CRITICAL CARE in OB, PART 2: Managing an eclamptic seizure and its aftermath

March 1, 2006

Few ob/gyns are prepared for the terrifying sight of a pregnant woman in the throes of an eclamptic convulsion. You can't predict which preeclamptic patients will go on to develop life-threatening eclampsia. But when they do, you can be ready to follow these seven important steps for stabilization and induction of labor within 24 hours.

[Editor's note: Beginning with this article, we are introducing a new technique to help Contemporary OB/GYN readers grasp the essential points in an article more quickly. Look for bracketing at the beginning and ending of the sentences/paragraphs that are critical to a quick grasp of many of the article's essential points. ]

Case Study

An ambulance rushes Jessica, a 19-year-old G1P0 with an intrauterine pregnancy at 36 weeks' gestation, to labor and delivery. She's had no prenatal care. Her family says she has been complaining of headache and visual disturbance for the last few days. They've witnessed a 3-minute seizure during which she drooled saliva but had no urinary or fecal incontinence. Her past medical/ surgical and social history are completely negative. Upon admission, her blood pressure is 170 mm Hg systolic over 110 mm Hg diastolic. She has 2 plus protein on her urine dip. Bedside ultrasound confirms a singleton intrauterine pregnancy consistent with 36 weeks of gestation. Fetal heart rate tracing is reassuring, and cervical exam reveals a Bishop score of 7. What's the diagnosis? What would you do next?

Eclampsia is defined as the on-set of seizures and/or unexplained coma during pregnancy (usually not before 20 weeks of gestation) or postpartum in patients with signs and symptoms of preeclampsia. In the Western world, the incidence ranges from 1 in 2,000 to 1 in 3,448 pregnancies.1-3 Incidence is higher in tertiary referral centers, in multiple gestation, and in patients with no prenatal care.4 Although most cases (90%) present in the third trimester or 48 hours following delivery, there have been rare cases (1.5%) at or before 20 weeks and as late as 23 days postpartum.

Our goal here is first and foremost to help narrow the experience gap by explaining the seven steps for managing an eclamptic seizure. We'll also provide the risk factors for eclampsia, discuss the often tricky diagnosis, and address the issues of anesthesia, mode of delivery, and postpartum management.

Risk factors to keep in mind

Similar to the risk factors for preeclampsia, those for eclampsia are: (1) gestational hypertension-preeclampsia with premonitoring signs/symptoms (like severe headaches, persistent visual changes, severe persistent epigastric pain, and altered mental status); (2) chronic hypertension; (3) first-time pregnancy; (4) multiple gestation; (5) pregestational diabetes; (6) history of renal disease; (7) collagen vascular disease; (8) hydatid mole; (9) fetal hydrops; and (10) family history of eclampsia.

Diagnosis is sometimes tricky

Sometimes the diagnosis of eclampsia is straightforward-when a pregnant woman has hypertension, proteinuria, generalized edema and convulsions, for instance. But not always. Patients can present with a broad spectrum of signs; 20% to 54% have severe hypertension (at least 160 mm Hg systolic and/or 110 mm Hg diastolic), 48% suffer from severe proteinuria and generalized edema, and 30% to 60% have mild or no hypertension (systolic blood pressure 140 to 160 mm Hg or diastolic 90 to 110 mm Hg), 14% have no proteinuria, and more than one quarter have no edema (26%).5