assigned to four treatment groups: prednisone tablets, placebo tablets, carbogen inhalation or room air inhalation. All were treated for 5 days. The audiometric data at admission was compared to that at day 6 and to data collected at follow-up (average 33 days). Results revealed no significant difference between the groups for early or late audiometric outcome. Age, time from onset of symptoms to initiation of treatment, tinnitus, audiogram configuration, and the presence of vertigo at onset did not significantly affect the outcome. The discrimination scores that were poor in all patient groups on admission improved within days in all groups. These findings suggest that steroids or carbogen inhalation have no therapeutic advantage over placebo. Also, regardless of treatment modality, hearing continued to improve for at least a month after treatment was stopped.