The Use of Magnesium Sulfate and Peripheral Nerve Blocks

Abstract

Objectives: With the popularization of ultrasound, nerve blocks have been widely implemented in current clinical practice. Although, they have seen limited success due to their shorter duration and suboptimal analgesia. Magnesium sulfate as a local anesthetic adjuvant for peripheral nerve blocks could enhance the effects of local anesthetics. However, previous investigations have not thoroughly investigated the analgesic efficacy of magnesium sulfate as an adjunct to local anesthetics for peripheral nerve blocks. Thus, we attempted to fill the gap in the existing literature by conducting a meta-analysis. Materials and Methods:We performed of a quantitative systematic review of randomized controlled trials published between May 30, 2011 and November 1, 2018. Inclusion criteria were: (1) magnesium sulfate used as adjuvant mixed with local anesthetic for nerve blockade, (2) complete articles and published abstracts of randomized controlled trials, (3) English language.Primary and Secondary Outcome Measures: The primary outcome measures were time of onset, total duration of the sensory blockade, and Visual Analog Scale pain scores. The secondary outcomes were postoperative oral and intravenous analgesics consumption and the incidence of nausea and vomiting. Results:The 21 trials analyzed in this study included 1323 patients. Magnesium sulfate effectively prolonged the total duration of sensory blockade (mean difference [MD] = 114.59 min, 95% confidence interval [CI]: 89.31-139.88), reducing Visual Analog Scale pain scores at 6 hours (MD = 1.36 points, 95% CI: −2.09 to −0.63) and 12 hours (MD = 1.54 points, 95% CI: −2.56 to −0.53) postsurgery.Magnesium sulfate also effectively reduced postoperative analgesic use within 24 hours postsurgery (standard MD = −2.06, 95% CI: −2.67 to −1.35). Furthermore, adjuvant magnesium sulfate significantly reduced the incidence of nausea and vomiting after transversus abdominis plane blockade (odds ratio: 0.39, 95% CI: 0.18-0.81). Conclusion:Adjuvant magnesium sulfate enhanced the anesthetic effects of local anesthetics and improved postoperative analgesia following the perineural blockade.

Magnesium Sulfate in Pediatric Abdominal Cancer Surgery: Safety and Efficacy in Ultrasound-Guided Transversus Abdominis Plane (US-TAP) Block in Conjugation with Levobupivacaine

“…Similar to our findings, Zeng et al discovered that adjuvant MgSO4 significantly decreased the total amount of analgesics consumed on the first postoperative day relative to the control group; 23 a subgroup analysis showed that MgSO4 significantly decreased the total quantity of analgesics consumed in TAP blockade patients. 21 Additionally, earlier research found that a single 50 mg bolus dose of MgSO4 given to children for caudal analgesia was effective in preventing intraoperative distress and delaying the beginning of postoperative pain.…”

Adductor Canal Blocks With Bupivacaine and Magnesium After Same-day Discharge Total Knee Arthroplasty Improve Postoperative Pain Relief and Decrease Opioid Consumption

“…In a recent meta-analysis of randomized controlled trials that evaluated 22 trials involving 1453 patients, Zeng and colleagues concluded that the addition of magnesium as an adjuvant to peripheral nerve blocks prolonged the total duration of sensory blockade, reduced VAS scores at 6 and 12 hours postsurgery, and reduced analgesic use in the first 24 hours postsurgery. The authors also reported a 44% reduction in the incidence of nausea and vomiting in patients receiving magnesium as an adjuvant to local anesthetic compared with patients receiving local anesthetic alone (95% confidence interval: 0.35-0.92, I 2 =0%; P =0.02) 27…”

“…The authors also reported a 44% reduction in the incidence of nausea and vomiting in patients receiving magnesium as an adjuvant to local anesthetic compared with patients receiving local anesthetic alone (95% confidence interval: 0.35-0.92, I 2 = 0%; P = 0.02). 27 Despite significant evidence supporting the use of magnesium in peripheral nerve blocks, not all reports support using magnesium as an adjunct. Zoratto et al, 28 in a prospective randomized control trial studying the addition of magnesium to ropivacaine in ACBs for TKA, reported no analgesic benefit when compared with the control group that only received a ropivacaine ACB.…”

Superficial Parasternal Intercostal Plane Blocks (SPIB) With Buprenorphine, Magnesium, and Bupivacaine for Management of Pain in Coronary Artery Bypass Grafting

“…The addition of magnesium and buprenorphine, individually as adjuvants to local anesthetic during regional anesthesia, has been shown to increase the duration of regional blocks, decrease pain scores, decrease opioid consumption, and decrease side effects from increased opioid consumption [28][29][30]. However, there are very few studies examining the addition of adjuvant medications to local anesthetic in regional anesthesia specifically for cardiac surgery.…”