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

Magnesium alleviates extracellular histone-induced apoptosis and defective bacterial phagocytosis in macrophages by regulating intracellular calcium signal

Extracellular histones have been determined as important mediators of sepsis, which induce excessive inflammatory responses in macrophages and impair innate immunity. Magnesium (Mg2+), one of the essential nutrients of the human body, contributes to the proper regulation of immune function. However, no reports indicate whether extracellular histones affect survival and bacterial phagocytosis in macrophages and whether Mg2+ is protective against histone-induced macrophage damage. Our clinical data revealed a negative correlation between circulating histone and monocyte levels in septic patients, and in vitro experiments confirmed that histones induced mitochondria-associated apoptosis and defective bacterial phagocytosis in macrophages. Interestingly, our clinical data also indicated an association between lower serum Mg2+ levels and reduced monocyte levels in septic patients. Moreover, in vitro experiments demonstrated that Mg2+ attenuated histone-induced apoptosis and defective bacterial phagocytosis in macrophages through the PLC/IP3R/STIM-mediated calcium signaling pathway. Importantly, further animal experiments proved that Mg2+ significantly improved survival and attenuated histone-mediated lung injury and macrophage damage in histone-stimulated mice. Additionally, in a cecal ligation and puncture (CLP) + histone-induced injury mouse model, Mg2+ inhibited histone-mediated apoptosis and defective phagocytosis in macrophages and further reduced bacterial load. Overall, these results suggest that Mg2+ supplementation may be a promising treatment for extracellular histone-mediated macrophage damage in sepsis.

MAGNESIUM SULFATE AMELIORATES HISTONE-INDUCED COAGULATION DYSFUNCTION AND LUNG DAMAGE IN MICE

ABSTRACT

Introduction: Extracellular histones have been determined as significant mediators of sepsis, which can induce endothelial cell injury and promote coagulation activation, and ultimately contribute to multiorgan failure. Evidence suggests that magnesium sulfate (MgSO 4 ) exerts a potential coagulation-modulating activity; however, whether MgSO 4 ameliorates histone-induced coagulation dysfunction and organ damage remains unclear. Methods: To measure circulating histone levels, blood specimens were collected from septic patients and mice, and the relationship between circulating histone levels, coagulation parameters, and Mg 2+ levels in sepsis was investigated. Furthermore, to explore the possible protective effects of MgSO 4 , we established a histone-induced coagulation model in mice by intravenous histone injection. The survival rate of mice was assessed, and the histopathological damage of the lungs (including endothelial cell injury and coagulation status) was evaluated using various methods, including hematoxylin and eosin staining, immunohistochemistry, immunofluorescence, electron microscopy, and quantitative polymerase chain reaction. Results: The circulating histone levels in septic patients and mice were significantly associated with several coagulation parameters. In septic patients, histone levels correlated negatively with platelet counts and positively with prothrombin time and D-dimer levels. Similarly, in cecal ligation and puncture mice, histones correlated negatively with platelet counts and positively with D-dimer levels. Interestingly, we also observed a positive link between histones and Mg 2+ levels, suggesting that Mg 2+ with anticoagulant activity is involved in histone-mediated coagulation alterations in sepsis. Further animal experiments confirmed that MgSO 4 administration significantly improved survival and attenuated histone-mediated endothelial cell injury, coagulation dysfunction, and lung damage in mice. Conclusion: These results suggest that therapeutic targeting of histone-mediated endothelial cell injury, coagulation dysfunction, and lung damage, for example, with MgSO 4 , may be protective in septic individuals with elevated circulating histone levels.

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.

Blood Products, Crystalloids, and Rapid Infusion: An Experimental Study With Magnesium

OBJECTIVES

Calcium and magnesium are concentration-dependent pro- and anticoagulant cofactors, and magnesium behaves similarly to calcium in the presence of citrate. The authors hypothesized that magnesium can cause clot formation (primary objective) when mixed with coagulation factor-containing blood products diluted with different crystalloids in a rapid- infuser reservoir. A secondary objective was the observation of any infuser alarms and stops in the event of clotting.

DESIGN

An experimental in vitro study with blood products, crystalloids, magnesium, and calcium in a rapid infuser with a reservoir using a closed-loop system.

SETTING

Anesthesia research laboratory at an urban academic tertiary medical center PARTICIPANTS: Not applicable.

INTERVENTIONS

Exposure of fresh frozen plasma (FFP) and packed red blood cells alone (control) or in combination with either normal saline (NS), lactated Ringer's solution (LR), or Plasma-Lyte A (PL) to increasing concentrations of magnesium sulphate (MgSO₄) up to 1 g. After each incremental MgSO₄ change, the authors applied a specific pump-flow sequence in a closed-loop system with a rapid-infuser reservoir, and if no clot was observed, the authors incrementally added calcium chloride (CaCl₂) up to 1 g.

MEASUREMENTS AND MAIN RESULTS

Observation of macroscopic clot and time to event, as well as occurrence and type of any pump alarms or stops. LR experiments resulted in clot observation in the reservoir by a dedicated observer after MgSO₄ 275 ± 206 mg (95% confidence interval [CI], 9-541). Adding MgSO₄ 1 g in the NS, PL, or the control experiments did not result in clot observation. Only when CaCl₂ 166.7 ± 51.64 mg (95% CI, 112.0-22.01) was added to the combination of blood products alone or mixed with NS and PL, clotting occurred. The mean FFP volume was 281 ± 48.6 mL (range, 204-340 mL) and was not different between groups (p = 0.44). Pump alarms and stops were inconsistent.

CONCLUSIONS

The addition of magnesium to a combination of LR with coagulation factor- containing blood products consistently resulted in a visible blood clot in the rapid-infuser reservoir in the authors' experimental setup. In addition to MgSO₄ 1 g in the control, NS, and PL experiments, CaCl₂ is needed before a clot can be observed.

Intraoperative MgSO4 infusion protects oxygenation and lung mechanics in COPD patients during general anesthesia. A randomized clinical trial

BACKGROUND

The purpose of this study was to examine the effects of an intraoperative MgSO₄ infusion on arterial oxygenation and lung mechanics in patients with moderate COPD undergoing cancer larynx surgery under general anesthesia (GA). Our primary outcome was arterial oxygenation determined by the PaO₂ and PaO₂ /FiO₂ . The secondary outcomes were lung mechanics (peak airway pressure, airway plateau pressure, dead space, lung compliance, airway resistance) and postoperative complications.

METHODS

In this randomized controlled double-blinded trial, 40 patients with an ASA classifications II and/or III who were diagnosed with moderate COPD and who were scheduled for cancer larynx surgery under GA were randomly allocated into two equal groups, the target (Mg group) and control group (C group). In the Mg group, 30 mg/kg of 10% MgSO₄ solution was administered intravenously for over 20 minutes as the loading dose, followed by the continuous infusion of 10 mg/kg/hr In the C group, the same loading and maintenance infusion rates were administered using 0.9% saline.

RESULTS

Unlike the C group (baseline "T0" to post-infusion "T1" interval 294 ± 97 vs 238 ± 71 mm Hg, respectively, P = .04 ± SD), the Mg group exhibited preserved intraoperative PaO₂ (T0 to T1 interval 271 ± 89 vs 257 ± 53 mm Hg, respectively, P = .54 ± SD) and PaO₂ /FiO₂ (C group T0 to T1 interval 404 ± 81 vs 349 ± 84, P = .04 and Mg group 394 ± 91 vs 379 ± 95, P = .61, respectively), and these effects were modest. Further, compared to the C group, the Mg group exhibited lower airway resistance, dead space, airway plateau pressure, and peak airway pressure, and higher dynamic compliance. The postoperative PaO₂ and PaO₂ /FiO₂ were higher in the Mg group compared to the C group.

CONCLUSIONS

Intraoperative infusion of MgSO₄ in patients with moderate COPD undergoing laryngectomy surgery under GA produces mild perioperative protective effects on both arterial oxygenation and lung mechanics.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03461328; registration date: 8 March 2018.

Effects of perioperative magnesium sulfate infusion on intraoperative blood loss and postoperative analgesia in patients undergoing posterior lumbar spinal fusion surgery: A randomized controlled trial

OBJECTIVE

Many studies have suggested the anti-nociceptive role for magnesium either as an adjunct for postoperative pain. Although several studies have been carried out to evaluate the anti-nociceptive effect of magnesium, there is still considerable uncertainty.

PATIENTS AND METHODS

Eighty patients who underwent posterior spinal fusion were randomly divided into two groups (magnesium and saline). Changes in cell count, magnesium concentration and coagulation status were assessed one hour after operation at both group and compared to baseline. At recovery room, their pain score was assessed according to 10 points visual analogue scale (VAS). Morphine consumption was evaluated at regular times after the surgery by patient controlled analgesia (PCA) device.

RESULTS

VAS scores were significantly lower in the magnesium group. Cumulative PCA morphine consumption after the surgery was significantly lower in the magnesium group. Pre and postoperative values for haemoglobin, platelet count, Prothrombin Time (PT), fibrinogen were not significantly different. There was a significant increase in activated Partial Thromboplastin Time (aPTT), International Normalized Ratio (INR), and bleeding time (BT), one hour after the operation in the magnesium group but intraoperative blood loss was similar in both groups.

CONCLUSIONS

Perioperative magnesium sulfate infusion improves the postoperative analgesia, decreases the amount of morphine consumption after the operation and does not change the intraoperative bleeding in patients undergoing posterior spinal fusion surgery.

Magnesium Therapy Improves Rotational Thromboelastometry Findings Prior to Liver Transplantation: A Randomized Clinical Trial

An important challenge during orthotopic liver transplantation (OLT) is optimal coagulation management. There are diverse studies regarding effect of Mg sulfate on coagulation system. This study evaluates the impact of Mg sulfate on the coagulation parameters of the rotational thromboelastometry (ROTEM) in patients about to undergo OLT. In this randomized clinical trial, 60 patients who were going to undergo OLT were randomly allocated into two groups. In the Mg group, the patients received a 1.5 g infusion of Mg 5 min before the surgical incision. In the control group, patients received a physiological saline instead of Mg. Plasma Mg levels before and after the infusions were measured in both groups. Also, three ROTEM tests: EXTEM, INTEM and FIBTEM were performed before and after the infusions. Baseline mean plasma magnesium levels were within normal range in the control and Mg groups: 2.06 and 2.18 mg/dl, respectively. After magnesium therapy, the mean plasma Mg level in the Mg group increased to 2.78 mg/dl in compared to the control group that was 2.01 mg/dl (P < 0.000). Mean value of the clotting time (CT) in the magnesium group were significantly decreased from 129.50 ± 7.76, 381.86 ± 8.51 and 114.26 ± 6.80 to 86.13 ± 3.4, 209.33 ± 6.68 and 81.56 ± 5.01 in the EXTEM, INTEM, and FIBTEM respectively after intervention in the Mg group (P = 0.001). Among patients with end-stage liver diseases who have ROTEM evidence of hypocoagulability, magnesium could correct CT parameter of the ROTEM tests.

Comparing remifentanil, magnesium sulfate, and dexmedetomidine for intraoperative hypotension and bleeding and postoperative recovery in endoscopic sinus surgery and tympanomastoidectomy

The study aimed to compare remifentanil, magnesium sulfate, and dexmedetomidine for intraoperative hypotension, bleeding volume, and recovery time in endoscopic sinus surgery and tympanomastoidectomy (TM). A double-blind clinical trial enrolled the patients undergoing endoscopic nasal sinus surgery and TM at Amirkabir Hospital (Arak, Iran), who were randomly assigned into three groups dexmedetomidine (DEX), remifentanil (REM), and magnesium sulfate (MgSO₄) to which we intravenously administered 1 μg/kg DEX, an intravenous dose of 1 μg/kg REM, and 40 mg/kg of intravenous MgSO₄, respectively. The blood loss, blood pressure (BP), heart ratio (HR), oxygen saturation (SaO₂), and recovery time were recorded. Significant differences were found statistically in bleeding rates among all groups (P = 0.0001). The least amount of blood loss (very mild bleeding) was observed at 82.85% in the DEX group. BP and HR were lower in this group than those in the other groups. While recovery score was significantly different in the three groups (P = 0.007), the recovery time was the highest in the DEX group, while the least in the REM group. Based on the present results Dexmedetomidine seems to better prevent from bleeding than the others. Moreover, DEX can cause lower BP and HR in subjects with lower propofol administration, but the recovery time is longer. This study was registered by IRCT2017021114056N11 in Iranian Registry Clinical Center.

Efficacy of Adjuvant Magnesium for Posttonsillectomy Morbidity in Children: A Meta-analysis

Objectives The perioperative administration of magnesium is known to reduce postoperative morbidities in adults, such as pain, agitation, and laryngospasm. The objective is to assess the effects of perioperative magnesium as the adjuvant to tonsillectomy as compared with tonsillectomy in children. Data Source Five databases (PubMed, SCOPUS, Embase, Web of Science, Cochrane). Method Two authors independently searched databases up to January 2017. We compared perioperative magnesium administration (magnesium groups) with no administration of magnesium (control group). The following outcomes were measured: postoperative pain intensity, analgesics administration, or other morbidities (laryngospasm, agitation, postoperative bleeding) in the postoperative 24 hours. Additionally, to evaluate the discrepancy of effects according to different administration routes, subgroup analyses regarding effects according to systemic or local administration of magnesium were performed. Results Nine prospective randomized controlled studies (n = 615) that evaluated the effect of magnesium in children having undergone tonsillectomy met inclusion criteria. Compared with control group, the time for first analgesic requirement was significantly delayed in magnesium groups (standardized mean difference = 0.75; 95% CI, 0.20-1.31; P = .0079). Laryngospasm (log odds ratio = -1.09; 95% CI,-2.11 to -0.07; P = .0362) and agitation score (standardized mean difference = -0.67; 95% CI, -0.97 to -0.36; P < .0001) in the recovery room also significantly decreased in magnesium groups. In subgroup analyses regarding pain and laryngospasm-related measurements, local administration of magnesium was shown to be more effective at reducing postoperative morbidities. Conclusions Perioperative magnesium regardless of route may offer pain, agitation, and laryngospasm relief without adverse effects in pediatric tonsillectomy. Based on the high heterogeneity of results within some parameters, further studies need to be performed to affirm these results.

The role of ionized calcium and magnesium in regional citrate anticoagulation and its impact on inflammatory parameters

INTRODUCTION

Regional anticoagulation with citrate has been found to be superior to heparin in terms of biocompatibility, and numerous protocols for regional citrate anticoagulation have been published, while a consensus on the target concentration of ionized calcium (Ca2+) in the extracorporeal circuit has not been reached so far.

METHODS

The aim of this in vitro study was to assess the impact of different citrate concentrations on coagulation as well as on complement activation and cytokine secretion and to investigate the impact of ionized magnesium (Mg2+) on these parameters.

RESULTS

We found that citrate effectively reduced coagulation, complement activation, and cytokine secretion in a dose-dependent manner and that a target Ca2+ concentration of 0.2-0.25 mM was required for efficient anticoagulation. Mg2+ triggered complement activation as well as interleukin (IL)-1β secretion in lipopolysaccharide (LPS)-stimulated whole blood in a dose-dependent manner and independently of Ca2+. Additionally, it was found to reduce activated clotting time (ACT) in samples with low Ca2+ levels, but not at physiological Ca2+.

CONCLUSIONS

Taken together, our data support the notion that regional citrate anticoagulation results in decreased release of inflammatory mediators in the extracorporeal circuit, requiring the depletion of both, Ca2+ and Mg2+.

Changes in blood coagulation after colloid administration in patients undergoing total hip arthroplasty: comparison between pentastarch and tetrastarches, a randomized trial

Background

Hydroxyethyl starch (HES) solutions are used as plasma expanders for correcting hypovolemia, but can lead to impaired coagulation. We evaluated the changes in hematological and hemostatic profiles with three types of HES.

Methods

Patients were randomized to receive volume replacement with 10% pentastarch 260/0.45 in 0.9% saline (Group-PEN, n = 25), 6% tetrastarch 130/0.4 in 0.9% saline (Group-TET_S, n = 25), or 6% tetrastarch 130/0.4 in a balanced electrolyte solution (Group-TET_B, n = 25). Coagulation was assessed using rotational thromboelastometry (ROTEM®) and other laboratory tests were performed, including measurements of hematological and hemostatic parameters and electrolytes.

Results

Post-operative ROTEM® parameters changed toward hypocoagulable states in all groups. The post-operative parameters of EXTEM and FIBTEM were more impaired in Group-PEN than in Group-TET_B. The percentage change in INTEM clot formation time (P = 0.004) and α-angle (P = 0.003) were smaller in Group-TET_S and Group-TET_B than in Group-PEN. The percentage change in the FIBTEM maximum clot firmness was greatest in Group-PEN (P = 0.011). The international normalized ratio of prothrombin time (P < 0.001) and the activated partial thromboplastin time (P < 0.001) were significantly prolonged in Group-PEN compared to those of Group-TET_B.

Conclusions

The 6% HES 130/0.4 in a balanced electrolyte solution seemed to have less of an impact on blood coagulation than the 10% HES 260/0.45. No differences in hemostatic profile were observed between the balanced electrolyte and saline-based 6% HES 130/0.4.

The effects of acute normovolaemic haemodilution on peri-operative coagulation in total hip arthroplasty

Total hip arthroplasty results in substantial blood loss in the peri-operative period. We evaluated the effects of acute normovolaemic haemodilution on blood coagulation and platelet function in 11 patients undergoing total hip arthroplasty. We performed acute normovolaemic haemodilution and haematological tests, rotational thromboelastometry (ROTEM(®) ) and whole-blood impedance aggregometry. Blood samples were obtained at three time points: (i) before the initiation of acute normovolaemic haemodilution; (ii) 20 min after completion of acute normovolaemic haemodilution; and (iii) 20 min after retransfusion. After acute normovolaemic haemodilution, ROTEM parameters demonstrated hypocoagulability. Clot formation time of INTEM was increased by 31.6% (p = 0.016), whereas the α-angle and maximum clot formation of INTEM decreased by 8.1% (p = 0.032) and 3.0% (p = 0.013) respectively, compared with baseline values. Clotting time and clot formation time of EXTEM were increased by 40.8% (p = 0.042) and 31.3% (p = 0.016), respectively, whereas the α-angle and maximum clot formation of EXTEM were decreased by 11.9% (p = 0.020) and 9.5% (p = 0.013), respectively. The maximum clot formation of FIBTEM decreased by 35.1% compared with the baseline value (p = 0.007). Following retransfusion, ROTEM values returned to baseline; clot formation time decreased and the α-angle and maximum clot formation increased. There were no significant changes in platelet aggregation during the study. At 20 min after the end of acute normovolaemic haemodilution, the international normalised ratio of prothrombin time was increased compared with the baseline value (p = 0.003). We conclude that acute normovolaemic haemodilution resulted in a hypocoagulable state compared with baseline values and that coagulation parameters returned to normal after retransfusion.

[Comparison of the effects of magnesium sulphate and dexmedetomidine on surgical vision quality in endoscopic sinus surgery: randomized clinical study]

BACKGROUND AND OBJECTIVES

Even a small amount of bleeding during endoscopic sinus surgery can corrupt the endoscopic field and complicate the procedure. Various techniques, including induced hypotension, can minimize bleeding during endoscopic sinus surgery. The aim of this study was to compare the surgical vision quality, haemodynamic parameters, postoperative pain, and other effects of magnesium, a hypotensive agent, with that of dexmedetomidine, which was initially developed for short-term sedation in the intensive care unit but also is an alpha 2 agonist sedative.

METHOD

60 patients between the ages of 18 and 45 years were divided into either the magnesium group (Group M) or the dexmedetomidine group (Group D). In Group M, magnesium sulphate was given at a pre-induction loading dose of 50mgkg(-1) over 10min and maintained at 15mgkg(-1)h(-1); in Group D, dexmedetomidine was given at 1mcgkg(-1) 10min before induction and maintained at 0.6mcgkg(-1)h(-1). Intraoperatively, the haemodynamic and respiratory parameters and 6-point intraoperative surgical field evaluation scale were recorded. During the postoperative period, an 11-point numerical pain scale, the Ramsay sedation scale, the nausea/vomiting scale, the adverse effects profile, and itching parameters were noted.

RESULTS

Group D showed a significant decrease in intraoperative surgical field evaluation scale scale score and heart rate. The average operation time was 50min, and Group M had a higher number of prolonged surgeries. No significant difference was found in the other parameters.

CONCLUSIONS

Due to its reduction of bleeding and heart rate in endoscopic sinus surgery and its positive impacts on the duration of surgery, we consider dexmedetomidine to be a good alternative to magnesium.

Analgesic effect of magnesium in post-tonsillectomy patients: a prospective randomised clinical trial

The aim of this study was to assess the analgesic, bleeding and nausea/vomiting effects of magnesium with and without metamizol on post-tonsillectomy patients. This prospective and randomised clinical trial included 54 patients aged 18-63 years who were scheduled for elective tonsillectomy. The patients were randomly divided into two groups and administered either magnesium with metamizol or only metamizol. They had been classified as physical status class I and II using the American Society of Anesthesiologists guidelines. All patients underwent the same surgical procedure performed by a single surgeon. The groups did not differ according to age, sex, or duration of anaesthesia or surgery. Postoperative pain, bleeding and nausea/vomiting were evaluated using the VAS and bleeding and nausea/vomiting scores on the first, fifth and tenth days. On the first, fifth and tenth postoperative days, the VAS scores of the magnesium with metamizol group were significantly lower than those of the metamizol-only group (p1 = 0.001; p5 = 0.015; p10 = 0.015). There were no significant differences in postoperative bleeding and nausea/vomiting scores between the two groups (p = 0.425 and p = 0.258, respectively). This study showed that magnesium enhanced the analgesic effect on post-tonsillectomy pain. Use of magnesium with an analgesic drug may be beneficial for management of post-tonsillectomy pain.