Evaluation of local anesthesia agents using a new force-sensitive lid speculum

Area of Science:

• Anesthesiology
• Ophthalmology
• Facial Nerve Blocks

Background:

• Facial nerve blocks are crucial for ophthalmic procedures.
• Evaluating anesthetic agents for akinesia is essential for surgical success.

Purpose of the Study:

• To compare the onset, completeness, and duration of facial akinesia using bupivacaine, mepivacaine, and lidocaine.
• To assess the utility of a novel force-sensitive lid speculum for measuring akinesia.

Main Methods:

• Modified O'Brien facial nerve block was performed using three anesthetic agents: bupivacaine 0.75%, mepivacaine 2%, and lidocaine 2%.
• A new force-sensitive lid speculum was employed to measure the completeness of facial akinesia.
• Onset, depth, and duration of akinesia were recorded for each agent.

Main Results:

• All three anesthetics achieved profound facial akinesia within six minutes.
• Bupivacaine demonstrated the longest duration of akinesia, lasting up to six hours.
• Mepivacaine provided adequate akinesia for approximately 90 minutes, while lidocaine lasted 15-30 minutes.
• The force-sensitive lid speculum proved effective in quantifying akinesia.

Conclusions:

• Bupivacaine is superior for prolonged facial akinesia compared to mepivacaine and lidocaine.
• The force-sensitive lid speculum is a valuable tool for assessing facial nerve block efficacy.
• Anesthetic choice should be guided by the required duration of akinesia for ophthalmic surgery.