Magnesium Sulfate for Prevention of Emergence Agitation in Lumbar Disc Surgery

Overview

This randomized, double-blind, controlled trial investigates the effect of intraoperative magnesium sulfate infusion on the incidence of postoperative emergence agitation in adult patients undergoing elective lumbar microdiscectomy under general anesthesia. Eligible participants (ASA physical status I-II, aged 18-70 years) will be randomly assigned to receive either magnesium sulfate or 0.9% saline during surgery. The primary outcome is the incidence of emergence agitation in the post-anesthesia care unit (PACU), assessed at admission and at 5, 10, 15, and 30 minutes using the Ramsay Sedation Scale. Secondary outcomes include postoperative pain scores (Numeric Rating Scale), intraoperative remifentanil consumption, recovery and extubation times, tramadol use in the PACU, and any adverse events related to magnesium infusion.

This prospective, randomized, double-blind, controlled trial will be conducted at Ondokuz Mayis University and Giresun Training and Research Hospital. The study aims to evaluate the effect of intraoperative magnesium sulfate infusion on postoperative emergence agitation (EA) in patients undergoing elective lumbar microdiscectomy under general anesthesia. Following ethics committee approval and written informed consent, adult patients aged 18-70 years, classified as ASA physical status I or II, scheduled for single-level lumbar microdiscectomy, will be enrolled. Exclusion criteria include severe cardiovascular disease, psychiatric disorders, neuromuscular disease, pregnancy, hepatic or renal dysfunction, use of calcium channel blockers, hypnotics, anxiolytics, antipsychotics, allergy to study drugs, or refusal to participate. Participants will be randomized (1:1) using a computer-generated sequence to either: Magnesium Group (Group M): 30 mg/kg magnesium sulfate IV bolus over 15 minutes after induction, followed by continuous infusion at 10 mg/kg/h until the end of surgery. Control Group (Group K): Equivalent volume and rate of 0.9% saline. All patients will receive standardized anesthesia, including premedication with midazolam, induction with propofol, fentanyl, and rocuronium, and maintenance with sevoflurane in 50% air/oxygen mixture. Remifentanil infusion (0.1-0.25 µg/kg/min) will be adjusted to maintain target bispectral index (BIS) values between 40 and 60. The primary outcome is the incidence of emergence agitation in the post-anesthesia care unit (PACU), measured at admission (T0) and at 5 (T1), 10 (T2), 15 (T3), and 30 (T4) minutes post-admission using the Ramsay Sedation Scale (RSS). Secondary outcomes include Numeric Rating Scale (NRS) pain scores at the same PACU time points, total intraoperative remifentanil consumption, recovery time (from sevoflurane discontinuation to eye opening), extubation time (from sevoflurane discontinuation to extubation), meperidine use in the PACU, and the incidence of adverse events (arrhythmia, neuromuscular blockade, respiratory difficulties) related to magnesium infusion. Sample size was calculated based on pilot data, requiring 32 participants per group for 80% power at a 0.05 significance level, with 35 enrolled per group to account for potential dropouts. Statistical analysis will use Student's t-test or Mann-Whitney U test for continuous variables, Chi-square or Fisher's exact test for categorical variables, with significance set at p \< 0.05. Analyses will be performed using SPSS v25.0.