Hearing impairment associated with spinal anesthesia.

Area of Science:

• Anesthesiology
• Otolaryngology
• Neurosurgery

Background:

• Post-spinal anesthesia hearing loss is theorized to result from reduced cerebrospinal fluid pressure affecting the inner ear via the cochlear aqueduct.
• Controversies exist regarding this phenomenon, necessitating systematic investigation into contributing factors.

Purpose of the Study:

• To investigate the impact of spinal needle diameter on the incidence of hearing loss following spinal anesthesia.
• To explore the relationship between spinal needle size and auditory function in patients undergoing surgery.

Main Methods:

• A prospective comparative study involving 30 patients undergoing spinal anesthesia.
• Audiometric tests were performed to assess hearing.
• Temporal bone CT scans were utilized to evaluate the dimensions of the cochlear and vestibular aqueducts.

Main Results:

• Hearing loss occurred in 26.67% of patients receiving a 22 G spinal needle, with recovery within 2-5 weeks.
• No statistically significant hearing loss was observed in patients who received a 27 G spinal needle.
• Acute balance problems were noted in three of the four patients experiencing hearing loss. No significant differences in aqueduct width were found between groups.

Conclusions:

• The diameter of the spinal needle used for spinal anesthesia appears to influence the occurrence of subsequent hearing loss.
• The patency of the bony canal is crucial for transmitting pressure changes to the inner ear.
• Predicting individual risk for this complication is not possible through radiological assessment of the bony canal.