A comparative evaluation of magnesium sulphate and nitroglycerine as potential adjuncts to lidocaine in intravenous regional anaesthesia

Abstract

Introduction:This randomized control trial was carried out to evaluate and compare the efficacy of magnesium sulphate and nitroglycerine (NTG) as adjuncts to lidocaine in intravenous regional anesthesia (IVRA).Materials and Methods:Seventy-five, ASA grade I and II patients, aged between 20–50 years, scheduled for hand and forearm surgery were selected and entered randomly into three study groups. Patients in group C received 3 mg/kg of preservative free lidocaine 2% diluted with saline to a total volume of 40 ml. Patients in group M received 3 mg/kg of preservative free lidocaine 2% mixed with 6 ml of 25% magnesium sulphate (1.5 g) diluted with saline to a total volume of 40 ml. Patients in group N received 3 mg/kg of preservative free lidocaine 2% mixed with 200 μg of nitroglycerine diluted with saline to a total volume of 40 ml. Sensory and motor block onset and recovery time, tourniquet pain onset time, intraoperative fentanyl requirement, the total number of patients requiring rescue analgesia and the time to first analgesia requirement, intra-operative and postoperative degree of analgesia were evaluated.Results:The sensory and motor block onset times were shorter in group M and N as compared to group C (P- = 0.004, 0.0036 for sensory block, 0.021, 0.038 for motor block. The mean time of onset of sensory block was earliest in group M and the mean time of onset of motor block was earliest in group N. Mean time of onset of tourniquet pain in the three groups was similar in groups M and N. The sensory and motor block recovery time were significantly prolonged in M and N group as compared to group C (P < 0.001). Intraoperative fentanyl requirement (P value– = 0.041), the total number of patients requiring rescue analgesia (P value = 0.009) and the time to first analgesia requirement (P value = 0.038) were lower in group M.Conclusion:The addition of both magnesium suphate and nitroglycerin (NTG) to lidocaine for intravenous regional anesthesia (IVRA) leads to early onset of sensory block and prolonged postoperative analgesia, with no side effects.

Evaluation of Analgesic Effect of Magnesium Sulphate in Intravenous Regional Anaesthesia- A Double Blind Study

“…A similar study showed that addition of magnesium sulphate and nitroglycerine to lignocaine for IVRA leads to early onset of sensory block. 7 A study was done where magnesium sulphate as an adjunct to lignocaine for IVRA shorten the onset of sensory and motor block. 8 In our study we observed that the total dose of lignocaine required to achieve surgical anaesthesia was significantly lower in magnesium group compared to the saline group.…”

A dose-finding randomised controlled trial of magnesium sulphate as an adjuvant in ultrasound-guided supraclavicular brachial plexus block

“…[18] used 150 mg of MgSO 4 in supraclavicular brachial plexus block, whereas Bansal et al . [19] used 1.5 g of MgSO 4 in intravenous regional anaesthesia (IVRA), without any reported side effect and neurotoxicity.…”

“…The findings of our study were in accordance with a study by Bansal et al . [19] In another study,[18] no statistical significance was observed in the onset time of sensory and motor block with magnesium (150 mg) used as an adjuvant to ropivacaine. This could be because the larger volume of local anaesthetic (30 ml) used in the study lead to a reduced effective concentration of magnesium.…”

Different adjuvants to lidocaine in bier’s block; comparison between ketamine, nitroglycerin, and magnesium

“…Bansal et al [14], compared the effect of adding 1.5 gram magnesium sulphate versus 200 µg nitroglycerin as adjuvant to lidocaine in intravenous regional block on seventy-five patients scheduled for hand and forearm surgeries and they found that both of magnesium and nitroglycerin accelerated the onset of sensory and motor block, prolonged the duration of sensory and motor block, and decreased the postoperative analgesic request without any side effects.…”