Lower-Dose Mepivacaine Plus Fentanyl May Improve Spinal Anesthesia for Knee Arthroscopy

Area of Science:

• Anesthesiology
• Pharmacology

Background:

• Previous studies suggest 30 mg mepivacaine with 10 μg fentanyl offers effective spinal anesthesia for knee arthroscopy and faster recovery.
• Optimizing anesthetic protocols is crucial for outpatient surgical procedures.

Purpose of the Study:

• To compare plain mepivacaine with reduced doses of mepivacaine combined with fentanyl for spinal anesthesia in outpatient knee arthroscopy.
• To evaluate the impact of varying mepivacaine and fentanyl doses on anesthetic efficacy and recovery profiles.

Main Methods:

• A randomized controlled trial involving patients undergoing knee arthroscopy.
• Four groups received different mepivacaine doses (37.5 mg, 30 mg, 27 mg, 24 mg) with 10 μg fentanyl, except for the 37.5 mg mepivacaine only group.
• Anesthetist and surgeon evaluation, post-anesthesia care unit assessments of sensory/motor block resolution, and patient satisfaction surveys were conducted.

Main Results:

• Groups receiving 27 mg or 24 mg mepivacaine with fentanyl were discontinued due to inadequate anesthesia.
• The 30 mg mepivacaine with 10 μg fentanyl group showed faster motor block resolution compared to 37.5 mg mepivacaine.
• No significant differences in overall recovery profiles were observed between the 37.5 mg and 30 mg mepivacaine with fentanyl groups.

Conclusions:

• Combining 10 μg fentanyl with lower mepivacaine doses can accelerate recovery after spinal anesthesia.
• The potential benefit of quicker recovery must be balanced against the risk of insufficient anesthetic effect.
• Patient satisfaction was high across all evaluated groups, indicating general acceptance of the anesthetic experience.