Effects of magnesium sulphate on intraoperative neuromuscular blocking agent requirements and postoperative analgesia in children with cerebral palsy

Prolonged magnesium sulfate infusion as adjuvant analgesia in postoperative transplant patients in the pediatric ICU: Preliminary results of a feasibility study

The opioid crisis has emphasized identification of opioid-sparing analgesics. This study was designed as a prospective trial with retrospective control group to determine feasibility for implementing a high-dose prolonged magnesium sulfate infusion for adjuvant analgesia in the pediatric intensive care unit. Approval was granted for study of children receiving total pancreatectomy with islet cell autotransplantation and liver transplantation ages 3-18 years. Study exclusions were pregnancy, neuromuscular disease, hypersensitivity, preoperative creatinine >1.5 times upper limit normal, arrhythmia or pacemaker presence, and clinician concern. Eleven patients were enrolled between January 2020 and December 2022. Magnesium sulfate bolus (50 mg/kg) followed by intravenous infusion (15 mg/kg/h) was initiated in the operating room and extended postoperatively (maximum 48 h). Serum magnesium levels were monitored serially. To prioritize safety, infusion dose was decreased by 5 mg/kg/h for levels greater than 3.5 mg/dL. Clinical team otherwise followed standard multimodal pain practice. Primary outcome was oral morphine equivalent per kg per day during intensive care course (maximum 7 days). Secondary outcomes focused primarily on magnesium safety, including hemodynamic variables, electrolyte variables, respiratory support, and opioid-related side effects. There were no serious adverse events. Treatment group trended toward slightly higher intravenous fluid requirement (~1 bolus), however no increase in blood product. Treatment and control groups were otherwise comparable in targeted outcomes and overall adverse event profile. Use of a high-dose magnesium sulfate infusion protocol for analgesic postoperative use in select transplant recipients appears feasible for continued optimization of study in the PICU.

Neurological manifestations of hypermagnesemia: a narrative review

Hypermagnesemia is a rare but potentially fatal electrolyte disorder. High serum magnesium levels have been associated with the development of neurological manifestations such as dysautonomia, muscle weakness, respiratory failure, and altered level of consciousness from drowsiness to coma. Although rare, some subjects, such as those with chronic renal failure and those taking magnesium supplements or medications, are at risk of developing this condition. Recognizing this electrolyte alteration promptly allows for an immediate initiation of a therapeutic strategy that is often resolutive when addressed in time. This paper aims to review the neurological complications associated with hypermagnesemia, their pathophysiology, and management.

The potential value of exosomes as adjuvants for novel biologic local anesthetics

The side effects of anesthetic drugs are a key preoperative concern for anesthesiologists. Anesthetic drugs used for general anesthesia and regional blocks are associated with a potential risk of systemic toxicity. This prompted the use of anesthetic adjuvants to ameliorate these side effects and improve clinical outcomes. However, the adverse effects of anesthetic adjuvants, such as neurotoxicity and gastrointestinal reactions, have raised concerns about their clinical use. Therefore, the development of relatively safe anesthetic adjuvants with fewer side effects is an important area for future anesthetic drug research. Exosomes, which contain multiple vesicles with genetic information, can be released by living cells with regenerative and specific effects. Exosomes released by specific cell types have been found to have similar effects as many local anesthetic adjuvants. Due to their biological activity, carrier efficacy, and ability to repair damaged tissues, exosomes may have a better efficacy and safety profile than the currently used anesthetic adjuvants. In this article, we summarize the contemporary literature about local anesthetic adjuvants and highlight their potential side effects, while discussing the potential of exosomes as novel local anesthetic adjuvant drugs.

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.

An Emerging Role for Epigenetics in Cerebral Palsy

Cerebral palsy is a set of common, severe, motor disabilities categorized by a static, nondegenerative encephalopathy arising in the developing brain and associated with deficits in movement, posture, and activity. Spastic CP, which is the most common type, involves high muscle tone and is associated with altered muscle function including poor muscle growth and contracture, increased extracellular matrix deposition, microanatomic disruption, musculoskeletal deformities, weakness, and difficult movement control. These muscle-related manifestations of CP are major causes of progressive debilitation and frequently require intensive surgical and therapeutic intervention to control. Current clinical approaches involve sophisticated consideration of biomechanics, radiologic assessments, and movement analyses, but outcomes remain difficult to predict. There is a need for more precise and personalized approaches involving omics technologies, data science, and advanced analytics. An improved understanding of muscle involvement in spastic CP is needed. Unfortunately, the fundamental mechanisms and molecular pathways contributing to altered muscle function in spastic CP are only partially understood. In this review, we outline evidence supporting the emerging hypothesis that epigenetic phenomena play significant roles in musculoskeletal manifestations of CP.

Magnesium Sulfate Enables Patient Immobilization during Moderate Block and Ameliorates the Pain and Analgesic Requirements in Spine Surgery, Which Can Not Be Achieved with Opioid-Only Protocol: A Randomized Double-Blind Placebo-Controlled Study

Spine surgery is painful despite the balanced techniques including intraoperative and postoperative opioids use. We investigated the effect of intraoperative magnesium sulfate (MgSO₄) on acute pain intensity, analgesic consumption and intraoperative neurophysiological monitoring (IOM) during spine surgery. Seventy-two patients were randomly allocated to two groups: the Mg group or the control group. The pain intensity was significantly alleviated in the Mg group at 24 h (3.2 ± 1.7 vs. 4.4 ± 1.8, p = 0.009) and 48 h (3.0 ± 1.2 vs. 3.8 ± 1.6, p = 0.018) after surgery compared to the control group. Total opioid consumption was reduced by 30% in the Mg group during the same period (p = 0.024 and 0.038, respectively). Patients in the Mg group required less additional doses of rocuronium (0 vs. 6 doses, p = 0.025). Adequate IOM recordings were successfully obtained for all patients, and abnormal IOM results denoting warning criteria (amplitude decrement >50%) were similar. Total intravenous anesthesia with MgSO₄ combined with opioid-based conventional pain control enables intraoperative patient immobilization without the need for additional neuromuscular blocking drugs and reduces pain intensity and analgesic requirements for 48 h after spine surgery, which is not achieved with only opioid-based protocol.

Resistance to Neuromuscular Blockade by Rocuronium in Surgical Patients with Spastic Cerebral Palsy

Individuals with spastic cerebral palsy (CP) often exhibit altered sensitivities to neuromuscular blocking agents (NMBAs) used for surgical intubation. We assessed usage of the NMBA rocuronium in patients with spastic CP and evaluated potential modifiers of dosing including gross motor function classification system (GMFCS) level, birthweight, gestational age, and the use of anticonvulsant therapy. In a case-control study, surgical patients with spastic CP (n = 64) or with idiopathic or non-neuromuscular conditions (n = 73) were enrolled after informed consent/assent. Patient data, GMFCS level, anticonvulsant use, and rocuronium dosing for intubation and post-intubation neuromuscular blockade were obtained from medical records. Findings reveal participants with CP required more rocuronium per body weight for intubation than controls (1.00 ± 0.08 versus 0.64 ± 0.03 mg/kg; p < 0.0001). Dosing increased with GMFCS level (Spearman's rho = 0.323; p = 0.005), and participants with moderate to severe disability (GMFCS III-V) had elevated rocuronium with (1.21 ± 0.13 mg/kg) or without (0.86 ± 0.09 mg/kg) concurrent anticonvulsant therapy. Children born full-term or with birthweight >2.5 kg in the CP cohort required more rocuronium than preterm and low birthweight counterparts. Individuals with CP exhibited highly varied and significant resistance to neuromuscular blockade with rocuronium that was related to GMFCS and gestational age and weight at birth.

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.

Efficacy of oral magnesium therapy in the treatment of chronic constipation in spastic cerebral palsy children: a randomized controlled trial

BACKGROUND

Constipation is a common problem in children with spastic cerebral palsy (sCP) with a prevalence that reaches 75%. We hypothesized that treating constipation in those children will improve their health and shorten time spent in daily care. Our aim was to evaluate the efficacy and safety of oral magnesium sulfate for treating chronic constipation in children with sCP.

METHODS

A prospective, double-blinded randomized control trial was carried out involving 100 children aged 2-12 years with sCP (level III-V of the Gross Motor Functional Classification system) and chronic constipation. They were followed up in the Pediatric neurology clinic, Children's hospital, Ain Shams University, May 2017- January 2019. The intervention group (O-Mg) received oral magnesium sulfate 1 mL/kg/day daily for 1 month compared to the placebo. Outcome measures were constipation improvement and decrease in bowel evacuation time after 1 month.

RESULTS

Initially, weekly bowel movements, constipation scores and stool consistency were comparable in both groups. After 1 month of regular administration of oral magnesium sulfate, the constipation score, stool frequency and consistency improved compared to the placebo group (P < 0.001). Effective safe treatment was achieved in 31 (68%) and 4 (9.5%) patients in the O-Mg and placebo groups, respectively (RR, 2.95; 95% CI 2.0-4.5) (P < 0.001). Painful bowel evacuation attempts spent by mothers decreased from 25 (55.6%) of the cases initially to 10 (22%) cases after one month in the O-Mg group (P = 0.001). In contrast, in the placebo group, the decrease went from 21 (50%) cases initially to 18 (42.9%) after 1 month and was not significant (P = 0.5).

CONCLUSIONS

Oral magnesium sulfate seems effective in alleviating chronic constipation and pain experience in children with sCP. Consequently, saving maternal time spent in daily bowel evacuation attempts.

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.

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.

Magnesium sulfate reduces the rocuronium dose needed for satisfactory double lumen tube placement conditions in patients with myasthenia gravis

Background

Using a minimum dose of neuromuscular blockade (NMB) to achieve intubation condition is one of the goals in anaesthesia management of patients with myasthenia gravis (MG) for thoracoscopic (VATS) thymectomy. However, tracheal intubation with double lumen tube (DLT) could be challenging if intubation condition is not optimal. This double-blind randomised controlled study was designed to investigate whether magnesium sulfate would reduce the rocuronium dose needed for DLT intubation and improve the DLT placement condition for patients with MG who were scheduled for video-assisted thoracoscopic (VATS) thymectomy.

Methods

Recruited patients were randomly assigned to receive magnesium sulfate 60 mg.kg^− 1 or normal saline (control) prior to the administration of NMB. Titrating dose of rocuronium was administered to achieve train of four (TOF) ratio less than 10% before DLT intubation. The primary outcome was the rocuronium dose required to achieve TOF ratio less than 10%. The secondary outcome was intubation condition for DLT placement.

Results

Twenty-three patients had received magnesium sulfate and 22 patients had received normal saline before rocuronium administration. The required rocuronium dose [mean (standard deviation)] were 0.10 (0.05) mg.kg^− 1 and 0.28(0.17) mg.kg^− 1 in patients who had magnesium sulfate and normal saline respectively(P < 0.0001). With a similar depth of neuromuscular blockade and depth of anaesthesia, 100% of patients in the magnesium sulfate group and 72.7% of patients in the control group showed excellent intubation condition (P = 0.027) respectively. The patients in both groups had similar emergence characteristics.

Conclusions

Magnesium sulfate is associated with a decrease in rocuronium requirement for an optimal DLT intubation condition in patients with MG for VATS thymectomy.

Trial registration

Clinical Trial Registry of China (http://www.chictr.org.cn) identifier: ChiCTR-1800017696, retrospectively registered on August 10, 2018.

Effects of magnesium chloride on rocuronium-induced neuromuscular blockade and sugammadex reversal in an isolated rat phrenic nerve-hemidiaphragm preparation: An in-vitro study

BACKGROUND

Magnesium potentiates the effects of nondepolarising muscle relaxants. However, few studies have used magnesium chloride (MgCl2). Sugammadex reverses neuromuscular block by steroidal nondepolarising muscle relaxants.

OBJECTIVES

To assess the effects of MgCl2 on rocuronium-induced neuromuscular blockade and its reversal by sugammadex.

DESIGN

In-vitro experimental study.

SETTING

Animal laboratory, Asan Medical Center, Seoul, South Korea, from 20 March 2016 to 3 April 2016.

ANIMALS

Forty male Sprague Dawley rats.

INTERVENTION

Left phrenic nerve-hemidiaphragms from 40 Sprague Dawley rats were allocated randomly to four groups (1, 2, 3 and 4 mmol l MgCl2 group, n = 10 each). Rocuronium was administered cumulatively until the first twitch of train-of-four (TOF) disappeared completely. Then, equimolar sugammadex was administered.

MAIN OUTCOME MEASURES

The effective concentration (EC) of rocuronium was obtained in each group. After administering sugammadex, recovery of the first twitch height and the TOF ratio were measured for 30 min.

RESULTS

EC50, EC90 and EC95 significantly decreased as the concentration of MgCl2 increased (all P ≤ 0.001), except the comparison between the 3 and 4 mmol l MgCl2 groups. After administration of sugammadex, the maximal TOF ratio (%) was lower in the 4 mmol l MgCl2 group than the 1 mmol l MgCl2 group [median 91.7 interquartile range (83.4 to 95.8) vs. 98.3 interquartile range (92.2 to 103.4), P = 0.049]. The mean time (s) from sugammadex injection to achieving maximal first twitch was significantly prolonged in the 4 mmol l MgCl2 group vs. the 1 mmol l MgCl2 and 2 mmol l MgCl2 groups [1483.9 (± 237.0) vs. 1039.0 (± 351.8) and 926.0 (± 278.1), P = 0.022 and 0.002, respectively].

CONCLUSION

Increases in MgCl2 concentration reduce the ECs of rocuronium. In addition, administering sugammadex equimolar to the administered rocuronium shows limited efficacy as MgCl2 concentration is increased.

TRIAL REGISTRATION

The in-vitro study was not registered in a database.

Management of pain in children and adolescents with cerebral palsy: a systematic review

AIM

To determine the efficacy of interventions for the management of pain in children and adolescents with cerebral palsy (CP).

METHOD

Electronic databases were searched from the earliest date possible to April 2018 using a mixture of subject headings and free text. Inclusion criteria comprised of studies with (1) diagnosis of CP, (2) under the age of 18 years, (3) intervention for the management of pain, (4) outcome measure of pain, and (5) studies published in English-language peer-reviewed journals.

RESULTS

Fifty-seven studies met the eligibility criteria. Pain related to (n=number of studies): hypertonia (n=17), spastic hip disease (n=13), procedures for the management of CP (n=7), postoperative (n=18), and other (n=2). Most of the studies were of level III to level V evidence.

INTERPRETATION

There is level II evidence to support intrathecal baclofen therapy for pain secondary to hypertonia in spastic and spastic-dyskinetic CP, and non-pharmacological interventions for procedural pain and pharmacological interventions for postoperative pain. Most studies were restricted by retrospective design and limited use of validated outcome measures. Future research is needed to explore multidisciplinary interventions for chronic pain and pain secondary to dystonia. Clinicians and researchers would benefit from a standardized approach to pain assessment.

WHAT THIS PAPER ADDS

The strongest evidence exists for pharmacological treatments for postoperative pain in children and adolescents with cerebral palsy (CP). There is moderate evidence for the efficacy of intrathecal baclofen for pain related to hypertonia in predominately spastic CP. There is a lack of standardization in the assessment of pain. There is limited evidence for multimodal and non-pharmacological strategies in paediatric CP.

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.

Magnesium sulphate improves pulmonary function after video-assisted thoracoscopic surgery: A randomised double-blind placebo-controlled study

BACKGROUND

Reduced lung volumes are unavoidable after lung resection surgery. Magnesium sulphate (MgSO4) administration has been reported to reduce the requirement for neuromuscular blocking drugs and postoperative analgesics in surgical patients.

OBJECTIVE

To investigate the effect of MgSO4 on pulmonary function after video-assisted thoracoscopic surgery (VATS).

DESIGN

A randomised, double-blind, placebo-controlled trial.

SETTING

A university tertiary care centre.

PATIENTS

Sixty-six patients scheduled for pulmonary lobectomy or segmentectomy via VATS.

INTERVENTION

Patients were allocated to one of two groups: the Mg (MgSO4 50 mg kg intravenously for 10 min, followed by a continuous infusion of 15 mg kg h during surgery) or the control (same volume of 0.9% saline).

MAIN OUTCOME MEASURES

Pulmonary function tests [forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and peak expiratory flow rate] were measured before surgery and at three time points after surgery (2, 24 and 48 h postoperatively) using a portable spirometer. Twelve months after surgery, pulmonary function test values were repeated at a regular outpatient follow-up visit.

RESULTS

FEV1 at 24 (1.7 ± 0.6 vs. 1.3 ± 0.5 l, P = 0.033) and 48 h (1.7 ± 0.6 vs. 1.4 ± 0.5 l, P = 0.021) and FVC at 24 (2.0 ± 0.8 vs. 1.6 ± 0.6 l, P = 0.038) and 48 h (2.2 ± 0.8 vs. 1.7 ± 0.7 l, P = 0.008) after surgery were significantly greater in the Mg group. Patients in the Mg group required less rocuronium than those in the control group (64.2 ± 19.9 vs. 74.9 ± 20.3 mg, respectively; P = 0.041). Consumption of postoperative patient-controlled analgesia was also significantly less at 24 and 48 h after surgery in the Mg group (P = 0.022 and 0.015, respectively), although pain scores and rescue analgesics were comparable. Five patients in the control group were diagnosed with postoperative pneumonia using clinical and radiological criteria before discharge. FEV1 and FVC at 12 months after surgery were not different between the two groups.

CONCLUSION

Intraoperative administration of MgSO4 improved pulmonary function and reduced the need for rocuronium and postoperative analgesics in patients who underwent VATS.

TRIAL REGISTRATION

cris.nih.go.kr identifier: KCT0001410.

Pain Management in Athletes With Impairment: A Narrative Review of Management Strategies

OBJECTIVE

To review the literature related to different treatment strategies for the general population of individuals with amputation, spinal cord injury, and cerebral palsy, as well as how this may impact pain management in a correlated athlete population.

DATA SOURCES

A comprehensive literature search was performed linking pain with terms related to different impairment types.

MAIN RESULTS

There is a paucity in the literature relating to treatment of pain in athletes with impairment; however, it is possible that the treatment strategies used in the general population of individuals with impairment may be translated to the athlete population. There are a wide variety of treatment options including both pharmacological and nonpharmacological treatments which may be applicable in the athlete.

CONCLUSIONS

It is the role of the physician to determine which strategy of the possible treatment options will best facilitate the management of pain in the individual athlete in a sport-specific setting.

Magnesium sulfate in pediatric anesthesia: the Super Adjuvant

Magnesium is an essential chemical element in all organisms, intervening in most cellular enzymatic reactions; thus, its importance in homeostasis and as a therapeutic tool in highly challenging patients such as pediatrics. The primary purpose of this paper was to review the role of magnesium sulfate as an adjuvant drug in pediatric anesthesia. This compound already has the scientific backing in certain aspects such as analgesia or muscle relaxation, but only theoretical or empirical backing in others such as organ protection or inflammation, where it seems to be promising. The multitude of potential applications in pediatric anesthesia, its high safety, and low cost make magnesium sulfate could be considered a Super Adjuvant.

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 role of magnesium sulfate in tracheal intubation without muscle relaxation in patients undergoing ophthalmic surgery

Background:

Muscle relaxant agents usually use to facilitate tracheal intubation; however, sometimes limitations exist. Magnesium (Mg) sulfate is a candidate for muscle relaxant substitute. This study was designed to determine the effect of Mg sulfate accompanied with propofol and fentanyl in patients undergoing ophthalmic surgery.

Materials and Methods:

In a double-blind randomized protocol and before tracheal intubation, Mg sulfate 40, 45, or 50 mg/kg in 100 ml of saline (Groups 1–3, respectively) or saline alone (Group 4) were administrated intravenously in 100 patients (n = 25 in each group) with the American Society of Anesthesiologist (ASA) physical Status I, II, or III. The patients' intubation condition in all subjects were determined and described.

Results:

The patients' demographic data including age, ASA, systolic and diastolic blood pressures, intraocular pressure, and body mass index were not significantly different between the groups. A better mask ventilation feasibility in Mg sulfate 45 group (Group 2) was observed when compared with Mg sulfate 50 (Group 3) (P = 0.022) and saline group (Group 4) (P = 0.021). In addition, the vocal cord movement and muscle relaxant requirement in saline group were significantly different from others groups (P < 0.05). The laryngoscopic time in saline group was greater than other groups significantly (P < 0.0001).

Conclusion:

Intravenous administration of Mg sulfate accompanied with propofol and fentanyl facilitates the tracheal intubation without neuromuscular blocking agents. To avoid Mg level increasing in plasma; however, the low dose of Mg sulfate is suggested.

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.

Comparative Evaluation of Dexmedetomidine and Magnesium Sulphate on Propofol Consumption, Haemodynamics and Postoperative Recovery in Spine Surgery: A Prospective, Randomized, Placebo Controlled, Double-blind Study

PURPOSE

Dexmedetomidine and magnesium sulfate have been used in anesthesia as adjuvant to provide hemodynamic stability and anesthetic agents sparing effect. We compared these effects of dexmedetomidine and magnesium sulfate in spine surgeries.

METHODS

Ninety patients were randomly assigned to three groups. Group D received dexmedetomidine loading dose 1 µg/kg over a period of 15 minutes and maintenance 0.5 µg/kg/h throughout the surgery. Group M received magnesium sulfate loading dose 50 mg/kg over a period of 15 minutes and maintenance 15 mg/kg/h throughout the surgery. Group C received same volume of normal saline. Heart rate (HR) and blood pressure values were recorded at various intervals. The induction and maintenance doses of anesthetics and recovery parameters were also recorded.

RESULTS

Heart rate in group D and group M were significantly decreased (p<0.05) during the whole intraoperative period compared to preoperative values. There was a significant difference in HR values between group C, D and M, during the whole intraoperaive period (p<0.05). Blood pressure values were statistically significantly lower in the group D and group M compared to group C after intubation and all time observations of surgery (p<0.05). Both drugs reduced the anesthetic agent's requirement during surgery. However, the recovery parameters were statistically significant increase with magnesium sulphate compared to dexmedetomidine and control groups.

CONCLUSION

Dexmedetomidine is more effective than magnesium sulfate for maintaining the hemodynamic stability in spine surgeries. Both these drugs also reduce the requirements of anesthetic agents. Recovery from dexmedetomidine is as rapid as control group compared to magnesium sulfate.

Prospective, randomized and controlled trial on magnesium sulfate administration during laparoscopic gastrectomy: effects on surgical space conditions and recovery profiles

BACKGROUND

The degree of neuromuscular blockade is one of the important factors that determine the condition of surgical space during laparoscopic surgery. Magnesium sulfate potentiates the actions of neuromuscular blocking agent, and we hypothesized that intraoperative magnesium sulfate infusion may improve surgical space condition during laparoscopic surgery.

METHODS

Eighty-four patients undergoing elective laparoscopic gastrectomy were randomized to receive isotonic saline (group C) or magnesium sulfate (group M, loading dose with 50 mg/kg over 10 min and then 15 mg/kg/h by continuous infusion) to maintain the moderate neuromuscular blockade using rocuronium. Two experienced surgeons scored the quality of surgical space condition using a 5-point surgical rating scale (SRS). The secondary outcomes included recovery profiles, postoperative pain and adverse events.

RESULTS

The SRS in group M was higher than that of group C. The proportion of patients with a SRS of 5 (optimal) was 2.7 % in the group C and 40.5 % in the group M (P < 0.0001) although a lower amount of rocuronium was required in group M than group C [24.2 (6.5) mg/h for group M vs. 27.5 (6) mg/h for group C; P = 0.017]. Pain after operation site was less severe in group M than in group C at postoperative 24 h (P = 0.009). Recovery profiles and adverse events were similar between the two groups.

CONCLUSION

Intraoperative administration of magnesium sulfate improved the quality of surgical space conditions and decreased neuromuscular blocking agent requirement and postoperative pain in patients undergoing laparoscopic gastrectomy.

Effect of magnesium sulphate on bi-spectral index (BIS) values during general anesthesia in children

BACKGROUND

Magnesium was reported to reduce both the anesthetic requirements and the period needed to reach a bi-spectral index value of 60 when used intra-operatively (Br J Anaesth 83:302-20, 1999; Anesth Analg 20:1273-5, 1988; Br J Anaesth 89:594-8, 2002; Anesth Analg 87:206-10, 1998; Br J Anaesth 89:594-8, 2002; Br J Anaesth 94:438-41, 2005) and to minimize the emergence agitation (Anaesthesia 61:1058-63, 2006). Previous studies examined the influence of magnesium on the anesthetic requirements while the bi-spectral Index values were kept within a constant range. We evaluated the effect of intraoperative magnesium on the bi-spectral index values during pediatric anesthesia while we kept other anesthetic variables unchanged.

METHODS

Eighty pediatric patients with ASA physical status I, age 2-8 years and scheduled for minor infra-umbilical elective procedures included in a prospective randomized controlled study. We randomly divided patients into two groups. Group I (40 patients); received a bolus dose 50 mg/kg of magnesium sulphate followed by an infusion at rate of 15 mg/kg/h throughout the procedure. Group II (40 patients); received the same amount in the form of ringer acetate for blinding. We compared between the groups regarding: 1) BIS values. 2) Hemodynamic parameters. 3) Arterial oxygen saturation 4) End-tidal CO2 5) Respiratory rate and 6) Tidal volume.

RESULTS

Magnesium group (Group I) showed significantly lower BIS values and shorter time to achieve BIS values below 60. Respiratory parameters (tidal volume and respiratory rate) were significantly lower in the magnesium group. Otherwise, no significant differences between the study group and the control group were detected.

DISCUSSION

Our study has the advantage of evaluating the direct effect of magnesium sulphate on the Bi-spectral index scale with keeping other intraoperative factors almost constant (as the type of operations, induction and maintenance techniques, end-tidal anesthetic concentration, analgesia and mode of ventilation) for accurate assessment.

CONCLUSION

Magnesium produced significantly lower BIS values, less time to reach BIS values below 60, lower tidal volume and lower respiratory rate during pediatric general anesthesia.

TRIAL REGISTRATION

Pan African Clinical Trial Registry, www.pactr.org , PACTR201312000666231 . Registered at 6 October 2013.

Magnesium: a versatile drug for anesthesiologists

Magnesium sulfate has been used in preeclampsia patients in order to prevent seizure. It is also used for the treatment of arrhythmia and asthma and as an anesthetic adjunct in patients undergoing surgery for pheochromocytoma. However, its potentiating effects on perioperative analgesia and muscle relaxation have drawn attention recently. These characteristics of magnesium (anesthetic- and analgesic-sparing effect) enable anesthesiologists to reduce the use of anesthetics during surgery and the use of analgesics after surgery. Magnesium sulfate has a high therapeutic index and cost-effectiveness. Considering these diverse characteristics useful for anesthesia, appropriate use of magnesium sulfate would improve surgical outcome and patients' satisfaction.

Effects of valproic acid and magnesium sulphate on rocuronium requirement in patients undergoing craniotomy for cerebrovascular surgery

BACKGROUND

Many anti-epileptics cause resistance to non-depolarizing neuromuscular blocking agents, but this has not been reported for valproic acid (VPA). We hypothesized that VPA would increase the rocuronium requirement and that magnesium sulphate (MgSO(4)) may reduce this increase.

METHODS

Fifty-five patients undergoing cerebrovascular surgeries were studied. Subjects were allocated into three groups at a 1:1:1 ratio: Groups VM, VC, and C. Groups VM and VC were given VPA premedication; Group C was not. A rocuronium injection (0.6 mg kg(-1) i.v.) was administered to Group VM, followed by MgSO(4) as a 50 mg kg(-1) i.v. bolus and 15 mg kg(-1) h(-1) infusion. The same volume of 0.9% saline was administered to the other groups. Supplementary rocuronium (0.15 mg kg(-1)) was given whenever the train-of-four count reached 2. Rocuronium requirements (primary outcome), mean arterial pressure (MAP), heart rate (HR), nausea, vomiting, shivering, and use of anti-emetics and nicardipine were compared.

RESULTS

Group VC showed the highest rocuronium requirement [mg kg(-1) h(-1): 0.47 (0.08) vs 0.33 (0.12) (Group C), 0.31 (0.07) (Group VM); P<0.001]. MAP, intraoperative HR, nausea, vomiting, shivering, and use of anti-emetics and nicardipine were not significantly different among the groups. Postoperative HR was lower in Group VM than in Group VC.

CONCLUSIONS

VPA increased the rocuronium requirement, and MgSO(4) infusion attenuated this increase.

The effects of magnesium sulfate on neuromuscular blockade by cisatracurium during induction of anesthesia

BACKGROUND

During the induction of anesthesia, patients are at risk of aspiration while awaiting full muscle relaxation. Magnesium has been shown to have synergistic effects with neuromuscular blocking drugs. We tested if magnesium, as an adjunct, increases the speed of onset of muscle relaxation, thereby decreasing the risk of aspiration.

METHODS

Eighty-eight American Society of Anesthesiologists (ASA) physical status 1 or 2 patients were randomly assigned to three groups. Group Mg-0 received 100 mL of normal saline, whereas groups Mg-25 and Mg-50 received magnesium sulfate at doses of 25 and 50 mg/kg, respectively. Anesthesia was induced with thiopental 5 mg/kg and cisatracurium 0.15 mg/kg. A peripheral nerve stimulator and single-twitch test was performed on the ulnar nerve until the twitch responses to stimulation had disappeared, and the times were recorded. Then the patients were intubated and anesthesia was maintained with 100 μg/kg/min of propofol. The intensity of blockade was measured at regular time intervals with the post-tetanic count test.

RESULTS

The mean times to muscle relaxation in groups Mg-0, Mg-25, and Mg-50 were 226, 209, and 188 s, respectively (P = 0.047). The intensity of the block increased with the dose of magnesium, and remained highest in group Mg-50 at all times measured (P < 0.05). The speed of onset and the intensity of muscle relaxation increased as higher doses of magnesium were used.

CONCLUSION

The increased speed of onset of muscle relaxation produced by magnesium is not substantial enough to justify its use in combination with cisatracurium in rapid sequence induction.

A randomised controlled trial comparing rocuronium priming, magnesium pre-treatment and a combination of the two methods

We investigated whether magnesium sulphate combined with rocuronium priming shortens the onset of neuromuscular blockade, compared with these methods used alone. Ninety-two patients scheduled for general anaesthesia were randomly allocated to one of four groups: controls were given 0.6 mg.kg(-1) rocuronium; patients in the prime group were given 0.06 mg.kg(-1) rocuronium three minutes before a further dose of 0.54 mg.kg(-1) rocuronium; patients in the magnesium group were given an infusion of 50 mg.kg(-1) magnesium sulphate before rocuronium and patients in the magnesium and prime group were given both the magnesium sulphate and the priming dose of rocuronium. Tracheal intubation was attempted 40 s after the rocuronium injection. The time to onset of neuromuscular blockade was the primary outcome; duration of blockade and tracheal intubating conditions were also measured. The group allocation and study drugs were coded and concealed until statistical analyses were completed. The magnesium and prime group had the shortest mean (SD) onset time (55 (16)s; p < 0.001), and best tracheal intubating conditions (p < 0.05). No statistical difference was found for the duration of blockade. As for adverse events, a burning or heat sensation was reported in eight (35%) and six (26%) patients in the magnesium and magnesium and prime groups, respectively. The combination of magnesium sulphate and rocuronium priming accelerated the onset or neuromuscular blockade and improved rapid-sequence intubating conditions, compared with either magnesium sulphate or priming used alone.