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

Influence of Intravenous Magnesium Sulfate Infusion on the Subjective Postoperative Quality of Recovery: A Meta-Analysis of Randomized Controlled Trials

This meta-analysis investigated the effects of intravenous magnesium sulfate on the postoperative recovery quality, as assessed using the Quality of Recovery (QoR) questionnaire, in adult surgical patients. Seven randomized controlled trials involving 622 patients were included. Compared with the placebo, magnesium sulfate significantly improved the global QoR score on postoperative day 1 (standardized mean difference [SMD]: 1.24; 95% confidence interval: 0.70-1.78; p < 0.00001). It also enhanced specific QoR dimensions, with substantial effects on pain (SMD: 1, p < 0.00001) and physical comfort (SMD: 0.85, p < 0.0001), a moderate effect on emotional state (SMD: 0.65, p = 0.002), and small improvements in physical independence (SMD: 0.43, p < 0.00001) and psychological support (SMD: 0.37, p < 0.0001). In addition, magnesium sulfate reduced the intraoperative opioid consumption (SMD: -0.66, p < 0.0001), postoperative pain severity, and the incidence of postoperative nausea and vomiting (risk ratio: 0.48, p = 0.008). The extubation times were unaffected, whereas the post-anesthesia care unit stay was slightly prolonged. These findings highlight the potential of magnesium sulfate as a valuable adjunct for multimodal analgesia and enhanced recovery. Future studies should aim to elucidate the optimal dosing strategies, timing of administration, and specific surgical populations that may derive maximum benefits.

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.

Efficacy and Safety of Intravenous Magnesium Sulfate in Spinal Surgery: A Systematic Review and Meta-Analysis

Optimizing pain management in spinal surgery is crucial for preventing adverse events due to delayed mobilization. Magnesium sulfate has potential benefits in spinal surgery because of its analgesic properties and modulation of neurotransmitters and autonomic nervous system. Existing evidence regarding the use of magnesium sulfate is partial and controversial, necessitating a comprehensive meta-analysis to evaluate its efficacy and safety. The aim of this study was to conduct a comprehensive meta-analysis to evaluate the efficacy and safety of magnesium sulfate in spinal surgery compared to other available options. This meta-analysis adhered to the PRISMA guidelines. Patients undergoing spinal surgery were included, with the intervention group receiving intravenous magnesium sulfate (MS) at various doses or combinations, whereas the comparison group received other alternatives or a placebo. The efficacy and safety outcomes were assessed. Data were collected from multiple databases and analyzed using Review Manager version 5.4. Heterogeneity was assessed and fixed- or random-effects models were applied. The meta-analysis included eight studies (n = 541). Magnesium sulfate demonstrated significant reductions in pain at 24 h (MD -0.20, 95% CI: -0.39 to -0.02) and opioid consumption (SMD -0.66, 95% CI: -0.95 to -0.38) compared to placebo. Additionally, a decrease in the use of muscle relaxants (SMD -0.91, 95% CI: -1.65 to -0.17) and remifentanil (SMD -1.52, 95% CI: -1.98 to -1.05) was observed. In contrast, an increase in extubation time (MD 2.42, 95% CI: 1.14 to 3.71) and verbal response (MD 1.85, 95% CI: 1.13 to 2.58) was observed compared to dexmedetomidine. In conclusion, magnesium sulfate administration in spinal surgery reduced pain and opioid consumption, and prolonged orientation and verbal response. No significant differences in blood pressure or heart rate were observed between the groups.

Effect of Pharmacoprophylaxis on Postoperative Outcomes in Adult Elective Colorectal Surgery: A Multi-Center Retrospective Cohort Study within an Enhanced Recovery after Surgery Framework

BACKGROUND

The application of enhanced recovery after surgery principles decreases postoperative complications (POCs), length of stay (LOS), and readmissions. Pharmacoprophylaxis decreases morbidity, but the effect of specific regimens on clinical outcomes is unclear.

METHODS AND MATERIALS

Records of 476 randomly selected adult patients who underwent elective colorectal surgeries (ECRS) at 10 US hospitals were abstracted. Primary outcomes were surgical site infection (SSI), venous thromboembolism (VTE), postoperative nausea and vomiting (PONV), pain, and ileus rates. Secondary outcomes included LOS and 7- and 30-day readmission rates.

RESULTS

POC rates were SSI (3.4%), VTE (1.5%), PONV (47.9%), pain (58.1%), and ileus (16.1%). Cefazolin 2 g/metronidazole 500 mg and ertapenem 1 g were associated with the shortest LOS; cefotetan 2 g and cefoxitin 2 g with the longest LOS. No SSI occurred with ertapenem and cefotetan. More Caucasians than Blacks received oral antibiotics before intravenous antibiotics without impact. Enoxaparin 40 mg subcutaneously daily was the most common inpatient and discharge VTE prophylaxis. All in-hospital VTEs occurred with unfractionated heparin. Most received rescue rather than around-the-clock antiemetics. Scopolamine patches, spinal opioids, and IV lidocaine continuous infusion were associated with lower PONV. Transversus abdominis plane block with long-acting local anesthetics, celecoxib, non-anesthetic ketamine bolus, ketorolac IV, lidocaine IV, and pregabalin were associated with lower in-hospital pain severity rates. Gabapentinoids and alvimopan were associated with lower ileus rates. Acetaminophen, alvimopan, famotidine, and lidocaine patches were associated with shorter LOS.

CONCLUSIONS

Significant differences in pharmacotherapy regimens that may improve primary and secondary outcomes in ECRS were identified. In adult ECRS, cefotetan or ertapenem may be better regimens for preventing in-hospital SSI, while ertapenem or C/M may lead to shorter LOS. The value of OA to prevent SSI was not demonstrated. Inpatient enoxaparin, compared to UFH, may reduce VTE rates with a similar LOS. A minority of patients had a documented PONV risk assessment, and a majority used as-needed rather than around-the-clock strategies. Preoperative scopolamine patches continued postoperatively may lower PONV and PDNV severity and shorter LOS. Alvimopan may reduce ileus and shorten LOS. Anesthesia that includes TAP block, ketorolac IV, and pregabalin use may lead to reduced pain rates. Acetaminophen, alvimopan, famotidine, and lidocaine patches may shorten LOS. Given the challenges of pain management and the incidence of PONV/PDNV found in this study, additional studies should be conducted to determine optimal opioid-free anesthesia and the benefit of newer antiemetics on patient outcomes. Moreover, future research should identify latent pharmacotherapy variables that impact patient outcomes, correlate pertinent laboratory results, and examine the impact of order or care sets used for ECRS at study hospitals.

Adjuvants for balanced anesthesia in ambulatory surgery

Balanced anesthesia relies on the simultaneous administration of different drugs to attain an anesthetic state. The classic triad of anesthesia is a combination of a hypnotic, an analgesic, and a neuromuscular blocker. It is predominantly the analgesic pillar of this triad that became more and more supported by adjuvant therapy. The aim of this approach is to evolve into an opioid-sparing technique to cope with undesirable side effects of the opioids and is fueled by the opioid epidemic. The optimal strategy for balanced general anesthesia in ambulatory surgery must aim for a transition to a multimodal analgesic regimen dealing with acute postoperative pain and ideally reduce the most common adverse effects patients are faced with at home; sore throat, delayed awakening, memory disturbances, headache, nausea and vomiting, and negative behavioral changes. Over the years, this continuum of "multimodal general anesthesia" adopted many drugs with different modes of action. This review focuses on the most recent evidence on the different adjuvants that entered clinical practice and gives an overview of the different mechanisms of action, the potential as opioid-sparing or hypnotic-sparing drugs, and the applicability specifically in ambulatory surgery.

Effect of intraoperative systemic magnesium sulphate on postoperative Richmond Agitation-Sedation Scale score after endovascular repair of aortic aneurysm under general anesthesia: A double-blind, randomized, controlled trial

Intraoperative magnesium has the effect of reducing postoperative opiate requirement, pain, and agitation. However, its effect on postoperative sedation and delirium is unclear. This study investigated the effect of magnesium on the postoperative Richmond Agitation-Sedation Scale (RASS) score and delirium following endovascular repair of aortic aneurysm (EVAR). Sixty-three consecutive patients diagnosed with abdominal (45) and thoracic (18) aortic aneurysm who underwent EVAR under general anesthesia were eligible. Patients were allocated randomly to the magnesium group (infusion of 30 mg•kg-1 magnesium in the first hour followed by 10 mg•kg-1 h-1 until the end of surgical procedure, targeting total 60 mg•kg-1) or the control group (0.9% saline at the same volume and rate). The primary outcome was whether magnesium had an effect on RASS score of patients at postoperative ICU admission. Secondary outcomes were effects on RASS score, numerical rating scale (NRS) score, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) until 24 h after postoperative ICU transfer, and length of ICU stay. At postoperative ICU admission, magnesium had no significant effect on the RASS score (0[-0.5 to 0] vs 0[0 to 0]; P = 0.114), but at 1 h the NRS score was statistically different, 2[0 to 4] vs 4[0 to 5] (P = 0.0406). However, other data (RASS score, NRS score, CAM-ICU and length of ICU stay) did not show a significant difference. Our results did not show that intraoperative magnesium of target total 60 mg•kg-1 affected postoperative RASS score for undergoing EVAR. Trial registration: The current study was registered according to WHO and ICMJE standards on 4 July 2018, under registration number the Japan Registry of Clinical Trials, iRCTs041190013.

Clinical efficacy of magnesium sulfate injection in the treatment of masseter muscle trigger points: a randomized clinical study

Objective

Myofascial pain syndrome with trigger points is the most common cause of nonodontogenic pain. Although injection of the trigger points is the most effective pain reduction treatment, many patients exhibit recurrence after a short period. Therefore, the aim of the current study was to evaluate the clinical efficacy of magnesium sulfate injections in the treatment of the masseter muscle trigger points when compared to saline injections.

Material and method

This study randomly (1:1) assigned 180 patients to one of two treatment groups based on whether their trigger points were injected with 2 ml of saline or magnesium sulfate. Pain scores, maximum mouth opening (MMO), and quality of life were measured at the pre-injection and 1, 3, and 6 months post-injection.

Results

The pain scores were significantly higher in the saline group during all follow-up assessments, whereas the MMO was significantly higher in the magnesium sulfate group up to 3 months of follow-up (p < 0.001). However, the difference in MMO ceased to be statistically significant after 6 months of follow-up (p = 0.121). Additionally, the patient’s quality of life score was significantly higher in the magnesium sulfate group compared to the saline group (p < 0.001).

Conclusion

Injection of magnesium sulfate is an effective treatment measure for myofascial trigger points. However, further studies with a proper design addressing the limitations of the current study are necessary.

ClinicalTrials: org (ID: NCT04742140) 5/2/2021.

The effects of magnesium sulfate added to epidurally administered local anesthetic on postoperative pain: a systematic review

BACKGROUND

This study evaluated the efficacy of epidurally administered magnesium associated with local anesthetics on postoperative pain control.

METHODS

The study protocol was registered in PROSPERO as CRD42021231910. Literature searches were conducted on Medline, Cochrane, EMBASE, CENTRAL, and Web of Science for randomized controlled trials comparing epidural administration of magnesium added to local anesthetics for postoperative pain in elective surgical adult patients. Primary outcomes were the time to the first Postoperative (PO) Analgesic Request (TFAR), 24-hour postoperative opioid consumption, and Visual Analog Scale (VAS) scores at the first six and 24 postoperative hours. Secondary outcomes included Postoperative Nausea and Vomiting (PONV), pruritus, and shivering. Quality of evidence was assessed using GRADE criteria.

RESULTS

Seventeen studies comparing epidural were included. Effect estimates are described as weighted Mean Differences (MD) and 95% Confidence Intervals (95% CI) for the main outcomes: TFAR (MD = 72.4 min; 95% CI = 10.22-134.58 min; p < 0.001; I² = 99.8%; GRADE: very low); opioid consumption (MD = -7.2 mg (95% CI = -9.30 - -5.09; p < 0.001; I² = 98%; GRADE: very low). VAS pain scores within the first six PO hours (VAS) (MD = -1.01 cm; 95% CI = -1.40-0.64 cm; p < 0.001; I² = 88%; GRADE: very low), at 24 hours (MD = -0.56 cm; 95% CI = -1.14-0.01 cm; p = 0.05; I² = 97%; GRADE: very low).

CONCLUSIONS

Magnesium sulfate delayed TFAR and decreased 24-hour opioid consumption and early postoperative pain intensity. However, imprecision and inconsistency pervaded meta-analyses, causing very low certainty of effect estimates.

Effects of Magnesium Sulfate on Intraoperative Blood Loss and Anesthetic Requirement in Meningioma Patients Undergoing Craniotomy with Tumor Removal: A Prospective Randomized Study

Background Meningioma brain tumor is associated with significant blood loss. Magnesium (Mg), a calcium blocker, can facilitate blood pressure control during surgery. This study aimed to evaluate effects of magnesium on blood loss, anesthetic requirement, and its neuroprotective effect in meningioma patients undergoing craniotomy.

Methods Eighty patients aged between 18 and 70, American Society of Anesthesiologists physical status I and II, diagnosed with meningioma and scheduled for craniotomy tumor removal were randomized into two groups. Group M (Mg) received intravenous magnesium sulfate 40 mg/kg over 30 minutes initiated at skin incision and followed by continuous infusion of 10 mg/kg/h until dura closure. Group N (NSS) received 0.9% NaCl as placebo. Anesthesiologists in charge, surgeons, and patients were all blinded. The assessed outcomes were perioperative blood loss, anesthetic requirement, and pre- and postoperative neurocognitive functions assessed by Montreal Cognitive Assessment (MoCA).

Results Thirty-eight patients in each group were analyzed. In group M, the intraoperative blood losses were 500 (70, 2300) mL, and 510 (100, 1600) mL in group N (p = 0.315). Patients who received blood within 24 hours were 39.5% in group M and 47.4% in group N (p = 0.644). No differences were observed in anesthetic requirement, intraoperative mean arterial pressure, hypotensive episodes, and vasopressor usages. There were no significant differences in postoperative MoCA score. Magnesium levels did not exceed acceptable levels.

Conclusions Magnesium administration in meningioma patients had no significant effects on blood loss, anesthetic requirement, and postoperative cognitive function.

Nonopioid Analgesics for the Perioperative Geriatric Patient: A Narrative Review

Management of acute perioperative pain in the geriatric patient can be challenging as the physiologic and pharmacokinetic changes associated with aging may predispose older patients to opioid-related side effects. Furthermore, elderly adults are more susceptible to postoperative delirium and postoperative cognitive dysfunction, which may be exacerbated by both poorly controlled postoperative pain and commonly used pain medications. This narrative review summarizes the literature published in the past 10 years for several nonopioid analgesics commonly prescribed to the geriatric patient in the perioperative period. Nonopioid analgesics are broken down as follows: medications prescribed throughout the perioperative period (acetaminophen and nonsteroidal anti-inflammatory drugs), medications limited to the acute perioperative setting (N-methyl-D-aspartate receptor antagonists, dexmedetomidine, dexamethasone, and local anesthetics), and medications to be used with caution in the geriatric patient population (gabapentinoids and muscle relaxants). Our search identified 1757 citations, but only 33 specifically focused on geriatric analgesia. Of these, only 21 were randomized clinical trials' and 1 was a systematic review. While guidance in tailoring pain regimens that focus on the use of nonopioid medications in the geriatric patient is lacking, we summarize the current literature and highlight that some nonopioid medications may extend benefits to the geriatric patient beyond analgesia.

Current Issues in the Use of Opioids for the Management of Postoperative Pain: A Review

Importance

Uncontrolled and indiscriminate prescribing of opioids has led to an opioid crisis that started in North America and spread throughout high-income countries. The aim of this narrative review was to explore some of the current issues surrounding the use of opioids in the perioperative period, focusing on drivers that led to escalation of use, patient harms, the move away from using self-reported pain scores alone to assess adequacy of analgesia, concerns about the routine use of controlled-release opioids for the management of acute pain, opioid-free anesthesia and analgesia, and prescription of opioids on discharge from hospital.

Observations

The origins of the opioid crisis are multifactorial and may include good intentions to keep patients pain free in the postoperative period. Assessment of patient function may be better than unidimensional numerical pain scores to help guide postoperative analgesia. Immediate-release opioids can be titrated more easily to match analgesic requirements. There is currently no good evidence to show that opioid-free anesthesia and analgesia affects opioid prescribing practices or the risk of persistent postoperative opioid use. Attention should be paid to discharge opioid prescribing as repeat and refill prescriptions are risk-factors for persistent postoperative opioid use. Opioid stewardship is paramount, and many governments are passing legislation, while statutory bodies and professional societies are providing advice and guidance to help mitigate the harm caused by opioids.

Conclusions and Relevance

Opioids remain a crucial part of many patients' journey from surgery to full recovery. The last few decades have shown that unfettered opioid use puts patients and societies at risk, so caution is needed to mitigate those dangers. Opioid stewardship provides a multilayered structure to allow continued safe use of opioids as part of broad pain management strategies for those patients who benefit from them most.

Impact of intraoperative intravenous magnesium on spine surgery: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The effectiveness and safety of intraoperative intravenous magnesium (IIM) on spine surgery remain uncertain, as recent randomized controlled trials (RCTs) yielded conflicting results. The purpose of this study was to determine the impact of IIM on spine surgery.

METHODS

A literature search was performed on multiple electronic databases, ClinicalTrial.gov and Google Scholar on July 12th 2021, and reference lists were examined. We selected RCTs comparing the effects of IIM with placebo treatment on spine surgery. We calculated pooled standard mean difference (SMD) or risk ratio (RR) with 95% confident interval (CI) under a random-effect model. We assessed risk of bias using Cochrane risk-of-bias tool and Jadad score was applied to assess the quality of each included trial. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to determine the confidence in effect estimates. Sensitivity analysis was conducted by omitting each included study one by one from the pooled analysis. PROSPERO Registration: CRD42021266170.

FINDINGS

Fourteen trials of 781 participants were included. Low- to moderate-quality evidence suggested that IIM reduces postoperative morphine consumption at 24 h (SMD: -1·61 mg, 95% CI: -2·63 to -0·58) and intraoperative remifentanil requirement (SMD: -2·09 ug/h, 95% CI: -3·38 to -0·81). High-quality evidence suggested that IIM reduces the risk of postoperative nausea and vomiting compared with placebo (RR: 0·43, 95% CI: 0·26 to 0·71). Besides, moderate-quality evidence suggested that recovery orientation time in the IIM group is longer than control group (SMD: 1·13 min, 95% CI: 0·83 to 1·43).

INTERPRETATION

IIM as adjuvant analgesics showed overall benefits on spine surgery in terms of reducing analgesic requirement and postoperative nausea and vomiting; however, potential risks of IIM, such as delayed anesthetic awakening, should not be ignored. Future evidence will inform the optimal strategy of IIM administration for patients undergoing spine surgery.

FUNDING

This study was funded by Beijing Municipal Natural Science Foundation (Grant No :7212117).

Analgesic Efficacy and Safety of Local Infiltration Following Lumbar Decompression Surgery: A Systematic Review of Randomized Controlled Trials

This systematic review aims to appraise available clinical evidence on the efficacy and safety of wound infiltration with adjuvants to local anesthetics (LAs) for pain control after lumbar spine surgery. A database search was conducted to identify randomized controlled trials (RCTs) pertinent to wound infiltration with analgesics or miscellaneous drugs adjunctive to LAs compared with sole LAs or placebo. The outcomes of interest were postoperative rescue analgesic consumption, pain intensity, time to first analgesic request, and the occurrence of adverse events. Twelve double-blind RCTs enrolling 925 patients were selected for qualitative analysis. Most studies were of moderate-to-good methodological quality. Dexmedetomidine reduced analgesic requirements and pain intensity within 24 h postoperatively, while prolonged pain relief was reported by one RCT involving adjunctive clonidine. Data on local magnesium seem promising yet difficult to interpret. No clear analgesic superiority could be attributed to steroids. Τramadol co-infiltration was equally effective as sole tramadol but superior to LAs. No serious adverse events were reported. Due to methodological inconsistencies and lack of robust data, no definite conclusions could be drawn on the analgesic effect of local infiltrates in patients undergoing lumbar surgery. The probable positive analgesic efficacy of adjunctive dexmedetomidine and magnesium needs further evaluation.

Perioperative Magnesium for Postoperative Analgesia: An Umbrella Review of Systematic Reviews and Updated Meta-Analysis of Randomized Controlled Trials

The purpose of this study was to summarize and evaluate evidence on the effectiveness of perioperative magnesium as an adjuvant for postoperative analgesia. We conducted an umbrella review of the evidence across systematic reviews and meta-analyses of randomized controlled trials (RCTs) on the effect of perioperative magnesium on pain after surgical procedures. Two independent investigators retrieved pain-related outcomes and assessed the methodological quality of the evidence of included studies using the A MeaSurement Tool to Assess systematic Reviews (AMSTAR) tool, and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system. In addition, an updated meta-analysis of postoperative pain-related outcomes with a trial sequential analysis (TSA) was conducted. Of the 773 articles initially identified, 17 systematic reviews and meta-analyses of 258 RCTs were included in the current umbrella review. Based on the AMSTAR tool, the overall confidence of the included systematic reviews was deemed critically low to low. Pain score, analgesic consumption, time to first analgesic request, and incidence of analgesic request were examined as pain-related outcomes. According to the GRADE system, the overall quality of evidence ranged from very low to moderate. While the updated meta-analysis showed the beneficial effect of perioperative magnesium on postoperative analgesia, and TSA appeared to suggest sufficient existing evidence, the heterogeneity was substantial for every outcome. Although the majority of included systematic reviews and updated meta-analysis showed a significant improvement in outcomes related to pain after surgery when magnesium was administered during the perioperative period, the evidence reveals a limited confidence in the beneficial effect of perioperative magnesium on postoperative pain.

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.

Effect of magnesium sulfate on renal colic pain: A PRISMA-compliant meta-analysis

BACKGROUND

Magnesium sulfate (MgSO4) is widely used in analgesia for different conditions. Recent randomized controlled trials (RCTs) have evaluated the effects of MgSO4 on renal colic; however, this new evidence has not been synthesized. Thus, we conducted a systematic review and meta-analysis to assess the efficacy and safety of MgSO4 in comparison with control for renal colic.

METHODS

PubMed, EMBASE, and Scopus databases were searched from inception to February 2020. We included RCTs that evaluated MgSO4 vs control for patients with renal colic. Data were independently extracted by 2 reviewers and synthesized using a random-effects model.

RESULTS

Four studies with a total of 373 patients were analyzed. Intravenous MgSO4 15 to 50 mg/kg did not significantly reduce renal colic pain severity at 15 minutes (mean difference [MD] = 0.35, 95% confidence interval [CI] -0.51 to 1.21; 2 RCTs), 30 minutes (MD = 0.19, 95% CI -0.74 to 1.13; 4 RCTs), and 60 minutes (MD = -0.28, 95% CI -0.72 to 0.16; 3 RCTs) in comparison with controls. In patients who failed to respond to initial analgesics, intravenous MgSO4 15 mg/kg or 2 ml of 50% solution provided similar pain relief to ketorolac or morphine at 30 minutes (P = .90) and 60 minutes (P = .57). No significant hemodynamic changes were observed with short-term use of MgSO4 in these studies.

CONCLUSION

MgSO4 provides no superior therapeutic benefits in comparison with control treatments. MgSO4 may be used as a rescue medication in patients not responding to initial analgesics. The short-term use of MgSO4 did not affect hemodynamic values.

Incidence of postoperative shivering decreased with the use of acetaminophen: a propensity score matching analysis

OBJECTIVES

The incidence of postoperative shivering is known to be inversely associated with core body temperature. However, previous studies have pointed out that the threshold of shivering could be affected by peripheral temperature or anesthetic agents. These reports pointed specific drugs, though, anesthesia techniques have since advanced considerably. This study aimed to investigate factors associated with postoperative shivering in the context of the current body warming practice.

METHODS

The institutional clinical research ethics committee of Kyushu University approved the study protocol (IRB Clinical Research number 2019-233). This retrospective study involved 340 patients who had undergone radical surgery for gynecological cancer treatment under general anesthesia at our center from December 2012 to June 2019. Logistic regression analysis was performed to estimate the odds ratio (OR) for the incidence of postoperative shivering.

RESULTS

Postoperative shivering developed in 109 out of 340 patients. After multivariate-adjusted logistic regression, the incidences of postoperative shivering decreased significantly with increasing patient age (OR = 0.96; 95%CI: 0.93-0.98; p = 0.0004). Volatile anesthesia technique was less inclined to shiver after surgery than TIVA (OR = 0.55; 95%CI: 0.30-0.99; p = 0.04). Acetaminophen was much less used in the shivering group than in the non-shivering group (OR = 0.49; 95%CI: 0.25-0.94; p = 0.03).

CONCLUSIONS

This study indicated that the development of shivering in patients receiving the anesthetic technique currently used in our hospital was associated with use of acetaminophen or volatile agents, and patient age.