Can Hyperbaric Oxygen Therapy (HBOT) cause sudden hearing loss?

Hyperbaric Oxygen Therapy and Sudden Hearing Loss: Risks and Complications

Yes, hyperbaric oxygen therapy (HBOT) can cause sudden hearing loss, primarily due to barotrauma to the middle and inner ear during treatment. 1

Mechanisms of HBOT-Related Hearing Loss

HBOT involves exposing patients to 100% oxygen at pressures higher than 1 atmosphere absolute (ATA) in a sealed chamber. This creates several potential mechanisms for hearing damage:

• Middle ear barotrauma: The most common complication, occurring in 17% of patients receiving HBOT for various indications 1
• Eustachian tube dysfunction: Reported in up to 45% of patients undergoing HBOT 1
• Sinus barotrauma: Can occur alongside ear barotrauma
• Inner ear damage: Pressure changes can potentially damage the delicate structures of the inner ear

Incidence and Risk Factors

The risk of ear barotrauma specifically during HBOT varies by study:

• 17% of patients experience difficulty equalizing middle ear pressure 1
• 6.25% of patients receiving HBOT specifically for sudden sensorineural hearing loss (SSNHL) experienced ear or sinus barotrauma 1

Risk factors that increase the likelihood of HBOT-related hearing complications:

• Pre-existing eustachian tube dysfunction
• Upper respiratory infections
• Inability to perform pressure-equalizing maneuvers
• Higher pressure protocols
• Faster compression rates

Prevention and Management

To minimize the risk of HBOT-induced hearing loss:

1. Pre-treatment screening:

   • Assess for pre-existing eustachian tube dysfunction
   • Evaluate middle ear function before initiating therapy

2. During treatment:

   • Use slower compression rates
   • Teach patients proper pressure-equalization techniques
   • Consider prophylactic decongestants in high-risk patients

3. Monitoring:

   • Regular assessment during treatment for symptoms of ear fullness, pain, or hearing changes
   • Immediate intervention if symptoms develop

Clinical Implications

The risk of hearing complications must be weighed against potential benefits when considering HBOT:

• For patients receiving HBOT for SSNHL, the treatment itself carries a small but real risk of causing the very problem it aims to treat
• The American Academy of Otolaryngology-Head and Neck Surgery guidelines note that while HBOT may provide some hearing benefit in SSNHL cases, this must be balanced against potential adverse effects including barotrauma 1
• The number needed to treat for a 25% improvement in hearing with HBOT is 5 patients, while approximately 1 in 16 patients may experience barotrauma 1

Special Considerations

• Patients with pre-existing hearing loss require particularly careful monitoring
• Concurrent systemic steroid use (common in SSNHL treatment) may decrease inflammation and edema that could lead to pressure equalization difficulties 1
• The risk-benefit analysis should consider the severity of the condition being treated with HBOT and alternative treatment options

In conclusion, while HBOT is generally considered safe, clinicians should be aware of its potential to cause sudden hearing loss through barotrauma mechanisms and take appropriate preventive measures, especially in patients with risk factors for ear injury.