Code Eclampsia: Navigating the Storm in ED Management

Imagine a third-year emergency medicine resident working overnight in the intensive care unit (ICU) when a new patient arrives from an outside hospital. The patient is a 35-year-old primigravid woman, estimated to be 27 weeks pregnant with twins. Her pregnancy has otherwise been uncomplicated, and she reports no significant medical history. She was accepted to the ICU for suspected necrotizing fasciitis of her lower extremity.

Her vitals on arrival include a blood pressure (BP) of 180/110 mmHg, a heart rate of 80, respiratory rate of 26, and 94 percent on 3L/min nasal cannula. She has never required oxygen at baseline.

Her exam is significant for a headache, decreased visual acuity secondary to blurry vision, increased work of breathing with coarse lung sounds bilaterally, and grade 2+-pitting edema of the lower extremities. She also has cellulitis covering a small portion of her left leg, but without crepitus.

After reviewing imaging from the outside hospital, and after evaluation by surgery, she is diagnosed with cellulitis and receives intravenous (IV) antibiotics. However, she does not require surgery for debridement. A chest X-ray is obtained because she has a new oxygen requirement, which shows pulmonary edema.

Based on her presentation and vital signs, the patient has severe preeclampsia and obstetrics/gynecology (OB/GYN) is consulted. The patient is given IV labetalol for BP control; she is started on IV magnesium for seizure prophylaxis. Despite analgesia, the patient continues to endorse headaches. OB/GYN evaluates and determines that she needs to be transported to the operating room for emergent cesarean delivery. The patient is given a dose of steroids for fetal lung maturation.

While OB/GYN is coordinating with the neonatal ICU and preparing the operating room, the patient begins to decompensate, with increasing oxygen requirements, escalating from nasal cannula to high-flow nasal cannula, and eventually requiring bi-level positive airway pressure (BiPAP). Shortly after initiating BiPAP, she develops a tonic-clonic seizure which, fortunately, is aborted with 4 mg IV of lorazepam. She maintains her airway and does not require intubation. Her BP is eventually controlled with a nicardipine drip after multiple push doses of IV labetalol and hydralazine. The patient is successfully transported to the operating room where she undergoes surgery with successful cesarean delivery of two infants. The patient and her newborns both make a full recovery and are eventually discharged home.

Preeclampsia and eclampsia are serious pregnancy-related conditions that fall under the umbrella of gestational hypertensive disorders and can pose significant risks to both the mother and the fetus. Preeclampsia typically occurs after the 20th week of pregnancy and is characterized by hypertension plus proteinuria or evidence of end organ dysfunction and are defined below:¹

• Hypertension
  • systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg on at least two occasions at least four hours apart after 20 weeks of gestation in a patient with a previously normal BP
  • If systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg, confirmation can be instead within minutes to facilitate timely antihypertensive therapy.
• Proteinuria
  • ≥300 mg/24-hour urine specimen or,
  • Protein:creatinine ratio of 0.3 mg/dL
• End organ dysfunction
  • renal insufficiency (serum creatinine >1.1 mg/dL or a doubling of serum creatinine in the absence of other renal disease)
  • new onset headache
  • visual disturbances
  • pulmonary edema
  • thrombocytopenia (platelet count <100,000/mm³)
  • impaired liver function (serum transaminase two times normal)
  • persistent right upper quadrant pain despite analgesia

Preeclampsia has variable presentations that range from mild to severe, and if left untreated, it can progress to eclampsia, which is a convulsive manifestation of gestational hypertensive disorders and is among the most severe form of disease. Eclampsia is defined by new-onset tonic-clonic, focal, or multifocal seizure in the absence of any additional causes of seizure such as epilepsy, intracranial hemorrhage or ischemia, or other acute causes such as severe hypoglycemia or substance use.¹ Eclampsia can occur before, during and up to six weeks after labor, and it is important to note that a significant proportion of patients (30 percent) do not present with classical signs of preeclampsia prior to a seizure episode.²

In addition to early engagement with OB/GYN, the main objective of management of eclampsia is termination of seizure. The American College of Obstetrics and Gynecologists (ACOG) in collaboration with the ACEP developed a Guide to Obstetric Emergencies in Non-obstetric Settings that includes guidance on management of eclampsia.

First-line therapy for eclamptic seizures is magnesium sulfate. Initial treatment includes:

1. loading dose: 4-6 g IV over 20-30 minutes followed by maintenance dose
2. maintenance dose: 1-2 g/hour
   1. If IV access has not been established, magnesium sulfate can be administered intramuscularly (IM)—10 g loading dose with 5 g IM administered in each buttock.
   2. Medication can be mixed with 1 mL 2 percent Xylocaine to reduce discomfort

Persistent or recurring seizure after magnesium sulfate loading dose: Continue IV magnesium maintenance dosing, administer one of the following medications and be prepared for possible intubation.

Preferred next medication class: benzodiazepines

1. lorazepam 4 mg IV over three to five minutes or,
2. diazepam 5-10 mg IV slowly
3. If no IV access, 10 mg IM midazolam

If the patient is still seizing:

• fosphenytoin 20 mg PE/kg IV at 150 mg PE/min

If persistent:

• levetiracetam 60 mg/kg IV, maximum 4,500 mg
• Consider intubation with propofol, consider consulting with neurology and plan for ICU admission

Once seizure has been aborted, consider the following steps in ongoing resuscitation

1. Assess BP: if systolic blood pressure >160 or diastolic blood pressure >110, initiate the Acute Hypertension Algorithm
2. OB evaluation ASAP
3. If seizure responds to magnesium and urgent transport to an obstetric unit for further evaluation is unavailable:
   1. Continue magnesium sulfate infusion 1-2 g/hr.
   2. Monitor magnesium levels every four hours (therapeutic range 4.9-8.5 mg/dL).
   3. Observe for magnesium toxicity.
4. Maintain infusion for at least 24-48 hours after last seizure or delivery, whichever occurred latest.
5. Obtain head computed tomography scan to rule out intracranial hemorrhage versus ischemia.
6. Perform a thorough neurological exam.
7. Preparation for delivery as applicable based on emergency department resources (i.e., admission to Labor and Delivery, transfer to facility with Labor and Delivery).

• If serum magnesium >9.6 mg/dL, the infusion should be stopped and can be restarted once the level decreases to <8.4 mg/dL.
• If a patient is demonstrating signs of respiratory depression secondary to magnesium toxicity, calcium gluconate or calcium chloride should be used as calcium directly antagonizes neuromuscular and cardiovascular effects of magnesium.
  • 10 percent calcium gluconate: 2-3 grams IV over three minutes
  • Ensure IV hydration to maintain magnesium excretion.
• Effects of magnesium toxicity compound as the serum magnesium levels (mg/dL) increase. For reference:
  • 9-8.5: therapeutic range
  • 5-12: loss of deep tendon reflexes
  • 12-15: respiratory depression
  • >18: effects of cardiac conduction
  • >30: cardiac arrest

Eclampsia is a severe complication of pregnancy that poses significant risks to both the mother and the fetus. It is associated with maternal and fetal morbidity and mortality if not managed properly. Early identification of preeclampsia and timely medical intervention, such as the administration of magnesium sulfate to prevent seizures and the delivery of the baby, are crucial in mitigating the dangers of eclampsia. With appropriate care and management, many patients can go on to have healthy pregnancies, but awareness and vigilance remain essential for safeguarding the health of both parent and child.

Dr. Wiltz is a PGY-3 in emergency medicine and chief resident at Case Western Reserve University/University Hospitals in Cleveland, Ohio. She is also president-elect of the Emergency Medicine Residents’ Association.

1. Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. Obstet Gynecol. 2020;135(6):e237-e260.
2. Aukes AM, Yurtsever FN, Boutin A, et al. Associations between migraine and adverse pregnancy outcomes: systematic review and meta-analysis. Obstet Gynecol Surv. 2019;74(12):738-748.
3. ACOG. Identifying and Managing Obstetric Emergencies in Nonobstetric Settings. https://www.acog.org/programs/obstetric-emergencies-in-nonobstetric-settings. Published 2024. Accessed April 1, 2025.
4. ACOG. Acute Hypertension in Pregnancy and Postpartum Algorithm. https://www.acog.org/-/media/secure/programs/acog_urgent-care-acute-hypertension-in-pregnancy-and-postpartum-algorithm.pdf. Accessed July 9, 2025.
5. Sibai BM. Magnesium sulfate prophylaxis in preeclampsia: Lessons learned from recent trials. Am J Obstet Gynecol. 2004;190(6):1520-1526.
6. Schoen JC, Campbell RL, Sadosty AT. Headache in pregnancy: an approach to emergency department evaluation and management. West J Emerg Med. 2015;16(2):291-301.
7. Kerrigan K, Smith L. Preeclampsia/Eclampsia. In: Swadron S, Nordt S, Mattu A, and Johnson W, eds. CorePendium. 5th ed. Burbank, CA: CorePendium, LLC. https://www.emrap.org/corependium/chapter/rec09jiLmoJ1dIM0l/PreeclampsiaEclampsia#h.y2w33fax0jwc. Updated February 7, 2025. Accessed April 4, 2025.