Effects of magnesium sulfate on traumatic brain edema in rats

svarietyofneuroprotectiveagentshavebeensynthesized .However ,besidessomeagentspresentlybeingevaluatedinclinicaltrails ,mostofthesecompoundshavelimitedclinicalusebecauseofneurotoxicityandbehavioralsideeffects .Recently ,severalstudiesdemonstratedthattraumaticinjurytothebraincausesadecreaseinmagnesiumconcentrationcorrelatedwithinjuryseverity .1Sincethen ,moreandmoreattentionhasbeen paidtoMgSO4 foritsneuroprotectiveeffects .Magnesiumsulfatehasbeenwidelyusedinclinicalpracticeforalmost 10 0 years.…     

Effects of magnesium sulfate on traumatic brain edema in ats

OBJECTIVE: To investigate the effects of magnesium sulfate on traumatic brain edema and explore its possible mechanism. METHODS: Forty-eight Sprague-Dawley (SD) rats were randomly divided into three groups: Control, Trauma and Treatment groups. In Treatment group, magnesium sulfate was intraperitoneally administered immediately after the induction of brain trauma. At 24 h after trauma, total tissue water content and Na(+), K(+), Ca(2+), Mg(2+) contents were measured. Permeability of blood-brain barrier (BBB) was assessed quantitatively by Evans Blue (EB) dye technique. The pathological changes were also studied. RESULTS: Water, Na(+), Ca(2+) and EB contents in Treatment group were significantly lower than those in Trauma group (P<0.05). Results of light microscopy and electron microscopy confirmed that magnesium sulfate can attenuate traumatic brain injury and relieve BBB injury. CONCLUSIONS: Treatment with MgSO4 in the early stage can attenuate traumatic brain edema and prevent BBB injury.     

Does ketamine or magnesium affect posttonsillectomy pain in children?

BACKGROUND: Many previous studies have suggested a role for the N-methyl-D-aspartate (NMDA) receptor antagonists ketamine and magnesium in decreasing postoperative pain and analgesic requirements in adults, but none has investigated these medications in children. METHODS: This randomized, double-blind, placebo-controlled study evaluated the effects of ketamine and magnesium in children undergoing tonsillectomy. Eighty patients, aged 3-12 years, were randomly assigned to four groups. Patients received either ketamine 0.15 mg.kg-1, magnesium sulphate 30 mg.kg-1, ketamine 0.15 mg.kg-1 plus magnesium sulphate 30 mg.kg-1, or placebo intravenously 5 min prior to the start of surgery. Intraoperative analgesia was standardized, and included fentanyl and dexamethasone. RESULTS: There were no differences among the groups with respect to pain assessment postoperatively. Compared with placebo, the treatment groups did not require less fentanyl in the postanaesthesia recovery room or consume less codeine in the first 24-h postoperatively. There was no evidence of synergism between ketamine and magnesium. There were no differences among the groups in the incidence of nausea, vomiting, sedation, bleeding, or dreaming postoperatively. CONCLUSION: This study did not demonstrate a decrease in pain or analgesic consumption in children undergoing tonsillectomy when pretreated with a small dose of ketamine and/or magnesium.     

Is magnesium sulfate by the intrathecal route efficient and safe?

The polypharmacological approach to the treatment of postoperative pain has become routine in an attempt to minimize the adverse side effects of opioids. Magnesium sulphate is a noncompetitive antagonist of the N-methyl-d-aspartate (NMDA) receptor and thus can modify nociceptive modulation. Intravenous administration of magnesium sulphate can improve postoperative analgesia and decrease the requirement for postoperative opiates, but the effects are inconsistent and have not been reliably accompanied by a reduction in the incidence of morphine-related adverse events. Several studies have shown that the administration of magnesium by the intrathecal route is safe and, in combination with opiates, extends the effect of spinal anaesthesia in both animal and human studies. The analysis of these studies justifies further investigation of the use of magnesium sulphate by the intrathecal route.     

Large-dose intravenous methotrexate-induced cutaneous toxicity: can oral magnesium oxide reduce pain?

IMPLICATIONS: Chemotherapy for cancer is associated with pain including cutaneous vasculitis. Magnesium, an N-methyl-D-aspartic acid-receptor antagonist, was used successfully to treat an adolescent with pain caused by cutaneous vasculitis secondary to methotrexate therapy.     

Does magnesium prophylaxis reduce the incidence of atrial fibrillation following coronary bypass surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether prophylactic magnesium reduces the incidence of atrial fibrillation post cardiac surgery. Altogether 113 papers were found using the reported search, of which 21 represented the best evidence on this topic. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses were tabulated. We conclude that prophylactic magnesium reduces the incidence of arrhythmias post cardiac surgery with a number needed to treat of only 13 to prevent an episode of supraventricular arrhythmia.     

Is intrathecal magnesium sulfate safe and protective against ischemic spinal cord injury in rabbits?

We performed three sets of experiments to investigate the safety of intrathecal magnesium and to determine its optimal dose for protection, if any, against ischemic spinal cord injury in rabbits. First, we examined neurotoxicity of 0.3, 1, 2, or 3 mg/kg of magnesium sulfate (n = 6 each). Significant sensory dysfunction was observed in the 3-mg/kg group 7 days after administration. Motor dysfunction was found in two rabbits in both the 2- and 3-mg/kg groups. The area of destruction in laminae V-VII was observed in one, two, and one rabbit in the 1-, 2-, and 3-mg/kg groups, respectively. Second, we investigated the temporal profile (6 h, 48 h, and 96 h [n = 3 each]) of histopathologic changes after 3 mg/kg of magnesium sulfate and confirmed similar changes in the rabbits with motor dysfunction at 48 and 96 h. Third, we evaluated the effects of 0.3 mg/kg or 1 mg/kg of magnesium sulfate or saline (n = 6 each) administered before ischemia on hindlimb motor function and histopathology after spinal cord ischemia (15 min). Magnesium did not improve neurologic or histopathologic outcome 96 h after reperfusion. The results indicate that intrathecal magnesium has a risk of neurotoxicity and shows no evidence of protective effects against ischemic spinal cord injury.     

Effects of magnesium sulphate on postoperative coagulation, measured by rotational thromboelastometry (ROTEM(®))

We investigated the effects of magnesium sulphate on blood coagulation profiles using rotational thromboelastometry in gynaecological patients undergoing pelviscopic surgery. Patients were randomly allocated to the magnesium group (n = 20) or control group (n = 20). The magnesium group received magnesium sulphate (50 mg.kg(-1) followed by continuous infusion of 15 mg.kg(-1).h(-1)), whereas the control group received the same volume of isotonic saline according to the same methods. Mean (SD) postoperative serum magnesium levels were 1.58 (0.17) mmol.l(-1) in the magnesium group compared with 0.98 (0.06) mmol.l(-1) in the control group (p < 0.001). Postoperative clotting time, clot formation time, α-angle and maximum clot firmness of INTEM, and clot formation time, α-angle, and maximum clot firmness of EXTEM were significantly different between the two groups (p < 0.05). Intra-operative infusion of magnesium sulphate seems to attenuate postoperative hypercoagulability by maintaining magnesium levels at the upper limit of the normal range.     

Effects of magnesium sulfate on brain mitochondrial respiratory function in rats after experimental traumatic brain injury

Objective:To study the effects of magnesium sulfate on brain mitochondrial respiratory function in rats after experimental traumatic brain injury and the possible mechanism.Methods:The middle degree brain injury in rats was made by BIM-III multi-function impacting machine.The brain mitochondrial respiratory function was measured with oxygen electrode and the ultra-structural changes were observed with transmission electron microscope(TEM).Results:1.The brain mitochondrial respiratory stage III and respiration control rate reduced significantly in the untreated groups within 24 and 72 hours.But treated Group A showed certain degree of recovery of respiratiory function;treated Group B showed further improvement.2. Untreated Group,treated Groups A and B had different degrees of mitochondrial ultra-structural damage respectively, which could be attenuated after the treatment with magnesium sulfate.Conclusions:The mitochondrial respiratory function decreases significantly after traumatic brain injury.But it can be apparently improved after magnesium sulfate management along with the attenuated damage of mitochondria discovered by TEM.The longer course of treatment can obtain a better improvement of mitochondrial respiratory function.     

Does magnesium offer any additional benefit in patients having anti-arrhythmic treatment for atrial fibrillation following cardiac surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether treatment with magnesium in addition to an anti-arrhythmic is beneficial to patients who have gone into atrial fibrillation after cardiac surgery. Altogether 466 papers were identified using the below mentioned search, of which 8 papers presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group, relevant outcomes and weaknesses were tabulated. We conclude that while the literature on magnesium prophylaxis and non-cardiac surgical studies on magnesium therapy for atrial fibrillation suggest that magnesium may be of benefit, there are currently no studies in post-cardiac surgery atrial fibrillation to support the use of magnesium therapy for these patients.     

Continuous infusion of magnesium–lidocaine mixture for prevention of ventricular arrhythmias during on-pump coronary artery bypass grafting surgery

BackgroundDuring on-pump coronary artery bypass grafting (CABG) surgery, the incidence of reperfusion ventricular fibrillation (VF) is high and post-bypass ventricular arrhythmias are common. Both reperfusion VF and ventricular arrhythmias can cause additional myocardial injury to the already ischemic myocardium. This trial aimed to test the assumption that continuous combined magnesium and lidocaine infusion would be efficient and long lasting for the prevention of post-myocardial vascularization ventricular arrhythmias including VF.MethodsEighty ASA III patients, who were candidates for CABG surgery, were randomly assigned into two groups: Group I (control group, n = 40) and Group II (Group ML, n = 40). After endotracheal intubation, patients of control group were infused with plain normal saline in a volume equivalent to study drugs’ mixture volume. Patients of Group ML were infused with magnesium–lidocaine mixture to achieve a bolus of magnesium sulfate 2 g and lidocaine 100 mg followed by continuous infusion of Mg sulfate 500 mg/h and lidocaine 1 mg/min. The initial cardiac rhythm after aortic cross clamp (ACC) release and the occurrence of post-CPB significant ventricular arrhythmias were recorded.ResultsThe incidences of reperfusion VF and post-CPB ventricular arrhythmias in Group ML were significantly lower than that in control group (22.5% vs. 72.5%) (P < 0.001) and (7.5% vs. 25%) (P < 0.05), respectively. However, in Group ML, this beneficial effect was associated with higher incidence of sinus bradycardia (72.5% vs. 17.5%) and hence pacing needs (22.5% vs. 0.0%) when compared with control group.ConclusionOur study concluded that, during on-pump CABG surgery, the combined administration of magnesium and lidocaine as a bolus dose starting after intubation followed by continuous infusion reduced the incidence of reperfusion VF by 62% and post-CPB ventricular arrhythmias by 70% on expense of increased the incidence of sinus bradycardia and pacing.     

The ionized fraction of serum total magnesium in hemodialysis patients: is it really lower than in healthy subjects?

AIM OF THE STUDY: Based on data in the literature, it remains unclear whether the ionized fraction of serum total magnesium (Mg) is lower in chronic hemodialysis (HD) patients compared to healthy subjects. PATIENTS AND METHODS: The ionized fraction of serum total Mg was investigated in 49 HD patients, pre- and post-dialysis, and compared to 30 healthy controls. The quality of the analytical performance of the Mg measurements has been emphasized by applying a reference method and/or rigorous internal quality control (IQC). In addition, the ionized fraction of serum total calcium (Ca) was measured in both populations, because the results for Mg should be related to those of Ca. RESULTS: In HD patients, the ionized fraction of serum total Mg was on average 65% (pre-dialysis 64.2% and post-dialysis 66.2%). In healthy controls, the ionized fraction was 64.9%. When the analytical variability was taken into account, no significant differences (p > 0.05) were observed between pre- and post-dialysis samples and controls. For Ca, an ionized fraction of 55.3% was found in HD patients, which was not significantly different from the fraction obtained in the control group (55.7%). CONCLUSION: The present study demonstrates that, compared to healthy controls, the ionized fraction of serum total Mg is not different in hemodialysis patients.     

Does the addition of magnesium to bupivacaine improve postoperative analgesia of ultrasound-guided thoracic paravertebral block in patients undergoing thoracic surgery?

Purpose

Magnesium is a plentiful intracellular cation that has been reported to possess analgesic effect. The present study was aimed to see whether addition of magnesium to bupivacaine in thoracic paravertebral block (TPVB) improved the analgesic effect after thoracic surgery.

Materials and methods

Fifty adult patients undergoing elective open thoracic surgery were divided into two equal groups. Group I received 12 ml of 0.5 % bupivacaine plus 0.9 % saline (3 ml) whereas Group II received 12 ml of 0.5 % bupivacaine plus 150 mg magnesium sulphate (in 3 ml 0.9 % saline) for TPVB. The following parameters were assessed: onset, dermatomal levels and duration of sensory block, duration of analgesia, visual analogue scale (VAS) for pain, postoperative intravenous morphine consumption, pulmonary function tests (peak expiratory flow rate [PEFR], forced expiratory volume in 1 s [FEV1] and forced vital capacity [FVC]) before and 24 h after surgery, and complications from the drugs and technique.

Results

Group II patients showed a significantly longer sensory block duration (224.6 ± 59.3 vs 160.1 ± 55.2 min, P < 0.05), longer duration of analgesia (388.8 ± 70.6 vs 222.2 ± 61.6 min, P < 0.05), less VAS during the postoperative 48 h, less need for postoperative morphine (16.2 ± 7.4 vs 29.5 ± 11.1 mg, P < 0.05) and lower incidence of somnolence (0 [0 %] vs 5 [20 %], P < 0.05). Furthermore, postoperative pulmonary function tests (PEFR, FEV1 and FVC) were significantly better in Group II whereas there was no significant difference between both groups regarding the sensory block dermatomal level or hemodynamic data.

Conclusion

Addition of magnesium to bupivacaine in TPVB improved the analgesic effect of bupivacaine in patients undergoing thoracic surgery.     

Inverse correlation between serum magnesium and parathyroid hormone in peritoneal dialysis patients: a contributing factor to adynamic bone disease?

Background Secondary hyperparathyroidism (SHPTH) is present in many patients with end-stage renal disease (ESRD) and has been linked to uremic bone disease. Parathyroid hormone (PTH) levels are affected by calcium, vitamin D, and phosphorus. Recent data suggests that serum magnesium may also modulate PTH levels. Objective The aim of this retrospective study was to investigate the impact of different calcium (Ca) and magnesium (Mg) concentrations of dialysis solutions on serum Mg and serum PTH levels in peritoneal dialysis (PD) patients. Patients and methods Two groups of PD patients-group A (n = 17) on “standard” Ca and Mg dialysis solution (SCa–MgD) (Ca: 1.62 mmol/l, Mg: 0.75 mmol/l and Lactate 35 mmol/l), and group B (n = 29) on “low” Ca and Mg dialysis solution (LCa–MgD) (Ca: 1.25 mmol/l, Mg: 0.25 mmol/l and Lactate 40 mmol/l), on PD for more than 6 months, were studied. Calcium carbonate (CaCO₃) was used as the phosphate (P) binder in 87% (40/46) of the patients. Biochemical parameters were evaluated every 1–2 months over 6 months and the mean values were computed. Results No significant differences were found between the two groups in all parameters except for serum Mg and PTH. Serum Mg was higher in SCa–MgD group compared to those in the LCa–MgD group (1.05 ± 0.19 vs 0.90 ± 0.23 mmol/l, respectively) and serum PTH was higher in LCa–MgD group compared to those in SCa–MgD group (72.3 ± 64.2 vs 31.1 ± 39.0 pmol/l, respectively) even though serum Ca was not different. There was a statistically significant inverse correlation between serum Mg and PTH levels (r = −0.357, p < 0.05). Conclusion Serum Mg is lower and serum PTH higher in patients dialyzed with lower Mg concentration dialysis solution compared to those with higher Mg concentration dialysis solution. Our study confirms previous reports that serum Mg may have a suppressive role on PTH synthesis and/or secretion, and thus may play a role in pathogenesis of adynamic bone disease that often develops in patients on chronic PD with high calcium and high magnesium concentrations.     

Bioabsorbable magnesium versus standard titanium compression screws for fixation of distal metatarsal osteotomies – 3 year results of a randomized clinical trial

Background

For the treatment of hallux valgus commonly distal metatarsal osteotomies are performed. Persistent problems due to the hardware and the necessity of hardware removal has led to the development of absorbable implants. To overcome the limitations of formerly used materials for biodegradable implants, recently magnesium has been introduced as a novel implant material. This is the first study showing mid-term clinical and radiological (MRI) data after using magnesium implants for fixation of distal metatarsal osteotomies.