Cochlear Function Monitoring after Spinal Anesthesia

Area of Science:

• Otoacoustic Emissions
• Auditory Neuroscience
• Anesthesiology

Background:

• Investigating the impact of spinal anesthesia on cochlear outer hair cell (OHC) function.
• Utilizing objective distortion product otoacoustic emissions (DPOAE) for cochlear function assessment.
• This study represents a significant contribution to OAE-based analyses of cochlear function during spinal anesthesia.

Purpose of the Study:

• To evaluate the effect of spinal anesthesia on the function of cochlear outer hair cells (OHCs).
• To determine the safety of spinal anesthesia for cochlear function using objective DPOAE testing.
• To assess changes in DPOAE levels and background noise during and after spinal anesthesia.

Main Methods:

• 20 patients undergoing ureterorenoscopic lithotripsy received spinal anesthesia (0.5% hyperbaric bupivacaine and fentanyl).
• Distortion product otoacoustic emissions (DPOAEs) and background noise were recorded before, immediately after, and 2 days post-anesthesia.
• Objective DPOAE measurements were used to assess cochlear outer hair cell function.

Main Results:

• No significant differences in DPOAEs were found immediately after spinal anesthesia compared to baseline.
• A significant increase in DPOAEs was noted at 5652 Hz immediately after anesthesia.
• Postoperative DPOAEs at 2002 Hz and 2380 Hz were significantly higher than baseline; background noise remained unchanged.

Conclusions:

• Spinal anesthesia demonstrates no detrimental effect on objectively evaluated cochlear function.
• The findings suggest spinal anesthesia is safe for cochlear outer hair cells (OHCs).
• This method is considered safe even for OHCs, which are highly susceptible to injury.