Bilateral hearing loss following a retrobulbar block

Area of Science:

• Ophthalmology
• Anesthesiology
• Neuroscience

Background:

• Retrobulbar blocks are a standard anesthetic technique for ophthalmic procedures in North America.
• Anesthesiologists play a crucial role in managing potential complications of regional anesthesia during eye surgery.
• Brainstem anesthesia is a known, though not common, complication associated with retrobulbar blocks.

Observation:

• A 46-year-old male with type 1 diabetes experienced sudden, complete, and bilateral hearing loss immediately after a retrobulbar block.
• Neurological examination revealed no other cranial nerve deficits, and the patient remained alert and oriented.
• Hearing function gradually returned to normal within three hours post-procedure.

Findings:

• This case represents the first documented instance of complete bilateral hearing loss as a complication of a retrobulbar block.
• The symptoms of brainstem anesthesia can be diverse, including auditory deficits, and are linked to the spread of local anesthetic.
• A potential pathway for anesthetic spread involves the connection between the optic nerve sheath and the subdural/subarachnoid spaces.

Implications:

• Highlights the importance of vigilance for rare neurological complications following retrobulbar blocks.
• Suggests that anesthesiologists should be prepared to recognize and manage diverse neurological symptoms, including hearing loss.
• Underscores the need for further understanding of the anatomical pathways influencing anesthetic spread and central nervous system effects.