Magnesium sulfate in eclampsia and pre-eclampsia: pharmacokinetic principles

Effects of magnesium sulfate combined with labetalol on inflammatory stress and pregnancy outcome of patients with gestational hypertension

Gestational hypertension (GH) is a common disorder during pregnancy that can cause adverse pregnancy outcomes. In the present study, magnesium sulfate (MgSO4) combined with labetalol was used for clinical treatment. Randomized controlled trial was conducted in 100 patients with GH, documented in the Department of Obstetrics and Gynecology (Taicang TCM Hospital) grouped into the experimental (Expt) and control (Ctrl) groups (n=50 cases/group). The Ctrl group was treated with MgSO4, whereas the Expt group was treated with MgSO4 + labetalol. The systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the Expt group were not significantly different from those in the Ctrl group (P>0.05). By contrast, the SBP and DBP were significantly lower after treatment than those before treatment in both groups (P<0.05). Whole blood viscosity, plasma viscosity and hematocrit were significantly lower in the Expt group compared with those in the Ctrl group after treatment (P<0.05). High mobility group box-1 protein, homocysteine and serum cystatin C levels in the Expt group were also markedly lower than those in the Ctrl group after treatment (P<0.05). In the Expt group, the rate of spontaneous vaginal delivery was much higher, whereas the rates of cesarean section and postpartum hemorrhage were markedly lower than those in the Ctrl group (P<0.05). The occurrence of fetal intrauterine distress, placental abruption, neonatal asphyxia, premature birth and neonatal death were also significantly lower in the Expt group than those in the Ctrl group (P<0.05). In conclusion, MgSO4 + labetalol could improve inflammatory stress and the hemodynamics of patients with GH, and may have a marked antihypertensive effect. Thus, it may improve pregnancy outcome and reduce perinatal complications.

Associations of essential metals with the risk of aortic arch calcification: a cross-sectional study in a mid-aged and older population of Shenzhen, China

Vascular calcification is a strong predictor of cardiovascular events. Essential metals play critical roles in maintaining human health. However, the association of essential metal levels with risk of aortic arch calcification (AoAC) remains unclear. We measured the plasma concentrations of nine essential metals in a cross-sectional population and evaluated their individual and combined effects on AoAC risk using multiple statistical methods. We also explored the mediating role of fasting glucose. In the logistic regression model, higher quartiles of magnesium and copper were associated with the decreased AoAC risk, while higher quartile of manganese was associated with higher AoAC risk. The least absolute shrinkage and selection operator penalized regression analysis identified magnesium, manganese, calcium, cobalt, and copper as key metals associated with AoAC risk. The weighted quantile sum regression suggested a combined effect of metal mixture. A linear and positive dose-response relationship was found between manganese and AoAC in males. Moreover, blood glucose might mediate a proportion of 9.38% of the association between manganese exposure and AoAC risk. In summary, five essential metal levels were associated with AoAC and showed combined effect. Fasting glucose might play a significant role in mediating manganese exposure-associated AoAC risk.

A Comprehensive Review of Magnesium Sulfate Infusion: Unveiling the Impact on Hemodynamic Stability During Laryngoscopy and Tracheal Intubation in Ear, Nose, and Throat Surgeries

This comprehensive review explores the potential of magnesium sulfate infusion in mitigating hemodynamic instability during laryngoscopy and tracheal intubation in ear, nose, and throat (ENT) surgeries. Hemodynamic fluctuations during these procedures pose challenges, and magnesium sulfate, with its vasodilatory, antiarrhythmic, and neuroprotective properties, emerges as a promising intervention. The review critically examines existing literature, emphasizing patient selection criteria, dosage protocols, and a comparative analysis with other hemodynamic stabilizers. Safety considerations, including known adverse effects and risk-benefit assessments, and monitoring and management strategies are elucidated. The implications for ENT surgery are discussed, highlighting the potential for enhanced hemodynamic management and individualized approaches. The review concludes with a call for continued research, emphasizing the ongoing evolution of understanding and practice incorporating magnesium sulfate into perioperative care. The insights offered aim to guide clinicians in navigating this dynamic landscape for improved patient outcomes in ENT surgeries.

Uterotonics, magnesium sulphate and antibiotics during childbirth and peripartum: Important obstetric drugs for the anaesthesiologist

The main causes of maternal mortality are comorbidities, hypertensive pregnancy syndrome, obstetric haemorrhage, and maternal sepsis. For this reason, uterotonics, magnesium sulphate, and antibiotics are essential tools in the management of obstetric patients during labour and in the peripartum period. These drugs are widely used by anaesthesiologists in all departments, and play a crucial role in treatment and patient safety. For the purpose of this narrative review, we performed a detailed search of medical databases and selected studies describing the use of these drugs in patients during pregnancy, delivery and the pospartum period. Uterotonics, above all oxytocin, play an important role in the prevention and treatment of pospartum haemorrhage, and various studies have shown that in obstetric procedures, such as scheduled and emergency caesarean section, they are effective at lower doses than those hitherto accepted. We also discuss the use of carbetocin as an effective alternative that has a therapeutic advantage in certain clinical circumstances. Magnesium sulphate is the gold standard in the prevention and treatment of eclampsia, and also plays a neuroprotective role in preterm infants. We describe the precautions to be taken during magnesium administration. Finally, we discuss the importance of understanding microbiology and the pharmacology of antibiotics in the management of obstetric infection and endometritis, and draw attention to the latest trends in antibiotic regimens in labour and caesarean section.

Use of non-invasive cardiac monitoring to guide discontinuation of postpartum magnesium sulfate in individuals with preeclampsia with severe features

OBJECTIVES

To determine the utility of using total peripheral systemic vascular resistance assessed using non-invasive cardiac monitor for individualizing the duration of postpartum magnesium sulfate in individuals with preeclampsia with severe features.

STUDY DESIGN

Single center pilot randomized controlled trial in which singleton pregnant individuals with preeclampsia with severe features were randomized to 24 h of postpartum magnesium sulfate per standard of care (control group) or individualized duration of postpartum magnesium sulfate based on reduction in post-delivery systemic vascular resistance (intervention group). Systemic vascular resistance was assessed with non-invasive cardiac monitoring using the Cheetah® system. A 30 % reduction (maintained for 1 h) from baseline post-delivery systemic vascular resistance was used as a cutoff for discontinuation of postpartum magnesium sulfate. Our primary outcome was duration of postpartum magnesium sulfate use in hours. Secondary outcomes included a composite of maternal morbidities associated with preeclampsia.

RESULTS

Of 53 individuals enrolled, we excluded 6 from this analysis due to insufficient data to assess primary outcome. Baseline characteristics of the control (n = 26) and intervention (n = 21) groups were similar. Six (28.6 %) individuals in intervention group met the systemic vascular resistance criteria and had their postpartum magnesium sulfate discontinued before 24 h. The duration of postpartum magnesium sulfate infusion was shorter in the intervention group (21.6 ± 4.7 h; range: 7-24 h) compared with control group (24 h, p = 0.02). There was no difference in secondary outcomes between the two groups. There was no difference in adverse outcomes in individuals that had magnesium discontinued earlier than 24 h.

CONCLUSION

Non-invasive monitoring of systemic vascular resistance can be a valuable tool to individualize the duration of postpartum magnesium sulfate for preeclampsia with severe features. These findings should be conformed in a larger trial.

Postoperative Magnesium Sulfate Repletion Decreases Narcotic Use in Abdominal-Based Free Flap Breast Reconstruction

BACKGROUND

 Microsurgical breast reconstruction after mastectomy is now the standard of care for breast cancer patients. However, the costs and resources involved in free flap reconstruction can vary across different medical settings. To enhance patient outcomes in a cost-effective manner, we investigated the effect of intravenous magnesium sulfate (IV Mg) on postoperative opioid usage in this context.

METHODS

 A retrospective chart review was performed on all consecutive patients who underwent abdominal-based free flap breast reconstruction in a single institute following an enhanced recovery after surgery (ERAS) protocol. Patients who received IV Mg were compared with those who did not receive supplementation. Serum magnesium levels at different time points, narcotic consumption in units of oral morphine milligram equivalents (MMEs), and other postoperative recovery parameters were compared.

RESULTS

 Eighty-two patients were included. Those who received IV Mg on postoperative day 0 (n = 67) showed significantly lower serum magnesium levels before repletion (1.5 vs. 1.7 mg/dL, p = 0.004) and significantly higher levels on postoperative day 1 after repletion (2.2 vs. 1.7 mg/dL, p = 0.0002) compared to patients who received no magnesium repletion (n = 13). While both groups required a similar amount of narcotics on postoperative day 0 (20.2 vs. 13.2 MMEs, p = 0.2), those who received IV Mg needed significantly fewer narcotics for pain control on postoperative day 1 (12.2 MMEs for IV Mg vs. 19.8 MMEs for No Mg, p = 0.03). Recovery parameters, including maximal pain scores, postoperative mobilization, and length of hospital stay, did not significantly differ between the two groups.

CONCLUSION

 This is the first study to describe the potential analgesic benefits of routine postoperative magnesium repletion in abdominal-based free flap reconstruction. Further research is necessary to fully understand the role of perioperative magnesium supplementation as part of an ERAS protocol.

The Efficacy of Magnesium Sulfate (MgSO4) Wet Dressing in Reducing Eyelid Swelling and Bruising after Blepharoplasty: A Randomized, Controlled, and Observer-Blinded Assessment Study

The purpose of this study was to evaluate the effects of wet dressing with 50% magnesium sulfate (MgSO4) solution on decreasing eyelid swelling and bruising after blepharoplasty. Fifty-eight patients (23 male and 35 female) who underwent bilateral blepharoplasty were enrolled in our randomized clinical trial. One side of the periorbital area (upper and lower eyelids) per patient received a wet dressing with 50% MgSO4 solution randomly, and the other side was cooled with an ice pack from the first postoperative day for two consecutive days (30 minutes per time and twice a day). The eyelid edema and ecchymosis were evaluated and classified using respective graded scales. Degrees of eyelid edema were similar after surgery in both groups (p > 0.05) and were significantly decreased with time. Compared with the cooled ones, less swelling was observed in the eyelids treated by MgSO4 wet compress on postoperative day 5 (p < 0.01). Both the incidence and area of ecchymosis were lower in the MgSO4 group than those in the cooling group (p < 0.01 and p < 0.05, respectively). Moreover, the majority of patients (39/58, 67.2%) indicated a preference for MgSO4 wet dressing over ice cooling. MgSO4 wet dressing can be conveniently applied to alleviate eyelid swelling and reduce recovery time after blepharoplasty.

A Bioactive Gelatin-Methacrylate Incorporating Magnesium Phosphate Cement for Bone Regeneration

Maintaining proper mechanical strength and tissue volume is important for bone growth at the site of a bone defect. In this study, potassium magnesium phosphate hexahydrate (KMgPO4·6H2O, MPC) was applied to gelma-methacrylate hydrogel (GelMA) to prepare GelMA/MPC composites (GMPCs). Among these, 5 GMPC showed the best performance in vivo and in vitro. These combinations significantly enhanced the mechanical strength of GelMA and regulated the degradation and absorption rate of MPC. Considerably better mechanical properties were noted in 5 GMPC compared with other concentrations. Better bioactivity and osteogenic ability were also found in 5 GMPC. Magnesium ions (Mg2+) are bioactive and proven to promote bone tissue regeneration, in which the enhancement efficiency is closely related to Mg2+ concentrations. These findings indicated that GMPCs that can release Mg2+ are effective in the treatment of bone defects and hold promise for future in vivo applications.

Maternal antioxidant micronutrient deficiencies among pre-eclamptic women in Enugu, Nigeria: a cross-sectional analytical study

OBJECTIVES

To determine the prevalence of antioxidant micronutrient deficiencies in pregnant women with pre-eclampsia and healthy pregnant women, and to assess the relationships between trace element deficiency in pregnancy and the severity of pre-eclampsia in Enugu, Nigeria.

METHODS

We performed a secondary analysis of a cross-sectional analytical study of serum concentrations of copper, selenium, zinc, magnesium, and manganese in 81 pregnant women with pre-eclampsia and healthy pregnant women (controls) who were matched for age, gestational age, body mass index, and parity. This study was performed at the University of Nigeria Teaching Hospital, Ituku-Ozalla, Enugu. Participants' sera were analyzed with an atomic absorption spectrophotometer.

RESULTS

Trace element deficiencies were common and similar between women with pre-eclampsia and controls. However, women with pre-eclampsia were more likely to be deficient in manganese than controls (odds ratio = 2.28, 95% confidence interval: 1.90-2.75). Among the micronutrients studied, only manganese concentrations were significantly lower in women without severe symptoms of pre-eclampsia than in those with severe symptoms of pre-eclampsia.

CONCLUSIONS

Micronutrient deficiency is common in pregnant women with pre-eclampsia and in healthy pregnant women in Enugu, Nigeria. Only manganese deficiency is higher in women with pre-eclampsia than in healthy pregnant women.

Antenatal Magnesium Sulfate and adverse gastrointestinal outcomes in Preterm infants-a systematic review and meta-analysis

INTRODUCTION

To evaluate the effect of antenatal magnesium sulfate (MgSO4) on mortality and morbidity outcomes related to the gastrointestinal system (GI) in preterm infants.

METHODS

Data sources: A systematic literature search was conducted in November 2022. PubMed, CINAHL Plus with Full Text (EBSCOhost), Embase (Elsevier), and CENTRAL (Ovid) were searched. There were 6695 references. After deduplication, 4332 remained. Ninety-nine full-text articles were assessed and forty four articles were included in the final analysis.

STUDY ELIGIBILITY CRITERIA

Randomized or quasi-randomized clinical trials and observational studies that evaluated at least one of the pre-specified outcomes were included. Preterm infants whose mothers were given antenatal MgSO4 were included and whose mothers did not receive antenatal MgSO4 were the comparators. The main outcomes and measures were: Necrotizing enterocolitis (NEC) (stage ≥ 2), surgical NEC, spontaneous intestinal perforation (SIP), feeding intolerance, time to reach full feeds, and GI-associated mortality.

STUDY APPRAISAL AND SYNTHESIS METHODS

A random-effects model meta-analysis was performed to yield pooled OR and its 95% CI for each outcome due to expected heterogeneity in the studies. The analysis for each predefined outcome was performed separately for adjusted and unadjusted comparisons. All included studies were assessed for methodological quality. The risk of bias was assessed using elements of the Cochrane Collaboration's tool 2.0 and the Newcastle-Ottawa Scale for randomized controlled trials (RCTs) and non-randomized studies (NRS), respectively. The study findings were reported as per PRISMA guidelines.

RESULTS

A total of thirty-eight NRS and six RCTs involving 51,466 preterm infants were included in the final analysis. There were no increased odds of stage ≥2 NEC, (NRS : n = 45,524, OR: 0.95; 95% CI: 0.84-1.08, I2- 5% & RCT's: n = 5205 OR: 1.00; 95% CI: 0.89-1.12, I2- 0%), SIP (n = 34,186, OR: 1.22, 95% CI: 0.94-1.58, I2-30%), feeding intolerance (n = 414, OR: 1.06, 95% CI: 0.64-1.76, I2-12%) in infants exposed to antenatal MgSO4. On the contrary, the incidence of surgical NEC was significantly lower in MgSO4 exposure infants (n = 29,506 OR:0.74; 95% CI: 0.62-0.90, ARR: 0.47%). Studies assessing the effect on GI-related mortality were limited to make any conceivable conclusion. The certainty of evidence (CoE) for all outcomes was adjudged as 'very low' as per GRADE.

CONCLUSION

Antenatal magnesium sulfate did not increase the incidence of gastrointestinal-related morbidities or mortality in preterm infants. With the current evidence concerns, regarding the adverse effects of MgSO4 administration leading to NEC/SIP or GI-related mortality in preterm infants should not be a hurdle in its routine use in antenatal mothers.

Pathophysiology and treatment of adults with arrhythmias in the emergency department, part 1: Atrial arrhythmias

PURPOSE

This article, the first in a 2-part review, aims to reinforce current literature on the pathophysiology of cardiac arrhythmias and various evidence-based treatment approaches and clinical considerations in the acute care setting. Part 1 of this series focuses on atrial arrhythmias.

SUMMARY

Arrhythmias are prevalent throughout the world and a common presenting condition in the emergency department (ED) setting. Atrial fibrillation (AF) is the most common arrhythmia worldwide and expected to increase in prevalence. Treatment approaches have evolved over time with advances in catheter-directed ablation. Based on historic trials, heart rate control has been the long-standing accepted outpatient treatment modality for AF, but the use of antiarrhythmics is often still indicated for AF in the acute setting, and ED pharmacists should be prepared and poised to help in AF management. Other atrial arrhythmias include atrial flutter (AFL), atrioventricular nodal reentry tachycardia (AVNRT), and atrioventricular reentrant tachycardia (AVRT), which warrant distinction due to their unique pathophysiology and because each requires a different approach to utilization of antiarrhythmics. Atrial arrhythmias are typically associated with greater hemodynamic stability than ventricular arrhythmias but still require nuanced management according to patient subset and risk factors. Since antiarrhythmics can also be proarrhythmic, they may destabilize the patient due to adverse effects, many of which are the focus of black-box label warnings that can be overreaching and limit treatment options. Electrical cardioversion for atrial arrhythmias is generally successful and, depending on the setting and/or hemodynamics, often indicated.

CONCLUSION

Atrial arrhythmias arise from a variety of mechanisms, and appropriate treatment depends on various factors. A firm understanding of physiological and pharmacological concepts serves as a foundation for exploring evidence supporting agents, indications, and adverse effects in order to provide appropriate care for patients.

Comprehensive Review of Hypertensive Disorders Related to Pregnancy

Hypertensive disorder of pregnancy is a common complication during pregnancy that affects approximately 10% of pregnancies and is responsible for nearly 14% of maternal deaths worldwide. It affects the mother and the fetus simultaneously, sometimes putting the health of the mother and the fetus at odds with each other. It may present with only hypertension and proteinuria or with life-threatening complications in the mother such as eclampsia; stroke; acute pulmonary edema; acute renal failure; disseminated intravascular coagulation; placental abruption; hemolysis, elevated liver enzymes, and low platelet syndrome; pregnancy loss; and fetal growth restriction and prematurity resulting from the frequent need of delivering preterm in the fetus. In this review, we aimed to describe hypertensive disorders of pregnancy, mainly preeclampsia and chronic hypertension in pregnancy, by discussing the pathophysiology, the central role of abnormal placentation, the release of antiangiogenic factors in the circulation and immunological factors, the clinical outcome in the mother and the fetus, and the diagnostic criteria and principles of management of both the conditions. We also discuss possible screening methods and prevention of preeclampsia using low-dose aspirin and eclampsia prophylaxis.

VASCULAR AND RENAL MECHANISMS OF PREECLAMPSIA

Preeclampsia (PE) is a multisystem obstetric disorder that affects 2-10% of pregnancies worldwide and it is a leading cause of maternal and fetal morbidity and mortality. The etiology of PE development is not clearly delineated, but since delivery of the fetus and placenta often leads to symptom resolution in the most cases of PE, it is hypothesized that the placenta is the inciting factor of the disease. Current management strategies for PE focus on treating the maternal symptoms to stabilize the mother in an attempt to prolong the pregnancy. However, the efficacy of this management strategy is limited. Therefore, identification of novel therapeutic targets and strategies is needed. Here, we provide a comprehensive overview of the current state of knowledge regarding mechanisms of vascular and renal pathophysiology during PE and discuss potential therapeutic targets directed at improving maternal vascular and renal function.

Magnesium Sulfate Use in Pregnancy for Preeclampsia Prophylaxis and Fetal Neuroprotection: Regimens in High-Income and Low/Middle-Income Countries

Magnesium sulfate is one of the most commonly used medications in obstetrics, most notably for the prevention of eclamptic seizures and fetal neuroprotection of the extremely preterm neonate. Pharmacokinetic and pharmacodynamic studies have demonstrated a variety of IV and IM regimens are effective for these indications. Existing models and data can be used to tailor treatment regimens to increase coverage in poor resource areas, maximize efficacy and minimize toxicity for patients of different weights and renal function.

Diagnostic value of ophthalmic artery Doppler indices for prediction of preeclampsia at 28-32 weeks of gestation

OBJECTIVE

The aim of this study was to examine the diagnostic value of ophthalmic artery Doppler indices in predicting preeclampsia along with other markers in the third trimester of pregnancy.

METHODS

Normotensive pregnancies were included during 28-32 weeks of gestation to undergo uterine and ophthalmic artery Doppler ultrasound. Maternal and fetal characteristics were documented at the visit between the 28 and 32 weeks of gestation, and pregnancy-associated plasma protein A (PAPP-A) values in the first trimester were collected to be integrated into a multiparametric prediction model.

RESULTS

Of 795 included participants, 48 cases progressed to preeclampsia. All assessed ophthalmic Doppler parameters including first and second peak systolic velocities (PSVs), second to first peak ratio (PR), and pulsatility index (PI), were statistically different in patients who developed preeclampsia later on. The average PR (sensitivity: 100% [95% CI, 0.81-1.00]; specificity: 90% [95% CI, 0.86-0.93]) and PI between the eyes, PAPP-A multiple of median and uterine artery PI were determined to be the most important predictors of PE, which were subsequently integrated into a multiple regression model (sensitivity: 94% [95% CI, 0.70-1.00]; specificity: 93% [95% CI, 0.89-0.96]).

CONCLUSION

This study provided a screening method for individuals at higher risk of progressing to preeclampsia in the third trimester of pregnancy.

Iatrogenic Hypermagnesemia in a Patient With Preeclampsia Caused by Misinterpretation of the Magnesium Reporting Unit Following Magnesium Sulfate Administration

Because of the lack of standardization, different laboratories report plasma magnesium sulfate or magnesium level in different units, leading to errors in diagnosis and case management; especially when a patient's workup was done in a hospital and then transferred to another hospital. Failure to recognize or understand the reporting units can confuse clinicians and healthcare workers, leading to erroneous interpretations and, consequently, to misdiagnosis of hypermagnesemia or hypomagnesemia. In this report, we present a 32-year-old female patient at 31 weeks of gestation with a history of a multi-substance use disorder who was transferred to the hospital after taking 2.5mg of fentanyl. At the ER, her blood pressure and liver function tests were found to be high. Her albumin was 3.4 g/dl, aspartate transaminase (AST) was 104 IU/l, alanine transaminase (ALT) was 19 IU/l, and anaplastic lymphoma kinase (ALK) phosphatase was 148 IU/l; however, the renal function test was within the normal range. She had a few twitching movements. Her troponin I was high at 648 ng/L, and her B-type natriuretic peptide was 186.1 pg/mL, but her ECG showed a normal result. Magnesium was initiated on a 6 mg bolus, then 2 mg/dl due to preeclampsia concerns. She was transferred to another hospital ICU that used mEq/L as a reporting unit for magnesium and magnesium sulfate levels. The travel nurse did not alert the physician, thinking that magnesium sulfate was still within with therapeutic range of 4.8-8.4 mg/dL. However, considering 4.0-7.0 is the therapeutic range of magnesium sulfate utilizing mEq/L as a reporting unit instead of mg/dL, the patient was found to be at a supratherapeutic level, reaching up to 8.2 mEq/L. The physician discounted the magnesium sulfate. Her blood picture showed normocytic normochromic anemia. Her hemoglobin was 10.9 g/dl, her hematocrit was 33.8%, her mean corpuscular volume (MCV) was 92.5 fL, and her mean corpuscular hemoglobin (MCH) was 29.5 fL. Her platelets were within the normal range (169 10exp9/L). Her temperature was 99.6 F with increased white blood cells (17.7 10e9/L). The fetus was delivered via C-section on the third day of admission in the setting of persistently low fetal heart rates. The patient was extubated on the fourth day of admission and later transferred to the ward and discharged on the fifth day. Monitoring the magnesium level while administrating magnesium sulfate is essential to avoid iatrogenic hypermagnesemia. Utilizing different units at the same laboratory or across different laboratories could lead to the healthcare providers misinterpreting the result, which can lead to misdiagnosing iatrogenic hypermagnesemia. Therefore, standardizing magnesium units across the Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathologists (CAP)-accredited laboratories is highly recommended. A unified unit reporting protocol will allow healthcare providers, constantly and correctly, to interpret the results and avoid misdiagnosing iatrogenic hypermagnesemia, and it will facilitate reporting and exchange of results among the different laboratories.

Critical Hypermagnesemia in Preeclamptic Women Under a Magnesium Sulfate Regimen: Incidence and Associated Risk Factors

Magnesium sulfate is used as prophylaxis and treatment of severe preeclampsia/eclampsia, albeit its safety and toxicity are a concern. We designed this study to estimate the incidence of critical hypermagnesemia in severely preeclamptic women under a magnesium sulfate regimen at 8 h following its administration and to identify the associated risk factors as the primary outcomes. Also, secondary outcomes were to compare baseline characteristics, laboratory findings, and maternal-neonatal complications stratified by the baseline serum magnesium (Mg²⁺) in those women, and to assess the degree of agreement between patellar reflex and serum Mg²⁺ concentration 8 h following magnesium sulfate administration. We conducted a retrospective study including severely preeclamptic women receiving magnesium sulfate from June 2016 to May 2021. We enrolled 429 women in the study. Two-hundred sixty-one (60.8%) of the included women developed critical hypermagnesemia. Preeclamptic women with high baseline serum Mg²⁺ concentration demonstrated significantly affected renal functions, hepatic transaminase activities, and low platelet count as well as more reported maternal complications compared to those with low baseline serum Mg². Multivariable logistic regression revealed that a lower gestational age, a higher uric acid concentration, and a higher baseline serum Mg²⁺ concentration were independently associated with an increased risk of critical hypermagnesemia. The agreement between deep tendon reflex assessment and serum Mg²⁺ concentration was slight although not significant. The maternal-neonatal outcomes were non-significant in women with critical hypermagnesemia. More vigilant monitoring through assessment of both serum Mg²⁺ concentration and deep tendon reflex should be considered especially in high-risk women.

Controlled magnesium ion delivery system for in situ bone tissue engineering

Magnesium cation (Mg²⁺) has been an emerging therapeutic agent for inducing vascularized bone regeneration. However, the therapeutic effects of current magnesium (Mg) -containing biomaterials are controversial due to the concentration- and stage-dependent behavior of Mg²⁺. Here, we first provide an overview of biochemical mechanism of Mg²⁺ in various concentrations and suggest that 2-10 mM Mg²⁺in vitro may be optimized. This review systematically summarizes and discusses several types of controlled Mg²⁺ delivery systems based on polymer-Mg composite scaffolds and Mg-containing hydrogels, as well as their design philosophy and several parameters that regulate Mg²⁺ release. Given that the continuous supply of Mg²⁺ may prevent biomineral deposition in the later stage of bone regeneration and maturation, we highlight the controlled delivery of Mg²⁺ based dual- or multi-ions system, especially for the hierarchical therapeutic ion release system, which shows enhanced biomineralization. Finally, the remaining challenges and perspectives of Mg-containing biomaterials for future in situ bone tissue engineering are discussed as well.

Exogenous Melatonin Directly and Indirectly Influences Sheep Oocytes

Understanding whether and how melatonin (MT) may impact sheep oocyte development competence is central to our ability to predict how sheep oocytes will respond to artificially regulated estrus. Implanting MT can make sheep enter estrus during the non-breeding season. One study found that the blastocyst rate increased under MT treatment, while another found that the blastocyst rate decreased. Therefore, we conducted a meta-analysis of MT directly and indirectly influencing sheep oocytes. A total of 433 articles were collected from which 20 articles and 34 treatments were finally selected. A method for estimating the default value was established for the litter size analysis. We found that exogenous MT add into in vitro maturation medium was positively related to the blastocyst rate in the lab. However, subcutaneous implanting MT did not affect the in vivo ovulation rate, fertilization rate, blastocyst rate, or pregnancy rate at farm. MT did not affect the in vitro cleavage rate. However, MT improved the in vivo cleavage rate. We hypothesized that implanted MT could increase the concentration of MT in oviduct fluid in vivo, and also that in vitro MT could increase the early cleavage rate of sheep zygotes without affecting the total cleavage rate. In the analysis of oocyte apoptosis caused by injury, the results suggested that pyroptosis would be more suitable for further research. MT produces responses in all body organs, and thus implanting of MT during non-breeding seasons should consider the effect on animal welfare.

Modulatory effect of two regimens of magnesium sulfate on the systemic inflammatory response in pregnant women with imminent eclampsia

OBJECTIVE

This study compared the modulatory effect of two intravenous magnesium sulfate (MgSO₄) regimens on the systemic inflammatory response in pregnant women diagnosed with imminent eclampsia.

STUDY DESIGN

In a single-blind cross-sectional study, 33 women were allocated according to the Zuspan (n = 16) and Sibai (n = 17) MgSO₄ regimens, and treated for 24 h. Blood samples were collected pre-administration of the loading dose, at 24 h of the maintenance dose of MgSO₄, and at 48 h, when patients were without treatment. Plasma was used to determine interleukin (IL)-1 beta (IL-1β), IL-6, IL-10, tumor necrosis factor-alpha (TNF-α), heat shock protein (Hsp70), and heme oxygenase-1 (HO-1) by ELISA.

RESULTS

The treatment with the Zuspan's regimen didn't change plasma concentrations of TNF-α, IL-10, and Hsp70 in the three-time points studied. However, it decreased IL-1β at 24 h and 48 h and IL-6 at 48 h, and increased HO-1 concentration at 48 h. On the other hand, compared to the pre-treatment period, Sibai's regimen induced a significant decrease in TNF-α, IL-1β, IL-6, and Hsp70, while increased HO-1 levels both at 24 h and 48 h and, IL-10 concentration at 48 h.

CONCLUSIONS

Sibai's regimen determined an early and efficient immunoregulatory effect on systemic inflammatory response in preeclampsia, suggesting that the maintenance dose of two grams of MgSO₄ was better than one gram in the treatment of imminent eclampsia.

High risk and low prevalence diseases: Eclampsia

INTRODUCTION

Eclampsia is a rare partum and puerperal condition that carries a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of the care of patients with eclampsia, including presentation, evaluation, and evidence-based management in the emergency department (ED).

DISCUSSION

Eclampsia is a hypertensive disease of pregnancy defined by new onset tonic-clonic, focal, or multifocal seizures or unexplained altered mental status in a pregnant or postpartum patient in the absence of other causative etiologies. However, signs and symptoms of preeclampsia and prodromes of eclampsia are often subtle and non-specific, making the diagnosis difficult. Thus, it should be considered in pregnant and postpartum patients who present to the ED. Laboratory testing including complete blood cell count, renal and liver function panels, electrolytes, glucose, coagulation panel, fibrinogen, lactate dehydrogenase, uric acid, and urinalysis, as well as imaging to include head computed tomography, can assist, but these evaluations should not delay management. Components of treatment include emergent obstetric specialist consultation, magnesium administration, and blood pressure control in patients with hypertension. Definitive treatment of eclampsia requires emergent delivery in pregnant patients. If consultants are not in-house, emergent stabilization and immediate transfer are required.

CONCLUSIONS

An understanding of eclampsia can assist emergency clinicians in rapid recognition and timely management of this potentially deadly disease.

Maternal and fetal serum concentrations of magnesium after administration of a 6-g bolus dose of magnesium sulfate (MgSO4 ) to women with imminent preterm delivery

INTRODUCTION

Magnesium sulfate is used world-wide to treat pregnant women at imminent risk of preterm delivery in order to protect the brain of the premature infant. Previous research has shown that magnesium sulfate decreases the risk of cerebral palsy by ~30% in infants born preterm. Despite this, the dosage required for optimal neuroprotection remains unknown. We aimed to investigate whether 6 g magnesium sulfate given as a single bolus dose was tolerable for the women and infants and whether the desired target concentration in the mother's blood was reached and non-toxic level in the infant could be ensured.

MATERIAL AND METHODS

In total, 49 women who were at risk of delivery prior to 32 weeks of gestation were recruited. They received a bolus dose of 6 g magnesium sulfate intravenously between 1 and 24 h prior to giving birth and were closely monitored during and after infusion. Blood samples from the patients were analyzed at different time-points (20-30 min after start of infusion, 1, 2, 6 and 24 h) post-administration. Blood samples from the umbilical cord were also taken directly after birth to assess the concentration of magnesium in the infant.

RESULTS

None of the women who received magnesium sulfate reached serum magnesium concentrations >3.3 mmol/L. In all, 72% of the women showed serum magnesium levels within the therapeutic interval (2.0-3.5 mmol/L) and no adverse events were observed during the infusion. The serum magnesium levels in the mothers declined to pre-bolus-levels within 24 h after delivery. Serum magnesium levels in the umbilical cord samples ranged from 0.87 to 1.4 mmol/L, which means that all but two were within the normal expected range for a newborn premature infant.

CONCLUSIONS

A bolus dose of 6 g magnesium sulfate was well tolerated and without any serious side effects in either mother or infant. Most of our women reached the targeted concentration range of serum magnesium levels after infusion was completed. Their infants had magnesium levels within acceptable levels, regardless of gestational week or mother's body mass index.

Hypertensive Disorders of Pregnancy: Common Clinical Conundrums

Importance

Hypertensive complications of pregnancy comprise 16% of maternal deaths in developed countries and 7.4% of deaths in the United States. Rates of preeclampsia increased 25% from 1987 to 2004, and rates of severe preeclampsia have increased 6.7-fold between 1980 and 2003.

Objective

The aim of this study was to review current and available evidence for common clinical questions regarding the management of hypertensive disorders of pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines on hypertension in pregnancy were reviewed.

Results

Severe gestational hypertension should be managed as preeclampsia with severe features. Serum uric acid levels can be useful in predicting development of superimposed preeclampsia for women with chronic hypertension. When presenting with preeclampsia with severe features before 34 weeks, expectant management should be considered only when both maternal and fetal conditions are stable. In the setting of hypertensive disorders of pregnancy, oral antihypertensive medications should be initiated when systolic blood pressure is greater than 160 mm Hg or when diastolic blood pressure is greater than 110 mm Hg, with the most ideal agents being labetalol or nifedipine. Furthermore, although risk of preeclampsia recurrence in future pregnancy is low, women with a history of preeclampsia should be managed with 81 mg aspirin daily for preeclampsia prevention.

Conclusions and Relevance

Despite the frequency with which hypertensive disorders of pregnancy are encountered clinically, situations arise frequently with limited evidence to guide providers in their management. An urgent need exists to better understand this disease to optimize outcomes for impacted patients.

Duration of Postpartum Magnesium Sulphate for the Prevention of Eclampsia: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the optimal duration of postpartum magnesium sulphate to prevent eclampsia.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, and ClinicalTrials.gov databases were searched from inception until January 2020 and limited to English-language human randomized controlled trials. Search strategy included the key works "eclampsia," "magnesium sulphate," and "postpartum."

METHODS OF STUDY SELECTION

Title, abstract, and full-text review was performed using Covidence data-management software. Of the 3,629 articles screened, 10 studies were included in the final review. Studies were included if they compared two different time points of magnesium sulphate postpartum in women with either preeclampsia or eclampsia.

TABULATION, INTEGRATION AND RESULTS

Two authors reviewed studies independently. RevMan software was used to calculate risk difference (RD) for categorical outcomes and mean difference for continuous outcomes. Shorter duration of magnesium sulphate (12 hours or less) was not associated with increased risk of eclampsia compared with 24-hour postpartum regimens (RD -0.01, 95% CI -0.02 to 0.01, I2 70%). Studies randomizing women with preeclampsia did not show increased risk of eclampsia with shorter regimens (RD 0, 95% CI -0.01 to 0.01, I2 0%), nor did trials randomizing those with eclampsia (RD -0.04, 95% CI -0.14 to 0.07, I2 87%). Secondary outcomes, including flushing, duration of Foley catheter insertion, time to ambulation, and duration of hospital stay, were all reduced with shorter-duration magnesium sulphate.

CONCLUSION

This systematic review and meta-analysis suggests that a shorter duration of postpartum magnesium sulphate does not increase the risk for eclamptic seizure; however, data remain underpowered to render firm conclusions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020182432.

A retrospective review of the risk factors affecting the therapeutic serum concentrations of magnesium sulfate in pre-eclamptic patients

WHAT IS KNOWN AND OBJECTIVE

To identify factors that may affect the therapeutic serum magnesium levels after intravenous administration for seizure prophylaxis in pre-eclamptic patients.

METHODS

One hundred and two women with PE with severe features were identified categorized into two groups: subtherapeutic and therapeutic group. Multivariate logistic regression analysis and receiver operation characteristic curve analysis were conducted for the risk factors influencing the serum magnesium concentration.

RESULTS

Among 102 eligible patients, 63 (62%) patients did not attain ideal therapeutic serum magnesium levels. Those patients had elevated albumin levels (p < 0.05), higher creatinine clearance (Ccr) (p < 0.001), and higher body mass index (BMI) (p < 0.001). Logistic regression analysis identified BMI and Ccr as independent risk factors for subtherapeutic serum magnesium concentration (p < 0.05). Receiver operating characteristic (ROC) curve analysis revealed a greater area under the curve for BMI than for Ccr in predicting subtherapeutic serum magnesium levels (0.787 vs. 0.774).

WHAT IS NEW AND CONCLUSION

Maternal body weight and renal function were independent risk factors for subtherapeutic serum magnesium concentration in the early stage after administration.

Associations of multiple plasma metals with the risk of metabolic syndrome: A cross-sectional study in the mid-aged and older population of China

BACKGROUND

Metal exposures have been reported to be related to the progress of metabolic syndrome (MetS), however, the currents results were still controversial, and the evidence about the effect of multi-metal exposure on MetS were limited. In this study, we intended to evaluate the relationships between metal mixture exposure and the prevalence of MetS in a mid-aged and older population of China.

METHODS

The plasma levels of 13 metals (aluminum, magnesium, calcium, iron, manganese, cobalt, copper, arsenic, zinc, selenium, cadmium, molybdenum and thallium) were detected by inductively coupled plasma mass spectrometry (ICP-MS) in 1277 adults recruited from the Eighth Affiliated Hospital of Sun Yat-Sen University (Shenzhen, China). Logistic regression, the adaptive least absolute shrinkage and selectionator operator (LASSO) penalized regression analysis and restricted cubic spline (RCS) analysis were used to explore the associations and dose-response relationships of plasma metals with MetS. To evaluate the cumulative effect of metals, the Bayesian Kernel Machine Regression (BKMR) model was applied.

RESULTS

The concentrations of magnesium and molybdenum were lower in the MetS group (p < 0.05). In the single-metal model, the adjusted ORs (95%CI) in the highest quartiles were 0.44 (0.35, 0.76) for magnesium and 0.30 (0.17, 0.51) for molybdenum compared with the lowest quartile. The negative associations and dose-dependent relationships of magnesium and molybdenum with MetS were further validated by the stepwise model, adaptive LASSO penalized regression and RCS analysis. The BKMR models showed that the metal mixture were associated with decreased MetS when the chemical mixtures were≥ 25th percentile compared to their medians, and Mg, Mo were the major contributors to the combined effect. Moreover, concentrations of magnesium were significantly related to blood glucose, and molybdenum was related with BMI, blood glucose and blood pressure.

CONCLUSIONS

Elevated levels of plasma magnesium and molybdenum were associated with decreased prevalence of MetS. Further investigations in larger perspective cohorts are needed to confirm our findings.

Effect of Mg-Gluconate on the Osmotic Fragility of Red Blood Cells, Lipid Peroxidation, and Ca2+-ATPase (PMCA) Activity of Placental Homogenates and Red Blood Cell Ghosts From Salt-Loaded Pregnant Rats

Preeclampsia (PE) is a pregnancy-specific syndrome with multisystem involvement which leads to fetal, neonatal, and maternal morbidity and mortality. A model of salt-loaded pregnant rats has been previously studied, sharing several pathological characteristics of preeclamptic women. In this study, it was compared the effects of the treatment with an oral magnesium salt, magnesium gluconate (Mg-gluconate), on the osmotic fragility of red blood cells, lipid peroxidation, and PMCA activity of placental homogenates and red blood cell ghosts in salt-loaded pregnant rats. Mg-gluconate has a higher antioxidant capacity than MgSO₄ due to the presence of several hydroxyl groups in the two anions of this salt. Salt-loaded pregnant rats received 1.8% NaCl solution ad libitum as a beverage during the last week of pregnancy. On day 22nd of pregnancy, the rats were euthanized and red blood cells and placenta were obtained. Salt-loaded pregnant rats showed an increased level of lipid peroxidation and a lowered PMCA activity in placental and red blood cell ghosts, as well as an increased osmotic fragility of their red blood cells. The treatment of the salt-loaded pregnant rats with Mg-gluconate avoids the rise in the level of lipid peroxidation and the concomitant lowering of the PMCA activity of their red blood cell membranes, reaching values similar to those from control pregnant rats. Also, this treatment prevents the increase of the osmotic fragility of their red blood cells, keeping values similar to those from control pregnant rats. Mg-gluconate seems to be an important candidate for the replacement of the MgSO₄ treatment of preeclamptic women.

Associations of plasma multiple metals with risk of hyperuricemia: A cross-sectional study in a mid-aged and older population of China

BACKGROUND

Metal exposures are suspected to associate with the risk of hyperuricemia (HUA), but the current results are still conflicting.

OBJECTIVE

To investigate the associations between multiple plasma metal exposures and HUA risk.

METHODS

A cross-sectional study was conducted in 1406 Chinese Han adults who underwent routine physical examination in the Eighth Affiliated Hospital of Sun Yat-Sen University in Shenzhen. The plasma levels of 13 metals were measured by the inductively coupled plasma mass spectrometry (ICP-MS). Multivariable logistic, linear regression models, least absolute shrinkage and selection operator (LASSO) penalized regression analysis, and restricted cubic spline (RCS) models were applied to assess the associations.

RESULTS

The median plasma uric acid concentration in HUA group (434 μmol/L) was significantly higher than that in non-HUA group (305 μmol/L). The multivariate-adjusted odds ratios (95% confidence intervals) of HUA were 1.62(1.08-2.43) for magnesium, 1.61(1.05-2.47) for copper, 1.62(1.06-2.49) for zinc, 1.87(1.26-2.81) for arsenic, 1.50(1.01-2.23) for selenium, and 1.70(1.16-2.49) for thallium based on the single-metal logistic regression models, comparing the highest versus the lowest quartile of metal levels. Further multi-metal logistic, linear regression models and the LASSO analysis all indicated positive associations of zinc, arsenic with HUA risk or uric acid levels. RCS model indicated an inverted V-shaped positive association between zinc levels and HUA risk (p for non-linearity = 0.048, p for overall association = 0.022), while arsenic levels showed a positive and linear dose-response relationship with HUA risk (p for non-linearity = 0.892, p for overall association<0.001).

CONCLUSIONS

Higher plasma levels of zinc and arsenic might increase HUA risk and showed positive dose-response relationships. Further cohort studies in larger population are required to testify our findings.

Case Series: Video-Assisted Minimally Invasive Cardiac Surgery During Pregnancy

Surgical intervention is expected to improve maternal outcomes in pregnant patients with heart disease once the conservative treatment fails. For pregnant patients with heart disease, the risk of cardiac surgery under cardiopulmonary bypass (CPB) must be balanced due to the high fetal loss. The video-assisted minimally invasive cardiac surgery (MICS) has been progressively applied and shows advantages in non-pregnant patients over the years. We present five cases of pregnant women who underwent a video-assisted minimally invasive surgical approach for cardiac surgery and the management strategies. In conclusion, the video-assisted MICS is feasible and safe to pregnant patients, with good maternal and fetal outcomes under the multidisciplinary assessment and management.

Efficacy of Magnesium Sulfate on Maternal Mortality in Eclampsia

Eclampsia is a common complication of preeclampsia patients and can be life-threatening for both the mother and the fetus. Hence, timely intervention and appropriate management of this detrimental condition are extremely crucial. Eclampsia is described as the occurrence of generalized convulsions in patients with preeclampsia. Magnesium sulfate (MgSO₄) is the drug of choice for treating and preventing eclampsia. This review aims to study and analyze the available literature on the pathogenesis of eclampsia, the pharmacology of MgSO₄, and its effectiveness in the management of eclampsia. Other proposed treatments and their comparative study with MgSO₄ are also discussed. Additionally, we examine the data regarding the impact of eclampsia, its public health burden, and the cost-effectiveness of MgSO₄. One of the major drawbacks associated with the use of MgSO₄ in low-income countries has been the cost of treatment and the lack of resources. We have analyzed the trials that have proposed alternate treatment regimens which could shape new guidelines to resolve these issues. For this review, we extensively studied abstract and full-text articles from multiple databases. This article discusses the pathophysiology of eclampsia, the pharmacology of MgSO₄, the issues surrounding eclampsia management, and how MgSO₄ benefits these patients.

Neurocritical care of the pregnant patient

INTRODUCTION

An estimated 0.1%-0.8% of obstetric patients require admission to an intensive care unit (ICU) during pregnancy or the puerperium. When neurologic emergencies occur in pregnancy, collaboration between the neurointensivist, obstetric anesthesiologist, and obstetrician is key in minimizing morbidity and mortality.

PRINCIPLES

Care of the critically ill pregnant patient mirrors that of the critically ill nonpregnant patient with some minor exceptions. Special care must be taken to consider the normal physiologic changes of pregnancy as well as possible fetal exposure to medical interventions. Timing and method of delivery must be carefully considered when caring for patients with neurologic emergencies. Common neurologic emergencies in pregnancy include hypertensive disorders of pregnancy, intracranial neoplasms, noneclamptic seizures, cerebrovascular disorders, and ventriculoperitoneal shunt malfunctions.

CONCLUSION

While neurologic emergencies in pregnancy are overall rare, when they do occur, they can be devastating. As in the nonpregnant population, prompt recognition and rapid intervention are crucial in optimizing patient outcomes. When neurologic emergencies occur in pregnancy, maternal and fetal care is optimized through a multidisciplinary care team.

Magnesium sulfate reduces postoperative pain in women with cesarean section: A meta-analysis of randomized controlled trials

OBJECTIVES

The use of magnesium sulfate (MgSO₄ ) as an adjunct in different anesthetic regimens for cesarean section (CS) delivery often reports conflicting results. This study aimed to review the effectiveness of MgSO₄ on improving postoperative analgesia after CS systematically.

METHODS

PubMed, Embase, and the Cochrane library were searched for randomized controlled trials (RCTs) published from inception to February 2020.

RESULTS

A total of 880 women were included (440 in each group). MgSO₄ had a statistically significant effect compared to the control group on the highest VAS (weighted mean difference [WMD] = -0.74, 95% confidence interval [CI] = -1.03 to -0.46, p < 0.001, I²  = 91.7%, p_{heterogeneity}  < 0.001) and the last VAS (WMD = -0.47, 95% CI = -0.71 to -0.23, p < 0.001, I²  = 95.0%, p_{heterogeneity}  < 0.001). MgSO₄ prolonged the time to the first use of analgesia compared to the control group (standardized mean difference [SMD] = -3.03 min, 95% CI = -4.32 to -1.74, p < 0.001, I²  = 96.3%, p_{heterogeneity}  < 0.001). MgSO₄ decreased the consumption of analgesia compared to the control group (SMD = -3.20 mg of IV morphine equivalent, 95% CI: -5.45 to -0.95, p = 0.005, I²  = 97.6%, p_{heterogeneity}  < 0.001).

DISCUSSION

MgSO₄ decreases the highest VAS in women who underwent general anesthesia, spinal anesthesia, or epidural for CS (all p < 0.05). Additional MgSO₄ significantly reduces postoperative pain in women undergoing CS.

Population Pharmacokinetics of Magnesium Sulfate in Preeclampsia and Associated Factors

Background and Objective

The pharmacokinetic basis of magnesium sulphate (MgSO₄) dosing regimens for preeclampsia (PE) prophylaxis and treatment is not clearly established. The aim of study is to develop a population pharmacokinetic (PK) model of MgSO₄ in PE, and to determine key covariates having an effect in MgSO₄ pharmacokinetics in preeclampsia (PE) and to determine key covariates having an effect in MgSO₄ PK.

Methods

A prospective cohort study was conducted from June 2016 to February 2018 in patients with PE administered MgSO₄ as a 4-g bolus followed by continuous infusion at a rate of 1 g/h. Serum magnesium concentrations were obtained before treatment administration and 2, 6, 12, and 18 h after the initial dose. The software Monolix was used to estimate population PK parameters of MgSO₄ [clearance (CL), volume of distribution (V), half-life] and to develop a PK model with baseline patient demographic, clinical, and laboratory covariates.

Results

The study population consisted of 109 patients. The PK profile of MgSO₄ was adequately described by a one-compartment PK model. The model estimate of the population CL was 1.38 L/h; for V, it was 13.3 L; and the baseline magnesium concentration was 0.77 mmol/L (1.87 mg/dL). The baseline body weight and serum creatinine statistically influenced MgSO₄ CL and V, respectively. The model was parameterized as CL and V.

Conclusion

The PK of MgSO₄ in pregnant women with PE is significantly affected by creatinine and body weight. Pregnant women with PE and higher body weight have a higher V and, consequently, a lower elimination rate of MgSO₄. Pregnant women with PE and a higher serum creatinine value show lower CL and, therefore, lower MgSO₄ elimination rate.

Magnesium sulphate for treating acute bronchiolitis in children up to two years of age

BACKGROUND

Acute bronchiolitis is a significant burden on children, their families and healthcare facilities. It mostly affects children younger than two years of age. Treatment involves adequate hydration, humidified oxygen supplementation, and nebulisation of medications, such as salbutamol, epinephrine, and hypertonic saline. The effectiveness of magnesium sulphate for acute bronchiolitis is unclear.

OBJECTIVES

To assess the effects of magnesium sulphate in acute bronchiolitis in children up to two years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, CINAHL, and two trials registries to 30 April 2020. We contacted trial authors to identify additional studies. We searched conference proceedings and reference lists of retrieved articles. Unpublished and published studies were eligible for inclusion.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs, comparing magnesium sulphate, alone or with another treatment, with placebo or another treatment, in children up to two years old with acute bronchiolitis. Primary outcomes were time to recovery, mortality, and adverse events. Secondary outcomes were duration of hospital stay, clinical severity score at 0 to 24 hours and 25 to 48 hours after treatment, pulmonary function test, hospital readmission within 30 days, duration of mechanical ventilation, and duration of intensive care unit stay.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used GRADE methods to assess the certainty of the evidence.

MAIN RESULTS

We included four RCTs (564 children). One study received funding from a hospital and one from a university; two studies did not report funding sources. Comparator interventions differed among all four trials. Studies were conducted in Qatar, Turkey, Iran, and India. We assessed two studies to be at an overall low risk of bias, and two to be at unclear risk of bias, overall. The certainty of the evidence for all outcomes and comparisons was very low except for one: hospital re-admission rate within 30 days of discharge for magnesium sulphate versus placebo. None of the studies measured time to recovery, duration of mechanical ventilation, duration of intensive care unit stay, or pulmonary function. There were no events of mortality or adverse effects for magnesium sulphate compared with placebo (1 RCT, 160 children). The effects of magnesium sulphate on clinical severity are uncertain (at 0 to 24 hours: mean difference (MD) on the Wang score 0.13, 95% confidence interval (CI) -0.28 to 0.54; and at 25 to 48 hours: MD on the Wang score -0.42, 95% CI -0.84 to -0.00). Magnesium sulphate may increase hospital re-admission rate within 30 days of discharge (risk ratio (RR) 3.16, 95% CI 1.20 to 8.27; 158 children; low-certainty evidence). None of our primary outcomes were measured for magnesium sulphate compared with hypertonic saline (1 RCT, 220 children). Effects were uncertain on the duration of hospital stay in days (MD 0.00, 95% CI -0.28 to 0.28), and on clinical severity on the Respiratory Distress Assessment Instrument (RDAI) score at 25 to 48 hours (MD 0.10, 95% CI -0.39 to 0.59). There were no events of mortality or adverse effects for magnesium sulphate, with or without salbutamol, compared with salbutamol (1 RCT, 57 children). Effects on the duration of hospital stay were uncertain (magnesium sulphate: 24 hours (95% CI 25.8 to 47.4), magnesium sulphate + salbutamol: 20 hours (95% CI 15.3 to 39.0), and salbutamol: 24 hours (95% CI 23.4 to 76.9)). None of our primary outcomes were measured for magnesium sulphate + epinephrine compared with no treatment or normal saline + epinephrine (1 RCT,120 children). Effects were uncertain for the duration of hospital stay in hours (MD -0.40, 95% CI -3.94 to 3.14), and for RDAI scores (0 to 24 hours: MD -0.20, 95% CI -1.06 to 0.66; and 25 to 48 hours: MD -0.90, 95% CI -1.75 to -0.05).

AUTHORS' CONCLUSIONS

There is insufficient evidence to establish the efficacy and safety of magnesium sulphate for treating children up to two years of age with acute bronchiolitis. No evidence was available for time to recovery, duration of mechanical ventilation and intensive care unit stay, or pulmonary function. There was no information about adverse events for some comparisons. Well-designed RCTs to assess the effects of magnesium sulphate for children with acute bronchiolitis are needed. Important outcomes, such as time to recovery and adverse events should be measured.

The effects of maternal body mass index and plurality on maternal and umbilical cord serum magnesium levels in preterm birth at less than 32 weeks of gestation

OBJECTIVE

To evaluate the effects of maternal body mass index (BMI) and plurality on maternal and umbilical cord serum magnesium levels after antenatal magnesium sulfate treatment.

METHODS

This was a retrospective cohort analysis of 135 women treated with antenatal magnesium sulfate at less than 32 weeks of gestation between January 2012 and June 2018. Subjects were stratified into groups according to maternal BMI (group I [18.5-22.9 kg/m²], group II [23.0-24.9 kg/m²], and group III [≥25.0 kg/m²]) and plurality (singleton and twin). Univariable and multivariable analyses were performed to compare the umbilical cord serum magnesium levels between the groups.

RESULTS

Maternal serum magnesium levels were not significantly different between the maternal BMI groups and singleton and twin pregnancies. Umbilical cord serum magnesium levels were significantly different among the maternal BMI groups (3.3±1.2 mg/dL in group I, 3.3±1.2 mg/dL in group II, and 4.0±1.4 mg/dL in group III, P=0.003). The trend of increase in magnesium levels was statistically significant (P=0.001, Jonckheere-Terpstra test). Umbilical cord serum magnesium levels were not significantly different according to plurality. However, in the multivariable analysis, maternal BMI and plurality were not significantly associated with umbilical cord serum magnesium levels after adjusting for indication and total dose of magnesium sulfate treatment, gestational age at delivery, mode of delivery, neonatal sex, and birth weight.

CONCLUSION

Maternal BMI and plurality were not significantly associated with maternal or umbilical cord serum magnesium levels after exposure to antenatal magnesium sulfate treatment.

Abnormal Umblical Artery Doppler is Utilized for Fetuses with Intrauterine Growth Restriction Birth at 280/7-336/7 Gestational Weeks

Purpose: To compare short-term perinatal outcomes in preterm infants with intrauterine growth restriction (IUGR) in those with absent or reversed end-diastolic umbilical artery blood flow (AREDF) to those with normal end-diastolic umbilical artery blood flow (NEDF). Methods: This study included preterm births (28^0/7-33^6/7 gestational weeks) with IUGR with AREDF (n = 86) or NEDF (n = 27). Results: There were lower mean gestational weeks, birth weights, and a higher ratio of corticosteroid application in the AREDF group (p < 0.05). The mean length of neonatal intensive care unit stay of the AREDF group was significantly longer (p < 0.001). Sepsis and feeding intolerance ratios in the AREDF group were also significantly higher (p = 0.041 and p < 0.001 respectively). Conclusions: Patients with IUGR and umbilical Doppler abnormalities have longer neonatal intensive care unit stays.

Interrupted versus continuous magnesium sulfate and blood loss at cesarean delivery

OBJECTIVE

Magnesium sulfate is standard of care for prevention of eclampsia in women with preeclampsia with severe features. The American College of Obstetrics and Gynecology endorses its use throughout labor, delivery and the immediate postpartum period. Some providers pause magnesium sulfate infusion preoperatively due to concern for increased risk of uterine atony and postpartum hemorrhage. Using a non-inferiority analysis, we investigated the effect of interrupted versus continuous infusion of magnesium sulfate on postpartum hemorrhage in women with preeclampsia with severe features undergoing cesarean delivery.

STUDY DESIGN

Retrospective non-inferiority cohort study of women with preeclampsia with severe features treated with magnesium sulfate undergoing cesarean delivery with singleton pregnancies at tertiary care hospital from 2013 to 2018. The primary outcome was postpartum hemorrhage. Secondary outcomes included estimated blood loss, change in hematocrit and a composite of postpartum hemorrhage severity, including transfusion of blood products, use of more than one uterotonic and additional surgical interventions.

RESULTS

Of 249 women, magnesium sulfate infusion was interrupted in 171 (69%) and continued in 78 (31%). Women with interrupted magnesium sulfate infusion were more likely to be Caucasian (73% vs 67%, p = .024), have chronic hypertension (23% vs 1%, p < .001), labor prior to cesarean delivery (84% vs 55%, p < .001), undergo primary cesarean delivery (86% vs 67%, p = .005), and experience shorter surgical time (50 vs 55 min, p = .026). The rate of postpartum hemorrhage for those receiving interrupted magnesium sulfate infusion (9.9%) and continuous magnesium sulfate infusion (10.2%) was similar, falling within the non-inferiority margin (absolute difference 0.3%, 95% CI -7.8 to 8.4%, p = .88). There were no significant differences in the secondary outcomes.

CONCLUSION

Interrupted magnesium sulfate infusion is non-inferior to continued magnesium sulfate infusion for rates of postpartum hemorrhage in women with preeclampsia with severe features undergoing cesarean delivery.

Microneedle-Assisted Percutaneous Transport of Magnesium Sulfate

OBJECTIVE

In vitro diffusion experiments were performed to assess the permeation of magnesium sulfate across pig skin.

METHODS

The mean thickness of the dermatomed porcine skin was 648 ± 12 µm. Magnesium concentration was measured using inductively coupled plasma-optical emission spectroscopy. Transdermal flux of magnesium sulfate across MN-treated and untreated porcine skin was obtained from the slope of the steady-state linear portion of cumulative amount versus time curve.

RESULTS

Statistical analysis of the results was done with Student's t-test. The transdermal flux of magnesium sulfate across microneedle-treated porcine skin was 134.19 ± 2.4 µg/cm2/h and transdermal flux across untreated porcine skin was 4.64 ± 0.05 µg/cm2/h. Confocal microscopy was used to visualize the microchannels created by a solid microneedle roller (500 µm).

CONCLUSION

From our confocal microscopy studies, it was evident that the 500 μm long microneedles disrupted the stratum corneum and created microchannels measuring 191 ± 37 µm. The increase in transdermal flux across the microneedle-treated skin was statistically significant compared to that of controls, i.e., without the application of microneedles. With the application of microneedles, the transdermal flux of magnesium permeated over 12 h was approximately 33-fold higher in comparison to passive diffusion across an intact stratum corneum.

Provider practices for the prevention of eclampsia and attitudes toward magnesium sulfate: results of a nationwide survey

OBJECTIVE

To survey OB-GYNs regarding their practice patterns and perspectives when it comes to using magnesium sulfate (magnesium) in the prevention of eclampsia.

STUDY DESIGN

We conducted a cross-sectional web-based 18-item survey given to 564 practicing OB-GYNs in the Pregnancy-Related Care Research Network. The survey used clinical scenarios to look at provider practices for preventing eclampsia in patients who have preeclampsia and relative contraindications to magnesium. Next, we assessed provider attitudes toward magnesium and inquired about their experiences with complications related to its use. The survey also contained an embedded educational component that addressed the signs and symptoms of magnesium toxicity followed by a 2-item quiz for those providers who self-identified as having never treated magnesium toxicity.

RESULTS

Nearly 30% of OB-GYNs contacted completed the survey. For patients with preeclampsia and a contraindication to magnesium such as myasthenia gravis, 44.4% of respondents would administer an alternative antiepileptic and 42.5% of them would administer no antiepileptic at all. For patients with pulmonary edema complicating preeclampsia, 32.5% would give magnesium at the usual dose, 33.1% would give magnesium at less than the usual dose, 12.3% would give an alternative antiepileptic and 22.1% would give no antiepileptic at all. For patients with laboratory evidence of renal compromise complicating preeclampsia, most respondents (89.6%) said they would give magnesium at less than the usual dose. Regarding complications of magnesium that clinicians have encountered, over one-third of respondents have administered calcium gluconate for magnesium toxicity in patients with preeclampsia. For those providers who have not treated magnesium toxicity and were prompted to receive the educational component and quiz, all knew the correct initial bolus dosing of magnesium and the majority were able to identify symptoms of toxicity. The majority (81.8%) of respondents said that continuous magnesium infusions cause an increased demand for dedicated personnel to care for the patients on them. Almost 57% of respondents endorsed the need for an alternative antiepileptic to magnesium in the prevention of eclampsia. Most write-in responses supporting this need cited a concern with magnesium's safety and side effects.

CONCLUSION

There is wide variation among OB-GYNs regarding the prevention of eclampsia and complications of magnesium are not uncommon. The survey revealed that OB-GYNs are using alternative antiepileptics in scenarios where there is concern for magnesium's safety profile. In addition, over half of those surveyed believe there is a need for validated antiepileptics other than magnesium for the prevention of eclampsia in patients with preeclampsia. These findings suggest that OB-GYNs would support further research into alternative antiepileptics in the prevention of eclampsia.

Effect of magnesium sulfate combined with labetalol on serum sFlt-1/PlGF ratio in patients with early-onset severe pre-eclampsia

The aim of the present study was to investigate the therapeutic effect of magnesium sulfate combined with labetalol on the early-onset severe pre-eclampsia (ES-PE) and explore the role of soluble fms-like tyrosine kinase-1 (sFlT-1), placental growth factor (PlGF), and sFlt-1/PlGF ratio in the treatment. A total of 164 ES-PE patients admitted to the Maternity and Child Health Care Hospital of Hubei (Wuhan, China) were assigned to this observational study. Among them, 83 patients were enrolled in group A and treated with magnesium sulfate combined with labetalol hydrochloride, and 81 patients were enrolled in group B and treated with magnesium sulfate. The therapeutic effect, adverse reactions and pregnancy outcomes in the two groups were analyzed. Serum sFlt-1 and PlGF concentrations, before and after treatment, were measured by enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of pre-treatment serum sFlt-1/PlGF ratio for the clinical outcome. The effective rate was significantly higher in group A than that in group B. Group A presented superior pregnancy outcomes over group B. The serum sFlt-1 concentration and sFlt-1/PlGF ratio after treatment were significantly lower than those before treatment in groups A and B, whereas PlGF concentration was significantly higher after treatment in both groups. After treatment, group A had markedly lower serum sFlt-1 concentration and sFlt-1/PlGF ratio than group B, and markedly higher PlGF concentration than group B. The area under curve (AUC) of serum sFlt-1/PlGF ratio before treatment for the prediction of the clinical efficacy was 0.737. In conclusion, magnesium sulfate combined with labetalol could be effectively used for the treatment of ES-PE. The results of ELISA revealed that the balance of sFlT-1 and PlGF was improved after treatment and the sFlT-1/PlGF ratio was decreased. The assessment of sFlt-1/PlGF ratio before treatment was shown to have a certain predictive value for the efficacy of ES-PE treatment.

Risk factors for sub-therapeutic serum concentrations of magnesium sulfate in severe preeclampsia of Chinese patients

Background

Magnesium sulfate (MgSO₄) is the standard drug for eclampsia prophylaxis and treatment. In China, the effective therapeutic serum magnesium level is 1.8–3.0 mmol/L. There is little information on how to achieve and maintain effective therapeutic concentrations. This study aimed to investigate risk factors for sub-therapeutic serum concentrations of MgSO₄ in patients with severe preeclampsia.

Methods

Patients with severe preeclampsia who received MgSO₄ intravenous infusion were retrospectively reviewed. The maternal demographic characteristics, regimens for the administration of MgSO₄, and lab test results of patients were collected. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve analysis were conducted for the risk factors influencing the serum magnesium concentration.

Results

A total of 93 patients with severe preeclampsia were included in the study. 52 (55.91%) patients did not attain therapeutic serum magnesium levels. A multivariate logistic regression analysis identified creatinine clearance (Ccr), whether the loading dose was given, and measurement time of serum magnesium concentration (referring to the time from start of MgSO4 infusion to blood draw for serum sampling) as independent risk factors for sub-therapeutic serum magnesium concentration (P < 0.05). ROC curve analysis indicated that the continuous variable Ccr had a significant predictive value for the serum magnesium concentration, which resulted in a cutoff point of 133 mL/min; while measurement time had limited predictive value, with cutoff point of 2.375 h.

Conclusions

Ccr, whether the loading dose was given, and measurement time were independent risk factors for sub-therapeutic serum magnesium concentration. A loading dose of MgSO₄ everytime before the maintenance dose, as well as the duration of MgSO4 maintenance dose of more than 2.375 h are recommended for all the patients with severe PE. Routine evaluation of serum magnesium levels is a recommended practice for women with severe PE and whose Ccr is ≥133 mL/min.

Magnesium, Oxidative Stress, Inflammation, and Cardiovascular Disease

Hypomagnesemia is commonly observed in heart failure, diabetes mellitus, hypertension, and cardiovascular diseases. Low serum magnesium (Mg) is a predictor for cardiovascular and all-cause mortality and treating Mg deficiency may help prevent cardiovascular disease. In this review, we discuss the possible mechanisms by which Mg deficiency plays detrimental roles in cardiovascular diseases and review the results of clinical trials of Mg supplementation for heart failure, arrhythmias and other cardiovascular diseases.

Postoperative Multimodal Analgesia in Cardiac Surgery

Multimodal pain management of cardiac surgical patients is a paradigm shift in postoperative care. This promising approach features complementary medications and techniques that spare opioids and improves symptomatic and functional recovery. Although the specific elements remain to be defined, the collaboration of the health care team and patient and continuous iterative programmatic improvements are important pillars of this approach.

Antenatal magnesium sulfate treatment and risk of necrotizing enterocolitis in preterm infants born at less than 32 weeks of gestation

Antenatal magnesium sulfate (MgSO4) treatment is widely used for fetal neuroprotection in women at risk of preterm delivery. However, some studies have recently suggested that in utero MgSO4 exposure is associated with an increased risk of necrotizing enterocolitis (NEC). This study aimed to investigate the association between antenatal MgSO4 treatment and risk of NEC. This retrospective cohort study included 756 infants born at 24‒31 weeks' gestation. Subjects were classified into three groups: period 1, when MgSO4 treatment protocol for fetal neuroprotection was not adopted (n = 267); period 2, when the protocol was adopted (n = 261); and period 3, when the protocol was withdrawn because of concern of risk of NEC (n = 228). Rates of NEC (≥ stage 2b) were analyzed according to time period and exposure to antenatal MgSO4. Significant difference in the rate of NEC was not found across the three time periods (2.6% vs. 6.5% vs. 4.8% in periods 1, 2 and 3, respectively, p = 0.103). The rate of NEC was comparable between the infants exposed and unexposed to antenatal MgSO4 (5.1% vs. 3.6%, p = 0.369). These results showed that antenatal MgSO4 treatment was not associated with risk of NEC in our study population.

Preeclampsia, eclampsia, and posterior reversible encephalopathy syndrome

Preeclampsia is a disorder of pregnancy associated with gestational hypertension and end-organ dysfunction. Patients with eclampsia, by definition, have seizures as part of the clinical syndrome. However, patients with preeclampsia can also have other neurologic symptoms and deficits. Both disorders can be associated with radiographic abnormalities similar to that of posterior reversible encephalopathy syndrome, suggesting a common pathophysiology or unified clinical spectrum of disorders. This chapter reviews the pathophysiology, clinical presentation, diagnostic findings, and prognosis of patients with neurologic complications associated with preeclampsia and eclampsia.

Antenatal Magnesium Sulfate and Preeclampsia Differentially Affect Neonatal Cerebral Oxygenation

INTRODUCTION

Magnesium sulfate (MgSO4) is frequently administered for maternal and fetal neuroprotection in preeclampsia (PE) and imminent preterm birth, respectively.

OBJECTIVE

To assess whether MgSO4 affects neonatal cerebral oxygenation, blood flow, and cerebral autoregulation (CAR) during the first postnatal days independently from PE.

METHODS

148 neonates <32 weeks gestational age were included. Cerebral fractional tissue oxygen extraction (cFTOE) was extracted from a daily 2-h period, during which peak systolic blood flow velocity (PSV) and resistance index (RI) of the pericallosal artery were obtained. The percent time of impaired CAR (correlation coefficient between mean arterial blood pressure and cerebral oxygen saturation >0.5) was determined. Linear mixed models were applied.

RESULTS

MgSO4 exposure was recorded in 77 neonates. Twenty-nine neonates were born following PE. MgSO4 independently lowered cFTOE (B: -0.026, 95% CI: -0.050 to 0.002, p < 0.05) but did not affect PSV and RI. PE was associated with a lower cFTOE (B: -0.041, 95% CI: -0.067 to -0.015, p < 0.05) and a tendency towards both lower PSV (B: -4.285, 95% CI: -9.067 to 0.497, p < 0.1) and more impaired CAR (B: 4.042, 95% CI: -0.028 to 8.112, p < 0.1), which seemed to be strongly mediated by fetal brain sparing. MgSO4 did not alter CAR.

CONCLUSIONS

In contrast to fetal brain sparing in PE, MgSO4 seems to lower cFTOE by lowering cerebral oxygen demands in preterm neonates without affecting the cerebrovasculature.

Safety of prolonged magnesium sulfate infusions during treatment for severe pediatric status asthmaticus

OBJECTIVE

Magnesium sulfate (Mg) is one of several "second-tier" therapies for treating severe status asthmaticus. Pediatric reports primarily describe bolus use with limited data regarding prolonged infusions. We sought to describe the safety of prolonged Mg infusions during therapy of status asthmaticus in critically ill children.

DESIGN

Single center, retrospective study.

SETTING

Thirty-four-bed tertiary level medical/surgical/cardiac surgical pediatric intensive care unit.

PATIENTS

Pediatric patients 2 to 18 years of age admitted with status asthmaticus receiving Mg infusion for more than 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN FINDINGS

A total of 154 children received Mg infusions for a median of 53.4 hours (interquartile range = 36.6-74.8). The most common adverse event (AE) was hypotension (48.1%), almost exclusively diastolic (94%), and was mostly limited to 1 blood pressure measurement (78%). 2.9% of events required intervention (fluids, decrease Mg infusion). Other AEs included nausea/emesis (22.7%), transient weakness (14.9%), and flushing (6.5%). Five patients experienced serious AEs including hypotonia (n = 1), escalation to continuous or bilevel positive airway pressure (n = 3), and sedation (n = 1), all attributed to progression of underlying medical disease. No patient required endotracheal intubation. Supratherapeutic levels (>6 mg/dL) were uncommon (2%) and were not more likely to be associated with AEs. Most (81%) patients were therapeutic by the 2nd Mg level check.

CONCLUSION

Prolonged Mg infusions were well tolerated in pediatric status asthmaticus patients. While diastolic hypotension was not uncommon, rarely were interventions deemed necessary. No serious AEs were attributed to Mg. Toxicity was uncommon suggesting that Mg levels could potentially be checked less frequently than historically reported.