I.V. infusion of magnesium sulphate during spinal anaesthesia improves postoperative analgesia

Efficacy of dexmedetomidine versus magnesium sulfate as an adjuvant to intraperitoneal bupivacaine in pediatric laparoscopic surgery: a randomized clinical trial

BACKGROUND

We evaluated the efficacy of dexmedetomidine versus magnesium sulfate as an adjuvant to intraperitoneal (IP) bupivacaine in pediatric laparoscopic inguinal herniorrhaphy.

METHODS

Ninety-seven male children, ASA I-II, 1-6 years old, undergoing laparoscopic inguinal herniorrhaphy, were randomized to receive before peritoneal insufflation, IP 2 mg.kg-1 bupivacaine 0.5% combined with either 1 μg.kg-1 of dexmedetomidine (Group D), 30 mg.kg-1 of magnesium sulfate (Group M), or normal saline (Group C). All tested drugs were diluted to the volume of 10 mL with normal saline. FLACC pain scores, need for rescue analgesics, time to flatus and first stool, emetic events, adverse effects, functional recovery, and parents' satisfaction were recorded for the first 48 h postoperatively.

RESULTS

FLACC scores were significantly higher in Group C than in the other two groups at 6, 8, 12, 18, 24, and 48 hours after surgery with no differences between Groups D and M. Rescue analgesia was significantly higher in Group C with none of the children in Groups D and M requiring rescue analgesia (p = 0.001). Times to first flatus and stool, emetic events, and adverse effects did not differ among groups. Times to return to normal functional activity were comparable in all groups. Parents' satisfaction was greater in Groups D and M than in Group C (p = 0.026).

CONCLUSION

Dexmedetomidine and magnesium sulfate added to IP bupivacaine improved the analgesia afforded by bupivacaine in the first two postoperative days in children scheduled for laparoscopic herniorrhaphy.

Magnesium Sulfate Versus Lidocaine as an Adjunct for Renal Colic in the Emergency Department: A Randomized, Double-Blind Controlled Trial

STUDY OBJECTIVE

We wished to determine whether the addition of magnesium sulfate (MgSO4) or lidocaine to diclofenac could improve the analgesic efficacy in emergency department (ED) patients with acute renal colic.

METHODS

In this prospective, double-blinded, randomized controlled trial of patients aged 18 to 65 years with suspected acute renal colic, we randomized them to receive 75 mg intramuscular (IM) diclofenac and then intravenous (IV) MgSO4, lidocaine, or saline solution control. Subjects reported their pain using a numerical rating scale (NRS) before drug administration and then 5, 10, 20, 30, 60, and 90 minutes afterwards. Our primary outcome was the proportion of participants achieving at least a 50% reduction in the NRS score 30 minutes after drug administration.

RESULTS

We enrolled 280 patients in each group. A 50% or greater reduction in the NRS score at 30 minutes occurred in 227 (81.7%) patients in the MgSO4 group, 204 (72.9%) in the lidocaine group, and 201 (71.8%) in the control group, with significant differences between MgSO4 and lidocaine (8.8%, 95% confidence interval [CI] [1.89 to 15.7], P=.013) and between MgSO4 and control (9.9%, 95% CI [2.95 to 16.84], P=.004). Despite this, differences between all groups at every time point were below the accepted 1.3 threshold for clinical importance. There were no observed differences between groups in the frequency of rescue analgesics and return visits to the ED for renal colic. There were more adverse events, although minor, in the MgSO4 group.

CONCLUSION

Adding intravenous MgSO4, but not lidocaine, to IM diclofenac offered superior pain relief but at levels below accepted thresholds for clinical importance.

The impact of magnesium on shivering incidence in cardiac surgery patients: A systematic review

Background and objective

This scientific review involves a sequential analysis of randomized trial research focused on the incidence of shivering in patients undergoing cardiac surgery. The study conducted a comprehensive search of different databases, up to the end of 2020. Only randomized trials comparing magnesium administration with either placebo or no treatment in patients expected to experience shivering were included. The primary objective was to evaluate shivering occurrence, distinguishing between patients receiving general anesthesia and those not. Secondary outcomes included serum magnesium concentrations, intubation time, post-anesthesia care unit stay, hospitalization duration, and side effects. Data collection included patient demographics and various factors related to magnesium administration.

Material and methods

This scientific review analyzed 64 clinical trials meeting inclusion criteria, encompassing a total of 4303 patients. Magnesium was administered via different routes, primarily intravenous, epidural, and intraperitoneal, and compared against placebo or control. Data included demographics, magnesium dosage, administration method, and outcomes. Heterogeneity was assessed using the I2 statistic. Some studies were excluded due to unavailability of data or non-responsiveness from authors.

Result

and discussion: Out of 2546 initially identified articles, 64 trials were selected for analysis. IV magnesium effectively reduced shivering, with epidural and intraperitoneal routes showing even greater efficacy. IV magnesium demonstrated cost-effectiveness and a favorable safety profile, not increasing adverse effects. The exact dose-response relationship of magnesium remains unclear. The results also indicated no significant impact on sedation, extubation time, or gastrointestinal distress. However, further research is needed to determine the optimal magnesium dose and to explore its potential effects on blood pressure and heart rate, particularly regarding pruritus prevention.

Conclusion

This study highlights the efficacy of intravenous (IV) magnesium in preventing shivering after cardiac surgery. Both epidural and intraperitoneal routes have shown promising results. The safety profile of magnesium administration appears favorable, as it reduces the incidence of shivering without significantly increasing costs. However, further investigation is required to establish the ideal magnesium dosage and explore its potential effects on blood pressure, heart rate, and pruritus prevention, especially in various patient groups.

Prevention of Shivering Post Subarachnoid Block: Comparison between Different Doses of Intravenous Magnesium Sulphate

Background and Objectives: Shivering is a common complication of subarachnoid block (SAB). Magnesium sulphate has been proven to be effective in preventing shivering. The aim of this study was to compare the effectiveness and adverse effects in hemodynamic parameters between 50 mg/kg and 30 mg/kg of intravenous magnesium sulphate for prevention of shivering post-subarachnoid block. Materials and Methods: Eighty-six patients scheduled for surgery under SAB, aged between 18 to 65 years old with American Society of Anesthesiologists physical status I and II were randomised into two groups. Group A received a bolus of 50 mg/kg, while Group B received 30 mg/kg of intravenous magnesium sulphate, given over a 20 min duration following SAB. Shivering grade was recorded intraoperatively according to the Crossley and Mahajan shivering scale. Mean arterial pressure (MAP), heart rate, tympanic temperature, oxygen saturation and the use of vasopressors were recorded. Results: Forty-five percent of patients in Group A and 20% of patients in Group B did not exhibit shivering (p-value < 0.01). High-grade shivering was observed in 12.5% in Group A and 40% in Group B, respectively (p-value 0.02). The MAP trend was lower in Group B (p-value < 0.01), but the incidence of hypotension was not significant in both groups. The use of vasopressors was also similar between groups. Group B showed a lower oxygen saturation trend (p-value 0.04). The trends of heart rate and tympanic temperature were not significant in both groups. No patients had episodes of bradycardia or oxygen desaturation. Conclusions: In this study, intravenous magnesium sulphate 50 mg/kg is the lowest effective dose for prevention and treatment of high-grade shivering post-SAB without significant hemodynamic adverse events.

Effect of intravenous magnesium on postoperative pain control for major abdominal surgery: a randomized double-blinded study

Background

This study aimed to evaluate the postoperative analgesic effect of magnesium sulfate during abdominal surgery.

Methods

This randomized double-blinded study involved 84 patients candidates for abdominal surgery into two same groups. In the magnesium group, at first 25 mg/kg/1 h magnesium sulfate; and then, 100 mg/kg/24 h was infused in the intensive care unit. The pain intensity (the primary outcome), was assessed using the numeric rating scale (NRS) every 3 h. If the NRS was > 3, morphine (as a secondary outcome) was used and evaluated. The results were analyzed using SPSS ver. 19 software, and statistical significance was set at P < 0.05

Results

Demographic parameters were similar between the groups. The pain intensity were similar at first and then at the third hour in both groups (P = 0.393 and P = 0.172, respectively), but thereafter between 6 and 24 h, the pain severity was significantly lower in the magnesium group (4.4 ± 1.3 in the control and 3.34 ± 1 in the magnesium group at 6th hour and P = 0.001). In addition, morphine intake in the first 24 h in the two groups had a significant difference, with 13.2 ± 5.7 mg in control group and 8 ± 3.5 mg in magnesium group (P = 0.001).

Conclusions

In this study, intravenous magnesium sulfate after abdominal surgeries for 24 h resolved the pain intensity after six hours and reduced morphine dosage.

Effect of Intraoperative Magnesium Sulfate Administration on Blood Glucose Control following Total Joint Arthroplasty in Patients with Diabetes

Magnesium deficiency, which is known to be highly prevalent among patients with diabetes, has been associated with insulin resistance and poor glucose control. Here, we aimed to investigate the effects of intraoperative magnesium administration on postoperative glucose control in patients with diabetes. We retrospectively reviewed the medical records of patients with type 2 diabetes who had undergone total joint arthroplasty at a tertiary hospital, where intraoperative magnesium sulfate injections were frequently performed for postoperative analgesia. The patients were grouped based on whether treated with magnesium or not (magnesium vs. control groups). We investigated postoperative blood glucose levels and sliding scale insulin requirements. After propensity matching, 170 patients were allotted to each group. Both the mean glucose level and the incidence of a mean glucose level of >200mg/dL were significantly lower in the magnesium group than in the control group (p = 0.040 and 0.013, respectively). There was also a lower insulin requirement in the magnesium group (p = 0.043). Multivariate logistic regression revealed that magnesium treatment was significantly related to a less frequent incidence of a mean blood glucose level of >200 mg/dL (p = 0.047). This study demonstrated that magnesium sulfate infusion was associated with an improved postoperative blood glucose profile in patients with diabetes.

Evaluation of the Effects of Oral Magnesium Sachet on the Prevention of Spinal Anesthesia-Induced Headache After Cesarean Section: A Randomized Clinical Trial

Background: Post-dural puncture headache (PDPH) is a common complication of spinal anesthesia. It often goes away after a few days but may be more severe in some patients and persists for weeks. Objectives: This study aimed to evaluate the effect of oral magnesium on the prevention of PDPH after cesarean section for the first time. Methods: In this double-blind, randomized clinical trial, 100 candidates for elective cesarean section under spinal anesthesia were randomly divided into 2 groups: (i) the intervention group that received 300 mg of oral magnesium powder and (ii) the control group that received starch powder. The frequency and severity of headache and amount of analgesic consumption in both groups were measured 1, 2, and 3 days after cesarean section. Data were analyzed using SPSS version 22 at 95% CI. Results: The frequency of PDPH 1, 2, and 3 days after surgery was 8% vs 24% (P = 0.029), 10% vs 26% (P = 0.039), and 12% vs 18% (P = 0.401) in the intervention and control groups, respectively. The mean and SD of pain severity was 0.52 ± 1.83 vs 1.5 ± 2.84 (P = 0.03) on the first day, 0.70 ± 2.19 vs 1.58 ± 2.86 (P = 0.05) on the second day, and 0.82 ± 2.32 vs 1.18 ± 2.62 on the third day (P = 0.43) in the intervention and control groups, respectively. Although more patients in the control group received rescue analgesia, no significant difference was seen between the 2 study groups. Conclusions: In women candidates for cesarean section, oral administration of 300 mg magnesium 2 hours before surgery significantly reduces the frequency and severity of PDPH, but its impact on reducing analgesic consumption is not significant.

The effect of intravenous magnesium on postoperative morphine consumption in noncardiac surgery: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Several studies suggest that systemic magnesium reduces postoperative opioid consumption and the intensity of pain, but others report conflicting results. The efficacy and safety profile of intravenous magnesium in noncardiac surgery remain uncertain.

OBJECTIVES

The aim of this review was to investigate the effect of intravenous magnesium on the consumption of postoperative morphine in the first 24 h in adults undergoing noncardiac surgery.

DESIGN

Systematic review and meta-analysis with trial sequential analysis.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL from their inception until January 2019.

ELIGIBILITY CRITERIA

All randomised clinical trials comparing intravenous magnesium versus placebo in noncardiac surgery were systematically searched in the databases. Observational studies, case reports, case series and nonsystematic reviews were excluded.

RESULTS

Fifty-one trials (n=3311) were included for quantitative meta-analysis. In comparison with placebo, postoperative morphine consumption at 24-h was significantly reduced in the magnesium group, with a mean difference [95% confidence interval (CI)] of -5.6 mg (-7.54 to -3.66, P < 0.001, I = 92%, level of evidence low). The trial sequential analysis for the effect of magnesium on postoperative morphine consumption was conclusive. Patients who received magnesium had a longer time to the first analgesia request [143 (103 to 183) min, P < 0.001, I = 99%, level of evidence low] and a lower incidence of shivering [0.26 (0.15 to 0.44), P < 0.001, I = 35%, level of evidence very low]. However, no significance differences were demonstrated in postoperative pain scores in the first 24 h (mean difference, 95% CI) -0.30 (-0.69 to 0.09, P = 0.13, I = 91%, level of evidence low), bradycardia (odds ratio, 95% CI) 1.13 (0.43 to 2.98, P = 0.80, I = 35%, level of evidence very low) and postoperative nausea and vomiting (odds ratio, 95% CI) 0.90 (0.67 to 1.22, P = 0.49, I = 25%, level of evidence moderate).

CONCLUSION

The current meta-analysis demonstrates that the use of intravenous magnesium as part of multimodal analgesia may reduce morphine consumption in the first 24 h after surgery and delay the time to the first request for analgesia in patients undergoing noncardiac surgery. However, the included studies were of low-quality with substantial heterogeneity.

TRIAL REGISTRATION

CRD42018086846.

Magnesium for Pain Treatment in 2021? State of the Art

Background: Magnesium (Mg) is commonly used in clinical practice for acute and chronic pain and has been reported to reduce pain intensity and analgesics consumption in a number of studies. Results are, however, contested. Objectives: This review aims to investigate randomised clinical trials (RCTs) on the effectiveness of Mg treatment on pain and analgesics consumption in situations including post-operative pain, migraine, renal pain, chronic pain, neuropathic pain and fibromyalgia. Results: The literature search identified 81 RCTs (n = 5447 patients) on Mg treatment in pain (50 RCTs in post-operative pain, 18 RCTs in migraine, 5 RCTs in renal pain, 6 RCTs in chronic/neuropathic pain, 2 RCTs in fibromyalgia). Conclusion: The level of evidence for the efficacy of Mg in reducing pain and analgesics consumption is globally modest and studies are not very numerous in chronic pain. A number of gaps have been identified in the literature that need to be addressed especially in methodology, rheumatic disease, and cancer. Additional clinical trials are needed to achieve a sufficient level of evidence and to better optimize the use of Mg for pain and pain comorbidities in order to improve the quality of life of patients who are in pain.

Association between ionized magnesium and postoperative shivering

PURPOSE

Ionized magnesium (iMg) is considered to be the biologically active fraction of circulating total serum Mg (tMg). However, only the relationship between tMg and postoperative shivering has been studied. To our knowledge, hitherto no clinical studies have investigated the association between serum ionized magnesium concentration ([iMg]) and postoperative shivering. Therefore, we aimed to retrospectively examine this association, focusing on hypomagnesemia and depletion of [iMg].

METHODS

This retrospective study involved 421 patients who underwent pancreaticoduodenectomy under general anesthesia at our center from December 2012 to September 2019. Logistic regression analysis was performed to estimate the odds ratio (OR) for the incidence of postoperative shivering.

RESULTS

Postoperative shivering developed in 111 out of 421 patients. The post-surgical concentration of [iMg] was significantly associated with postoperative shivering in the non-adjusted model, but not in the multivariable-adjusted model. In multivariable-adjusted analysis, progressive decrease of [iMg] by 0.1 mmol/L significantly increased the risk of postoperative shivering (OR: 1.64, 95% CI 1.02-2.64, p = 0.04). The multivariable-adjusted OR for postoperative shivering was 3.65 (95% CI 1.25-13.55, p = 0.02) in subjects with post-surgical [iMg] less than 0.6 mmol/L and decrease in [iMg] during surgery compared with those with post-surgical [iMg] more than 0.6 mmol/L and constant or increased of [iMg] during surgery.

CONCLUSION

A decrease in the [iMg] during surgery was significantly associated with postoperative shivering. Subjects who had an [iMg] lower than 0.6 mmol/L post-surgery and decreased [iMg] during surgery had a significantly higher risk of postoperative shivering. Intraoperative depletion of [iMg] was significantly associated with shivering.

Intra-articular magnesium to alleviate postoperative pain after arthroscopic knee surgery: a meta-analysis of randomized controlled trials

Objective

We aimed to evaluate the safety and efficacy of intra-articular (IA) magnesium (Mg) for postoperative pain relief after arthroscopic knee surgery.

Methods

We searched PubMed, Embase, Medline, Cochrane library, and Web of Science to identify randomized controlled trials that compared postoperative pain outcomes with or without IA Mg after knee arthroscopy. The primary outcomes were pain intensity at rest and with movement at different postoperative time points and cumulative opioid consumption within 24 h after surgery. Secondary outcomes included the time to first analgesic request and side effects.

Results

In total, 11 studies involving 677 participants met the eligibility criteria. Pain scores at rest and with movement 2, 4, 12, and 24 h after surgery were significantly lower, doses of supplementary opioid consumption were smaller, and the time to first analgesic requirement was longer in the IA Mg group compared with the control group. No significant difference was detected regarding adverse reactions between the groups.

Conclusions

Intra-articular magnesium is an effective and safe coadjuvant treatment for relieving postoperative pain intensity after arthroscopic knee surgery.

Protocol registration at PROSPERO: CRD42020156403.

Effects of magnesium sulfate administration in attenuating chronic postsurgical pain in rats

Chronic postsurgical pain (CPSP) is a serious issue for many postoperative patients. Though there are numerous treatment options for the prevention of CPSP, none of them is optimal as the mechanisms of the transition from acute to chronic postoperative pain have not been elucidated. Ketamine and opioids have been administered for chronic postoperative pain treatment but induce severe adverse reactions and/or physical dependency. Here, we examined whether pre-administration of the nonselective N-methyl-d-aspartate (NMDA) receptor antagonist magnesium sulfate attenuates CPSP behavior and alters the expression of glutamate ionotropic receptor NMDA type subunit 1a (Grin1 mRNA) in a rat skin/muscle incision and retraction (SMIR) model. We assessed the effects of a single subcutaneous magnesium sulfate injection on nociceptive behaviors including guarding pain, mechanical hyperalgesia, and heat hypersensitivity in rats after SMIR surgery. We used reverse transcription-quantitative PCR (RT-qPCR) to evaluate Grin1 mRNA expression in the dorsal horn of the spinal cord on postoperative day 14. Compared with the vehicle, magnesium sulfate administration before SMIR surgery reduced mechanical hyperalgesia for 17 d Grin1 gene expression was significantly higher on the ipsilateral side than the contralateral side (P = 0.001) on postoperative day 14. The magnesium sulfate injection prevented Grin1 mRNA upregulation in the spinal cord dorsal horn. A single magnesium sulfate injection mitigated SMIR-induced mechanical hyperalgesia possibly by modulating Grin1 expression. Preoperative magnesium sulfate administration could prove to be a simple and safe CPSP treatment.

Antitussive effect of a magnesium infusion during anesthetic emergence in patients with double-lumen endotracheal tube: a randomized controlled trial

Background

A double-lumen endotracheal tube (DLT) inserted into the bronchus can stimulate the respiratory tracts, causing coughing. Opioids have been introduced to prevent emergence cough. However, the administration of a significant opioid dose at the end of surgery may result in undesirable events. Magnesium, common intracellular ion, suppress bronchial smooth muscle contraction and have antitussive effect. We investigated the antitussive effects of a magnesium infusion during anesthetic emergence in patients who underwent thoracic surgery requiring one-lung ventilation (OLV) anesthesia with a DLT.

Methods

One-hundred forty patients undergoing OLV anesthesia with a DLT were enrolled in this prospective, randomized double-blinded trial. In combination with a low dose of remifentanil, patients were randomly allocated to receive either magnesium sulphate (infusion of 15 mg/kg/hour after a single bolus of 30 mg/kg) or normal saline during the operation and emergence. Primary outcomes were the severity and incidence of cough during emergence.

Results

The severity of cough was assessed by the cough severity grading score: 0, no cough; 1, single cough; 2, cough persistence <5 seconds; 3, cough persistence ≥5 seconds. There was a significant difference in the severity score of cough between the groups [median (IQR): 2 (0 to 3) in control group vs. 0 (0 to 1) in magnesium group, P=0.003]. However, there was no significant difference in the overall incidence of cough between both groups [42 (64.6%) in control group vs. 31 (47.7%) in magnesium group, P=0.077].

Conclusions

Magnesium attenuated the severity of cough during emergence after OLV anesthesia using a DLT without adverse events.

Magnesium and Pain

In terms of antinociceptive action, the main mode of action of magnesium involves its antagonist action at the N-methyl-d-aspartate (NMDA) receptor, which prevents central sensitization and attenuates preexisting pain hypersensitivity. Given the pivotal function of NMDA receptors in pain transduction, magnesium has been investigated in a variety of pain conditions. The oral and parenteral administration of magnesium via the intravenous, intrathecal, or epidural route may alleviate pain and perioperative anesthetic and analgesic requirements. These beneficial effects of magnesium therapy have also been reported in patients with neuropathic pain, such as malignancy-related neurologic symptoms, diabetic neuropathy, postherpetic neuralgia, and chemotherapy-induced peripheral neuropathy. In addition, magnesium treatment is reportedly able to alleviate fibromyalgia, dysmenorrhea, headaches, and acute migraine attacks. Although magnesium plays an evolving role in pain management, better understanding of the mechanism underlying its antinociceptive action and additional clinical studies is required to clarify its role as an adjuvant analgesic.

Magnesium Sulfate Treatment During Total Knee Arthroplasty Decreases Postoperative Urinary Retention: A Retrospective Propensity Score-Matched Analysis

Postoperative urinary retention (POUR) is a common complication after total knee arthroplasty. Currently, there are no clinical data regarding the effects of magnesium sulfate on POUR. Here, we investigated the effects of intraoperative magnesium sulfate infusion in patients with POUR following total knee arthroplasty. We reviewed the medical records of patients who underwent elective unilateral total knee arthroplasty under spinal anesthesia between June 2016 and May 2018. The patients were grouped based on whether they were treated with magnesium (magnesium group) or not (control group). We investigated the incidence of POUR and the postoperative analgesic requirement. Totally, 483 patients were included in the analysis. After propensity score matching with the control group, the magnesium group showed a lower incidence of POUR (odds ratio, 0.49; 95% CI, 0.29–0.83; p = 0.011) and lesser opioid consumption (p = 0.049) than the control group. Multivariate logistic regression analysis revealed that intraoperative continuous infusion of magnesium (p = 0.008) and age (p = 0.001) were significantly related to the incidence of POUR. This retrospective observational study demonstrated that administration of magnesium sulfate was associated with a lower incidence of POUR following total knee arthroplasty.

Effects of Perioperative Magnesium Sulfate Administration on Postoperative Chronic Knee Pain in Patients Undergoing Total Knee Arthroplasty: A Retrospective Evaluation

We aimed to investigate whether perioperative magnesium sulfate administration was associated with the incidence of chronic persistent postoperative pain (PPP) following total knee arthroplasty (TKA). This retrospective observational study was performed at a single tertiary academic hospital. We reviewed the medical records of adult patients who were admitted between August 2012 and July 2017. Patients who received magnesium sulfate during surgery were the magnesium group. The presence of PPP, one year after TKA, was evaluated using a binary logistic regression analysis. A total of 924 patients were included in the analysis, and 148 patients (16.0%) experienced PPP one year after TKA. In the multivariable model, the magnesium group had a 62% lower rate of PPP one year after TKA compared to the control group (odds ratio (OR): 0.38, 95% confidence interval (CI): 0.16 to 0.90; p = 0.027). This finding was similar in the sensitivity analysis using propensity score adjustment (OR: 0.38, 95% CI: 0.16 to 0.93; p = 0.036). We showed that perioperative magnesium sulfate administration was associated with a lower rate of PPP one year after TKA. Our results suggest that magnesium sulfate administered perioperatively is effective for the alleviation of acute and chronic pain after surgery.

Different Analgesic Routes of Magnesium Sulfate: Intravenous versus Pectoralis II Interfascial Plane Block for Breast Cosmetic Surgeries

Purpose

The purpose of the study is to evaluate the most effective analgesic route of magnesium sulfate (MgSO₄) either intravenous (i.v.) or pectoralis interfascial plane block.

Patients and Methods

Fifty adult female patients were divided into two equal groups: i.v. MgSO₄ and Pecs II block MgSO₄ (Pecs MgSO₄) group. After general anesthesia, in i.v. MgSO₄ group, the local anesthetic (LA) for Pecs II block was prepared by adding 3 mL saline to 57 mL bupivacaine 0.25% divided equally for each side. A bolus i.v. solution of MgSO₄ 10% 0.5 mL.kg^-1 diluted in saline in a total volume of 100 mL was given over 15 minutes. Then, the solution for continuous i.v. infusion; 30 mL MgSO₄ 10% and 70 mL saline was infused at the rate of 0.5 mL.kg^-1.h^-1 intraoperatively. For PecsMgSO₄ group, LA formed of 3 mL MgSO₄ 10% added to 57 mL bupivacaine 0.25%. Whereas, 100 mL saline was given as bolus i.v. followed by continuous infusion of 100 mL normal saline at the rate of 0.5 mL.kg^-1.h^-1.

Results

In the group received MgSO₄-bupivacaine Pecs II block, there was a nonsignificant decrease in postoperative morphine consumption compared to i.v. administration of MgSO₄. The two groups were comparable in the intensity of pain and sedation scores.

Conclusion

The use of bupivacaine Pecs II block enhanced with addition of MgSO₄ to pectoralis interfascial plane block or intravenously in patients underwent breast cosmetic surgeries under general anesthesia was associated with comparable results of the postoperative morphine requirements, intensity of postoperative pain, and extension of the duration of postoperative analgesia. The intraoperative hemodynamic effects i.v. MgSO₄ were superior to the pectoralis interfascial plane route of administration.

Effectiveness of Magnesium in Preventing Shivering in Surgical Patients: A Systematic Review and Meta-analysis

BACKGROUND

Clinical trials regarding the antishivering effect of perioperative magnesium have produced inconsistent results. We conducted a systematic review and meta-analysis with Trial Sequential Analysis to evaluate the effect of perioperative magnesium on prevention of shivering.

METHODS

We searched PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and 2 registry sites for randomized clinical trials that compared the administration of magnesium to a placebo or no treatment in patients undergoing surgeries. The primary outcome of this meta-analysis was the incidence of shivering. The incidence of shivering was combined as a risk ratio with 95% CI using a random-effect model. The effect of the route of administration was evaluated in a subgroup analysis, and Trial Sequential Analysis with a risk of type 1 error of 5% and power of 90% was performed. The quality of each included trial was evaluated, and the quality of evidence was assessed using the Grading of Recommendation Assessment, Development, and Evaluation approach. We also assessed adverse events.

RESULTS

Sixty-four trials and 4303 patients (2300 and 2003 patients in magnesium and control groups, respectively) were included. The overall incidence of shivering was 9.9% in the magnesium group and 23.0% in the control group (risk ratio, 0.42; 95% CI, 0.33-0.52). Subgroup analysis revealed that the incidence of shivering was lower with IV (risk ratio, 0.29; 95% CI, 0.29-0.54; Grading of Recommendation Assessment, Development, and Evaluation, moderate), epidural (risk ratio, 0.24; 95% CI, 0.13-0.43; Grading of Recommendation Assessment, Development, and Evaluation, low), and intrathecal administration (risk ratio, 0.64; 95% CI, 0.43-0.96; Grading of Recommendation Assessment, Development, and Evaluation, moderate). Only trials with low risk of bias were included for Trial Sequential Analysis. The Z-cumulative curve for IV magnesium crossed the Trial Sequential Analysis monitoring boundary for benefit even though only 34.9% of the target sample size had been reached. The Z-cumulative curve for epidural or intrathecal administration did not cross the Trial Sequential Analysis monitoring boundary for benefit. No increase in adverse events was reported.

CONCLUSIONS

Perioperative IV administration of magnesium effectively reduced shivering and Trial Sequential Analysis suggested that no more trials are required to confirm that IV magnesium effectively reduces shivering.

Use Profile of Magnesium Sulfate in Anesthesia in Brazil

Objectives: The use of magnesium sulfate in the perioperative period has several benefits, including analgesia, inhibition of the release of catecholamines and prevention of vasospasm. The aim of this survey was to provide an overview of the use of magnesium sulfate in anesthesia. Method: This was a prospective descriptive cross-sectional study. An online questionnaire was sent to 9,869 Brazilian anesthesiologists and trainees. The questionnaire comprised closed questions mainly regarding the frequency, clinical effects, adverse events, and doses of magnesium sulfate used in anesthesia. Results: Of the 954 doctors who responded to the survey, 337 (35.32%) reported using magnesium sulfate in anesthesia. The most commonly cited clinical effects for the use of magnesium sulfate in anesthesia were (n/%): postoperative analgesia (245/72.70%), reduction of anesthetic consumption (240/71.21%) and prevention and treatment of preeclampsia and seizures in eclampsia (220/65.28%). The most frequently reported adverse events were hypotension (187/55.48%), residual neuromuscular blockade (133/39.46%), hypermagnesemia (30/8.90%), and intravenous injection pain (26/7.71%). The intravenous doses of magnesium sulfate used in most general anesthesia inductions were between 30 and 40 mg.kg-1. Conclusions: Magnesium sulfate is an important adjuvant drug in the practice of anesthesia, with several clinical effects and a low incidence of adverse events when used at recommended doses.

Perioperative systemic magnesium sulphate to minimize acute and chronic post-thoracotomy pain: a prospective observational study

Background

Thoracotomy leads to acute and chronic post-thoracotomy pain (CPTP). The purpose of this study was to investigate the effect of magnesium sulphate (MgSO₄) administered perioperatively on acute postoperative and CPTP syndrome.

Methods

One hundred patients were enrolled in this prospective, observational study. Analgesic medication was provided according to the World Health Organization pain relief ladder (control group). The study group received additionally MgSO₄ (40 mg/kg over 10 minutes) during induction of anesthesia followed by an infusion over 24 hours (10 mg/kg/h). The presence and severity of pain were assessed before surgery, on postsurgical days 1-8, 30 and 90, respectively. The Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) was used pre- and postoperatively for documentation of neuropathic pain. The incidence and severity of CPTP were assessed by a telephone survey 30 and 90 days after surgery.

Results

Numerical rating scale (NRS) pain scores at rest were significantly lower in the study group receiving MgSO₄ at days 1 to 8 (P<0.05). Thirty days after surgery, 2.1% of the MgSO₄-patients had a LANSS score ≥12 compared to 14.3% in the control group (P=0.031). No patient had a LANSS score ≥12 in the study group compared to the control group (0% vs. 12.2%, P<0.05) 90 days following surgery.

Conclusions

MgSO₄ administration reduces postoperative pain at rest according to the NRS pain scores and is effective in preventing chronic neuropathic post-thoracotomy pain measured by LANSS score. Prospective-randomized trials are needed to confirm the results of the present study.

Effect of intravenous versus intraperitoneal magnesium sulfate on hemodynamic parameters and postoperative analgesia during laparoscopic sleeve gastrectomy-A prospective randomized study

Background and Aims:

Hemodynamic changes to pneumoperitoneum and postoperative pain can be detrimental in obese patients; we investigated whether intravenous (IV) or intraperitoneal (IP) magnesium sulphate (MgSo₄) administration could attenuate the hemodynamic stress response to pneumoperitoneum and improve postoperative pain control after laparoscopic sleeve gastrectomy (LSG).

Material and Methods:

In total, 120 patients scheduled for LSG were randomized to either, control group (Group C, IV and IP saline), Group I (IV 30 mg/kg MgSo₄), or Group P (IP 30 mg/kg MgSo₄). Outcome variables were mean arterial pressure (MAP), heart rate (HR), postoperative pain score, total analgesic consumption, and incidence of adverse events.

Results:

MAP and HR were significantly lower in Groups I and P than that in control group. Pain score was better in Groups I and P than in control group up to 2 h postoperative (P = 0.023, 0.010, respectively); it was significantly lower in Group P than other two groups at 4 h postoperative (P <0.001). Significantly, reduced postoperative analgesic consumption with delayed onset to first analgesic request were observed in magnesium groups compared to control (P = 0.001, respectively). Moreover, onset to first analgesic request was longer in Group P than Group I (P = 0.001). No serious side effects were noticed.

Conclusion:

The IV and IP administration of MgSo₄ significantly attenuated the circulatory response to pneumoperitoneum and reduced postoperative pain as well as opioid consumption as compared to controls in obese patients undergoing LSG with no serious adverse effects.

Magnesium Sulfate as Adjuvant in Prehospital Femoral Nerve Block for a Patient with Diaphysial Femoral Fracture: A Randomized Controlled Trial

Introduction

Prehospital management of traumatic pain is commonly based on morphine while locoregional analgesia techniques, especially the femoral nerve block (FNB), can be safely and efficiently used. Adjuvants uses can reduce local anesthetic doses and decrease their related risk. The aim of the study was to assess the analgesic effect of magnesium sulfate when used as an adjuvant in prehospital FNB.

Methods

This is a randomized double-blinded trial conducted in a prehospital medical department of an academic hospital. Patients with isolated diaphysial femoral fracture and eligible to participate were randomized into 2 groups. Group C had a FNB with 15 ml of lidocaine with epinephrine (300 mg) and 3 ml of normal saline solution. Group I had a FNB with 15 ml of lidocaine with epinephrine (300 mg) and 3 ml of MgS 15% (450 mg). The FNB was performed according to the WINNIE technique. Primary endpoints were morphine consumption and pain intensity during the first 6 hours. Secondary endpoints were the duration of the sensory block, time to the first analgesic request, and side effects occurrence.

Results

Twenty-four patients were enrolled in each group. Both groups were comparable according to demographic characteristics, initial pain scores, and vital constants. In group I, morphine requirements were significantly lower (2 ± 2 mg versus 5 ± 3 mg, p < 10^-3), analgesic onset was significantly faster, and the average time to the first analgesic request was longer (276 ± 139 min versus 160 ± 79 min, p < 10^-3). The average duration of sensory block was longer in group I (226 ± 64 min versus 116 ± 70 min p < 10^-3). No side effects were recorded.

Conclusion

Magnesium sulfate should be considered as an efficient and safe adjuvant to lidocaine in prehospital FNB. This trial is registered with (NCT03597945).

The use of intravenous magnesium sulfate on postoperative analgesia in orthopedic surgery: A systematic review of randomized controlled trials

INTRODUCTION

The aim of this systematic review is to investigate the effects of perioperative intravenous administration of MgSO4 on postoperative pain, analgesic consumption and adverse effects in patients undergoing orthopedic surgery.

METHODS

Two investigators independently searched for articles on randomized controlled trials (RCTs) from 1998 to 2016 in Pubmed, Web of science and Google scholar. We evaluated clinical outcomes, comparing postoperative pain scores, cumulative analgesic consumption, time to first analgesia, and adverse effects between orthopedic surgery patients with and without the administration of MgSO4.

RESULTS

After screening 2350 articles, 11 RCTs (with a total sample size of 535 subjects) were included in this systematic review. Perioperative intravenous administered MgSO4 could reduce postoperative pain intensity compared with control in 6 trials (55%), but without significant difference in 5 trials (45%). With MgSO4 treatments, postoperative analgesic consumption was significantly reduced in 8 trials (73%), and without significant difference in 2 trials (18%). Two trials evaluated the time to first request of analgesic after surgery and showed prolong of 2.3 hours and 93 minutes respectively. MgSO4 group had less postoperative nausea (relative risk [RR] = 0.32, 95% confidence interval [CI] = 0.12-0.82, number needed to harm [NNH] = 8.8), vomiting (RR = 0.38, 95% CI = 0.15-0.92, NNH = 9.7), and shivering (RR = 0.31, 95% CI = 0.11-0.88, NNH = 5.2).

CONCLUSION

Perioperative intravenous administration of MgSO4 in orthopedic surgery could reduce postoperative analgesic consumption and adverse effects such as vomiting, nausea, and shivering. These trials do not provide convincing evidence of beneficial effects on postoperative pain intensity and the time to first analgesic request. More trials should be conducted for the roles of MgSO4 in pain management for orthopedic surgery. However, intravenous MgSO4 administration should be considered as a strategy to relieve postoperative pain in orthopedic surgery patients.

Comparison of Prophylactic Intravenous Magnesium Sulfate with Tramadol for Postspinal Shivering in Elective Cesarean Section: A Placebo Controlled Randomized Double-blind Pilot Study

Background and Aims:

Cesarean sections are performed mostly under spinal anesthesia. Shivering is one of the distressing complications. The aim of the study was to compare the efficacy of intravenous (i.v) magnesium sulfate and tramadol with placebo (normal saline) on postspinal shivering in elective cesarean section when used as prophylaxis.

Methods:

One hundred and thirty-five pregnant women between 18 and 35 years age, belonging to the American Society of Anesthesiologists’ physical Status II, undergoing elective cesarean section under spinal anesthesia were enrolled into the study. Patients belonging to Group C (control group, n = 45) received isotonic saline 100 mL i.v, Group T (tramadol group, n = 45) received tramadol 0.5 mg/kg in 100 mL isotonic saline i.v, whereas those in Group M (magnesium sulfate group, n = 45) received magnesium sulfate 30 mg/kg in 100 mL isotonic saline i.v after administering spinal anesthesia. Incidence and grades of shivering were noted. Data were analyzed using one-way ANOVA test and Chi-square test.

Results:

The incidence of shivering in Group C, Group T, and Group M were 67.5%, 43.9%, and 39%, respectively. The incidence of shivering in Group M and Group T was significantly low when compared to Group C (P = 0.008; P = 0.026), whereas there was no statistically significant difference between Groups T and M (P = 0.654).

Conclusion:

Magnesium sulfate and tramadol significantly reduce the incidence of shivering compared to placebo when used as prophylaxis in pregnant women undergoing cesarean section under spinal anesthesia. Magnesium sulfate reduces the severity of the shivering.

Magnesium Sulfate Mediates Morphine Administration Reduction in Varicocelectomy Surgery

AIMS

Varicocelectomy is the most common operation carried out by doctors for male infertility treatment. The aim of varicocele treatment is to hinder the refluxing venous drainage to the testis, retaining arterial inflow, and lymphatic drainage. A lot of pain is generated after this surgery, and the use of opium should be reduced to nearest minimum, as all drugs are toxins. Thus the aim of the present study is to facilitate morphine usage reduction after varicocelectomy surgery.

MATERIAL AND METHODS

One-hundred (100) patients who were varicocelectomy candidate were randomized into two groups: experimental group contain 50 patients and control group contain 50 patients as well. In experimental group, 2 mL magnesium sulfate in 2 mL normal saline was injected into patient immediately after surgery. The control group received only 4 mL normal saline. Morphine dosage administered, and severity of pain monitoring was accessed and recorded with a visual analogue scale (VAS).

RESULT

Result indicated that administration of morphine dosage in the test group 0.21 ± 0.64 mg was significantly lower as compared to the control group 0.75 ± 1.30 mg during the first 24-hour after surgery (p = 0.01). Average VAS scores in the experimental and control groups in the first 4-hour interval were 0.91 ± 1.30 and 2.9 ± 2.50 (p = 0.02) respectively. We observed a significant difference in the VAS score for pain severity and the dosages of morphine administered.

CONCLUSIONS

The experimental group with magnesium sulfate in its drug formulation showed better pain control compared to the control group which received only normal saline, whose pain manifested after every few hours. This can be used for the formulation of opium for this surgery in a large scale.

Whether preventive low dose magnesium sulphate infusion has an influence on postoperative pain perception and the level of serum beta-endorphin throughout the total abdominal hysterectomy

OBJECTIVE

Due to the known role of preventive low dose magnesium sulphate on postoperative pain management, in this randomized, double-blinded, placebo-controlled study, we tried to investigate the possible relationship between low dose intra-operative magnesium sulphate infusion, postoperative analgesia and the level of serum beta-endorphin during total abdominal hysterectomy under general anesthesia.

METHODS

Forty women undergoing total abdominal hysterectomy were randomly allocated into 2 groups (20 in each arm). Fifteen minutes before induction of anaesthesia, the case group received a continuous intravenous infusion of magnesium sulphate (15mg/kg/h) and placebo control group received the same volume of isotonic saline. Pain scores were assessed at 0, 6, 12, and 24h after operations using Verbal Numeric Rating Scale. Pethidine consumption was recorded precisely. Serum level of beta-endorphin just 15min before the induction and at the end of the operations was determined by ELISA technique.

RESULTS

At 6 and 12h after the operations, Verbal Numeric Rating Scale in the case group was significantly lower than that of placebo control group (P=.0001). Over 24h after the operations, pethidine consumption was significantly lower in the case group compared with control group (P=.0001). In the case group, serum level of beta-endorphin was significantly decreased at the end of the operations compared with before the induction (P=.04).

CONCLUSION

We illustrated that preventive low dose intra-operative magnesium sulphate infusion reduces postoperative pain, has opioid sparing effect and declines serum beta-endorphin concentration during total abdominal hysterectomy.

Magnesium sulfate accelerates the onset of low-dose rocuronium in patients undergoing laryngeal microsurgery

STUDY OBJECTIVE

We evaluated the effect of magnesium sulfate-an enhancer of neuromuscular blockade-on onset and duration of low dose of rocuronium, and on operating conditions during laryngeal microsurgery.

DESIGN

Randomized, prospective, double-blinded study.

PATIENTS

Eighty-four patients scheduled for elective laryngeal microsurgery.

INTERVENTIONS

Patients were randomly allocated to receive different doses of rocuronium: 0.6 mg/kg (group C, n=28), 0.45 mg/kg (group LR, n=28), or 0.45 mg/kg plus magnesium sulfate 30 mg/kg (group LM, n=28).

MEASUREMENTS

We measured the onset time and duration of action of rocuronium, and evaluated the surgeon's satisfaction with the operating conditions.

MAIN RESULTS

Group LR showed significantly delayed onset time (group C: 87±22 seconds, group LR: 127±47 seconds, and group LM: 89±32 seconds; P=.001) and maximal suppression than did other groups (group C: 102±30 seconds, group LR: 155±66 seconds, and group LM: 105±36 seconds; P=.002). Duration of action of rocuronium was significantly longer in group C than in other groups (group C: 39±7 minutes, group LR: 28±8 minutes, group LRM: 31±8 minutes; P<.001). Laryngoscope placement score (P=.002), surgeon's satisfaction (P=.005), and sore throat (P=.035) were significantly worse in group LR.

CONCLUSIONS

Magnesium sulfate 30 mg/kg accelerated the onset and improved operating conditions of low-dose rocuronium without prolongation of action.

The effect of intravenous magnesium sulfate infusion on reduction of pain after abdominal hysterectomy under general anesthesia: a double-blind, randomized clinical trial

Background

Post-surgical pain is a physiological response to tissue trauma that produces unpleasant physiological effects with manifestations on various organic systems.

Objective

According to the effect of magnesium sulfate on the N-methyl-d-aspartate (NMDA) receptor, this study examined the effect of magnesium sulfate on the reduction of pain and the mean amount of narcotics consumed by patients after abdominal hysterectomies.

Methods

This double-blind clinical trial study was performed on 60 patients who had undergone abdominal hysterectomies in Shahid Sadoughi Hospital in Yazd, Iran, from 2013 to 2015. The patients were divided randomly into two groups of 30 members each. All of the patients received 2 mg of Midazolam and 2 mcg/kg of Fentanyl as the induction of anesthesia with propofol (2–2.5 mg/kg) and Atracurium 0.5 mg/kg was conducted. All of the patients received 5 mg of intravenous morphine 30 min after induction of anesthesia. Afterwards, the study group received 50 mg/kg of magnesium sulfate in 500 cm³ of Ringer’s serum during the 20 minutes, and 500 cm³ of Ringer’s serum was administered to the members of the placebo group. Visual analogue scale VAS scores were evaluated to reach the minimum difference of 0.8 in mean pain score

Results

The results of this study indicated that the mean pain scores immediately after surgery and at 1, 2, 6, and 12 hr after surgery were lower in the study group than in the placebo group. The mean value of narcotic consumption at all measured time points was higher in the placebo group. No significant differences were found between two groups concerning drug complications.

Conclusion

The results of this study indicated that the intravenous injection of magnesium sulfate can reduce pain, reduce morphine consumption, and reduce the side effects of morphine in patients after surgery.

Funding

This study was funded by Shahid Sadoughi University of Medical Sciences, Yazd, Iran

Clinical trial registration

The trial was registered at the Thai Clinical Trials Registry (http://www.clinicaltrials.in.th) with the registration ID: TCTR20160308001.

Magnesium sulfate improves postoperative analgesia in laparoscopic gynecologic surgeries: a double-blind randomized controlled trial

STUDY OBJECTIVE

The aim of this study is to compare the analgesic effect of intravenous infusion of magnesium sulfate to ketorolac during laparoscopic surgeries.

DESIGN

Double-blind randomized controlled trial.

SETTING

University-affiliated teaching hospital.

PATIENTS

Sixty women submitted to laparoscopic gynecologic oncology surgeries.

INTERVENTIONS

Intravenous ketorolac 30 mg in bolus followed by saline infusion (group K), intravenous magnesium sulfate 20 mg/kg in bolus followed by magnesium 2 mg kg(-1) h(-1) (group M) or intravenous saline solution 20 mL in bolus followed by saline infusion during the entire procedure (group S).

MEASUREMENTS

Postoperative pain, nausea, vomiting, sedation, opioid consumption, time to first dose of analgesic.

MAIN RESULTS

Magnesium sulfate reduced opioid consumption compared with placebo in the postoperative, but not in the intraoperative, period. Nausea, not vomiting, was reduced in ketorolac but not in the magnesium group. Pain intensity was higher in placebo than in the other 2 groups during all periods of observation. In the first 60 minutes, pain intensity was lower in the magnesium than in the ketorolac or the placebo group.

CONCLUSION

Intraoperative magnesium sulfate improves postoperative pain control, acting as an opioid-sparing adjuvant, and is similar to ketorolac 30 mg administered in the beginning of surgery.

Cold bupivacaine versus magnesium sulfate added to room temperature bupivacaine in sonar-guided femoral and sciatic nerve block in arthroscopic anterior cruciate ligament reconstruction surgery

BACKGROUND

Cooling of local anesthetic potentiates its action and increases its duration. Magnesium sulfate (MgSo₄) added to local anesthetic prolongs the duration of anesthesia and postoperative analgesia with minimal side effects.

AIM

The aim of this prospective, randomized, double-blind study was to compare the effect of cold to 4°C bupivacaine 0.5% and Mg added to normal temperature (20-25°C) bupivacaine 0.5% during sonar-guided combined femoral and sciatic nerve blocks on the onset of sensory and motor block, intraoperative anesthesia, duration of sensory and motor block, and postoperative analgesia in arthroscopic anterior cruciate ligament (ACL) reconstruction surgery.

PATIENTS AND METHODS

A total of 90 American Society of Anesthesiologists classes I and II patients who were scheduled to undergo elective ACL reconstruction were enrolled in the study. The patients were randomly allocated to 3 equal groups to receive sonar-guided femoral and sciatic nerve blocks. In Group I, 17 ml of room temperature (20-25°C) 0.5% bupivacaine and 3 ml of room temperature saline were injected for each nerve block whereas in Group II, 17 ml of cold (4°C) 0.5% bupivacaine and 3 ml of cold saline were injected for each nerve block. In Group III, 17 ml of room temperature 0.5% bupivacaine and 3 ml of MgSo₄ 5% were injected for each nerve block. The onset of sensory and motor block was evaluated every 3 min for 30 min. Surgery was started after complete sensory and motor block were achieved. Intraoperatively, the patients were evaluated for heart rate and mean arterial pressure, rescue analgesic and sedative requirements plus patient and surgeon satisfaction. Postoperatively, hemodynamics, duration of analgesia, resolution of motor block, time to first analgesic, total analgesic consumption, and the incidence of side effects were recorded.

RESULTS

There was no statistically significant difference in demographic data, mean arterial pressure, heart rate, and duration of surgery. Onset of both sensory and motor block was significantly shorter in both Groups II and III compared to Group I. Intraoperative anesthetic quality was comparable between groups with good patient and surgeon satisfaction. The time to first analgesia was significantly longer in Groups II and III compared to Group I with nonsignificant difference between each other. Moreover, the total opioid consumption was significantly lower in Groups II and III and duration of analgesia and motor block were significantly longer in Groups II and III compared to Group I. There was no difference in the incidence of side effects.

CONCLUSIONS

The use of cold 0.5% bupivacaine or the addition of Mg to normal temperature 0.5% bupivacaine prolongs the sensory and motor block duration without increasing side effects and enhances the quality of intra- and post-operative analgesia with better patient satisfaction in sonar-guided femoral and sciatic nerve block for arthroscopic ACL reconstruction surgery.

A comparison of intraperitoneal bupivacaine-tramadol with bupivacaine-magnesium sulphate for pain relief after laparoscopic cholecystectomy: A prospective, randomised study

Background and Aims:

In laparoscopic surgeries, intraperitoneal instillation of local anaesthetics and opioids is gaining popularity, for better pain relief. This study compared the quality and duration of post-operative analgesia using intraperitoneal tramadol plus bupivacaine (TB) or magnesium plus bupivacaine (MB).

Methods:

In this study, 186 patients undergoing laparoscopic cholecystectomy were randomly divided into two groups: group TB received intraperitoneal tramadol with bupivacaine and group MB received intraperitoneal magnesium sulphate (MgSO₄) with bupivacaine. The visual analogue scale (VAS) to assess pain, haemodynamic variables and side effects were noted and compared at different time points. The primary outcome was to compare the analgesic efficacy and duration of pain relief. The secondary outcomes included comparison of haemodynamic parameters and side effects among the two groups. The data analysis was carried out with unpaired Student's t-test and Chi-square test using software SPSS 20.0 version.

Results:

The mean of VAS pain score after 1, 2, 4, 6 and 24 h of surgery was more in TB group compared to MB group, and the difference was statistically significant (P < 0.05). The total rescue analgesia consumption in 24 h after surgery was 2.4 g (mean) of paracetamol in TB group and 1.4 g (mean) of paracetamol in MB group which was statistically significant (P < 0.05). There were no statistically significant differences in the secondary outcomes.

Conclusion:

Intraperitoneal instillation of bupivacaine-MgSO₄ renders patients relatively pain-free in first 24 h after surgery, with longer duration of pain-free period and less consumption of rescue analgesic as compared to bupivacaine-tramadol combination.

Effect of low-dose (single-dose) magnesium sulfate on postoperative analgesia in hysterectomy patients receiving balanced general anesthesia

Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH) pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate (N = 20) and normal saline (N = 20) groups randomly. The magnesium group received magnesium sulfate 50 mg·kg⁻¹ in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS) at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (P < 0.05). Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (P = 0.0001). Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH.

Preventive analgesia in hip or knee arthroplasty: a systematic review

OBJECTIVE

To analyze the efficacy and safety of preventive analgesia in patients undergoing hip or knee arthroplasty due to osteoarthritis.

METHODS

A systematic literature review was performed, using a defined a sensitive strategy on Medline, Embase and Cochrane Library up to May 2013. The inclusion criteria were: patients undergoing knee and/or hip arthroplasty, adults with moderate or severe pain (≥4 on a Visual Analog Scale). The intervention, the use (efficacy and safety) of pharmacological treatment (preventive) close to surgery was recorded. Oral, topical and skin patch drugs were included. Systematic reviews, meta-analysis, controlled trials and observational studies were selected.

RESULTS

A total of 36 articles, of moderate quality, were selected. The patients included were representative of those undergoing knee and/or hip arthroplasty in Spain. They had a mean age >50 years, higher number of women, and reporting moderate to severe pain (≥4 on a Visual Analog Scale). Possurgical pain was mainly evaluated with a Visual Analog Scale. A wide variation was found as regards the drugs used in the preventive protocols, including acetaminophen, classic NSAID, Cox-2, opioids, corticosteroids, antidepressants, analgesics for neuropathic pain, as well as others, such as magnesium, ketamine, nimodipine or clonidine. In general, all of them decreased post-surgical pain without severe adverse events.

CONCLUSIONS

The use or one or more pre-surgical analgesics decreases the use of post-surgical drugs, at least for short term pain.

Effect of pre-emptive magnesium sulfate infusion on the post-operative pain relief after elective cesarean section

Background:

The aim of this study was to evaluate the analgesic efficacy of pre-operative single dose of intravenous (I.V.) magnesium sulfate infusion in patients undergoing elective Cesarean section.

Materials and Methods:

Seventy pregnant women who underwent elective Cesarean section were randomly divided into two groups. Before induction of anesthesia, the magnesium group (Group A) received magnesium sulfate 50 mg/kg I.V. in bolus dose. The control group (Group B) received the same volume of isotonic saline. The pain scores at rest and also upon movement were evaluated up to 24 h post-operatively and analgesic requirement was recorded during the first 24 h after operation.

Results:

Cumulative analgesic consumption (24 h after operation was 11.2 ± 6.3 mg in group A vs. 13.9 ± 3.9 mg in group B). Post-operative pain scores (24 h after operation was 1.8 ± 2.1 in group A vs. 2.9 ± 1.2 in group B) and shivering incidents (8.57 in group A vs. 14.28 in group B) were significantly lower in Group A (P < 0.05). Mean arterial pressure just after intubation and during the immediate post-operative period was significantly lower in Group A (P < 0.05).

Conclusion:

Pre-operative intravenous magnesium sulfate infusion decrease post-operation pain and requirement of analgesia in Cesarean section.