High Risk Obstetrics Eclampsia Case File

High Risk Obstetrics Eclampsia Case File

Eugene C. Toy, MD, Edward Yeomans, MD, Linda Fonseca, MD, Joseph M. Ernest, MD

Case 15

A 29-year-old G1P0 African American female at 34 weeks’ gestation arrives at the hospital via ambulance with a history of a seizure at home witnessed by her husband. She has a history of chronic hypertension. The husband reports that over the preceding 2 days, she has been complaining about a worsening frontal headache, unrelieved by acetaminophen. On arrival to labor and delivery, she is postictal. Her blood pressure at admission is 180/116 mm Hg, with 4+ proteinuria. Her fundal height is 31 cm. After arrival, she has another tonic-clonic seizure involving both the upper and lower extremities. An ultrasound shows a fetus with an estimated fetal weight of 2000 g at the fifth percentile for gestational age.

➤ What is the most likely diagnosis?

➤ What are the next management steps?

➤ What are the potential complications of the patient’s condition?

ANSWERS TO CASE 15:

Eclampsia

Summary: A 29-year-old G1P0 at 34 weeks’ gestation with history of chronic hypertension with new onset seizure, elevated blood pressure, and proteinuria. The fetus measures in the fifth percentile for estimated fetal weight.

➤ Most likely diagnosis: Eclampsia.

➤ Next management step: Obtain IV access and administer intravenous magnesium sulfate, control blood pressure with intravenous agents.

➤ Potential complications: Include intrauterine growth restriction, abruption, DIC, renal dysfunction, liver dysfunction, intracranial hemorrhage, and stillbirth.

ANALYSIS

Objectives

1. Recognize the risk factors for preeclampsia/eclampsia.
2. Know how to administer magnesium sulfate to prevent seizures and to treat recurrent seizures.
3. Know the agents available for the treatment of recurrent seizures.
4. Understand the varied clinical presentations of the eclamptic patient.
5. Describe other clinical conditions that are part of the differential diagnosis of a seizure in pregnancy.

Considerations

This is a 29-year-old primigravida with chronic hypertension presenting at 34 weeks with new onset seizure, hypertension, and proteinuria.

The first priority is to stabilize the patient with respect to controlling the seizure and hypertension.

Eclampsia is the occurrence of a seizure in a patient with preeclampsia. The exact cause of eclampsia is unknown. Eclampsia occurs in approximately 0.5% of patients with mild preeclampsia and in 2% of patients with severe preeclampsia. The combination of seizures, hypertension, edema, and proteinuria make the diagnosis of eclampsia relatively certain. However, patients with eclampsia may present with a wide range of signs and symptoms. Although hypertension is typically associated with eclampsia, up to 16% may not present with hypertension. 10% of patients developing eclampsia prior to 32 weeks’ gestation will not have hypertension.

Table 15–1 RISK FACTORS FOR THE DEVELOPMENT OF PREECLAMPSIA

History of fetal growth restriction, abruptio placentae Multifetal gestation Hydrops fetalis Unexplained fetal growth restriction Antiphospholipid antibody syndrome or inherited thrombophilia Nulliparity Age > 40 y or < 18 y Chronic hypertension Family history of preeclampsia Preeclampsia in a previous pregnancy Chronic renal disease Vascular or connective tissue disorder Diabetes mellitus High body mass index

Although eclampsia is usually associated with proteinuria, it may be absent in up to 14% of cases. Edema, also typically associated with eclampsia, may be absent in 25% of women.

The clinician should be aware of certain symptoms that may be helpful in the diagnosis of eclampsia. These include persistent headaches (frontal and occipital), photophobia, altered mentation, visual changes, and epigastric, or right upper quadrant pain.

Risk factors for developing eclampsia are the same as for preeclampsia (Table 15–1). Eclamptic seizures may occur antepartum, intrapartum, or postpartum. Antepartum eclamptic convulsions occur in 38% to 53% of those patients with eclampsia and 11% to 44% occur postpartum.1 Almost all cases of postpartum eclampsia occur within the first 2 days postpartum. If there is a seizure more than 48 hours postpartum, a thorough neurological workup should be undertaken.2 This should include imaging of the brain and cerebrovascular anatomy, lumbar puncture, and lab tests to evaluate possible metabolic abnormalities. Approximately 90% of eclamptic seizures occur after 28 weeks’ gestation and approximately 8% occur between 21 and 28 weeks’ gestation. Only 1% to 2% of cases of eclampsia occur at 20 weeks’ gestation or less; these may be associated with placental abnormalities such as molar pregnancies or hydropic changes. The occurrence of a seizure at ≤ 20 weeks’ gestation also mandates a thorough neurologic workup.

APPROACH TO

Eclampsia

DEFINITIONS

ECLAMPSIA: Refers to the onset of convulsions in a woman with preeclampsia. Such convulsions are not attributable to an underlying seizure disorder or to other causes. It is prudent to remember that eclampsia can sometimes occur with minimal blood pressure elevation and little or no proteinuria, that is before preeclampsia has been clinically diagnosed.

CORTICAL BLINDNESS: Loss of vision due to vasogenic edema occurring most commonly in the occipital cortex. The diagnosis is made on imaging studies of the brain.

MAGNESIUM SULFATE: The consensus drug of choice for the treatment and prevention of eclampsia. The actual drug administered is magnesium sulfate septahydrate, of which elemental magnesium is 10% by weight.

Etiology

The exact cause of eclampsia is not known. Autopsies of individuals who have died from eclampsia usually show some cerebral pathology in the form of infarction, edema, and/or hemorrhage. Eclamptic patients may exhibit numerous neurologic abnormalities including focal deficits, cortical blindness and even coma; fortunately, these will rarely be permanent.

Differential Diagnosis of Eclampsia

When evaluating a pregnant patient with a seizure, other etiologies should be considered (see Table 15–2).1

Management of Eclampsia

The goals of management are:

1. Prevention of maternal injury and hypoxia
2. Prevention of recurrent seizures
3. Control of hypertension
4. Delivery of fetus and placenta

During the convulsions or immediately afterward, care should be taken to prevent maternal injury, maintain airway patency, and maternal oxygenation. The patient should be in the lateral decubitus position to minimize aspiration, and the side rails of the bed should be in the upright position. Maternal oxygenation should be maintained with supplemental oxygen.

Table 15–2 DIFFERENTIAL DIAGNOSIS OF ECLAMPSIA

Cerebrovascular accident Hypertensive crisis Space occupying lesions of the brain Epilepsy Metabolic disorders Infection of the CNS Illicit drug use Thrombotic thrombocytopenic purpura Gestational trophoblastic disease Thrombophilia Vasculitis Reversible posterior leukoencephalopathy syndrome (RPLS) Post-dural puncture syndrome

Magnesium sulfate is the drug of choice for the treatment and prevention of seizures and is given at an initial loading dose of 6 g intravenously over 15 minutes followed by a maintenance infusion of 2 g/h.1 An alternate dosing regimen seldom used in contemporary practice employs a 4 g IV loading dose of magnesium sulfate along with 5 g IM in each buttock followed by 5 g IM every 4 hours.2 Magnesium levels are not necessary if there are normal reflexes and normal renal function. If hypermagnesemia develops with significant cardiorespiratory depression, 10 cc of 10% solution of calcium gluconate can be used to reverse magnesium toxicity. This should be given slowly intravenously with maternal cardiac monitoring.

After receiving magnesium sulfate, up to 10% of eclamptic patients will have a recurrent seizure. For this, an additional 2 to 4 g bolus of magnesium sulfate can be given intravenously over a 3 to 5 minute period. If after the second bolus of magnesium sulfate another seizure occurs, sodium amobarbital 250 mg can be given intravenously over 3 to 5 minutes. If seizures persist, despite these interventions, then there should be consideration of the use of paralytic agents with intubation and mechanical ventilation. Magnesium sulfate infusion should be continued for 24 hours after delivery or after the last seizure. The goal of treating hypertension should be to maintain the systolic blood pressure between 140 and 160 mm Hg and the diastolic between 90 and 110 mm Hg. Hydralazine is used to treat hypertension using boluses of 5 to 10 mg every 15 to 20 minutes intravenously (total cumulative dose usually 30 mg). Labetalol may also be used in doses of 20 to 40 mg intravenously every 15 to 20 minutes (total cumulative dose 220 mg). Less often, oral nifedipine may be used, 10 to 20 mg every 30 minutes (total cumulative dose 50 mg in 1 h). Sodium nitroprusside is an effective agent for hypertensive crisis, but seldom used in obstetrics secondary to concern for cyanide toxicity. An arterial line should be in place for any patient receiving nitroprusside. It has an immediate onset of action and a duration of action between 1 and 10 minutes. In pregnancy, the initial rate of infusion should be 0.2 μg/kg/min (lower than 0.5 μg/kg/min in the nonpregnant patient) because most preeclamptic/eclamptic patients have depleted intravascular volume.

Maternal convulsions will result in maternal hypoxemia and hypercarbia which may cause fetal heart rate abnormalities. These fetal heart rate abnormalities will usually resolve spontaneously within 10 minutes. After the cessation of the convulsions, if the fetal heart rate abnormalities persist after 15 minutes, other complications such as abruption should be considered. Eclampsia is not an indication for cesarean delivery. The mode of delivery should be based on gestational age, fetal status, presence of labor, and cervical Bishop score. With a gestational age of less than 30 weeks, absence of labor, and a Bishop score of less than 5, most would proceed to cesarean delivery.

Either epidural analgesia or systemic opioids can be used for pain relief. Delivery is the definitive treatment for eclampsia.

Maternal Complications

Maternal death has increased in patients with eclampsia, the most common cause of intracranial hemorrhage (see Figure 15–1). Other complications that are increased include placental abruption, pulmonary edema, acute renal failure, disseminated intravascular coagulopathy, aspiration pneumonia, and cardiopulmonary collapse.3 Additional complications are listed in Table 15–3.

Figure 15–1. A fatal hypertensive intracerebral hemorrhage in a primigravid woman with eclampsia. (Reproduced, with permission, from Cunningham FG, Leveno KJ, Bloom SL, et al. Williams Obstetrics. 23rd ed.New York,NY: McGraw-Hill; 2010.)

Table 15–3 MATERNAL AND NEONATAL OUTCOMES ASSOCIATED WITH ECLAMPSIA

Cardiopulmonary arrest Abruption Pulmonary edema Aspiration pneumonia Disseminated intravascular coagulation Acute renal failure Liver hematoma Perinatal death HELLP syndrome Preterm birth

Perinatal Complications

Perinatal mortality is also increased and varies from 5% to 12%. Preterm delivery occurs in up to 50%.

Recurrence Risk

The recurrence risk for eclampsia in a subsequent pregnancy is 2%. However, the risk of preeclampsia in a subsequent pregnancy is 25%.

Comprehension Questions

15.1 Which of the following is most accurate regarding eclampsia?

A. Hypertension is nearly always present prior to an eclamptic seizure.

B. Proteinuria may be absent in approximately 14% of eclamptics.

C. Fetal bradycardia during an eclamptic seizure is generally an indication for cesarean section.

D. The majority of eclamptic seizures occur in the postpartum period.

15.2 A patient weighing 70 kg has an eclamptic seizure and has been given a 6-g loading dose of magnesium sulfate and then placed on a 2 g/h infusion. She has another seizure 30 minutes later. Which of the following should be the next step in management?

A. Immediately prepare for cesarean section.

B. Administer additional magnesium sulfate 2 g IV over 2 to 3 minutes.

C. Obtain a stat CT of the head.

D. Perform an ultrasound to evaluate the placenta for abruption.

15.3 A 26-year-old woman at 34 weeks’ gestation is admitted with a BP of 180/120 mm Hg and is noted to have a 3-minute tonic-clonic seizure. Which of the following management approaches is most appropriate?

A. Prevent maternal hypoxia and injury, administer magnesium sulfate, control blood pressure, decide on mode of delivery.

B. Prepare for immediate cesarean section, control blood pressure, administer magnesium sulfate after cesarean section.

C. Administer magnesium sulfate and wait for its effect on BP; if no change after 30 minutes, then administer antihypertensive agents.

D. Administer magnesium sulfate, use an intravenous antihypertensive agent to control BP to achieve a target of systolic blood pressure (SBP) of 120 and diastolic blood pressure (DBP) of 80 range, decide on mode of delivery.

15.4 During an eclamptic seizure, the fetal heart rate shows a heart rate of 150 beats per minute and persistent late decelerations. Which of the following should be the appropriate response?

A. Immediate delivery via cesarean section.

B. Allow in utero resuscitation and observe for 10 to 15 minutes, if the fetal heart rate pattern continues to be nonreassuring, then proceed with cesarean section if the mother is stable.

C. Allow for in utero resuscitation and after 10 minutes delivery by cesarean section even though the mother’s BP is 190/130 mm Hg.

D. Allow for in utero resuscitation, observe fetal heart rate pattern every 10 to 15 minutes, and if it continues to be nonreassuring, proceed with induction.

ANSWERS

15.1 B. Proteinuria may be absent in a significant number of patients. Hypertension is usually present with eclampsia although it may be absent in up to 16% of patients. Fetal bradycardia is usually present during an eclamptic seizure due to maternal respiratory difficulty and usually will resolve with cessation of the seizure. Immediate cesarean should not be performed, particularly in an unstable patient. The majority of seizures occur in the antepartum period.

15.2 B. Approximately 10% of patients will have a recurrent seizure. This may cause a change in the fetal status. It is best to allow for in utero resuscitation. Administration of an additional bolus of magnesium sulfate will usually be successful in treating the recurrent seizure.

15.3 A. Initially, the goal of managing eclampsia is to maintain maternal oxygenation and prevent injury. After this, magnesium sulfate for seizure prophylaxis should be given along with controlling the SBP to 140 to 160 and DBP 90 to 110 mm Hg. Only after the mother is stable should there be an assessment regarding mode of delivery.

15.4 C. The fetal heart rate pattern may be nonreassuring during and shortly after a convulsion. This will usually correct after 10 to 15 minutes. If the fetal heart rate continues to be nonreassuring, then one must consider abruption and if the mother is stable, delivery by cesarean section.

Clinical Pearls

See US Preventive Services Task Force Study Quality levels of evidence in Case 1

➤ Magnesium sulfate is the best agent for the prevention of seizures or recurrent seizures related to eclampsia (Level I).

➤ In up to 25% of cases of eclampsia, the blood pressure will be less than 140/90 mm Hg or there will be no proteinuria (Level II-2).

➤ The management of eclampsia includes stabilization of the mother, treatment and prevention of seizures, lowering of severe high blood pressure, and delivery of the baby, preferably vaginally (Level II-2).

➤ Seizures occurring greater than 48 hours postpartum should initiate a complete neurologic evaluation (Level II-3).

➤ The rate of eclampsia recurring in a subsequent pregnancy is 2% (Level ll-2).

REFERENCES

1. Sibai BM. Diagnosis, prevention, and management of eclampsia. Obstet Gynecol. 2005 Feb;105(2):402-410. 

2. Pritchard JA, Cunningham FG, Pritchard SA. The Parkland Memorial Hospital protocol for treatment of eclampsia: evaluation of 245 cases. Am J Obstet Gynecol. 1984 Apr 1;148(7):951-963. 

3. Sibai BM, Eclampsia VI. Maternal-perinatal outcome in 254 consecutive cases. Am J Obstet Gynecol. 1990 Sep;163(3):1049-1055. 

4. Miles JF Jr, Martin JN Jr, Blake PG, Perry KG Jr, Martin RW, Meeks GR. Postpartum eclampsia: a recurring perinatal dilemma. Obstet Gynecol. 1990 Sep;76(3 Pt 1):328-331.

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