Timing of Hyperbaric Oxygen Therapy for Sudden Sensorineural Hearing Loss
Hyperbaric oxygen therapy (HBOT) should be initiated within 2 weeks of symptom onset when used as initial therapy combined with steroids, or within 1 month when used as salvage therapy after failed steroid treatment. 1
Initial Therapy Window
HBOT combined with steroid therapy may be offered within 2 weeks of SSNHL onset as initial treatment, according to the American Academy of Otolaryngology-Head and Neck Surgery 2019 guidelines. 1
The Undersea and Hyperbaric Medical Society specifically recommends HBOT within 14 days of symptom onset for optimal outcomes. 2
Earlier intervention within this 2-week window is strongly associated with better hearing recovery, with research demonstrating that patients starting HBOT within 12 days showed 6.484 times greater improvement compared to those starting after 13 days. 3
Salvage Therapy Window
HBOT combined with steroid therapy may be offered as salvage treatment within 1 month (30 days) of SSNHL onset for patients who have incomplete recovery after initial corticosteroid therapy. 1
The American Academy of Otolaryngology-Head and Neck Surgery confirms HBOT as salvage therapy for patients who have failed both oral and intratympanic steroids, with treatment initiated within 3 months of symptom onset, though earlier intervention within 1 month is preferred. 4
Research supports salvage HBOT within 4 weeks of onset, showing significant improvement in pure tone hearing thresholds even in patients who failed primary corticosteroid treatment. 5
Critical Timing Considerations
The sooner HBOT is initiated, the better the outcomes, with multiple studies demonstrating that earlier treatment leads to significantly superior hearing recovery. 2, 3
Treatment within the first 10 days appears particularly beneficial, with one study showing dramatic improvements when HBOT was started within 72 hours of symptom onset (71.4% complete recovery rate). 6
Patients with severe to profound hearing loss (≥70 dB) benefit more from HBOT than those with mild losses, particularly when treatment is initiated early. 2, 7
Treatment Protocol
The standard HBOT protocol includes 10-20 sessions of 30-90 minutes each at >1 atmosphere absolute pressure with 100% oxygen. 2
Research suggests that 5-15 sessions provide optimal benefit, with no additional improvement observed beyond 10 sessions. 3
HBOT should always be combined with steroid therapy (either systemic or intratympanic) rather than used as monotherapy, except in cases where steroids are contraindicated. 1, 2
Common Pitfalls to Avoid
Do not delay HBOT referral while waiting for audiometric confirmation—the 2-week window is critical, and audiometry should be obtained as soon as possible within 14 days but should not delay treatment initiation. 1
Do not use HBOT as monotherapy in the initial treatment phase—guidelines specify it must be combined with steroid therapy for optimal outcomes. 1
Do not assume HBOT is ineffective after the 1-month salvage window—while outcomes are better with earlier treatment, some benefit may still be achieved up to 3 months post-onset. 4