Efficacy of magnesium as an adjuvant to bupivacaine in 3-in-1 nerve block for arthroscopic anterior cruciate ligament repair

Abstract

Background and Aims:Three-in-one and femoral nerve blocks are proven modalities for postoperative analgesia following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to evaluate the efficacy of magnesium (Mg) as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction.Methods:Sixty patients undergoing arthroscopic ACL reconstruction were randomly allocated to Group I (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of intravenous [IV] saline), Group II (3-in-1 block with 30 ml of 0.25% bupivacaine preceded by 1.5 ml of solution containing 150 mg Mg IV) or Group III (3-in-1 block with 30 ml containing 0.25% bupivacaine and 150 mg of Mg as adjuvant preceded by 1.5 ml of IV saline). Post-operatively, patients received morphine when visual analogue scale (VAS) score was ≥4. Quantitative parameters were compared using one-way ANOVA and Kruskal–Wallis test and qualitative data were analysed using Chi-square test.Results:Demographics, haemodynamic parameters, intra-operative fentanyl requirement, post-operative VAS scores and total morphine requirement were comparable between groups. Time to first analgesic requirement was significantly prolonged in Group III (789 ± 436) min compared to Group I (466 ± 290 min) and Group II (519 ± 274 min), (P = 0.02 and 0.05). Significantly less number of patients in Group III (1/20) received morphine in the first 6 h post-operatively, compared to Group I (8/20) and Group II (6/20) (P = 0.008 and 0.03). No side effects were observed.Conclusion:Mg as an adjuvant to bupivacaine in 3-in-1 block for ACL reconstruction significantly prolongs the time to first analgesic requirement and reduces the number of patients requiring morphine in the immediate post-operative period.

Magnesium for Pain Treatment in 2021? State of the Art

“…In post-operative pain, 49 RCTs studied the effectiveness of Mg in reducing pain (VAS) and/or on analgesics consumption (40 RCTs explored both parameters, 4 explored pain evolution only and 5 analgesics use only) [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ]; 44/49 RCTs explored the efficacy of Mg on the evolution of post-operative pain [ 33 , …”

“…A number of RCTs (16) did not show however any efficacy of Mg on pain [ 36 , 38 , 42 , 44 , 50 , 56 , 57 , 61 , 62 , 66 , 70 , 72 , 73 , 75 , 77 , 81 ]. Six intravenous Mg sulphate regimens ranging from non-bolus infusion to 50 mg/kg bolus followed by infusion showed no efficacy on pain.…”

“…Six intravenous Mg sulphate regimens ranging from non-bolus infusion to 50 mg/kg bolus followed by infusion showed no efficacy on pain. Concerning RCTs without bolus administration, four RCTs were negative with an infusion of 5 mg/kg during surgery in 60 subjects [ 36 ], with an infusion of 50 mg/kg during surgery in 50 subjects [ 44 ] and 75 subjects [ 38 ], and with an infusion of 150 mg/kg during surgery [ 42 ]. Concerning bolus administration of 50 mg/kg, five RCTs showed no efficacy on reduction of post-operative pain: two RCTs with an infusion of 8 mg/kg/h in 46 [ 62 ] and 60 subjects [ 61 ], one RCT with an infusion of 10 mg/kg/h for 24 h in 40 subjects [ 57 ] and two RCTs with an infusion of 15 mg/kg/h in 58 subjects [ 50 ] and 62 subjects [ 56 ] over 24 and 72 h. With a 40 mg/kg bolus followed by a 10 mg/kg/h infusion, no pain improvement was observed over 24 h in 40 subjects [ 66 ].…”

“…In post-operative pain, 49 RCTs studied the effectiveness of Mg in reducing pain (VAS) and/or on analgesics consumption (40 RCTs explored both parameters, 4 explored pain evolution only and 5 analgesics use only) ; 44/49 RCTs explored the efficacy of Mg on the evolution of post-operative pain [33][34][35][36][37][38][41][42][43][44][45][46][47][49][50][51][52][53][54][55][56][57][58][59][61][62][63][64][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] (n = 2988). Twenty-nine studies observed a significant decrease of VAS post-operative pain following intravenous administration of Mg sulphate (ranging from -2/10 [36] to −4/10 [58] at 12 h) compared to placebo or conventional treatment group [33]…”

Application of dexamethasone as an adjuvant to the local anesthetic in the performance of a US-guided femoral block for postoperative analgesia on patients after total knee joint replacement

“…Several reports in the literature on topic adjuvants to local anesthetics commented on magnesium sulphate as a prolonged PNB agent and better results on the visual acuity scale (VAS) pain assessment and a total dose of added analgesics (22,23). Magnesium demonstrates an antinociceptive effect in animal models and in humans.…”