Incidence

Can occur in ~5 per 10,000 live births (1,2); may be higher (5–100 per 10,000 live births) in developing countries (3)

Prevalence

• Antepartum: ~40–50%
• Intrapartum: ~20–40%
• Postpartum: ~10–40%

• Preterm delivery (~50%)
• HELLP syndrome (hemolysis, elevated liver enzymes, low platelets, ~10–15%)
• Placental abruption (~7–10%)
• Acute renal failure (~5–10%)
• Disseminated intravascular coagulation (~5%)
• Cardiopulmonary arrest (~5%)
• Pulmonary edema (~3–5%)
• Aspiration pneumonia (~2%)
• Liver hematoma (~1%)
• Stroke (ischemic or hemorrhagic, ~0.02%)

• Maternal mortality ~10% (63,000 maternal deaths annually)
• Neonatal mortality ~10%

History

• Eclampsia risk factors
• Neurologic or seizure disorder

Signs/Physical Exam

• Seizures: Generalized tonic–clonic seizures lasting ~60 seconds
• Coma

Labs/Studies

• Labs:
  • Urinalysis for proteinuria
  • CBC, especially platelets and Hct
  • CMP, including Mg²⁺
  • Coagulation studies, including PT/INR, PTT, and fibrinogen
  • Type and Cross
• Imaging studies:
  • CT head: Useful in identifying cerebral edema, loss of cortical sulci, and/or cerebral hemorrhage

• Magnesium sulfate (first line for seizures)
  • Dosing: 4–6 g IV bolus over 15 minutes, followed by 1–2 g/hr for seizure prophylaxis
  • Therapeutic level: ~6–8 mEq/mL
  • Contraindications: Heart block, Addison's disease, hepatitis, myasthenia gravis, markedly reduced renal function
  • Pregnancy class A
  • Possible interactions: Nifedipine (hypotension) and non-depolarizing neuromuscular blockade (prolonged duration)
  • Toxicity manifests with hyporeflexia and/or respiratory depression. Calcium gluconate (1 g IV) counteracts effects of magnesium.
• Phenytoin (second line for seizures)
  • Dosing: 10 mg/kg dose over 1 hour
  • Contraindications: 2^nd or 3^rd degree AV block, bradycardia, Adams–Stokes syndrome
  • Pregnancy class D
  • Adverse reactions: Blood dyscrasia, bullous or purpuric skin rash, QRS widening, cardiac arrest (rapid infusion), hyperglycemia, and hepatic dysfunction
• Diazepam (second line for seizures)
  • Dosing: 5–10 mg IV over 15 minutes; may be repeated every 15 minutes for a maximum dose of 30 mg
  • Contraindications: Narrow-angle glaucoma, hepatic failure, renal failure
  • Pregnancy class D: Freely crosses the placenta and accumulates in the fetal circulation
  • Adverse reactions: Cardiac arrest (rapid infusion), neonatal hypotonia, floppy infant syndrome, infantile kernicterus
• Lorazepam (second line for seizures)
  • Dosing: 4 mg IV infused over 5 minutes; repeat in 10 minutes for a maximum dose of 8 mg IV in a 12-hour period
  • Contraindications: Narrow-angle glaucoma, hepatic failure, renal failure
  • Pregnancy class D: Freely crosses the placenta and accumulates in fetal circulation
  • Adverse reactions: Cardiac arrest (rapid infusion), neonatal hypotonia, floppy infant syndrome, infantile kernicterus
• Hydralazine (first line for BP control)
  • Dosing: 5–10 mg IV every 15 minutes
  • Pregnancy class C
  • Possible interactions: Severe hypotension may occur if co-administered with MAOIs and/or beta-blockers.
  • Adverse reactions: Uterine hypoperfusion, reflex tachycardia
• Labetalol (first line for BP control)
  • Dosing: 20 mg IV every 10 minutes up to a maximum dose of 300 mg
  • Contraindications: Cardiogenic shock, bradycardia, pulmonary edema, AV nodal block, reactive airway disease, and CHF
  • Pregnancy class C
  • Adverse reactions: Neonatal bradycardia
• Nifedipine (second line for BP control)
  • Dosing: 10 mg PO TID titrated to effect for a maximum dose of 120 mg/day
  • Pregnancy class C
  • Possible interactions: May cause severe hypotension if administered with magnesium sulfate

Surrogate consent may be necessary if the patient is in a postictal state or is comatose.

• Neuraxial anesthesia (spinal or epidural)—if platelets and coagulation are normal. If an epidural catheter is already in place and properly functioning, the anesthetist may consider bolusing with a fast onset local anesthetic (chloroprocaine, lidocaine with bicarbonate, etc.) to avoid general anesthesia.
  • Hypotension may accompany initiation or bolusing of neuraxial anesthesia. Patients with preeclampsia are often intravascularly volume depleted (increased systemic vascular resistance).
• General anesthesia may be necessary in emergent deliveries or if the patient has coagulation abnormalities.
  • Severe hypertension, with resultant intracranial hemorrhage, may accompany laryngoscopy.
  • Airway edema may increase difficulty of laryngoscopy.
  • Prolonged duration of non-depolarizing neuromuscular blockade in parturients on magnesium sulfate

• Pulse oximetry: Decrease in SpO₂ in the setting of pulmonary edema, respiratory depression, and/or pulmonary aspiration
• Blood pressure monitoring: Consider invasive blood pressure monitoring in the setting of refractory hypertension (BP >180/120)
• CVP: May be useful in determining volume status and for infusion of vasodilators
• EKG
• Fetal heart tracing

• General anesthesia for emergent deliveries
  • Rapid-sequence intubation with cricoid pressure to minimize risk of aspiration
  • Avoid hypertensive response to laryngoscopy with deepening of intravenous or inhalational anesthetic, opioids (e.g., remifentanil), beta blockers (esmolol has a short duration of action), or vasodilators (e.g., nitroglycern, calcium channel blockers).

• General anesthesia is maintained with a combination of volatile anesthetic and nitrous oxide.
  • Following delivery of fetus, decrease volatile anesthetic to <0.5 MAC to minimize decreases in uterine tone.
  • IV opioids can be given following clamping of the cord.

Standard extubation criteria; may be precluded by airway edema. Additionally, ensure that the mother is awake, alert, and capable of protecting their airway.