Magnesium sulfate in pediatric anesthesia: the Super Adjuvant

Effects of intra-operative magnesium sulfate infusion on orthognathic surgery: A prospective and randomized controlled trial

Purpose

To comprehensively understand the effects of intra-operative infusion of magnesium sulfate on patients who underwent orthognathic surgery, including remifentanil consumption, postoperative pain, postoperative nausea and vomiting (PONV), inflammatory response, and serum magnesium levels.

Methods

Seventy-five adult patients undergoing orthognathic surgery under general balanced anesthesia were randomly divided into two groups. One group (Group M) received 50 mg/kg of magnesium sulfate in 20 mL 0.9 % saline after intubation, followed by a continuous infusion at a rate of 15 mg/kg/h until 30 min before the anticipated end of surgery. The other group (Group C) received an equal volume of isotonic saline as a placebo. (Clinical trial registration number: chiCTR2100045981).

Results

The primary outcome was remifentanil consumption. The secondary outcomes included the pain score assessed using the verbal numerical rating scale (VNRS) and PONV assessed using a Likert scale. Remifentanil comsumption in Group M was lower than Group C (mean ± SD: 0.146 ± 0.04 μg/kg/min vs. 0.173 ± 0.04 μg/kg/min, P = 0.003). At 2 h after surgery, patients in Group C suffered more severe PONV than those in Group M (median [interquartile range, IQR]: 1 [3] vs. 1 [0], mean rank: 31.45 vs. 42.71, P = 0.040). At post-anesthesia care unit (PACU), postoperative pain in Group C was severe than Group M (3 [1] vs. 3 [0], mean rank: 31.45 vs. 42.71, P = 0.013). Changes in haemodynamics and surgical field scores did not differ between the groups (all P > 0.05). The levels of cytokines (IL-4, IL-6, IL-8, IL-10, TNF-a, and MIP-1β) were not significantly different between the groups after surgery (all P > 0.05). Postoperative serum magnesium levels in Group C were lower than those in Group M (0.74 ± 0.07 mmol/L vs. 0.91 ± 0.08 mmol/L, P = 0.000) and the preoperative level (0.74 ± 0.07 mmol/L vs. 0.83 ± 0.06 mmol/L, P = 0.219).

Conclusions

In orthognathic surgery, magnesium sulfate administration can reduce remifentanil requirement and relieve PONV and postoperative pain in the early postoperative phase.

The analgesic effects of magnesium in veterinary patients: a qualitative evidence synthesis

OBJECTIVE

To perform a qualitative evaluation of the analgesic effects of magnesium in domestic animals, including its anaesthetic sparing effects.

STUDY DESIGN

All database searches were made using PubMed and Google Scholar. Studies published after 1990, evaluating the use of magnesium and reporting information on analgesia, in dogs, cats, horses, cows, goats and sheep were selected (last search in August 2023). A reference check in the selected papers was performed to identify any study which was omitted. The CERQual (Confidence in Evidence from Reviews of Qualitative research) approach was used to assess confidence and analyse the evidence.

RESULTS

A total of 20 studies relevant to the analgesic effects of magnesium in veterinary patients and two reviews were included. All were published after 2006. Of the 20, five studies provided information about analgesia in the postoperative period in dogs with heterogenous results. Magnesium added epidurally increased the duration of the sensory block in several species. Motor block was also observed when added to spinal analgesia. Results regarding volatile agents sparing effect were conflicting. Occasional moderate adverse effects were reported in dogs, such as nausea and vomiting, when administered as a bolus in conscious animals, and hypotension when administered intraperitoneally. Collapse was reported in horses after epidural administration.

CONCLUSIONS AND CLINICAL RELEVANCE

The evidence of an analgesic effect of magnesium in veterinary patients remains scarce considering the paucity and low quality of published data. Further research may be helpful to establish the efficacy and indications of magnesium in multimodal analgesia in animals.

The effects of intraoperative magnesium sulfate administration on emergence agitation and delirium in pediatric patients: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The role of intraoperative magnesium for the prevention of emergence agitation or delirium is unclear as there have been conflicting results reported by several randomized controlled trials.

AIMS

The aim of this study was to investigate the effect of magnesium sulfate on emergence agitation or emergence delirium in pediatric patients.

METHODS

Electronic databases, including PubMed, EMBASE, CENTRAL, CINAHL, Scopus, and Web of Science, were searched to identify studies which evaluated the effects of magnesium on postoperative emergence agitation or emergence delirium. The primary outcome was the incidence of emergence agitation or emergence delirium during the post-anesthesia stay. The secondary outcome was the agitation or delirium score upon admission to the post-anesthesia care unit. We estimated the odds ratio and standardized mean difference using a random-effect model.

RESULTS

A total of 712 pediatric patients from 10 randomized controlled trials were included in the final analysis. The incidence of emergence agitation or emergence delirium was 29.7% in the magnesium group and 50.5% in the control group. The pooled effect size revealed that the administration of magnesium sulfate significantly reduced the incidence of postoperative emergence agitation or emergence delirium in pediatric patients undergoing surgery with general anesthesia (Odds ratio, 0.31; 95% confidence interval, 0.15 to 0.64; p = .002). Additionally, children in the magnesium group reported significantly lower agitation or delirium scores than those in the control group (standardized mean difference, -0.70; 95% confidence interval, -1.15 to -0.24; p = .003).

CONCLUSION

The administration of magnesium sulfate reduced the incidence and severity of emergence agitation or emergence delirium in pediatric patients after the use of general anesthesia during surgery.

Ionized Hypomagnesemia Is Associated With Increased Incidence of Postoperative Atrial Fibrillation After Esophageal Resection: A Retrospective Study

Introduction: Postoperative atrial fibrillation (POAF) is common after surgery for esophageal cancer and may prolong hospitalization and elevate mortality. POAF and hypomagnesemia are linked, but this is based on studies showing an association of POAF with serum total magnesium (tMg). In contrast, the relationship of POAF with ionized magnesium (iMg), which has physiological activity, has not been examined. In this study, the association between hypomagnesemia and POAF was investigated retrospectively to examine iMg as a possible predictive factor for POAF.

Methods: The subjects were 151 patients who underwent right transthoracoabdominal subtotal esophagectomy at Saitama Medical Center between January 2011 and December 2020. The incidence of POAF and predictive factors were examined retrospectively. Perioperative predictive factors were subjected to univariate analysis, and items with P<0.1 were then included in multivariate analysis, along with five potential POAF predictors reported in the literature (age, gender, body mass index, hypertension, and diabetes mellitus). P<0.05 was regarded as significant in the multivariate analysis.

Results: Of the 151 patients, 34 (23%) developed POAF. In univariate analysis, six factors with P<0.1 (oral statin, dyslipidemia, iMg level after anesthesia induction, maximum and minimum iMg during surgery, and iMg level immediately before admission to ICU) were identified. In multivariate analysis including these and the five literature factors as explanatory variables, iMg immediately before admission to ICU emerged as a predictive factor for POAF (iMg≥0.46 mmol/L, OR 0.32, 95%CI 0.14-0.74, p=0.01) (standard iMg range: 0.48-0.60 mmol/L).

Conclusion: The iMg level immediately before admission to ICU may be associated with the development of POAF. A further study is needed to evaluate changes in iMg in the ICU and iMg at the time of onset of POAF.

Manejo anestésico en paciente pediátrico con hiperglicinemia no cetósica

Se reporta un paciente pediátrico con diagnóstico de hiperglicinemia no cetósica (HNC), enfermedad neurometabólica poco frecuente ocasionada por una deficiencia en el sistema de segmentación de la glicina, codificada por los genes GLDC, GCSH, AMT y GCSL que conduce a niveles elevados de glicina en la sinapsis generando un efecto agonista prolongado en los receptores N-metil-D-aspartato (NMDA).  Se asocia con hipotonía, convulsiones y trastornos de la deglución, los cuales dependerán de la edad de presentación. Se revisa la literatura actual para el abordaje perioperatorio.

Effect of magnesium supplementation on emergence delirium and postoperative pain in children undergoing strabismus surgery: a prospective randomised controlled study

Background

The benefits of intraoperative magnesium supplementation have been reported. In this prospective, randomized study, the effects of magnesium supplementation during general anaesthesia on emergence delirium and postoperative pain in children were evaluated.

Methods

A total of 66 children aged 2 to 5 years who underwent strabismus surgery were assigned to the magnesium or to the control group. Preoperative anxiety was assessed using the modified Yale Preoperative Anxiety Scale. After anaesthesia induction, the magnesium group received an initial loading dose of 30 mg/kg magnesium sulphate over 10 min and, then, continuous infusion of 10 mg/kg per h until 10 min before the end of the surgery. The control group received an equal volume of normal saline via the same regimen. The Paediatric Anaesthesia Emergence Delirium (PAED) score, pain score, and respiratory events were assessed at the postanaesthetic care unit.

Results

Data obtained from 65 children were analyzed. The PAED and pain scores of the two groups did not differ significantly. There were 26 of 33 (78.8%) and 27 of 32 (84.4%) children with emergence delirium in the control and the magnesium groups, respectively (odds ratio 0.69, 95% CI 0.19–2.44; p = 0.561). The preoperative anxiety score was not significantly correlated with the PAED score. The incidence of respiratory events during the emergence period did not differ significantly between the two groups.

Conclusions

Magnesium supplementation during anaesthesia had no significant effects on the incidence of emergence delirium or postoperative pain in children undergoing strabismus surgery.

Trial registration

ClinicalTrials.gov (NCT03132701). Prospectively registered May 8, 2017.

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.

Neurotoxicity versus Neuroprotection of Anesthetics: Young Children on the Ropes?

Normal brain development in young children depends on a balance between excitation and inhibition of neurons, and alterations to this balance may cause apoptosis. During the perioperative period, both surgical stimuli and anesthetics can induce neurotoxicity. This article attempts to expand the perspective of a topical issue-anesthetic-induced neurotoxicity-by also considering the protective effect of general anesthetics against surgery-induced neurotoxicity, all of which may generate some controversy in the current literature. The "new" major factor influencing neurotoxicity-nociceptive stimulus-is discussed together with other factors to develop clinical and research strategies to obtain a balance between neurotoxicity and neuroprotection.