Acute magnesium toxicity in an obstetric patient undergoing general anaesthesia for caesarean delivery

Maternal cardiopulmonary resuscitation

The perinatal resuscitation history in Japan is short, with the earliest efforts in the field of neonatology. In contrast, the standardization and dissemination of maternal resuscitation is lagging. With the establishment of the Maternal Death Reporting Project and the Maternal Death Case Review and Evaluation Committee in 2010, with the aim of reducing maternal deaths, the true situation of maternal deaths came to light. Subsequently, in 2015, the Japan Council for the Dissemination of Maternal Emergency Life Support Systems (J-CIMELS) was established to educate and disseminate simulations in maternal emergency care; training sessions on maternal resuscitation are now conducted in all prefectures. Since the launch of the project and council, the maternal mortality rate in Japan (especially due to obstetric critical hemorrhage) has gradually decreased. This has been probably achieved due to the tireless efforts of medical personnel involved in perinatal care, as well as the various activities conducted so far. However, there are no standardized guidelines for maternal resuscitation yet. Therefore, a committee was set up within the Japan Resuscitation Council to develop a maternal resuscitation protocol, and the Guidelines for Maternal Resuscitation 2020 was created in 2021. These guidelines are expected to make the use of high-quality resuscitation methods more widespread than ever before. This presentation will provide an overview of the Guidelines for Maternal Resuscitation 2020.

Effects of Magnesium Sulfate on Intraoperative Blood Loss and Anesthetic Requirement in Meningioma Patients Undergoing Craniotomy with Tumor Removal: A Prospective Randomized Study

Background Meningioma brain tumor is associated with significant blood loss. Magnesium (Mg), a calcium blocker, can facilitate blood pressure control during surgery. This study aimed to evaluate effects of magnesium on blood loss, anesthetic requirement, and its neuroprotective effect in meningioma patients undergoing craniotomy.

Methods Eighty patients aged between 18 and 70, American Society of Anesthesiologists physical status I and II, diagnosed with meningioma and scheduled for craniotomy tumor removal were randomized into two groups. Group M (Mg) received intravenous magnesium sulfate 40 mg/kg over 30 minutes initiated at skin incision and followed by continuous infusion of 10 mg/kg/h until dura closure. Group N (NSS) received 0.9% NaCl as placebo. Anesthesiologists in charge, surgeons, and patients were all blinded. The assessed outcomes were perioperative blood loss, anesthetic requirement, and pre- and postoperative neurocognitive functions assessed by Montreal Cognitive Assessment (MoCA).

Results Thirty-eight patients in each group were analyzed. In group M, the intraoperative blood losses were 500 (70, 2300) mL, and 510 (100, 1600) mL in group N (p = 0.315). Patients who received blood within 24 hours were 39.5% in group M and 47.4% in group N (p = 0.644). No differences were observed in anesthetic requirement, intraoperative mean arterial pressure, hypotensive episodes, and vasopressor usages. There were no significant differences in postoperative MoCA score. Magnesium levels did not exceed acceptable levels.

Conclusions Magnesium administration in meningioma patients had no significant effects on blood loss, anesthetic requirement, and postoperative cognitive function.

Pearls and Oysters: Reversible Postpartum Pseudo-Coma State Associated With Magnesium Therapy: A Report of 2 Cases

Magnesium (Mg) competes with calcium in normal synaptic transmission, inhibiting neurotransmitter release. As a drug, it is usually given as a treatment for eclampsia and pre-eclampsia. Two eclamptic pregnant women treated with Mg developed a pseudo-coma state immediately after emergency Caesarian Section. The clinical presentation was flaccid quadriparesis, areflexia, an absence of absent respiratory effort and vestibular-ocular reflexes, but with preserved pupillary responses. Decremental responses on repetitive nerve stimulation were found in both women. Recovery was obtained after cessation of the Mg. The persistence of pupillary reflexes in the absence of reflexes involving striated muscles was an important clinical clue, indicating neuromuscular junction dysfunction.

Postpartum Respiratory Depression

Postpartum respiratory depression is a complex, multifactorial issue that encompasses a patient's baseline preexisting conditions, certain pregnancy-specific conditions or complications, as well as the iatrogenic element of various medications given in the peripartum period. In this review, we discuss many of these factors including obesity, sleep-disordered breathing, chronic lung disease, neuromuscular disorders, opioids, preeclampsia, peripartum cardiomyopathy, postpartum hemorrhage, amniotic fluid embolism, sepsis, acute respiratory distress syndrome (ARDS), and medications such as analgesics, sedatives, anesthetics, and magnesium. Current recommendations for screening, treatment, and prevention are also discussed.

Pre-eclampsia through the eyes of the obstetrician and anesthesiologist

Due to the high risk of morbidity and mortality from unrecognized and untreated pre-eclampsia, clinicians should have a high index of suspicion to evaluate, treat and monitor patients presenting with signs concerning for pre-eclampsia. Early blood pressure management and seizure prophylaxis during labor are critical for maternal safety. Intrapartum, special anesthetic considerations should be employed to ensure the safety of the parturient and fetus. Patients who have pre-eclampsia should be aware that they are at high risk for the future development of cardiovascular disease.

Optimizing the use of intravenous magnesium sulfate for acute asthma treatment in children

BACKGROUND

Asthma is the most common pediatric chronic disease and currently affects 7.1 million children in the United States. Many children experience acute asthma exacerbations. Many children also require hospitalization despite treatment in an emergency department with current standard therapy (corticosteroids, albuterol, and ipratropium). These hospitalizations may be avoided if effective adjunctive therapies can be developed to adequately treat severe exacerbations.

METHODS

Publications were searched in the PubMed database using the following keywords: magnesium AND asthma AND children AND randomized controlled trial. A total of 30 publications were returned. References of relevant articles were also screened. We included publications of controlled randomized trials where intravenous magnesium sulfate was studied in children (age < 18 years) with acute asthma (n = 7). We excluded studies in adults or trials with other formulations of magnesium (e.g., nebulized).

RESULTS

Previous studies have demonstrated that intravenous magnesium sulfate (IV MgSO₄ ) significantly improves respiratory function and reduces hospitalization rate in children with moderate to severe asthma exacerbations. Current dosing regimens involve a short infusion of 25-75 mg/kg over 20 min (maximum 2-2.5 g/dose), though no studies have directly compared dosages for relative efficacy. Several studies suggest utilizing a peak plasma concentration of magnesium higher than 4 mg/dL as a surrogate of efficacy. This review summarizes the literature regarding the use of IV MgSO₄ for the treatment of pediatric acute asthma.

CONCLUSIONS

We suggest that optimized dosing regimens could be developed using a linked pharmacokinetic-pharmacodynamic modeling and simulation approach. We propose the factors that should be considered in future clinical trial design in order to better understand the use of IV MgSO₄ in pediatric acute asthma. Pediatr Pulmonol. 2016;51:1414-1421. © 2016 Wiley Periodicals, Inc.

Iatrogenic magnesium toxicity following intravenous infusion of magnesium sulfate: risks and strategies for prevention

A 65-year-old man being treated with radiotherapy and chemotherapy for recurrent colonic adenocarcinoma was admitted for management of hypokalaemia and hypomagnesaemia secondary to diarrhoea. He was treated with intravenous infusions of potassium chloride and magnesium sulfate. Following an infusion of magnesium sulfate, he experienced a sudden neurological deterioration. A CT of the head revealed no haemorrhage or evidence of acute ischaemic injury. Results of serum biochemistry later that day revealed an elevated magnesium level. Iatrogenic magnesium toxicity was suspected. Further discussions between the pharmacist and ward staff confirmed that a medication error had been made in the preparation of the infusion resulting in an overdose of intravenous magnesium.

Maternal adverse effects of different antenatal magnesium sulphate regimens for improving maternal and infant outcomes: a systematic review

BACKGROUND

Antenatal magnesium sulphate, widely used in obstetrics to improve maternal and infant outcomes, may be associated with adverse effects for the mother sufficient for treatment cessation. This systematic review aimed to quantify maternal adverse effects attributed to treatment, assess how adverse effects vary according to different regimens, and explore women's experiences with this treatment.

METHODS

Bibliographic databases were searched from their inceptions to July 2012 for studies of any design that reported on maternal adverse effects associated with antenatal magnesium sulphate given to improve maternal or infant outcomes. Primary outcomes were life-threatening adverse effects of treatment (death, cardiac arrest, respiratory arrest). For randomised controlled trials, data were meta-analysed, and risk ratios (RR) pooled using fixed-effects or random-effects models. For non-randomised studies, data were tabulated by design, and presented as RR, odds ratios or percentages, and summarised narratively.

RESULTS

A total of 143 publications were included (21 randomised trials, 15 non-randomised comparative studies, 32 case series and 75 reports of individual cases), of mixed methodological quality. Compared with placebo or no treatment, magnesium sulphate was not associated with an increased risk of maternal death, cardiac arrest or respiratory arrest. Magnesium sulphate significantly increased the risk of 'any adverse effects' overall (RR 4.62, 95% CI 2.42-8.83; 4 trials, 13,322 women), and treatment cessation due to adverse effects (RR 2.77; 95% CI 2.32-3.30; 5 trials, 13,666 women). Few subgroup differences were observed (between indications for use and treatment regimens). In one trial, a lower dose regimen (2 g/3 hours) compared with a higher dose regimen (5 g/4 hours) significantly reduced treatment cessation (RR 0.05; 95% CI 0.01-0.39, 126 women). Adverse effect estimates from studies of other designs largely supported data from randomised trials. Case reports supported an association between iatrogenic overdose of magnesium sulphate and life-threatening consequences.

CONCLUSIONS

Appropriate administration of antenatal magnesium sulphate was not shown to be associated with serious maternal adverse effects, though an increase in 'minor' adverse effects and treatment cessation was shown. Larger trials are needed to determine optimal regimens, achieving maximal effectiveness with minimal adverse effects, for each antenatal indication for use. Vigilance in the use of magnesium sulphate is essential for women's safety.

Accidental intravenous infusion of a large dose of magnesium sulphate during labor: A case report

During labor and child delivery, a wide range of drugs are administered. Most of these medications are high-alert medications, which can cause significant harm to the patient due to its inadvertent use. Errors could be caused due to unfamiliarity with safe dosage ranges, confusion between similar looking drugs, mislabeling of drugs, equipment misuse, or malfunction and communication errors. We report a case of inadvertent infusion of a large dose of magnesium sulphate in a pregnant woman.

Trauma in pregnancy: an updated systematic review

We reviewed recent data on the prevalence, risk factors, complications, and management of trauma during pregnancy. Using the terms "trauma" and "pregnancy" along with specified mechanisms of injury, we queried the PubMed database for studies reported from Jan. 1, 1990, through May 1, 2012. Studies with the largest number of patients for a given injury type and that were population-based and/or prospective were included. Case reports and case series were used only when more robust studies were lacking. A total of 1164 abstracts were reviewed and 225 met criteria for inclusion. Domestic violence/intimate partner violence and motor vehicle crashes are the predominant causes of reported trauma during pregnancy. Management of trauma during pregnancy is dictated by its severity and should be initially geared toward maternal stabilization. Minor trauma can often be safely evaluated with simple diagnostic modalities. Pregnancy should not lead to underdiagnosis or undertreatment of trauma due to unfounded fears of fetal effects. More studies are required to elucidate the safest and most cost-effective strategies for the management of trauma in pregnancy.