Evaluation of the Effect of Using Magnesium Sulphate as an Adjuvant to Regional Anesthesia for Ophthalmic Surgery Using Peribulbar Block, MOHAMED ABD EL-RAOUF, OSMAN M. HEFZY, AHMED A. BAWDY, MOHAMED H. ABD EL-AZIZ and NORHAN A. SHERIF
Abstract
Background: Peribulbar block is commonly used for different ophthalmic surgeries. It is safe, inexpensive, and provides excellent anesthesia and akinesia [1]. It has become a common practice to use polypharmacy approach to enhance the onset and prolong the duration of the block, because no drug has yet been identified that specifically inhibits nocice-ption without associated side effects [2]. Research continues concerning different techniques and drugs that could provide better anesthesia and postoperative pain relief, one of these drugs is magnesium sulphate [3].
Introduction: Magnesium sulphate is a physiological calcium antagonist and competitive N-Methyl-D-Aspartate (NMDA) receptor antagonist. Studies evaluated its effect as an additive to local anesthetics in different regional techniques. Effect of magnesium sulfate supplementation was evaluated by degree of globe and lid akinesia, degree of postoperative pain, time to full motor recovery and duration of analgesia.
Aim of the Work: Is to evaluate the effect of magnesium sulphate as an adjuvant to regional anesthesia for ophthalmic surgery using peribulbar block.
Methods: The present study involved 2 groups; each group included 20 patients undergoing elective posterior segment surgery of the eye under local anesthesia.
•Group (M50) received 50mg of magnesium sulfate in addition to the local anesthetic (2% lidocaine + 0.5% bupivacaine + hyaluronidase).
•Control group (Group C) received only the local anesthetic (2% lidocaine + 0.5% bupivacaine + hyaluronidase).
Results: The addition of 50mg of magnesium sulphate, a competitive NMDA antagonist are safe and effective adjuvant to local anesthetic mixture of bupivacaine and lidocaine in peribulbar eye evidenced by fastening the onset of globe block, increasing duration of akinesia and analgesia with excellent patient and surgeon satisfaction and with the no systemic or local complication. Intraocular pressure was reduced below baseline after 15 minutes of the block.
Conclusion: It was found that the addition of 50mg of magnesium sulphate, a competitive NMDA antagonist is safe and effective as an adjuvant to local anesthetic mixture of bupivacaine and lidocaine in peribulbar eye evidenced by fastening the onset of globe block, increasing duration of akinesia and analgesia with excellent patient and surgeon satisfaction and with no systemic or local complication. Intraocular pressure was reduced below baseline after 15 minutes of the block, suggesting that magnesium sulphate in a dose of 50mg is a safe adjunct to local anesthetic mixture in peribulbar block.