Comparative study between rocuronium and magnesium sulfate as adjuvants to local anesthetics for peribulbar block

Abstract

Background & Objective: Peribulbar anesthesia is frequently used in cataract surgeries. Compared to retrobulbar anesthesia, this approach is associated with less significant consequences. However, the prolonged onset of orbital akinesia and the frequent need for block replenishment are considered drawbacks. We aimed to investigate the impact of adding rocuronium and magnesium sulfate to a commonly used local anesthetic combination on the onset of corneal anesthesia and the degree of lid and globe akinesia during peribulbar block in ocular surgeries. Patients and Methods: This prospective double-blinded randomized study was conducted in the ophthalmic surgery operating theater, Ain Shams University Hospital from January 2019 to April 2020. We enrolled 75 patients from both sexes, with American Society of Anesthesiology (ASA) physical status I–III, ages 40-80 y, and an axial globe length less than or equal to 26 mm planned for cataract surgery under peribulbar block in the study following institutional ethical board approval and written informed patient consents. Patients were randomly divided into three groups, 25 patients per group, based on the drugs they received: Group O (control group): received local anesthetic + 0.9% normal saline (1 ml). Group M: received local anesthetic + magnesium sulphate 50 mg in normal saline. Group R: received local anesthetic + rocuronium at a dose of 0.06 mg/kg (maximum 5 mg) in normal saline. Results: Our study found statistically significant more rapid onset of action (mean time to start surgery) in rocuronium group (7.00 ± 1.22 min) than control group and magnesium sulfate group (9.00 ± 1.47 and 9.00 ± 1.15 min) respectively, (P < 0.001); Moreover, no significant difference was noted between control group and magnesium sulfate group. In addition, no relevant difference was reported regarding duration of surgery between the groups. Conclusion: During cataract surgery, the addition of rocuronium to the local anesthetic mixture in the peribulbar nerve block has been found to enhance ocular akinesia and corneal anesthesia. Furthermore, the use of rocuronium demonstrated a significantly faster onset and shorter time needed to achieve the appropriate conditions to initiate the surgical procedure compared to the use of magnesium sulfate. Addition of magnesium sulfate showed good results regarding akinesia, corneal anesthesia and need for supplementary injections but it did not significantly fasten the onset of block and hence the time to start surgery. Key words: Cataract; Magnesium Sulfate; Peribulbar Block; Rocuronium Citation: Nagy M, Abo El-Ella S, El-Shafey MA, Helal AM, Zekry MR. Comparative study between rocuronium and magnesium sulfate as adjuvants to local anesthetics for peribulbar block. Anaesth. pain intensive care 2024;28(1):55−61; DOI: 10.35975/apic.v28i1.2157 Received: February 18, 2023; Reviewed: July 30, 2023; Accepted: December 23, 2023