Managing an eclamptic patient
Most Ob/Gyns have little experience managing acute eclampsia, but all maternity units and obstetricians need to be prepared to diagnose and manage this grave threat.
Hypertension is the hallmark of diagnosis. Hypertension is severe (at least 160 mm Hg systolic and/or at least 110 mm Hg diastolic) in 20% to 54% of cases, and it is mild (systolic pressure between 140 and 160 mm Hg or diastolic pressure between 90 and 110 mm Hg) in 30% to 60% of cases.2,3 In 16% of cases, there may be no hypertension at all.2
Proteinuria. Eclampsia usually is associated with proteinuria (at least 1+ on dipstick).1 However, when I studied a series of 399 women with eclampsia, I found substantial proteinuria (3+ or above on dipstick) in only 48% of cases; proteinuria was absent in 14%.2
Edema. A weight gain of more than 2 lb per week (with or without clinical edema) during the third trimester may be the first sign of eclampsia. However, in my series of 399 women, edema was absent in 26% of cases.2
TABLE 2
Signs and symptoms of eclampsia*
Hypertension and proteinuria in eclampsia may be severe, mild, or even absent
| CONDITION | FREQUENCY (%) IN WOMEN WITH ECLAMPSIA | REMARKS |
|---|---|---|
| SIGNS | ||
| Hypertension | 85 | Should be documented on at least 2 occasions more than 6 hours apart |
| Severe: 160/110 mm Hg or more | 20–54 | |
| Mild: 140–160/90–110 mm Hg | 30–60 | |
| No hypertension2 | 16 | |
| Proteinuria | 85 | |
| At least 1+ on dipstick2 | 48 | |
| At least 3+ on dipstick | 14 | |
| No proteinuria | 15 | |
| SYMPTOMS | ||
| At least 1 of the following: | 33–75 | Clinical symptoms may occur before or after a convulsion |
| Headache | 30–70 | Persistent, occipital, or frontal |
| Right upper quadrant or epigastric pain | 12–20 | |
| Visual changes | 19–32 | Blurred vision, photophobia |
| Altered mental changes | 4–5 | |
| * Summary of 5 series | ||
Symptoms of eclampsia
Several clinical symptoms can occur before or after a convulsion1:
- persistent occipital or frontal headaches,
- blurred vision,
- photophobia,
- epigastric and/or right upper quadrant pain, and
- altered mental status.
Usual times of onset
Eclamptic convulsions can occur during pregnancy or delivery, or after delivery ( TABLE 3).1-5
Approximately 91% of antepartum cases develop at 28 weeks or beyond. The remaining cases tend to occur between 21 and 27 weeks’ gestation (7.5%), or at or before 20 weeks (1.5%).2
When eclampsia occurs before 20 weeks, it usually involves molar or hydropic degeneration of the placenta, with or without a fetus.1 However, eclampsia can occur in the first half of pregnancy without molar degeneration of the placenta, although this is rare.1,2 These women are sometimes misdiagnosed as having hypertensive encephalopathy, seizure disorder, or thrombotic thrombocytopenia purpura. Thus, women who develop convulsions in association with hypertension and proteinuria in the first half of pregnancy should be assumed to have eclampsia until proven otherwise,1 and require ultrasound examination of the uterus to rule out molar pregnancy and/or hydropic or cystic degeneration of the placenta.
Postpartum cases tend to occur within the first 48 hours, although some develop beyond this limit and have been reported as late as 23 days postpartum.8
Late postpartum eclampsia occurs more than 48 hours but less than 4 weeks after delivery.8 These women have signs and symptoms consistent with preeclampsia along with their convulsions.8,9 Thus, women who develop convulsions with hypertension and/or proteinuria, or with headaches or blurred vision, after 48 hours postpartum should be assumed to have eclampsia and treated accordingly.8,9
When eclampsia occurs especially late, perform an extensive neurologic examination to rule out other cerebral pathology.1,10
Eclampsia is atypical if convulsions occur before 20 weeks’ gestation or beyond 48 hours postpartum. It also is atypical if convulsions develop or persist despite adequate magnesium sulfate, or if the patient develops focal neurologic deficits, disorientation, blindness, or coma. In these cases, conduct a neurologic exam and cerebral imaging to exclude neurologic pathology.8-10
TABLE 3
Usual times of onset*
91% of antepartum eclampsia cases occur at 28 weeks or later, although eclamptic convulsions can occur at any time during pregnancy or delivery, or postpartum
| ONSET | FREQUENCY (%) | REMARKS |
|---|---|---|
| Antepartum | 38–53 | Maternal and perinatal mortality, and the incidence of complications and underlying disease, are higher in antepartum eclampsia, especially in early cases |
| ≤20 weeks | 1.5 | |
| 21 to 27 weeks | 7.5 | |
| ≥28 weeks | 91 | |
| Intrapartum | 18–36 | Intrapartum eclampsia more closely resembles postpartum disease than antepartum cases |
| Postpartum | 11–44 | Late postpartum eclampsia occurs more than 48 hours but less than 4 weeks after delivery |
| ≤48 hours | 7–39 | |
| >48 hours | 5–26 | |
| * Summary of 5 series | ||
Differential diagnosis
As with other aspects of preeclampsia, the presenting symptoms, clinical findings, and many laboratory results in eclampsia overlap several other medical and surgical conditions.1,10 Of course, eclampsia is the most common cause of convulsions in a woman with hypertension and/or proteinuria during pregnancy or immediately postpartum. On rare occasions, other causes of convulsions in pregnancy or postpartum may mimic eclampsia.1 These potential diagnoses are particularly important when the woman has focal neurologic deficits, prolonged coma, or atypical eclampsia.
The differential diagnosis encompasses a variety of cerebrovascular and metabolic disorders:
- hemorrhage,
- ruptured aneurysm or malformation,
- arterial embolism, thrombosis,
- venous thrombosis,
- hypoxic ischemic encephalopathy,
- angiomas,
- hypertensive encephalopathy,
- seizure disorder,
- hypoglycemia, hyponatremia,
- posterior leukoencephalopathy syndrome,
- thrombotic thrombocytopenic purpura,
- postdural puncture syndrome, and
- cerebral vasculitis/angiopathy.
