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

Effect of low-molecular-weight heparin calcium combined with magnesium sulfate and labetalol on coagulation, vascular endothelial function and pregnancy outcome in early-onset severe preeclampsia

OBJECTIVE

This paper was aimed at unveiling the effect of low-molecular-weight heparin calcium (LMWH) combined with magnesium sulfate and labetalol on coagulation, vascular endothelial function, and pregnancy outcome in early-onset severe preeclampsia (EOSP).

METHODS

Pregnant women with EOSP were divided into the control group and the study group, each with 62 cases. Patients in the control group were treated with labetalol and magnesium sulfate, and those in the study group were treated with LMWH in combination with the control grou Blood pressure (systolic blood pressure [SBP] and diastolic blood pressure [DBP]), 24-h urine protein, coagulation indices [D-dimer (D-D), plasma fibrinogen (Fg), prothrombin time (PT), activated partial thromboplastin time (APTT), and prothrombin time (TT)], endothelial function [endothelin (ET-1) and nitric oxide (NO)], oxidative stress indices [oxidized low-density lipoproteins (ox-LDL), lipid peroxidation (LPO), superoxide dismutase (SOD), and malondialdehyde (MDA)], pregnancy outcome, and adverse effects occurred in the two groups were compared.

RESULTS

After treatment, lower SBP, DBP, and 24-h urine protein levels; lower Fg and D-D levels; higher PT, APPT, and TT levels; higher NO levels; lower ET-1 levels; lower ox-LDL, MDA, and LPO levels; higher SOD levels; and lower incidence of adverse pregnancy and adverse reactions were noted in the study group in contrast to the control group.

CONCLUSION

EOSP patients given with LMWH combined with magnesium sulfate and labetalol can effectively reduce the patient's blood pressure and urinary protein level; improve coagulation function, oxidative stress, and vascular endothelial function indices; reduce the adverse pregnancy outcomes; and improve the safety of treatment.

Evaluation of intravenous infusion of labetalol versus magnesium sulfate on cerebral hemodynamics of preeclampsia patients with severe features using transcranial doppler

PURPOSE

It is essential to understand the underlying pathophysiological mechanisms of preeclampsia cerebral complications. This study aimed to compare the cerebral hemodynamic effects of magnesium sulfate (MgSO4) and labetalol in pre-eclampsia patients with severe features.

METHODS

Singleton pregnant women who suffered from late onset preeclampsia with severe features were enrolled and subjected to baseline Transcranial doppler (TCD) evaluation and then randomly assigned to either the magnesium sulfate group or labetalol group. TCD to measure middle cerebral artery (MCA) blood flow indices including mean flow velocity (cm/s), mean end-diastolic velocity (DIAS), and pulsatility index (PI) and to estimate CPP and MCA velocity were performed as basal measurements before study drug administration and at post-treatment one and six hours after administration. The occurrence of seizures and any adverse effects were recorded for each group.

RESULTS

Sixty preeclampsia patients with severe features were included and randomly allocated into two equal groups. In group M the PI was 0.77 ± 0.04 at baseline versus 0.66 ± 0.05 at 1hour and 0.66 ± 0.05 at 6 hours after MgSO4 administration (p value < 0.001) also the calculated CPP was significantly decreased from 103.3 ± 12.7mmHg to 87.8 ± 10.6mmHg and 89.8 ± 10.9mmHg (p value < 0.001) at 1 and 6 hours respectively. Similarly, in group L the PI was significantly decreased from 0.77 ± 0.05 at baseline to 0.67 ± 0.05 and 0.67 ± 0.06 at 1 and 6 hours (p value < 0.001) after labetalol administration. Moreover, the calculated CPP was significantly decreased from 103.6 ± 12.6 mmHg to 86.2 ± 13.02mmHg at 1 hour and to 83.7 ± 14.6mmHg at 6 hours (p value < 0.001). In terms of changes in blood pressure and the heart rate, they were significantly lower in the labetalol group.

CONCLUSION

Both magnesium sulfate and labetalol reduce CPP while maintaining cerebral blood flow (CBF) in preeclampsia patients with severe features.

TRIAL REGISTRATION

The institutional review board of the Faculty of Medicine, Zagazig University approved this study with the reference number (ZU-IRB#: 6353-23-3-2020) and it was registered at clinicaltrials.gov (NCT04539379).

Eclampsia in the 21st century

The reported incidence of eclampsia is 1.6 to 10 per 10,000 deliveries in developed countries, whereas it is 50 to 151 per 10,000 deliveries in developing countries. In addition, low-resource countries have substantially higher rates of maternal and perinatal mortalities and morbidities. This disparity in incidence and pregnancy outcomes may be related to universal access to prenatal care, early detection of preeclampsia, timely delivery, and availability of healthcare resources in developed countries compared to developing countries. Because of its infrequency in developed countries, many obstetrical providers and maternity units have minimal to no experience in the acute management of eclampsia and its complications. Therefore, clear protocols for prevention of eclampsia in those with severe preeclampsia and acute treatment of eclamptic seizures at all levels of healthcare are required for better maternal and neonatal outcomes. Eclamptic seizure will occur in 2% of women with preeclampsia with severe features who are not receiving magnesium sulfate and in <0.6% in those receiving magnesium sulfate. The pathogenesis of an eclamptic seizure is not well understood; however, the blood-brain barrier disruption with the passage of fluid, ions, and plasma protein into the brain parenchyma remains the leading theory. New data suggest that blood-brain barrier permeability may increase by circulating factors found in preeclamptic women plasma, such as vascular endothelial growth factor and placental growth factor. The management of an eclamptic seizure will include supportive care to prevent serious maternal injury, magnesium sulfate for prevention of recurrent seizures, and promoting delivery. Although routine imagining following an eclamptic seizure is not recommended, the classic finding is referred to as the posterior reversible encephalopathy syndrome. Most patients with posterior reversible encephalopathy syndrome will show complete resolution of the imaging finding within 1 to 2 weeks, but routine imaging follow-up is unnecessary unless there are findings of intracranial hemorrhage, infraction, or ongoing neurologic deficit. Eclampsia is associated with increased risk of maternal mortality and morbidity, such as placental abruption, disseminated intravascular coagulation, pulmonary edema, aspiration pneumonia, cardiopulmonary arrest, and acute renal failure. Furthermore, a history of eclamptic seizures may be related to long-term cardiovascular risk and cognitive difficulties related to memory and concentration years after the index pregnancy. Finally, limited data suggest that placental growth factor levels in women with preeclampsia are superior to clinical markers in prediction of adverse pregnancy outcomes. This data may be extrapolated to the prediction of eclampsia in future studies. This summary of available evidence provides data and expert opinion on possible pathogenesis of eclampsia, imaging findings, differential diagnosis, and stepwise approach regarding the management of eclampsia before delivery and after delivery as well as current recommendations for the prevention of eclamptic seizures in women with preeclampsia.

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.

Efficacy of Diltiazem for the Control of Blood Pressure in Puerperal Patients with Severe Preeclampsia: A Randomized, Single-Blind, Controlled Trial

BACKGROUND

Postpartum preeclampsia is a serious disease related to high blood pressure that occurs commonly within the first six days after delivery.

OBJECTIVE

To evaluate if diltiazem improves blood pressure parameters in early puerperium patients with severe preeclampsia. Methodology. A randomized, single-blind longitudinal clinical trial of 42 puerperal patients with severe preeclampsia was carried out. Patients were randomized into two groups: the experimental group (n = 21) received diltiazem (60 mg) and the control group (n = 21) received nifedipine (10 mg). Both drugs were orally administered every 8 hours. Systolic, diastolic, and mean blood pressures as well as the heart rate were recorded and analyzed (two-way repeated measures ANOVA) at baseline and after 6, 12, 18, 24, 30, 36, 42, and 48 hours. Primary outcome measures were all the aforementioned blood pressure parameters. Secondary outcome measures included the number of hypertension and hypotension episodes along with the length of stay in the intensive care unit.

RESULTS

No statistical differences were found between groups (diltiazem vs. nifedipine) regarding basal blood pressure parameters. Interarm differences in blood pressure (systolic, diastolic, and mean) and heart rate were statistically significant between treatment groups from 6 to 48 hours. Patients in the diltiazem group had lower blood pressure levels than patients in the nifedipine group. Significantly, patients who received diltiazem had fewer hypertension and hypotension episodes and stayed fewer days in the intensive care unit than those treated with nifedipine.

CONCLUSIONS

Diltiazem controlled arterial hypertension in a more effective and uniform manner in patients under study than nifedipine. Patients treated with diltiazem had fewer collateral effects and spent less time in the hospital. This trial is registered with NCT04222855.

Journal of Clinical Monitoring and Computing 2019 end of year summary: monitoring tissue oxygenation and perfusion and its autoregulation

Tissue perfusion monitoring is increasingly being employed clinically in a non-invasive fashion. In this end-of-year summary of the Journal of Clinical Monitoring and Computing, we take a closer look at the papers published recently on this subject in the journal. Most of these papers focus on monitoring cerebral perfusion (and associated hemodynamics), using either transcranial doppler measurements or near-infrared spectroscopy. Given the importance of cerebral autoregulation in the analyses performed in most of the studies discussed here, this end-of-year summary also includes a short description of cerebral hemodynamic physiology and its autoregulation. Finally, we review articles on somatic tissue oxygenation and its possible association with outcome.

Alterations in transcranial Doppler indices of pregnant women with complicated preeclampsia

OBJECTIVES

We aimed to investigate alterations in transcranial Doppler indices (TCD) of the cerebral arteries between normotensive and preeclampsia (PE) pregnancies according to the presence of cerebral symptoms.

STUDY DESIGN

This cross-sectional study included 48 PE and 20 normotensive pregnancies, respectively. Doppler indices of the anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA, respectively) were compared between the PE and normotensive group.

MAIN OUTCOME MEASURES

Mean cerebral velocity (MCV), pulsatility index (PI), and resistance index (RI) were calculated using cerebral velocities. The cerebral perfusion pressure (CPP), resistance area product (RAP), and cerebral flow index (CFI) were computed using velocity and blood pressure. The PE group was subdivided according to the presence of cerebral symptoms and the TCD indices were compared between these groups.

RESULTS

MCV and CFI of the PCA as well as CPP and RAP of all arteries were significantly higher, while PI and RI were significantly lower in PE group (P < 0.05). PI of the MCA had the highest sensitivity (91.7%), while PI of the PCA and RAP of the MCA had the highest specificity (95.0% each) for predicting PE-related cerebral complications. The positive likelihood ratio was highest in PI of the PCA (14.58). Among these parameters, CPP and RAP of the PCA were higher in PE patients showing cerebral symptoms than in those without symptoms.

CONCLUSIONS

These results suggest that pregnant women with PE had altered TCD indices and that prominent changes, thereof, especially in the PCA, contribute to the development of cerebral symptoms.

Magnesium sulfate and ophthalmic artery Doppler velocimetry in patients with severe preeclampsia: a case series

Background

In the present study, we used Doppler velocimetry in the ophthalmic artery to evaluate the hemodynamic status of the intracranial vasculature. This is the first time in the literature that indices of ophthalmic artery Doppler sonography of women with preeclampsia were evaluated before and after the use of magnesium sulfate to prevent eclampsia.

Case presentation

Indices of ophthalmic artery Doppler sonography of six women with severe preeclampsia at 27 to 33 weeks of gestational age were evaluated before and after the use of magnesium sulfate (10 minutes, 30 minutes, and 60 minutes after the magnesium sulfate loading dosage. The patients’ ages were 26 years (patient 01), 29 years (patient 02), 20 years (patient 03), 21 years (patient 04), 20 years (patient 05), and 19 years (patient 06). The ethnic group of patients 01 and 04 was white and the ethnic group of patients 02, 03, 05 and 06 was mulatto.

Conclusions

The apparent increase in resistance index and pulsatility index values, although there is no statistical significance in this series of cases, and the decrease in peak ratio values after the administration of magnesium sulfate reflect an increase in the impedance to flow in the ophthalmic artery and consequently a reduction in cerebral perfusion after the use of magnesium sulfate. This may explain how magnesium sulfate protects women with severe preeclampsia against cerebral damage and prevents acute convulsions in these patients. We believe that this case series report may have a broader clinical impact across medicine because the mechanism of how magnesium sulfate can protect patients and prevent acute convulsions is controversial.

Cerebrovascular Dysfunction in Preeclamptic Pregnancies

Preeclampsia is a hypertensive, multisystem disorder of pregnancy that affects several organ systems, including the maternal brain. Cerebrovascular dysfunction during preeclampsia can lead to cerebral edema, seizures, stroke, and potentially maternal mortality. This review will discuss the effects of preeclampsia on the cerebrovasculature that may adversely affect the maternal brain, including cerebral blood flow (CBF) autoregulation and blood-brain barrier disruption and the resultant clinical outcomes including posterior reversible encephalopathy syndrome (PRES) and maternal stroke. Potential long-term cognitive outcomes of preeclampsia and the role of the cerebrovasculature are also reviewed.

Magnesium Therapy in Pre-eclampsia Prolongs Analgesia Following Spinal Anaesthesia with Fentanyl and Bupivacaine: An Observational Study

BACKGROUND

Magnesium has anti-nociceptive effects and potentiates opioid analgesia following its systemic and neuraxial administration. However, there is no study evaluating the effects of intravenous (IV) magnesium sulphate (MgSO4) therapy on spinal anaesthesia characteristics in severely pre-eclamptic patients.

AIMS

The aim of this study was to compare spinal anaesthesia characteristics in severely pre-eclamptic parturients treated with MgSO4 and healthy preterm parturients undergoing caesarean section. Thus, our primary outcome was regarded as the time to first analgesic request following spinal anaesthesia.

STUDY DESIGN

Case-control Study.

METHODS

Following approval of Institutional Clinical Research Ethics Committee and informed consent of the patients, 44 parturients undergoing caesarean section with spinal anaesthesia were enrolled in the study in two groups: Healthy preterm parturients (Group C) and severely pre-eclamptic parturients with IV MgSO4 therapy (Group Mg). Following blood and cerebrospinal fluid (CSF) sampling, spinal anaesthesia was induced with 9 mg hyperbaric bupivacaine and 20 μg fentanyl. Serum and CSF magnesium levels, onset of sensory block at T4 level, highest sensory block level, motor block characteristics, time to first analgesic request, maternal haemodynamics as well as side effects were evaluated.

RESULTS

Blood and CSF magnesium levels were higher in Group Mg. Sensory block onset at T4 were 257.1±77.5 and 194.5±80.1 sec in Group C and Mg respectively (p=0.015). Time to first postoperative analgesic request was significantly prolonged in Group Mg than in Group C (246.1±52.8 and 137.4±30.5 min, respectively, p<0.001; with a mean difference of 108.6 min and 95% CI between 81.6 and 135.7). Side effects were similar in both groups. Group C required significantly more fluids.

CONCLUSION

Treatment with IV MgSO4 in severe pre-eclamptic parturients significantly prolonged the time to first analgesic request compared to healthy preterm parturients, which might be attributed to the opioid potentiation of magnesium.

Contemporary clinical management of the cerebral complications of preeclampsia

The neurological complications of preeclampsia and eclampsia are responsible for a major proportion of the morbidity and mortality arising from these conditions, for women and their infants alike. This paper outlines the evidence base for contemporary management principles pertaining to the neurological sequelae of preeclampsia, primarily from the maternal perspective, but with consideration of fetal and neonatal aspects as well. It concludes with a discussion regarding future directions in the management of this potentially lethal condition.

Maternal and neonatal separation and mortality associated with concurrent admissions to intensive care units

BACKGROUND

Concurrent admission of a mother and her newborn to separate intensive care units (herein referred to as co-ICU admission), possibly in different centres, can magnify family discord and stress. We examined the prevalence and predictors of mother-infant separation and mortality associated with co-ICU admissions.

METHODS

We completed a population-based study of all 1 023 978 singleton live births in Ontario between Apr. 1, 2002, and Mar. 31, 2010. We included data for maternal-infant pairs that had co-ICU admission (n = 1216), maternal ICU admission only (n = 897), neonatal ICU (NICU) admission only (n = 123 236) or no ICU admission (n = 898 629). The primary outcome measure was mother-infant separation because of interfacility transfer.

RESULTS

The prevalence of co-ICU admissions was 1.2 per 1000 live births and was higher than maternal ICU admissions (0.9 per 1000). Maternal-newborn separation due to interfacility transfer was 30.8 (95% confidence interval [CI] 26.9-35.3) times more common in the co-ICU group than in the no-ICU group and exceeded the prevalence in the maternal ICU group and NICU group. Short-term infant mortality (< 28 days after birth) was higher in the co-ICU group (18.1 per 1000 live births; maternal age-adjusted hazard ratio [HR] 27.8, 95% CI 18.2-42.6) than in the NICU group (7.6 per 1000; age-adjusted HR 11.5, 95% CI 10.4-12.7), relative to 0.7 per 1000 in the no-ICU group. Short-term maternal mortality (< 42 days after delivery) was also higher in the co-ICU group (15.6 per 1000; age-adjusted HR 328.7, 95% CI 191.2-565.2) than in the maternal ICU group (6.7 per 1000; age-adjusted HR 140.0, 95% CI 59.5-329.2) or the NICU group (0.2 per 1000; age-adjusted HR 4.6, 95% CI 2.8-7.4).

INTERPRETATION

Mother-infant pairs in the co-ICU group had the highest prevalence of separation due to interfacility transfer and the highest mortality compared with those in the maternal ICU and NICU groups.

Doppler sonography of maternal cerebral arteries in pregnancy: side-to-side differences

BACKGROUND/AIMS

To study side-to-side differences in blood flow of the common and internal carotid arteries, and the vertebral arteries (VAs) in women with uncomplicated pregnancies as a first step to build a reference values chart.

METHODS

A total of 155 healthy pregnant women between 20 and 40 weeks' gestation were included. Doppler sonography of the common and internal carotid arteries and VAs was performed on both sides. Parameters measured included diameter, peak systolic velocity, systolic-diastolic ratio, end-diastolic velocity, pulsatility index and resistance index. Statistical analysis was performed using the S-Plus 8.0 program. Normality was determined using the Kolmogorov-Smirnov test. Differences between sides were tested using Student's paired t test, association using linear correlation, and agreement using the Bland-Altman method.

RESULTS

Mean values were equal between sides for all parameters with the exception of the end-diastolic velocity in the VAs. The association and agreement between the measurements taken from the right and left sides were poor. Bland-Altman plots also indicated low agreement between sides. All parameters showed significant right-to-left differences.

CONCLUSION

Despite the equality between means, right and left flows through the vessels studied differed as there was poor association and agreement.

Maternal mortality in developing countries: challenges in scaling-up priority interventions

Although maternal mortality is a significant global health issue, achievements in mortality decline to date have been inadequate. A review of the interventions targeted at maternal mortality reduction demonstrates that most developing countries face tremendous challenges in the implementation of these interventions, including the availability of unreliable data and the shortage in human and financial resources, as well as limited political commitment. Examples from developing countries, such as Sri Lanka, Malaysia and Honduras, demonstrate that maternal mortality will decline when appropriate strategies are in place. Such achievable strategies need to include redoubled commitments on the part of local, national and global political bodies, concrete investments in high-yield and cost-effective interventions and the delegation of some clinical tasks from higher-level healthcare providers to mid- or lower-level healthcare providers, as well as improved health-management information systems.

Obstetric care in low-resource settings: what, who, and how to overcome challenges to scale up?

BACKGROUND

Each year, approximately 2 million babies die because of complications of childbirth, primarily in settings where effective care at birth, particularly prompt cesarean delivery, is unavailable.

OBJECTIVE

We reviewed the content, impact, risk-benefit, and feasibility of interventions for obstetric complications with high population attributable risk of intrapartum-related hypoxic injury, as well as human resource, skill development, and technological innovations to improve obstetric care quality and availability.

RESULTS

Despite ecological associations of obstetric care with improved perinatal outcomes, there is limited evidence that intrapartum interventions reduce intrapartum-related neonatal mortality or morbidity. No interventions had high-quality evidence of impact on intrapartum-related outcomes in low-resource settings. While data from high-resource settings support planned cesarean for breech presentation and post-term induction, these interventions may be unavailable or less safe in low-resource settings and require risk-benefit assessment. Promising interventions include use of the partograph, symphysiotomy, amnioinfusion, therapeutic maneuvers for shoulder dystocia, improved management of intra-amniotic infections, and continuous labor support. Obstetric drills, checklists, and innovative low-cost devices could improve care quality. Task-shifting to alternative cadres may increase coverage of care.

CONCLUSIONS

While intrapartum care aims to avert intrapartum-related hypoxic injury, rigorous evidence is lacking, especially in the settings where most deaths occur. Effective care at birth could save hundreds of thousands of lives a year, with investment in health infrastructure, personnel, and research--both for innovation and to improve implementation.

Magnesium sulfate decreases cerebral perfusion pressure in preeclampsia

OBJECTIVE

To determine the cerebral hemodynamic effect of magnesium sulfate (MgSO4) in preeclampsia.

DESIGN

Prospective observational study.

SETTING

Tertiary Care Medical Center.

POPULATION

Preeclamptic patients (systolic < 160, diastolic < 110 mmHg).

METHODS

Transcranial Doppler (TCD) of the middle cerebral arteries (MCA) of 15 preeclamptics, before and after IV MgSO4. No vasoactive drugs other than MgSO4 were given. 11 patients with mild range BP (140/90-160/110 mmHg) had measurements at baseline, 30 and 120 minutes after MgSO4, and 7 patients with elevated CPP had baseline and 30 minute measurements. Hemodynamic parameters were compared with normative curves.

MAIN OUTCOME MEASURES

Mean arterial pressure (MAP), heart rate (HR), cerebral perfusion pressure (CPP), resistance index (RI), resistance area product (RAP), and cerebral flow index (CFI).

RESULTS

Eight women had normal baseline CPP, and 11 had normal CFI. 11 had mild preeclampsia range blood pressure and MgSO4 had no significant effect on CPP, CFI, HR, MCA velocities, or RAP but did decrease the MAP in the first 30 minutes (107 +/- 8 to 100 +/- 9 mmHg; p = 0.035), mainly due to a drop in diastolic pressure (87 +/- 10 to 82 +/- 9 mmHg; p = 0.004). 7 patients with elevated baseline CPP had a significant reduction in CPP, but no change in CFI, after MgSO4.

CONCLUSIONS

MgSO4 does not significantly effect CPP or CFI in preeclamptics with baseline blood pressure in the mild range, but does significantly reduce CPP in those with high baseline CPP. This may be important in the prevention of hypertensive encephalopathy.

[Anesthetic management of parturients with pre-eclampsia and eclampsia]

Preeclampsia is a pregnancy-associated illness affecting multiple organ systems. Symptoms typically occur after the 20th week of gestation and consist of hypertension (>140/90 mmHg) and proteinuria (>300 mg/day). It is one of the leading causes of premature birth worldwide and early diagnosis and treatment are essential for both fetal and maternal health. Therapy is aimed at lowering blood pressure sufficiently to prevent the most severe complications such as intracranial hemorrhages. At the same time attention must be paid to the possible untoward effects of blood pressure medications on uteroplacental perfusion and fetal well being. Magnesium is the cornerstone for both prevention and control of eclamptic cerebrovascular events. In cases of severe preeclampsia and eclampsia prompt delivery is indicated, often carried out by Cesarean section (>34 weeks of gestation). Compared to general anesthesia, regional anesthesia techniques offer certain advantages to both mother and fetus and in the absence of contraindications are the methods of choice.

The role of the anaesthetist in the management of the pre-eclamptic patient

PURPOSE OF REVIEW

Recent literature on the anaesthetist's role in the management of the patient with severe pre-eclampsia is reviewed, with particular emphasis on the role of regional anaesthesia.

RECENT FINDINGS

Laboratory findings in pre-eclamptic women include increased levels of markers of oxidative stress and circulating tyrosine kinase 1, and inflammatory activation of leucocytes. Magnesium sulphate is the most effective agent for seizure prophylaxis. The optimal pharmacological agents for acute control of blood pressure remain controversial. The benefits of epidural analgesia in labour are well established. Single-shot spinal anaesthesia for caesarean section is safe in the absence of contraindications. Successful use of combined spinal-epidural anaesthesia has been described. Most studies on maternal haemodynamics have employed heart rate and blood pressure data as surrogate measures of cardiac output. Noninvasive cardiac output studies provide further insight into the haemodynamic response during neuraxial techniques for caesarean section.

SUMMARY

The value of regional anaesthesia cannot be over-emphasized. Recent research into spinal anaesthesia for caesarean section suggests a lower susceptibility to hypotension and probably less impairment of cardiac output than in healthy parturients. Noninvasive cardiac output measurement may also have advantages in critical care management.