In relation to opioid consumption, no significant differences were observed at 6 h (SMD−0.35, 95%CI−0.82 to 0.13; participants = 244; studies = 3; I2 = 63%) or 24 h (SMD−0.36, 95% CI−1.07 to 0.35; participants = 243; studies = 3; I2 = 83%) (Figure 5). When magnesium was compared to a placebo, it was found to significantly reduce opioid consumption (SMD−0.66, 95%CI −0.95 to −0.38; participants = 196; studies = 6; I2 = 0%), both at 6 and 24 h (SMD−0.71, 95% CI −1.12 to −0.30; participants = 98; studies = 3; I2 = 0%). In terms of overall or at six or 24 h, there were no significant differences between MS and dexamethasone (SMD 0.10, 95% CI−0.13 to 0.33; participants = 292; studies = 6; I2 = 0%). Test results for the subgroup are 1.82 and the overall impact are 1.00.

The MS group’s use of muscle relaxants was significantly lower among participants (252) and studies (3) (SMD −0.91, 95% CI−1.93 to −0.10; I2 = 92%) (Figure 6) MS had a significantly decreased consumption of muscle relaxants when compared to a placebo. The total impact test is 1.77 and the chi2 value is 0.73.

Vasoactive agent use did not differ significantly (OR 1.87, 95% CI 1.01 to 3.46; participants = 315; studies = 4; I2 = 0%) from (Figure 7). Not at all in contrast to a placebo. The chi2 value is 1.72 and the overall impact test is 1.99.

Regarding global heart rate (MD 2.37, 95% CI −0.66 to 5.10; participants = 797; studies = 17; I2 = 24%), there were no significant changes between the groups or in any of the follow-up time-based subgroups (Figure 8). The MS group displayed a considerably greater heart rate in comparison to the placebo. When MS was compared with clonidine, no discernible differences were found. Test results for subgroup difference are 0.40 and total effect are 0.55.

Figure 9 indicates that there were no significant variations in mean arterial pressure (MAP) across the groups (MD 1.81, 95% CI−2.55 to 6.17; 950 participants, 20 studies, and 57% I2). Notably, there were no variations when compared to the placebo group. MS displayed a considerably decreased MAP in contrast to clonidine. Regarding dexmedetomidine, there were no notable variations. The subgroup test is 0.55 while the overall effect test is 0.45.

There was no statistically significant difference in extubating time between the groups (Figure 10; participants = 364, studies = 5, I2 = 94%; MD 0.91, 95% CI -0.98–2.80). With respect to the placebo group, there were no appreciable variations. The MS group had a considerably longer extubation time in comparison to dexmedetomidine. The overall effect test result is 0.94, and chi2 is 71.91.

Figure 11 shows that the MS group’s responsiveness to verbal orders was considerably higher (MD 1.22, 95% CI -0.166 to 2.61; participants = 291; studies = 4; I2 = 76%). With respect to the placebo group, there were no appreciable variations. In contrast to the clonidine group, the MS group displayed a noticeably slower response time to spoken instructions. Chi2 is 12.27 and the test for the total effect is 1.73.

Additionally, the orientation time was substantially longer in the MS group compared to the placebo group (MD: 2.07, 95% CI 0.82 to 3.32; participants = 146; studies = 3; I2 = 59%) (Figure 12). The test effect was 3.25 overall, and the chi2 was 4.91.

Visual inspection of funnel plots revealed significant publication bias across most variables, as evidenced by notable asymmetry in the distribution of studies. Detailed analysis of these asymmetries and their implications is presented in the supplementary materials.

The therapeutic benefits of magnesium in postoperative pain management likely stem from its multifaceted neuroprotective and anti-inflammatory mechanisms (Hassan et al., 2020). Through the promotion of neuroplasticity, magnesium provides protection against neuronal deterioration and postoperative cognitive dysfunction (Hassan et al., 2020). Its antioxidant properties are demonstrated through the neutralization of reactive oxygen species (ROS), specifically via hydrogen peroxide (H2O2) elimination and hydrogen (H2) liberation, contributing significantly to its anti-inflammatory effects in treating intervertebral disc degeneration (IVDD) (Hassan et al., 2020; Zhang et al., 2023).

The neuroprotective profile of magnesium extends to its modulation of S100B protein levels, a recognized biomarker of oxidative stress and amyloid precursor (Zhang et al., 2023). Clinical investigations have revealed that magnesium’s efficacy in managing postoperative sore throat is comparable to corticosteroids, potentially contributing to enhanced patient satisfaction. This finding is particularly noteworthy given that patient-reported outcome measures (PROMs) were primarily limited to Visual Analog Scale (VAS) assessments (Park et al., 2015). The comparison with corticosteroids merits special attention, considering their adverse metabolic effects, particularly on glucose homeostasis. The therapeutic benefit appears to be mediated through magnesium’s anti-inflammatory properties, resulting in reduced postoperative nausea, vomiting, and subsequent throat discomfort (Lu et al., 2013; Mori et al., 2010).

A significant limitation across studies was the absence of minimum clinically important difference (MCID) assessments, highlighting a crucial area for future investigation. The marked reduction in opioid consumption observed with magnesium administration, compared to placebo, can be mechanistically explained by its non-competitive N-methyl-D-aspartate (NMDA) receptor antagonism. This mechanism results in decreased glutamate release and inhibition of excessive calcium influx into neurons, thereby providing neuroprotection and maintaining cellular integrity (Newcomer and Krystal, 2001). Similar opioid-sparing effects have been documented with other NMDA receptor antagonists, including gabapentin and ketamine (Newcomer and Krystal, 2001).

The neuroprotective properties of magnesium sulfate have broader clinical applications, as evidenced by its recommended use in reducing cerebral palsy incidence among preterm infants, particularly those at risk of delivery before 32 weeks gestation (Jameson and Bernstein, 2019). Through dual mechanisms of neuronal process stabilization and vasodilation, intracerebral magnesium sulfate reduces the incidence of cerebral vasospasm and delayed cerebral ischemia. Complementary intravenous hydrogen therapy may enhance these effects through additional antioxidant benefits, potentially improving clinical outcomes and reducing cerebral oxidative stress (Takeuchi et al., 2021).

Our analysis revealed lower mean arterial pressure in the magnesium group compared to the corticosteroid group, attributable to magnesium’s vasodilatory properties. Magnesium exerts its hypotensive effect through multiple mechanisms: direct relaxation of blood vessels, calcium channel antagonism, and competition with sodium in vascular smooth muscle cells. Furthermore, magnesium enhances endothelial function and vascular wall integrity, promoting vasodilation and reducing inflammation (Houston, 2011). The observed increase in heart rate in our meta-analysis likely represents a compensatory response to this vasodilation, while the higher mean arterial pressure in the corticosteroid group can be attributed to adrenergic system activation.

The hypotensive properties of magnesium contribute to reduced perioperative bleeding (Rayssiguier et al., 2010). Additionally, magnesium modulates sympathetic nervous system activity through catecholamine blockade (Göral et al., 2011). While the magnesium group demonstrated prolonged activated partial thromboplastin time, other coagulation parameters remained comparable between groups (Wang et al., 2024).

Magnesium’s ability to reduce muscle relaxant requirements is attributed to its inhibition of acetylcholine receptor responses in muscle cells. This synergistic effect potentially allows for dose reduction of muscle relaxants during surgical procedures. However, careful dose titration of both vecuronium and magnesium sulfate is essential to prevent adverse effects and excessive muscle relaxation (Aal-Hamad et al., 2023).

Careful monitoring of magnesium levels is crucial, as concentrations exceeding 4–5 mmol/L (9.7–12.2 mg/dL) are considered hazardous. Hypermagnesemia can manifest as weakness, nausea, dizziness, and confusion, with increased mortality risk in hospitalized patients. The prevalence ranges from 3.0% to 5.7%–9.3% in the general population, with higher rates in hospital settings. Patients with renal insufficiency require particularly vigilant monitoring and management to prevent serious complications (Srivastava et al., 2016).

The prolonged recovery period observed in the magnesium group, characterized by delayed orientation time and verbal response, likely results from the combination of its hypotensive and muscle-relaxant effects. The vasodilatory properties may lead to reduced cerebral perfusion and oxygenation, contributing to extended recovery times and temporary cognitive effects. The muscle-relaxant properties may further impair patient responses during the recovery phase, affecting both verbal communication and orientation capabilities.

Dexmedetomidine served as a key comparator in our meta-analysis, providing important insights into alternative therapeutic approaches. As an α2-adrenoceptor agonist, dexmedetomidine demonstrates significant efficacy in reducing surgical stress responses. Our analysis revealed that dexmedetomidine was more effective than magnesium in reducing both fentanyl and propofol consumption. Srivastav et al.'s findings demonstrated superior hemodynamic stability with dexmedetomidine compared to other interventions (Srivastava et al., 2016). This enhanced hemodynamic profile and greater efficacy in reducing opioid and propofol consumption can be attributed to dexmedetomidine’s high affinity and selectivity for α2-adrenergic receptors. However, these benefits are accompanied by an increased risk of bradycardia and hypotension compared to magnesium therapy (Srivastava et al., 2016).

While Kumar’s study reported superior pain control with dexmedetomidine compared to magnesium plus ropivacaine combination, our meta-analysis found no significant differences in pain outcomes between the interventions. Notably, we observed increased muscle relaxant consumption in the dexmedetomidine group. In comparison with placebo, dexmedetomidine demonstrated advantages in orientation time and verbal response parameters. The prolongation of local anesthetic effects observed with dexmedetomidine can be attributed to its vasoconstrictive properties (Yoshitomi et al., 2008).

Recent meta-analyses have highlighted specific safety concerns with dexmedetomidine administration during spinal surgery. The risk of bradycardia and intraoperative hypotension is particularly pronounced when administered as a loading dose in combination with total intravenous anesthesia (Wang et al., 2024). These risks were notably elevated in patients receiving inhalation anesthesia. While the inhalation anesthesia subgroup demonstrated reduced blood loss, this effect was not observed consistently across all administration methods (Wang et al., 2024).

Magnesium demonstrates significant potential for synergistic effects when combined with other analgesic modalities. The modest effects observed in comparisons between magnesium sulfate and corticosteroids may be attributed to limited sample sizes and short follow-up periods (typically 24 h). Evidence suggests enhanced patient outcomes when magnesium is combined with various analgesic interventions, including opioids, local anesthetics, and regional anesthesia techniques (Fairley et al., 2017). This multimodal approach may provide more comprehensive pain management strategies, though longer-term monitoring beyond the immediate postoperative phase is needed to fully evaluate these benefits.

Considerable variation exists in magnesium administration protocols (Tsaousi et al., 2020). Our meta-analysis evaluated various approaches, including:

• Loading doses: 30–50 mg/kg in saline, administered over 10–30 min pre-anesthesia.

While visual analysis of forest plots did not reveal clear associations between administration protocols and outcomes, this observation requires cautious interpretation given the lack of formal statistical analysis.

Magnesium’s therapeutic benefits extend beyond spinal surgery. Evidence demonstrates its efficacy in.

• Reducing postoperative atrial fibrillation in cardiac surgery (Fairley et al., 2017).

Meta-analyses have documented significant reductions in:

• 24-h morphine consumption.

Our study expanded upon previous meta-analyses by incorporating additional outcome measures, including remifentanil and muscle relaxant consumption. Key findings include.

• Peak pain reduction occurred at varying timepoints (6–12 h) across studies (Tsaousi et al., 2020; Kumar et al., 2023).

Unlike previous meta-analyses focusing on total anesthesia duration, our study specifically examined orientation and verbal response times, though findings aligned with established observations regarding prolonged anesthetic effects.