••• Chapter 13^ Hypertension and Pregnancy^123
❍ How should magnesium toxicity be treated?
Calcium gluconate 1 g IV over 5 to 10 minutes.
❍ Can magnesium be used in association with calcium channel blockers, such as nifedipine?
The simultaneous use of these drugs may, on very rare occasions, result in profound neuromuscular blockade,
including cardiac depression and muscle weakness (reversal can be achieved with 10% solution calcium gluconate).
❍ How does magnesium affect the fetal heart rate pattern?
It may decrease the variability.
❍ How should you treat a recurrent eclamptic seizure in spite of magnesium treatment (approximately 10%
of cases)?
An additional 2 g dose of magnesium should be given IV and may be repeated once in some women. If seizure
activity is still present, then traditional anticonvulsant therapy should be initiated
❍ When should sodium amobarbital be used?
250 mg intravenously over 3 to 5 minutes may be used to treat recurrent convulsions in spite of adequate
magnesium therapy.
❍ What percentage of eclamptic seizures develop before overt proteinuria is identified?
10% to 14%.
❍ Can eclampsia occur without hypertension?
In 16% of the eclamptic cases, hypertension is absent. (It is severe in 20–54% and mild in 30–60%.)
❍ When does eclampsia develop?
90% develop at or beyond 28 weeks. 38% to 53% develop antepartum, 18% to 36% intrapartum, and 11% to
44% postpartum.
❍ Which condition may be associated with eclampsia prior to 20 weeks?
Molar pregnancy.
❍ Name some common symptoms that may precede eclampsia.
Persistent occipital or frontal headaches, blurred vision, photophobia, epigastric pain, and right upper quadrant pain.
❍ When is cerebral imaging indicated?
For patients with focal neurological deficits or prolonged coma, and for patients with atypical features of eclampsia,
such as onset before 20 weeks, late postpartum eclampsia or eclampsia refractory to adequate therapy with
magnesium sulfate.
❍ What conditions are in the differential diagnosis of eclampsia?
Hypertensive encephalopathy, seizure disorder, brain tumors, hypoglycemia, thrombophilia, thrombotic
thrombocytopenic purpura, vasculitis, encephalitis, meningitis, and ruptured cerebral aneurysm.