Tehran University Medical Journal

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Background: Propofol, an anesthetic noted to give rapid recovery, causes discomfort at the site of injection. A number of methods to reduce propofol-induced pain have been tried, including pretreatment with lidocaine, with varying results. Here, we evaluate the efficacy of magnesium sulfate compared to that of lidocaine and normal saline in mitigating propofol-induced pain.
Methods: One hundred ASA I and II adults, aged 20-50 years, scheduled for elective surgery requiring two IV lines with 20-gauge cannulae in the dorsum of each hand, were enrolled in this study. The patients were randomly placed into two groups of 50 patients. In each patient, one hand was the case study and other hand was the control. Group A received 10% magnesium sulfate in one hand and normal saline in the other hand. Group B received 10% magnesium sulfate in one hand and 1% lidocaine in the other hand. All injections had a volume of 2 ml. After 30 seconds, 2 cc of 1% propofol was injected simultaneously into each hand. Pain was assessed according to the VAS rating system, ranging from 0 (no pain) to 10 (the most severe pain), with a minimum interval of 3 as significant pain. Data were analyzed by chi-square and independent t tests. A P value <0.05 was considered significant.
Results: In Group A, the mean pain in the hand premedicated with magnesium was 1.46±1.07, compared to 4.54±2.15 for that of the other hand that had received normal saline (P=0.001). In group B, the mean pain in the hand that had received magnesium was 0.82±1.34, compared to 0.78±1.07 for that of the other hand, which had received lidocaine (P=0.86).
Conclusion: Intravenous magnesium and lidocaine pretreatments are equally effective in attenuating propofol-induced pain, and were better than normal saline in attenuating propofol-induced pain.

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Background: Magnesium Sulfate (MgSO4) has been used as a pharmacologic agent in different situations for many years in the treatment of tachyarrhythmias, myocardial ischemia, preeclampsia, and tocolysis among others. The analgesic effect of MgSO4 for postoperative pain has been used since the 1990s. Postoperative pain is one of the most common complications in the perioperative period and can result in serious consequences in different organs if left untreated. Inguinal herniorrhaphy is among the most common surgeries and is almost always accompanied by severe pain. The object of this study is to determine the effect of a pre-induction infusion of MgSO4 on the reduction of postsurgical pain after herniorrhaphy.
Methods: This double-blind, randomized clinical trial included 105 ASA class I and class II herniorrhaphy patients at Shariati Hospital in years 2004 and 2005. For statistical analysis, the 2 and T tests were used. The patients were divided into three groups based on block randomization. Patients in the following groups received: Group A, 200 ml of normal saline infusion (placebo) Group B, 25 mg/kg MgSO4 in 200 ml of normal saline Group C, 50 mg/kg MgSO4 in 200 ml of normal saline. All groups were infused twenty minutes before induction of anesthesia using identical methods and dosage in all three groups. Heart rate and mean arterial pressure (MAP) at pre- and postintubation and so at skin incision time were charted. Visual analog scale (VAS) pain score, nausea, vomiting and the amount of morphine used before recovery room discharge and in six, twelve and twenty-four hours after recovery discharge was recorded.
Results: The average age for the different groups was as follows: Group A: 33.6, Group B: 37.37, Group C: 32.74. Nausea and vomiting between the case and control groups were not statistically different (60% vs. 71.4%, p=0.0499), nor was the amount of Morphine used. On recovery room discharge, the VAS scores were 8.1, 7.2, and 5.5 for the first, second and third groups, respectively (P<0.001). However, no statistical significance was found for the VAS scores six hours after recovery room discharge.
Conclusion: The results in this study show that pre-induction with MgSO4 has no remarkable effect on decreasing postoperative pain or morphine use for inguinal herniorrhaphy.

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Background: Sore throat after surgery is the second most common cause of complications in recovery. It causes decreased patient satisfaction, and it affects patients’ well-being after surgery. The aim of this study was to compare the effects of ketamine and magnesium sulfate gargle on sore throat after laminectomy.
Methods: In this randomized clinical trial, 69 candidates for laminectomy patients in Shohade-Tajrish hospital from June 2021 to December 2022 were randomly assigned to three groups of ketamine (n=25), magnesium (n=23) and control (n=21). The Magnesium group received magnesium sulfate gargle (30 mg/kg in a total of 30 ml 5% Dextrose water), Ketamine gargle (0.5 mg/kg in a total of 30 ml 5% Dextrose water), and the control group received 30 ml 5% Dextrose water gargle. Standard similar anesthesia protocols were applied for all patients. In PACU (0) and 2, 4, 24 hours afterward sore throat was assessed using a visual analog scale (VAS) scoring. Conclusion: The preventive effect of "magnesium sulfate gargle" on sore throat after laminectomy is much better than "ketamine" or "placebo" gargle.