Action of magnesium sulfate in the treatment of preeclampsia-eclampsia

Alternative magnesium sulphate regimens for women with pre-eclampsia and eclampsia

BACKGROUND

Magnesium sulphate is the drug of choice for the prevention and treatment of women with eclampsia. Regimens for administration of this drug have evolved over the years, but there is no clarity on the comparative benefits or harm of alternative regimens. This is an update of a review first published in 2010.

OBJECTIVES

To assess if one magnesium sulphate regimen is better than another when used for the care of women with pre-eclampsia or eclampsia, or both, to reduce the risk of severe morbidity and mortality for the woman and her baby.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (29 April 2022), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised trials and cluster-randomised trials comparing different regimens for administration of magnesium sulphate used in women with pre-eclampsia or eclampsia, or both. Comparisons included different dose regimens, intramuscular versus intravenous route for maintenance therapy, and different durations of therapy. We excluded studies with quasi-random or cross-over designs. We included abstracts of conference proceedings if compliant with the trustworthiness assessment.

DATA COLLECTION AND ANALYSIS

For this update, two review authors assessed trials for inclusion, performed risk of bias assessment, and extracted data. We checked data for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

For this update, a total of 16 trials (3020 women) met our inclusion criteria: four trials (409 women) compared regimens for women with eclampsia, and 12 trials (2611 women) compared regimens for women with pre-eclampsia. Most of the included trials had small sample sizes and were conducted in low- and middle-income countries. Eleven trials reported adequate randomisation and allocation concealment. Blinding of participants and clinicians was not possible in most trials. The included studies were for the most part at low risk of attrition and reporting bias. Treatment of women with eclampsia (four comparisons) One trial compared a loading dose-alone regimen with a loading dose plus maintenance dose regimen (80 women). It is uncertain whether either regimen has an effect on the risk of recurrence of convulsions or maternal death (very low-certainty evidence). One trial compared a lower-dose regimen with standard-dose regimen over 24 hours (72 women). It is uncertain whether either regimen has an effect on the risk of recurrence of convulsion, severe morbidity, perinatal death, or maternal death (very low-certainty evidence). One trial (137 women) compared intravenous (IV) versus standard intramuscular (IM) maintenance regimen. It is uncertain whether either route has an effect on recurrence of convulsions, death of the baby before discharge (stillbirth and neonatal death), or maternal death (very low-certainty evidence). One trial (120 women) compared a short maintenance regimen with a standard (24 hours after birth) maintenance regimen. It is uncertain whether the duration of the maintenance regimen has an effect on recurrence of convulsions, severe morbidity, or side effects such as nausea and respiratory failure. A short maintenance regimen may reduce the risk of flushing when compared to a standard 24 hours maintenance regimen (risk ratio (RR) 0.27, 95% confidence interval (CI) 0.08 to 0.93; 1 trial, 120 women; low-certainty evidence). Many of our prespecified critical outcomes were not reported in the included trials. Prevention of eclampsia for women with pre-eclampsia (five comparisons) Two trials (462 women) compared loading dose alone with loading dose plus maintenance therapy. Low-certainty evidence suggests an uncertain effect with either regimen on the risk of eclampsia (RR 2.00, 95% CI 0.61 to 6.54; 2 trials, 462 women) or perinatal death (RR 0.50, 95% CI 0.19 to 1.36; 2 trials, 462 women). One small trial (17 women) compared an IV versus IM maintenance regimen for 24 hours. It is uncertain whether IV or IM maintenance regimen has an effect on eclampsia or stillbirth (very low-certainty evidence). Four trials (1713 women) compared short postpartum maintenance regimens with continuing for 24 hours after birth. Low-certainty evidence suggests there may be a wide range of benefit or harm between groups regarding eclampsia (RR 1.99, 95% CI 0.18 to 21.87; 4 trials, 1713 women). Low-certainty evidence suggests there may be little or no effect on severe morbidity (RR 0.96, 95% CI 0.71 to 1.29; 2 trials, 1233 women) or side effects such as respiratory depression (RR 0.80, 95% CI 0.25 to 2.61; 2 trials, 1424 women). Three trials (185 women) compared a higher-dose maintenance regimen versus a lower-dose maintenance regimen. It is uncertain whether either regimen has an effect on eclampsia (very low-certainty evidence). Low-certainty evidence suggests that a higher-dose maintenance regimen has little or no effect on side effects when compared to a lower-dose regimen (RR 0.79, 95% CI 0.61 to 1.01; 1 trial 62 women). One trial (200 women) compared a maintenance regimen by continuous infusion versus a serial IV bolus regimen. It is uncertain whether the duration of the maintenance regimen has an effect on eclampsia, side effects, perinatal death, maternal death, or other neonatal morbidity (very low-certainty evidence). Many of our prespecified critical outcomes were not reported in the included trials.

AUTHORS' CONCLUSIONS

Despite the number of trials evaluating various magnesium sulphate regimens for eclampsia prophylaxis and treatment, there is still no compelling evidence that one particular regimen is more effective than another. Well-designed randomised controlled trials are needed to answer this question.

Preeclampsia: Recent Advances in Predicting, Preventing, and Managing the Maternal and Fetal Life-Threatening Condition

Preeclampsia accounts for one of the most common documented gestational complications, with a prevalence of approximately 2 to 15% of all pregnancies. Defined as gestational hypertension after 20 weeks of pregnancy and coexisting proteinuria or generalized edema, and certain forms of organ damage, it is life-threatening for both the mother and the fetus, in terms of increasing the rate of mortality and morbidity. Preeclamptic pregnancies are strongly associated with significantly higher medical costs. The maternal costs are related to the extra utility of the healthcare system, more resources used during hospitalization, and likely more surgical spending due to an elevated rate of cesarean deliveries. The infant costs also contribute to a large percentage of the expenses as the babies are prone to preterm deliveries and relevant or causative adverse events. Preeclampsia imposes a considerable financial burden on our societies. It is important for healthcare providers and policy-makers to recognize this phenomenon and allocate enough economic budgets and medical and social resources accordingly. The true cellular and molecular mechanisms underlying preeclampsia remain largely unexplained, which is assumed to be a two-stage process of impaired uteroplacental perfusion with or without prior defective trophoblast invasion (stage 1), followed by general endothelial dysfunction and vascular inflammation that lead to systemic organ damages (stage 2). Risk factors for preeclampsia including race, advanced maternal age, obesity, nulliparity, multi-fetal pregnancy, and co-existing medical disorders, can serve as warnings or markers that call for enhanced surveillance of maternal and fetal well-being. Doppler ultrasonography and biomarkers including the mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), and serum pregnancy-associated plasma protein A (PAPP-A) can be used for the prediction of preeclampsia. For women perceived as high-risk individuals for developing preeclampsia, the administration of low-dose aspirin on a daily basis since early pregnancy has proven to be the most effective way to prevent preeclampsia. For preeclamptic females, relevant information, counseling, and suggestions should be provided to facilitate timely intervention or specialty referral. In pregnancies complicated with preeclampsia, closer monitoring and antepartum surveillance including the Doppler ultrasound blood flow study, biophysical profile, non-stress test, and oxytocin challenge test can be arranged. If the results are unfavorable, early intervention and aggressive therapy should be considered. Affected females should have access to higher levels of obstetric units and neonatal institutes. Before, during, and after delivery, monitoring and preparation should be intensified for affected gravidas to avoid serious complications of preeclampsia. In severe cases, delivery of the fetus and the placenta is the ultimate solution to treat preeclampsia. The current review is a summary of recent advances regarding the knowledge of preeclampsia. However, the detailed etiology, pathophysiology, and effect of preeclampsia seem complicated, and further research to address the primary etiology and pathophysiology underlying the clinical manifestations and outcomes is warranted.

Magnesium: The recent research and developments

Magnesium is the fourth most abundant mineral in the human body, which facilitates more than 300 enzymatic reactions. Magnesium is essential for nucleic material and protein synthesis, neuromuscular conduction, cardiac contractility, energy metabolism, and immune system function. Gastrointestinal system and kidneys closely regulate magnesium absorption and elimination to maintain adequate storage of magnesium. Magnesium deficiency has been linked to many diseases and poor health outcomes. Magnesium has also been proven to be an effective therapeutic agent in many diseases, such as bronchial asthma, cardiac arrhythmia, and pre-eclampsia.

HISTORY OF STUDY OF PRE-ECLAMPSIA AND ECLAMPSIA IN OBSTETRICS

Pre-eclampsia/eclampsia is one of the most serious pregnancy complications in modern obstetrics. The article presents the historical data about the study of pre-eclampsia and eclampsia since the 4th century BC. The evolution of terminology is presented. According to the development of medical science there appeared a new theory of the etiology and the conception of pathogenesis developed. It shows the contribution of Russian scientists to improve methods of diagnosis, treatment and prevention of this complication of pregnancy. The achievements of modern obstetric science allow to predict pre-eclampsia from early pregnancy. Despite long history of studying, many aspects of this problem still remain unresolved.

Magnesium in obstetric anesthesia and intensive care

Magnesium, one of the essential elements in the human body, has numerous favorable effects that offer a variety of possibilities for its use in obstetric anesthesia and intensive care. Administered as a single intravenous bolus dose or a bolus followed by continuous infusion during surgery, magnesium attenuates stress response to endotracheal intubation, and reduces intraoperative anesthetic and postoperative analgesic requirements, while at the same time preserving favorable hemodynamics. Applied as part of an intrathecal or epidural anesthetic mixture, magnesium prolongs the duration of anesthesia and diminishes total postoperative analgesic consumption with no adverse maternal or neonatal effects. In obstetric intensive care, magnesium represents a first-choice medication in the treatment and prevention of eclamptic seizures. If used in recommended doses with close monitoring, magnesium is a safe and effective medication.

Magnesium sulfate for acute traumatic brain injury

BACKGROUND

The purpose of this systematic review was to evaluate the effect of magnesium sulfate in the treatment of acute traumatic brain injury.

MATERIALS AND METHODS

A systematic search of ClinicalTrials.gov, the Cochrane Library database, EMBASE, MEDLINE, Web of Science, and the World Health Organization trial registry, plus manual searches of gray literature, was undertaken in April 2013. Two reviewers independently extracted the data with a predefined data extraction form. RevMan 5 software was used to synthesize data and calculate the risk ratio for mortality with the 95% confidence interval. For the Glasgow Outcome Scale and posttreatment Glasgow Coma Scale data, the weighted mean difference was calculated with the 95% confidence interval.

RESULTS

A total of 8 randomized controlled trials with a total of 786 patients were included. Meta-analysis showed that there was no significant difference between the groups for mortality. The Glasgow Outcome Scale of the treatment group was higher than that of the control group, although the significance was borderline. The Glasgow Coma Scale score change posttreatment was significantly higher than that of the control.

CONCLUSIONS

The present meta-analysis of existing randomized controlled trials does not identify a significant beneficial effect in the mortality of traumatic brain injury patients; however, it suggests that magnesium sulfate shows a tendency to improve the Glasgow Outcome Scale and Glasgow Coma Scale scores, which is a promising result for traumatic brain injury therapy. Further effort is necessary to explore which subgroup of traumatic brain injury patients could benefit from magnesium sulfate.

The effect of high concentration of magnesium with ropivacaine, gentamicin, rocuronium, and their combination on neuromuscular blockade

Background

Magnesium, ropivacaine, gentamicin, and rocuronium block neuromuscular (NM) transmission by different mechanisms. Therefore, concurrent administration of these agents may induce prolonged muscle paralysis via synergistic interaction. This study investigated the efficacy and safety of NM block caused by the administration of high concentrations of magnesium in combination with ropivacaine, gentamicin, and rocuronium.

Methods

Eighty-three left phrenic nerve-hemidiaphragms from male SD rats (150-250 g) were hung in Krebs solution. Three consecutive single twitch tension (ST, 0.1 Hz) and one tetanic tension (TT, 50 Hz for 1.9 s) were obtained before drug application and at each new drug concentration. The concentration of MgCl₂ and MgSO₄ in Krebs solution was increased until an 80 to 90% reduction in ST was reached. To test the effects of combinations of NM agents, a Krebs solution was premixed with MgCl₂ alone, MgCl₂ and ropivacaine, or MgCl₂, ropivacaine, and gentamicin. The concentration of ropivacaine, gentamicin, or rocuronium was then progressively increased until an 80 to 90% reduction in ST was reached. The effective concentrations were estimated with a probit model.

Results

The potency of MgCl₂ was greater than that of MgSO₄, and pretreatment with MgCl₂ increased the potency of gentamicin and rocuronium. Unexpectedly, MgCl₂ did not potentiate ropivacaine, and the potency of gentamicin and rocuronium failed to show an increase when premixed with 0.5 µM ropivacaine.

Conclusions

The concomitant administration of high concentrations of magnesium and ropivacaine together with clinically relevant concentrations of gentamicin or rocuronium potentiated NM blockade but not with clinically relevant concentrations of ropivacaine.

Magnesium sulfate treatment improves outcome in patients with subarachnoid hemorrhage: a meta-analysis study

OBJECTIVE

To elucidate the role of magnesium sulfate in patients with subarachnoid hemorrhagic (SAH) brain injury

METHOD

Studies for the meta-analysis were identified from PubMed (1966 to 2009), Embase (1980 to 2009), and two Chinese journals (1989 to 2009). Paper selection was based on randomized controlled trials comparing magnesium sulfate to placebo treatment in patients with SAH. Two independent review authors extracted the data and assessed trial quality. Meta-analysis was performed using the Cochrane Review Manger software.

RESULTS

Five trials involving 482 patients were included in the review. Magnesium sulfate reduced the risk of poor outcome and reduced the occurrence of delayed cerebral ischemia. In the treatment groups, relative risk for poor outcome was 0.73 (CI 0.57-0.93) and 0.66 (CI 0.47-0.92) for delayed cerebral ischemia. Case fatality assessment at three to six months did not show statistically significant data (RR 0.88; CI 0.61-1.29).

CONCLUSION

Magnesium sulfate appears to be an effective treatment option in the management of SAH. Further clinical trials are needed before magnesium sulfate can become a routine treatment for SAH.

The role of genetics in pre-eclampsia and potential pharmacogenomic interventions

The pregnancy-specific condition pre-eclampsia not only affects the health of mother and baby during pregnancy but also has long-term consequences, increasing the chances of cardiovascular disease in later life. It is accepted that pre-eclampsia has a placental origin, but the pathogenic mechanisms leading to the systemic endothelial dysfunction characteristic of the disorder remain to be determined. In this review we discuss some key factors regarded as important in the development of pre-eclampsia, including immune maladaptation, inadequate placentation, oxidative stress, and thrombosis. Genetic factors influence all of these proposed pathophysiological mechanisms. The inherited nature of pre-eclampsia has been known for many years, and extensive genetic studies have been undertaken in this area. Genetic research offers an attractive strategy for studying the pathogenesis of pre-eclampsia as it avoids the ethical and practical difficulties of conducting basic science research during the preclinical phase of pre-eclampsia when the underlying pathological changes occur. Although pharmacogenomic studies have not yet been conducted in pre-eclampsia, a number of studies investigating treatment for essential hypertension are of relevance to therapies used in pre-eclampsia. The pharmacogenomics of antiplatelet agents, alpha and beta blockers, calcium channel blockers, and magnesium sulfate are discussed in relation to the treatment and prevention of pre-eclampsia. Pharmacogenomics offers the prospect of individualized patient treatment, ensuring swift introduction of optimal treatment whilst minimizing the use of inappropriate or ineffective drugs, thereby reducing the risk of harmful effects to both mother and baby.

Magnesium sulfate administration in subarachnoid hemorrhage

Magnesium offers theoretic vascular and neuroprotective benefits for patients with subarachnoid hemorrhage. An electronic literature search was conducted to identify original research studies describing intravenous magnesium treatment in patients with SAH published in English between January 1990 and October 2010. Seventeen articles were identified and reviewed, including one phase III randomized-controlled clinical trial and six phase II randomized-controlled trials. Study quality was low for most of the included studies, with the phase III trial considered to be of moderate quality. Due to inconsistently reported benefits and the occurrence of side effects, phase II data suggested that intravenous magnesium for SAH provided either no overall net benefit or uncertain trade-offs. Benefit was likewise not supported in the single phase III clinical trial.

Magnesium sulphate versus diazepam for eclampsia

BACKGROUND

Eclampsia, the occurrence of a seizure in association with pre-eclampsia, remains a rare but serious complication of pregnancy. A number of different anticonvulsants are used to control eclamptic fits and to prevent further fits.

OBJECTIVES

The objective of this review was to assess the effects of magnesium sulphate compared with diazepam when used for the care of women with eclampsia. Magnesium sulphate is compared with phenytoin and with lytic cocktail in other Cochrane reviews.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 September 2010) and CENTRAL (2010, Issue 3).

SELECTION CRITERIA

Randomised trials comparing magnesium sulphate (intravenous or intramuscular administration) with diazepam for women with a clinical diagnosis of eclampsia.

DATA COLLECTION AND ANALYSIS

Two authors assessed and extracted data independently.

MAIN RESULTS

We have included seven trials, involving 1396 women. Three trials (1030 women) were good quality. Magnesium sulphate was associated with a reduction in maternal death (seven trials;1396 women; risk ratio (RR) 0.59, 95% confidence interval (CI) 0.38 to 0.92) and recurrence of seizures (seven trials;1390 women; RR 0.43, 95% CI 0.33 to 0.55) compared to diazepam. There were no clear differences in other measures of maternal morbidity.There was no clear difference in perinatal mortality (four trials; 788 infants; RR 1.04, 95% CI 0.81 to 1.34) or neonatal mortality (four trials; 759 infants; RR 1.18, 95% CI 0.75 to 1.84). In the magnesium sulphate group, fewer liveborn babies had an Apgar score less than seven at one minute (two trials; 597 babies; RR 0.75, 95% CI 0.65 to 0.87) or at five minutes (RR 0.70, 95% CI 0.54 to 0.90), and fewer appeared to need intubation at the place of birth (two trials; 591 infants; RR 0.67, 95% CI 0.45 to 1.00). There was no difference in admission to a special care nursery (four trials; 834 infants; RR 0.91, 95% CI 0.79 to 1.05), but fewer babies in the magnesium sulphate group had a length of stay more than seven days (three trials 631 babies; RR 0.66, 95% CI 0.46 to 0.96).

AUTHORS' CONCLUSIONS

Magnesium sulphate for women with eclampsia reduces the risk ratio of maternal death and of recurrence of seizures, compared with diazepam.

Magnesium sulphate and other anticonvulsants for women with pre-eclampsia

BACKGROUND

Eclampsia, the occurrence of a seizure (fit) in association with pre-eclampsia, is rare but potentially life-threatening. Magnesium sulphate is the drug of choice for treating eclampsia. This review assesses its use for preventing eclampsia.

OBJECTIVES

To assess the effects of magnesium sulphate, and other anticonvulsants, for prevention of eclampsia.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (4 June 2010), and the Cochrane Central Register of Controlled Trials Register (The Cochrane Library 2010, Issue 3).

SELECTION CRITERIA

Randomised trials comparing anticonvulsants with placebo or no anticonvulsant, or comparisons of different drugs, for pre-eclampsia.

DATA COLLECTION AND ANALYSIS

Two authors assessed trial quality and extracted data independently.

MAIN RESULTS

We included 15 trials. Six (11,444 women) compared magnesium sulphate with placebo or no anticonvulsant: magnesium sulphate more than a halved the risk of eclampsia (risk ratio (RR) 0.41, 95% confidence interval (CI) 0.29 to 0.58; number needed to treat for an additional beneficial outcome (NNTB) 100, 95% CI 50 to 100), with a non-significant reduction in maternal death (RR 0.54, 95% CI 0.26 to 1.10) but no clear difference in serious maternal morbidity (RR 1.08, 95% CI 0.89 to 1.32). It reduced the risk of placental abruption (RR 0.64, 95% CI 0.50 to 0.83; NNTB 100, 95% CI 50 to 1000), and increased caesarean section (RR 1.05, 95% CI 1.01 to 1.10). There was no clear difference in stillbirth or neonatal death (RR 1.04, 95% CI 0.93 to 1.15). Side effects, primarily flushing, were more common with magnesium sulphate (24% versus 5%; RR 5.26, 95% CI 4.59 to 6.03; number need to treat for an additional harmful outcome (NNTH) 6, 95% CI 5 to 6).Follow-up was reported by one trial comparing magnesium sulphate with placebo: for 3375 women there was no clear difference in death (RR 1.79, 95% CI 0.71 to 4.53) or morbidity potentially related to pre-eclampsia (RR 0.84, 95% CI 0.55 to 1.26) (median follow-up 26 months); for 3283 children exposed in utero there was no clear difference in death (RR 1.02, 95% CI 0.57 to 1.84) or neurosensory disability (RR 0.77, 95% CI 0.38 to 1.58) at age 18 months.Magnesium sulphate reduced eclampsia compared to phenytoin (three trials, 2291 women; RR 0.08, 95% CI 0.01 to 0.60) and nimodipine (one trial, 1650 women; RR 0.33, 95% CI 0.14 to 0.77).

AUTHORS' CONCLUSIONS

Magnesium sulphate more than halves the risk of eclampsia, and probably reduces maternal death. There is no clear effect on outcome after discharge from hospital. A quarter of women report side effects with magnesium sulphate.

Magnesium sulphate versus phenytoin for eclampsia

BACKGROUND

Eclampsia, the occurrence of a seizure in association with pre-eclampsia, remains a rare but serious complication of pregnancy. A number of different anticonvulsants have been used to control eclamptic fits and to prevent further seizures.

OBJECTIVES

The objective of this review was to assess the effects of magnesium sulphate compared with phenytoin when used for the care of women with eclampsia. Magnesium sulphate is compared with diazepam and with lytic cocktail in other Cochrane reviews.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2010).

SELECTION CRITERIA

Randomised trials comparing magnesium sulphate (intravenous or intramuscular administration) with phenytoin for women with a clinical diagnosis of eclampsia.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted data.

MAIN RESULTS

We have included data from seven trials, involving 972 women. One large trial (775 women) was of good quality. Magnesium sulphate was associated with a substantial reduction in the recurrence of seizures, when compared to phenytoin (six trials, 972 women; risk ratio (RR) 0.34, 95% confidence interval (CI) 0.24 to 0.49). The trend in maternal mortality favours magnesium sulphate, but the difference does not reach statistical significance (three trials, 847 women; RR 0.50, 95% CI 0.24 to 1.05). There were reductions in the risk of pneumonia (one trial, RR 0.44, 95% CI 0.24 to 0.79), ventilation (one trial, RR 0.68, 95% CI 0.50 to 0.91) and admission to an intensive care unit (one trial, RR 0.67, 95% CI 0.50 to 0.89) associated with the use of magnesium sulphate rather than phenytoin.For the baby, magnesium sulphate was associated with fewer admissions to a special care baby unit (SCBU) (one trial, 518 babies; RR 0.73, 95% CI 0.58 to 0.91) and fewer babies who died or were in SCBU for more than seven days (one trial, 643 babies; RR 0.77, 95% CI 0.63 to 0.95) than phenytoin. There was no clear difference in perinatal deaths (two trials, 665 babies; (RR 0.85, 95% CI 0.67 to 1.09).

AUTHORS' CONCLUSIONS

Magnesium sulphate, rather than phenytoin, for women with eclampsia reduces the risk ratio of recurrence of seizures, probably reduces the risk of maternal death, and improves outcome for the baby. Magnesium sulphate is the drug of choice for women with eclampsia. The use of phenytoin should be abandoned.

Magnesium sulphate versus lytic cocktail for eclampsia

BACKGROUND

Eclampsia, the occurrence of a seizure in association with pre-eclampsia, is a rare but serious complication of pregnancy. A number of different anticonvulsants have been used to control eclamptic fits and to prevent further seizures.

OBJECTIVES

The objective of this review was to assess the effects of magnesium sulphate compared with lytic cocktail (usually chlorpromazine, promethazine and pethidine) when used for the care of women with eclampsia. Magnesium sulphate is compared with diazepam and with phenytoin in other Cochrane reviews.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (July 2010) and the Cochrane Central Register of Trials (The Cochrane Library 2010, Issue 2).

SELECTION CRITERIA

Randomised trials comparing magnesium sulphate (intravenous or intramuscular administration) with lytic cocktail for women with a clinical diagnosis of eclampsia.

DATA COLLECTION AND ANALYSIS

Two review authors (L Duley and D Chou) assessed trial quality and extracted data.

MAIN RESULTS

We included three small trials (total 397 women) of average quality in the review. Magnesium sulphate was associated with fewer maternal deaths (risk ratio (RR) 0.14, 95% confidence interval (CI) 0.03 to 0.59; 3 trials, 397 women) and was better at preventing further seizures (RR 0.06, 95% CI 0.03 to 0.12; 3 trials, 397 women) than lytic cocktail. Magnesium sulphate was also associated with less respiratory depression (RR 0.12, 95% CI 0.02 to 0.91; 2 trials, 198 women), less coma (RR 0.04, 95% CI 0.00 to 0.74; 1 trial, 108 women), and less pneumonia (RR 0.20, 95% CI 0.06 to 0.67; 2 trials, 307 women). There was no clear difference in the RR for any death of the baby (RR 0.35, 95% CI 0.05 to 2.38, random effects; 2 trials, 177 babies).

AUTHORS' CONCLUSIONS

Magnesium sulphate, rather than lytic cocktail, for women with eclampsia reduces the RR of maternal death, of further seizures and of serious maternal morbidity (respiratory depression, coma, pneumonia). Magnesium sulphate is the anticonvulsant of choice for women with eclampsia; the use of lytic cocktail should be abandoned.

Alternative magnesium sulphate regimens for women with pre-eclampsia and eclampsia

BACKGROUND

Magnesium sulphate remains the drug of choice for both prevention and treatment of women with eclampsia. Regimens for administration of this drug have evolved over the years, but have not yet been formally evaluated.

OBJECTIVES

To assess the comparative effects of alternative regimens for the administration of magnesium sulphate when used for the care of women with pre-eclampsia or eclampsia, or both.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2010).

SELECTION CRITERIA

Randomised trials comparing different regimens for administration of magnesium sulphate used for the care of women with pre-eclampsia or eclampsia, or both.

DATA COLLECTION AND ANALYSIS

All four review authors assessed trial quality and extracted data independently.

MAIN RESULTS

We identified 17 studies of which six (866 women) met the inclusion criteria: two trials (451 women) compared regimens for women with eclampsia and four (415 women) for women with pre-eclampsia.Treatment of eclampsia: one trial compared loading dose alone with loading dose plus maintenance therapy for 24 hours (401 women). There was no clear difference between the groups in the risk ratio (RR) of recurrence of convulsions (RR 1.13, 95% confidence interval (CI) 0.42 to 3.05) or stillbirth (RR 1.13, 95% CI 0.66 to 1.92), and the CIs are wide. One trial compared a low dose regimen with a standard dose regimen over 24 hours (50 women). This study was too small for any reliable conclusions about the comparative effects.Prevention of eclampsia: one trial compared intravenous with intramuscular maintenance regimen for 24 hours (17 women). This trial was too small for any reliable conclusions. Three trials compared short maintenance regimens postpartum with continuing for 24 hours after the birth (398 women), even taken together these trials were too small for any reliable conclusions.

AUTHORS' CONCLUSIONS

Although strong evidence supports the use of magnesium sulphate for prevention and treatment of eclampsia, trials comparing alternative treatment regimens are too small for reliable conclusions.

A review of the effects of vitamins and other dietary supplements on seizure activity

The role of pharmacological and surgical management of epilepsy continues to expand, but these treatments are often associated with significant side effects and morbidity. As a result, many patients with epilepsy and their physicians alike have gained interest in the role of vitamins and other dietary supplements for seizure management. In this review, we examine the potential anticonvulsant and proconvulsant effects of commonly used dietary supplements, as well as their potential effects on cognition or behavior. Our review was conducted through a literature search focusing on clinical trials involving patients with epilepsy and their seizure response to dietary supplementation. We summarize findings from previous clinical studies and comment on practical considerations regarding dietary supplementation for patients with epilepsy.

Magnesium in obstetrics

Magnesium is a critical physiological ion, and magnesium deficiency might contribute to the development of pre-eclampsia, to impaired neonatal development and to metabolic problems extending into adult life. Pharmacologically, magnesium is a calcium antagonist with substantial vasodilator properties but without myocardial depression. Cardiac output usually increases following magnesium administration, compensating for the vasodilatation and minimising hypotension. Neurologically, the inhibition of calcium channels and antagonism of the N-methyl-d-aspartic acid (NMDA) receptor raises the possibility of neuronal protection, and magnesium administration to women with premature labour may decrease the incidence of cerebral palsy. It is the first-line anticonvulsant for the management of pre-eclampsia and eclampsia, and it should be administered to all patients with severe pre-eclampsia or eclampsia. Magnesium is a moderate tocolytic but the evidence for its effectiveness remains disputed. The side effects of magnesium therapy are generally mild but the major hazard of magnesium therapy is neuromuscular weakness.

New developments in pre-eclampsia

It is quite clear that pre-eclampsia is not simply pregnancy-induced hypertension; rather, it is a multisystem disease with pathophysiological changes secondary to reduced organ perfusion. This reduction can be explained by vasospasm secondary to increased sensitivity of the vasculature to usual circulating pressors, and vascular occlusion secondary to activation of the coagulation cascade. Although pre-eclampsia becomes clinically evident late in pregnancy, pathological and pathophysiological changes antedate the clinical syndrome by weeks to months. The syndrome occurs only in pregnancy and is cured by the removal of fetoplacental tissues.

Based on these findings, we have proposed that the inciting pathophysiological change of preeclampsia is reduced trophoblastic perfusion, which produces an agent that perturbs endothelial cells. The altered endothelial functions associated with this insult increase sensitivity to pressors, activate the coagulation cascade and produce the clinical and pathological findings of preeclampsia. Although we feel this hypothesis could explain pre-eclampsia, it is possible that its major value will be to stimulate others to approach this disorder by considering all facets of its pathophysiology rather than merely its hypertensive component.

The appreciation of pre-eclampsia as a disease present from early pregnancy and the potential role of vasodilator prostaglandins have already stimulated therapeutic trials of aspirin in women at very high risk with encouraging results. At present, information is insufficient to determine the risk/benefit ratio of this therapy in lower risk patients, and aspirin therapy should not be used in these women. Another potential modification of therapy, the substitution of phenytoin for magnesium sulphate, does not seem warranted on the basis of either currently available data or on theoretical grounds.

Fruitful directions for research in the near future will be the explanation of the abnormal trophoblastic invasion of pre-eclampsia and the determination of how reduced perfusion translates into a multisystem disease. In addition, aspirin therapy or other potential prophylactic therapies would be greatly aided by the development of new tests with reasonable positive predictive values, in order to identify preeclampsia prior to clinically evident disease.

Cerebral Hemodynamics in Preeclampsia: Cerebral Perfusion and the Rationale for an Alternative to Magnesium Sulfate

Preeclampsia and eclampsia continue to be major causes of maternal death. Currently, approximately 18% of U.S. maternal deaths are attributed to hypertensive disorders and eclampsia, and several hundred women die from eclampsia and its complications every year. In the United States, preeclamptic women have received magnesium sulfate as a seizure prophylaxis agent for 3 decades, and this practice is becoming more widely accepted internationally. In addition to a recognized failure rate, there are financial, logistic, and safety concerns associated with the universal administration of magnesium sulfate. Many institutions in the developing world lack the necessary equipment and expertise to administer the medication, and many preeclamptic patients thus do not receive magnesium sulfate before their first seizure. As effective as it has been in reducing mortality from eclampsia, magnesium sulfate is also associated with appreciable morbidity and mortality from administration errors and magnesium toxicity. The availability of an easily administered, cheap, safe, and orally administered alternative to magnesium sulfate would be welcomed in the developing world and would provide an extremely useful alternative therapy to the current standard of care. Recent advances in the understanding of the pathophysiology of preeclampsia and eclampsia, primarily related to cerebral perfusion and blood flow, could allow us to reduce the seizure rate in treated preeclamptic women even further than what is currently reported. This article deals with the rationale behind the use of labetalol as an alternative to magnesium sulfate for the prevention of eclampsia.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to recall that hypertensive diseases of pregnancy contribute a significant portion of today's maternal mortality, explain that methods of preventing eclampsia are not applicable worldwide, and state that understanding of the pathophysiology of preeclampsia/eclampsia may assist in developing safe and effective medications that can be used universally.

Magnesium sulfate: role as possible attenuating factor in vasospasm morbidity

BACKGROUND

Among the many complications of SAH, one of the most important is vasospasm. Several treatment alternatives have been proposed for this condition, with far-from-ideal results being obtained. Magnesium sulfate recently returned to the scene (with still unproven benefit) as an adjuvant in the treatment of vasospasm.

METHODS

Seventy-two patients diagnosed with SAH by aneurysm rupture were submitted to microsurgery craniotomy and subdivided in 2 groups. Group 1, formed by 48 patients, received prophylactic hypervolemic and hemodilution therapy in addition to nimodipine. Group 2, composed of 24 patients, received the same treatment of group 1 with the addition of magnesium sulfate in continuous infusion from 120 to 150 mg a day, keeping serum magnesium levels close to double normal values.

RESULTS

Age was 49 +/- 12.6 years. Ratio of female to male was 3.16:1. Most patients were admitted in a Hunt-Hess grade 2 (46.4%) and Fisher grade 3 (52.8%). Anterior communicating artery aneurysms were the most common in location (38.8%). Both groups were compared, and there was no statistical difference related to age, sex, and Glasgow, Fisher, or Hunt-Hess admission grades. No statistical difference in vasospasm incidence was found between the two groups. However, in group 1, vasospasm was correlated with a longer hospitalization time (P = .0003), different from group 2, in which patients with vasospasm receiving magnesium sulfate required less hospitalization time.

CONCLUSION

Magnesium did not seem to interfere in vasospasm frequency but apparently acted favorably in decreasing morbidity and length of hospital stay.

Serum magnesium levels as related to symptomatic vasospasm and outcome following aneurysmal subarachnoid hemorrhage

INTRODUCTION

Recent evidence suggests that magnesium may be neuroprotective in the setting of cerebral ischemia, and therapeutic magnesium infusion has been proposed for prophylaxis and treatment of delayed ischemic neurological deficit (DIND) resulting from vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). We studied the association between serum magnesium levels, the development of DIND, and the outcomes of patients with SAH.

METHODS

We studied 128 consecutive patients with aneurysmal SAH treated at our institution between 1990 and 1997 who had a serum magnesium level measured at least once during the acute phase of their hospitalization. Delayed ischemic neurological deficit was defined as severe (major focal deficit or coma), moderate (incomplete focal deficit or decreased sensorium without coma), or none.

RESULTS

There was no significant difference in mean, minimum, or maximum serum magnesium levels between patients with and without DIND (1.93, 1.83, 2.02 versus 1.91, 1.84, 1.97 mg/dL, respectively). Similarly, no difference was found in mean serum magnesium levels among patients with severe (1.94 mg/dL), moderate (1.92 mg/dL), or no DIND (1.91 mg/dL). Analyses of serum magnesium levels before (0-4 days following SAH), during (4-14 days following SAH), and after (greater than 14 days following SAH) the period of highest risk for vasospasm revealed no association with the development or severity of DIND. Permanent deficit or death resulting from vasospasm and Glasgow Outcome Scale score at longest follow-up were similarly unaffected by serum magnesium levels overall or during any time interval. Forty (31.5%) patients were hypomagnesemic (less than 1.7 mg/dL) during hospitalization, but no difference in outcome (p = 0.185) or development of DIND (p = 0.785) was found when compared to patients with normal (1.7-2.1 mg/dL) or high (greater than 2.1 mg/dL) magnesium serum levels.

CONCLUSION

We identified no relationship between serum magnesium levels and the development of DIND or outcome following aneurysmal SAH. Based on these data, magnesium supplementation to normal or high-normal physiological ranges seems unlikely to be beneficial for DIND resulting from vasospasm. However, no inference can be made regarding the value of therapeutic infusion of magnesium to supraphysiological levels.

[Magnesium sulfate in obstetrics: current data]

OBJECTIVE

To review the available evidence regarding history, pharmacology, physiology, maternal/fetal side effects, and efficacy of magnesium sulfate in pregnant women.

DATA SOURCES

The literature in Medline was searched from 1966 through April 2003 using the terms "magnesium sulfate," "tocolytic," "preeclampsia," "eclampsia," and "pregnancy." Reviews of bibliographies of retrieved articles provided additional references.

RESULTS

Magnesium sulfate (MgSO4) has long been used for prophylaxis of preterm delivery (tocolytic affect) and eclampsia prophylaxis (neuroprotective effect). Randomized controlled trials and systematic reviews have demonstrated the efficacy of magnesium sulfate in preventing eclampsia in patients with preeclampsia or in patients with eclampsia. Whether magnesium sulfate should be administered to patients with severe preeclampsia or to mild preeclampsia is discussed in the manuscript. Inversely, it appears that magnesium sulfate is ineffective in delaying birth or preventing preterm birth when it is used as a tocolytic. Furthermore, there is evidence that high cumulative doses of magnesium sulfate may be associated with increased infant mortality.

CONCLUSION

The evidence to date confirms the efficacy of magnesium sulfate therapy for women with eclampsia and preeclampsia. However, magnesium sulfate should not be used in order to treat preterm labor.

Visual disturbances and seizures associated with pregnancy: a diagnostic dilemma and the role of radiological techniques as an aid to diagnosis

We present two cases of visual disturbances associated with tonic-clonic seizures during pregnancy and the associated radiological findings. We review the use of neuroimaging techniques as an aid to diagnosis and their role in elucidating the pathophysiology of cortical blindness.

Evidence and practice: the magnesium sulphate story

There is now strong evidence from systematic reviews of randomised trials to support the use of magnesium sulphate for the prevention and treatment of eclampsia. Magnesium sulphate more than halves the risk of eclampsia for women with pre-eclampsia (relative risk (RR) 0.41, 95% confidence interval (CI) 0.29-0.58; number needed to treat (NNT) 102 (95% CI 72-173) compared to placebo. For treatment of eclampsia, magnesium sulphate lowers the risk of maternal death (RR 0.59, 95% CI 0.37-0.94) and of recurrence of further fits (RR 0.44, 95% CI 0.34-0.57) compared to diazepam. Magnesium sulphate also reduces the risk of further fits compared to phenytoin (RR 0.31, 95% CI 0.20-0.47) and to lytic cocktail (RR 0.09, 95% CI 0.03-0.24).

Magnesium sulfate treatment in experimental spinal cord injury: emphasis on vascular changes and early clinical results

Injury to the spinal cord results in disruption of neurons, cell membranes, axons, myelin, and endothelial cells. The aim of this study was to demonstrate the protective effect of magnesium sulfate on the blood-spinal cord barrier after acute spinal cord injury (SCI). This experiment was conducted in two parts. In the first, rats were injected intravenously with Evans blue 2 h after SCI. The laminectomy-only group had no trauma. Contusion injury (50 g-cm) was applied to the trauma and treatment groups. Magnesium sulfate (600 mg/kg) was given to the treatment group immediately after injury. For the second part, clinical evaluations were performed 24 h post surgery. Then, following Evans blue injection, spinal cord samples were obtained from the laminectomy-only, trauma, and treatment groups. For the control group, nontraumatized spinal cord samples were taken after Evans blue injection following clinical examination. Laminectomy did not affect the spinal cord Evans blue content in 2-h and 24-h groups. The trauma increased tissue Evans blue content, and 24-h samples showed more remarkable tissue Evans blue content, suggesting secondary injury. Application of 600 mg/kg of magnesium resulted in lower Evans blue content in the spinal cord than with injury. Remarkable clinical neuroprotection was observed in the treatment groups. Magnesium sulfate showed vaso- and neuroprotective properties after contusion injury to the rat spinal cord. The authors also demonstrated secondary injury of the blood-spinal cord barrier with the Evans blue clearance technique for the first time.

Effect of magnesium sulphate in experimental spinal cord injury: evaluation with ultrastructural findings and early clinical results

Excitotoxic mechanisms have been implicated in the pathophysiology of spinal cord injury (SCI). The authors have studied the protection against secondary damage to rat spinal cord with magnesium sulphate, a well-known N-methyl-D-aspartate antagonist. Rats were randomly allocated into 5 groups. Group 1 rats were controls and normal spinal cord samples were obtained after clinical examination. 50 g-cm contusion injury was introduced to Group 2. Group 3 was vehicle, 1 cc of physiologic saline was injected post-trauma. Group 4 and 5 were treatment groups and 100 mg/kg and 600 mg/kg of Magnesium sulphate was given immediately after trauma, intraperitoneally. Animals were evaluated with inclined plane, Tarlov motor scale and Basso-Beattie-Bresnahan scale 24h after SCI. Spinal cord samples for ultrastructural evaluations were obtained following clinical examinations. Magnesium treatment improved neurological outcome. Electron microscopic results showed obvious neuroprotection in the treatment groups. Application of 600 mg/kg of magnesium revealed better ultrastructural findings and clinical results than 100 mg/kg. These findings demonstrated that magnesium sulphate possesses neuroprotection on spinal cord ultrastructure and on functional scores after acute contusion injury to the rat spinal cord.

Hypomagnesemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Hypomagnesemia frequently occurs in hospitalized patients, and it is associated with poor outcome. We assessed the frequency and time distribution of hypomagnesemia after aneurysmal subarachnoid hemorrhage (SAH) and its relationship to the severity of SAH, delayed cerebral ischemia (DCI), and outcome after 3 months.

METHODS

Serum magnesium was measured in 107 consecutive patients admitted within 48 hours after SAH. Hypomagnesemia (serum magnesium <0.70 mmol/L) at admission was related to clinical and initial computed tomographic characteristics by means of the Mann-Whitney U test. Hypomagnesemia at admission and during the DCI onset period (Days 2-12) was related to the occurrence of DCI and hypomagnesemia at admission, and hypomagnesemia that occurred any time during the first 3 weeks after SAH was related to outcome.

RESULTS

Hypomagnesemia at admission was found in 41 patients (38%) and was associated with more cisternal (P = 0.006) and ventricular (P = 0.005) blood, a longer duration of unconsciousness (P = 0.007), and a worse World Federation of Neurosurgical Societies scale score at admission (P = 0.001). The crude hazard ratio for DCI with hypomagnesemia at admission was 2.4 (95% confidence interval, 1.0-5.6), and after multivariate adjustment it was 1.9 (95% confidence interval, 0.7-4.7). The hazard ratio of hypomagnesemia from Days 2 to 12 for patients with DCI was 3.2 (range, 1.1-8.9) after multivariate adjustment. The crude odds ratio for poor outcome (Glasgow Outcome Scale score, 1-3) with hypomagnesemia at admission was 2.5 (range, 1.1-5.5). Hypomagnesemia at admission did not contribute to the prediction of outcome in the multivariate model.

CONCLUSION

Hypomagnesemia is frequently present after SAH and is associated with severity of SAH. Hypomagnesemia occurring between Days 2 and 12 after SAH predicts DCI.

Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial

BACKGROUND

Anticonvulsants are used for pre-eclampsia in the belief they prevent eclamptic convulsions, and so improve outcome. Evidence supported magnesium sulphate as the drug to evaluate.

METHODS

Eligible women (n=10141) had not given birth or were 24 h or less postpartum; blood pressure of 140/90 mm Hg or more, and proteinuria of 1+ (30 mg/dL) or more; and there was clinical uncertainty about magnesium sulphate. Women were randomised in 33 countries to either magnesium sulphate (n=5071) or placebo (n=5070). Primary outcomes were eclampsia and, for women randomised before delivery, death of the baby. Follow up was until discharge from hospital after delivery. Analyses were by intention to treat.

FINDINGS

Follow-up data were available for 10,110 (99.7%) women, 9992 (99%) of whom received the allocated treatment. 1201 of 4999 (24%) women given magnesium sulphate reported side-effects versus 228 of 4993 (5%) given placebo. Women allocated magnesium sulphate had a 58% lower risk of eclampsia (95% CI 40-71) than those allocated placebo (40, 0.8%, vs 96, 1.9%; 11 fewer women with eclampsia per 1000 women). Maternal mortality was also lower among women allocated magnesium sulphate (relative risk 0.55, 0.26-1.14). For women randomised before delivery, there was no clear difference in the risk of the baby dying (576, 12.7%, vs 558, 12.4%; relative risk 1.02, 99% CI 0.92-1.14). The only notable difference in maternal or neonatal morbidity was for placental abruption (relative risk 0.67, 99% CI 0.45-0.89).

INTERPRETATION

Magnesium sulphate halves the risk of eclampsia, and probably reduces the risk of maternal death. There do not appear to be substantive harmful effects to mother or baby in the short term.

Magnesium sulfate therapy after aneurysmal subarachnoid hemorrhage

OBJECT

Vasospasm remains a significant source of neurological morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH), despite advances in current medical, surgical, and endovascular therapies. Magnesium sulfate therapy has been demonstrated to be both safe and effective in preventing neurological complications in obstetrical patients with eclampsia. Evidence obtained using experimental models of brain injury, cerebral ischemia, and SAH indicate that Mg may also have a role as a neuroprotective agent. The authors hypothesize that MgSO4 therapy is safe, feasible, and has a beneficial effect on vasospasm and, ultimately, on neurological outcome following aneurysmal SAH.

METHODS

A prospective randomized single-blind clinical trial of high-dose MgSO4 therapy following aneurysmal SAH (Hunt and Hess Grades II-IV) was performed in 40 patients, who were enrolled within 72 hours following SAH and given intravenous MgSO4 or control solution for 10 days. Serum Mg++ levels were maintained in the 4 to 5.5 mg/dl range throughout the treatment period. Clinical management principles were the same between groups (including early use of surgery or endovascular treatment, followed by aggressive vasospasm prophylaxis and treatment). Daily transcranial Doppler (TCD) ultrasonographic recordings were obtained, and clinical outcomes were measured using the Glasgow Outcome Scale (GOS). The patients' GOS scores and the TCD recordings were analyzed using the independent t-test. Forty patients were enrolled in the study: 20 (15 female and five male patients) received treatment and 20 (11 female and nine male patients) comprised a control group. The mean ages of the patients in these groups were 46 and 51, respectively, and the mean clinical Hunt and Hess grades were 2.6 +/- 0.68 in the MgSO4 treatment group and 2.3 +/- 0.73 in the control group (mean +/- standard deviation [SD], p = 0.87). Fisher grades were similar in both groups. Mean middle cerebral artery velocities were 93 +/- 27 cm/second in MgSO4-treated patients and 102 +/- 34 cm/second in the control group (mean +/- SD, p = 0.41). Symptomatic vasospasm, confirmed by angiography, occurred in six of 20 patients receiving MgSO4 and in five of 16 patients receiving placebo. Mean GOS scores were 3.8 +/- 1.6 and 3.6 +/- 1.5 (mean +/- SD, p = 0.74) in the treatment and control groups, respectively. Significant adverse effects from treatment with MgSO4 did not occur.

CONCLUSIONS

Administration of high-dose MgSO4 following aneurysmal SAH is safe, and steady Mg++ levels in the range of 4 to 5.5 mg/dl are easily maintained. This treatment does not interfere with neurological assessment, administration of anesthesia during surgery, or other aspects of clinical care. We observed a trend in which a higher percentage of patients obtained GOS scores of 4 or 5 in the group treated with MgSO4, but the trend did not reach a statistically significant level. A larger study is needed to evaluate this trend further.

Angioplasty for cerebral vasospasm from eclampsia

BACKGROUND

Neurological deterioration in eclampsia is considered to be secondary to cerebral vasospasm. Magnesium sulfate therapy improves symptoms and controls seizures, possibly related to its vasorelaxive effects in spastic arteries. Some cases, however, are refractory to magnesium therapy. To our knowledge, there is no report of angioplasty for vasospasm from eclampsia in the literature.

METHODS

A 27-year-old woman presented 10 days postpartum with severe mental status changes and left arm and bilateral leg weakness that were refractory to magnesium therapy. Cerebral angiography demonstrated diffuse, severe vasospasm. We treated her with angioplasty of the bilateral middle and posterior cerebral arteries, basilar artery, and bilateral internal carotid arteries.

RESULTS

Angioplasty resulted in excellent angiographic improvement. The patient immediately became responsive and appropriate with improved strength in all extremities. She continued to improve throughout her hospital stay and was discharged 10 days postangioplasty.

CONCLUSIONS

Cerebral angioplasty is an effective treatment for vasospasm from eclampsia refractory to magnesium therapy. Angiography should be considered early in the course of neurological deterioration, but delayed therapy may also be effective.

Cerebral blood flow velocity response to magnesium sulfate in patients after subarachnoid hemorrhage

Magnesium sulfate therapy, standard in preventing seizures in preeclampsia, is under active investigation as a neuroprotective agent. The authors studied the effect of magnesium as a cerebral vasodilator by measuring the cerebral blood flow velocity (CBFV) response to a 5g intravenous bolus of MgSO4 compared with a saline placebo after subarachnoid hemorrhage (SAH). Transcranial Doppler ultrasonography of the middle cerebral artery (MCA) was measured after each infusion. Patients were studied up to three times after SAH at prescribed time intervals. Fourteen patients (11 women, 3 men; mean age 58 years) underwent 29 studies. All patients underwent hypertensive, hypervolemic therapy. Four patients developed cerebral vasospasm. Doubling serum magnesium levels did not affect MCA CBFV but slightly lowered mean arterial blood pressure and systemic vascular resistance. Intravenous magnesium bolus did not reduce elevated CBFV in the subset of SAH patients with clinical vasospasm. The role of magnesium sulfate as a cerebral vasodilator in patients with SAH requires further study.

Intravenous administration of magnesium sulfate in acute stroke: a randomized double-blind study

A randomized, placebo-controlled, double-blind study was performed as a pilot study to examine the benefit of the administration of magnesium sulfate given intravenously as a protective substance during the first 24 hours following a stroke. Patients who had cortical infarction in the middle cerebral artery territory with moderate to severe neurologic deficits lasting for more than 15 minutes with onset less than 24 hours were included. The patients were treated with magnesium sulfate or placebo for 5 days and examined by a blinded investigator. Patients had follow-up for 30 days. The primary efficacy variable was the proportion of patients reaching mild to moderate neurologic deficit on the Orgogozo scale (80 points) and relative functional independence on the Barthel index (60 points). Orgogozo scale and Mathew scale values were obtained on admission and days 2, 4, 8, and 30 after stroke. Barthel activities of daily living index and Rankin disability score were obtained on day 30. Forty-one patients (22 given treatment and 19 given placebo) demonstrated significant beneficial effects on the Orgogozo scale (84 +/- 11 vs. 64 +/- 10, p < 0.0001) and (83 +/- 14 vs. 70 +/- 15, p < 0.009), respectively. At the end of 1-month follow-up, the Barthel ADL index was nonsignificantly higher and the Rankin disability score was marginally significantly lower in the magnesium-treated group (84 +/- 26 vs. 71.8 +/- 26, p < 0.143) than in control subjects (2.3 +/- 1.1 vs. 3 +/- 1.3, p < 0.077). Intravenous magnesium sulfate had significant positive effect on the outcome in patients with acute stroke. Further studies on a larger scale are needed to confirm these findings.

Magnesium sulfate in the management of patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study

OBJECTIVE

To evaluate the effect of magnesium sulfate (MgSO4) on the clinical course of patients with severe aneurysmal subarachnoid hemorrhage (SAH).

METHODS

Ten patients with Fisher Grade 3 aneurysmal SAH were evaluated. The patients were given a bolus as well as a constant infusion of intravenous MgSO4 up to 10 days postictus. Blood magnesium levels were obtained to adjust the daily requirement of MgSO4. The goal was to raise the serum level to 2.0 to 2.5 mmol/L or twice the baseline serum level. Daily transcranial Doppler (TCD) ultrasonography was performed on each patient, insonating both anterior cerebral and middle cerebral arteries. Further management followed standard protocols, including the use of nimodipine and hypervolemic therapy. TCD ultrasonographic findings, as well as clinical evidence of cerebral vasospasm, were documented. All patients had a 3-month assessment using the Glasgow Outcome Scale.

RESULTS

After administration of a 20 mmol MgSO4 bolus infusion and an average daily continuous infusion of 84.7 mmol, 8 of 10 patients achieved the predetermined serum magnesium levels. No adverse affects were noted during the infusions. Five patients exhibited evidence of vasospasm on TCD ultrasonography; vasospasm was severe in two patients (velocities, >200 cm/s). Three patients, including the two patients in whom TCD ultrasonography demonstrated severe vasospasm, exhibited clinical evidence of vasospasm. Two patients had a Glasgow Outcome Scale score of 3; the remainder had Glasgow Outcome Scale scores of 5.

CONCLUSION

Administration guidelines for the use of MgSO4 in aneurysmal SAH were established. A prospective double-blind placebo-controlled trial is required to establish the effectiveness of MgSO4 for treating vasospasm in aneurysmal SAH.

Prevention of eclampsia

Eclampsia continues to be a major cause of maternal morbidity and mortality rates, especially in underdeveloped nations. Our data indicate that eclampsia may represent the end stage of at least two very different pathophysiological pathways: one in which cerebral perfusion is low because of vasospasm and another in which cerebral perfusion is increased because of abnormal autoregulation and a failure of the normal protective mechanisms. Magnesium sulfate has been extensively used in the management and prevention of eclamptic seizures in the United States and has been recently shown to be superior to both diphenylhydantoin and diazepam. We have shown that magnesium sulfate is a potent vasorelaxant and that its action may depend on improving cerebral perfusion. Nimodipine, a calcium channel blocker with selective cerebrovascular effect, is currently under investigation in severe preeclampsia. The data show that it is as effective as magnesium sulfate in preventing eclampsia, with less maternal and fetal side effects. Magnesium sulfate and nimodipine have opposite effects on the estimated cerebral perfusion pressure as determined with the Doppler ultrasound. We speculate that the estimated cerebral perfusion pressure may be used to determine the type of cerebrovascular abnormality and the most appropriate treatment in each individual patient with preeclampsia.

Mg2+ modulates membrane sphingolipid and lipid second messenger levels in vascular smooth muscle cells

In vitro studies with smooth muscle cells from rat aorta and dog cerebral blood vessels indicate that variation in free Mg2+, within the pathophysiological range of Mg2+ concentrations, found in human serum, causes sustained changes in membrane phospholipids and lipid second messengers. Incorporation of [3H]palmitic acid into phosphatidylcholine (PC) and sphingomyelin (SM) was altered within 15-30 min after modifying the extracellular Mg2+ ion level ([Mg2+]o). Decreased Mg2+ produced a fall in both [3H]SM and [3H]PC over the first 2 h. After an 18-h incubation, the [3H]PC/[3H]SM ratio changed from about 20:1 to about 50:1. Increased [Mg2+]o resulted in a 2- to 3-fold increase in [3H]SM compared to only a small increase in [3H]PC over the same period. There was a reciprocal relationship between [3H]ceramide and [3H]1,2-DAG levels with highest [3H]ceramide and lowest [3H]-1,2-DAG levels seen at lowest [Mg2+]o. The results indicate that a fall in extracellular ionized Mg2+ concentration produces a rapid and sustained decrease in membrane sphingomyelin and a moderate rise in intracellular ceramide. A major effect of lowering [Mg2+]o appears to be a down-regulation of SM synthase. The increased membrane SM content and a concomitant decrease in cell ceramide, in the presence of elevated [Mg2+]o, may be relevant to the apparent protective role of adequate Mg intake on vascular function in humans.

Drug management of hypertensive disorders of pregnancy

Drugs used in the acute and long-term management of hypertension in pregnancy and the preeclampsia-eclampsia syndrome have been reviewed and their therapeutic effects and maternal and fetal adverse effects have been considered. The review also focuses on recent developments in the areas of prevention and management of pre-eclampsia-eclampsia syndrome. Although a number of new drugs have emerged, as potentially useful in the management of hypertension in pregnancy and pre-eclampsia-eclampsia syndrome, some remain at the cornerstone of therapy; for example, methyldopa for long-term treatment of chronic hypertension, hydralazine or nifedipine for rapid reduction of severely elevated blood pressure, and magnesium sulphate for eclampsia. Some of these agents, especially the calcium antagonists, show promise in that their use is associated with fewer side effects. Safety for the fetus, however, has not been adequately evaluated yet. Neither aspirin nor calcium supplements appear to improve the outcome in pregnancy. Currently, the dilemma whether to treat hypertension in pregnancy and pre-eclampsia-eclampsia syndrome with old, established, cost-effective drugs or the promising newer drugs provides an interesting academic challenge.

Magnesium taurate and fish oil for prevention of migraine

Although the pathogenesis of migraine is still poorly understood, various clinical investigations, as well as consideration of the characteristic activities of the wide range of drugs known to reduce migraine incidence, suggest that such phenomena as neuronal hyperexcitation, cortical spreading depression, vasospasm, platelet activation and sympathetic hyperactivity often play a part in this syndrome. Increased tissue levels of taurine, as well as increased extracellular magnesium, could be expected to dampen neuronal hyperexcitation, counteract vasospasm, increase tolerance to focal hypoxia and stabilize platelets; taurine may also lessen sympathetic outflow. Thus it is reasonable to speculate that supplemental magnesium taurate will have preventive value in the treatment of migraine. Fish oil, owing to its platelet-stabilizing and antivasospastic actions, may also be useful in this regard, as suggested by a few clinical reports. Although many drugs have value for migraine prophylaxis, the two nutritional measures suggested here may have particular merit owing to the versatility of their actions, their safety and lack of side-effects and their long-term favorable impact on vascular health.