RISK FACTORS: Nulliparity 5-1, Age > 40 3:1, African American 1.5.1, Family history of PIH 5:1, Chronic HTN 10:1, Chronic renal disease 20:1, Antiphospholipid syndrome 10-1, Diabetes 2:1, Twins 4:1, High BMI 3:1
Medical Care: Eclamptic convulsions are life-threatening emergencies and require the proper treatment to decrease maternal morbidity and mortality.
Presentation: If the patient develops convulsions at home, she usually is brought to the hospital in a comatose (ie, postictal) condition. These patients should be cared for by a team of qualified physicians (preferably obstetricians) and nurses. Patients should undergo continuous intensive monitoring. They should be placed in a monitored labor room with minimal noise and external stimuli.
Initial management: As with any seizure, the initial management is to clear the airway and administer adequate oxygenation. The patient should be positioned in the left lateral position to help improve uterine blood flow and obstruction of the vena cava by the gravid uterus. The patient should be protected against maternal injury during the seizure, ie, the guardrails should be up on the bed, a padded tongue blade is placed between the teeth, and secretions are suctioned from the patient's mouth.
Intravenous access: After the seizure has ended, a 16- to 18-gauge intravenous line should be obtained for drawing specimens for laboratory studies and administering fluids. Intravenous fluids should be limited to isotonic solutions to replace urine output and about 700 mL/d to replace insensible losses.
Control of the seizure: Do not attempt to shorten or abolish the initial seizure. A syringe containing 2-4 g of magnesium sulfate should be the only anticonvulsant at the bedside. Magnesium sulfate is administered intramuscularly or intravenously to decrease and prevent further convulsions.
Laboratory workup: A complete blood count, chemistry panel, and liver function tests should be conducted. A urinalysis should be sent to evaluate for proteinuria, and a 24-hour urine collection for protein should be initiated.
Hypertension control: Record blood pressure every 10 minutes. Control blood pressure (diastolic 90-100 mm Hg) with administration of antihypertensive medications (ie, hydralazine, labetalol).
Monitoring: Carefully monitor the neurologic status, urine output, respirations, and fetal status for all patients. An indwelling Foley catheter should be placed in the bladder to help collect and record urine output.
Invasive monitoring: Pulmonary artery pressure monitoring may be necessary for accurate fluid management in eclamptic patients. This is particularly important in patients who have evidence of pulmonary edema or oliguria/anuria.
Assessment of medical condition: Once the seizure is controlled and the patient has regained consciousness, the general medical condition is assessed. Induction of labor may be initiated when the patient is stable.
Delivery
Delivery is the treatment for eclampsia after proper stabilization. If the patient is undelivered, no attempt should be made to deliver the infant either vaginally or by cesarean delivery until the acute phase of the seizure or coma has passed. The mode of delivery should be based on obstetric indications but should be chosen with an awareness of the fact that vaginal delivery is preferable from a maternal standpoint.
In the absence of fetal malpresentation or fetal distress, oxytocin should be initiated to induce labor in the following situations:
At 30 weeks' gestation or greater, irrespective of the cervical dilation or effacement
Prior to 30 weeks' gestation with a favorable cervix
Patients with an unfavorable cervix with a gestational age of 30 weeks or less, once stabilized, should be delivered electively by cesarean delivery. This approach is preferred because pregnancies prior to 30 weeks' gestation with eclampsia have a higher risk of complications intrapartum. Intrapartum complications include the following:
Fetal growth retardation (30%)
Fetal distress (30%)
Abruption (23%)
Fetal monitoring
Fetal heart rate and intensity of the contractions should be monitored closely. Fetal bradycardia is a common finding following the eclamptic seizure and has been reported to last from 30 seconds to 9 minutes. The interval from the onset of the seizure to the fall in the fetal heart rate is typically 5 minutes. Transitory fetal tachycardia may occur following the bradycardia.
During the recovery phase, the fetal heart rate tracing may reveal a loss of beat-to-beat variability and late decelerations. The mechanism for the fetal tracing abnormalities is most likely due to a decrease in uterine blood flow caused by the intense vasospasm and uterine hyperactivity during the convulsion. If the fetal heart tracing does not improve following a seizure, other conditions should be considered. Growth restricted and preterm fetuses may take longer to recover following a seizure. Consider placental abruption if uterine hyperactivity remains and fetal bradycardia persists.
Surgical Care:
Patients with eclampsia may need to be delivered immediately by cesarean delivery, depending on the maternal and fetal condition.
Stabilize the patient before initiating cesarean delivery during the acute phase because delivery may aggravate oliguria and other manifestations of the disease.
The anesthesiologist should be informed of the maternal condition and may be helpful if endotracheal intubation or an operative delivery is necessary.
For nonemergent cesarean delivery, epidural anesthesia is preferred and can be induced in a steplike fashion, being careful not to cause maternal hypotension.
The use of spinal anesthesia is controversial because of the possibility of extreme sympathetectomy, resulting in maternal hypotension and uteroplacental insufficiency.
Diet:
Patients with eclampsia should have nothing by mouth until medically stabilized.
During a seizure, maintaining the patient's airway and being careful to help avoid aspiration of stomach contents is important.
Activity:
Strict bedrest
Left lateral hip roll to help improve uterine blood flow to the fetus
DRUG TREATMENT : The goals of pharmacotherapy are to reduce morbidity, prevent complications, and correct eclampsia. Drugs of choice include magnesium sulfate, phenytoin, diazepam, hydralazine, labetalol, and nifedipine.
1. ANTICONVULSANTS :
- MAGNESIUM SULPHATE : Several studies have revealed that magnesium sulfate is the drug of choice for treating eclamptic seizures. Magnesium sulfate is successful in controlling seizures in >95% of cases. Agent has physiologic advantages to the fetus by increasing uterine blood flow.
Mechanism of action of magnesium sulfate therapy is that it inhibits the release of acetylcholine at the motor endplate. In addition, magnesium has a direct effect on skeletal muscle by virtue of its competitive antagonistic effects with calcium.
Magnesium sulfate is excreted exclusively by the kidneys and has little antihypertensive effect. It is an effective anticonvulsant and helps prevent recurrent seizures and maintain uterine and fetal blood flow.
Can be administered both IV and IM. Intravenous route is preferred over IM route because administration is controlled more easily and time to therapeutic levels is shorter. Intramuscular administration of magnesium sulfate tends to be more painful and less convenient. If IV access or close patient monitoring is unavailable, this is an effective therapy.
The goals of magnesium therapy are to terminate ongoing seizures and prevent further seizures. Patient should be evaluated qh to assure that deep tendon reflexes are present, respirations are at least 12 breaths per min, and urine output is at least 100 mL during the preceding 4 h.
When using magnesium sulfate IV, close monitoring of patient and fetus is necessary.
Magnesium therapy usually is continued for 12-24 h following delivery and may be stopped when the hypertension resolves and the patient has shown adequate diuresis.
Renally compromised patients should be monitored with magnesium levels, with aggressive adjustments made to facilitate levels at 6-8 mg/dL. Patients with increased urine output may need maintenance dose increased to 3 g/h to maintain therapeutic levels. Monitor patient for signs of worsening condition and magnesium toxicity.
The Parkland IM protocol is as follows:
Magnesium sulfate 4 g IV over 5 min, plus magnesium sulfate 10 g deep IM (3-in needle) divided in both buttocks and mixed with 1 mL 2% lidocaine. If a seizure persists more than 15 min after above dose, administer an additional 2 g of magnesium sulfate IV over 3-5 min.
Magnesium sulfate 5 g IM q4h, starting 4 h later unless patellar reflexes are absent, respiratory depression occurs, or urine output is <100 mL in the prior 4 h. Therapeutic levels are 4.8-8.4 mg/dL. With the above protocol, serum magnesium levels usually are 4-7 mg/dL in a patient with an average volume of distribution and normal renal function.
Actual serum magnesium levels are monitored only in patients with symptomatic magnesium toxicity or renal compromise.
Patients may have seizures while receiving magnesium sulfate. If seizure occurs in first 20 min after loading dose, the convulsion usually is short, and no additional treatment is indicated. If seizure occurs >20 min after the loading dose, an additional 2-4 g of magnesium may be administered.
DOSE : Initial: 4-6 g bolus IV over 15-20 min; if convulsion occurs after initial bolus, an additional 2 g IV over 3-5 min may be administered
Approximately 10-15% of patients will have another convulsion after the loading dose
Maintenance: 2-4 g/h IV maintenance drip
If magnesium level is >10 mg/dL at 4 h after initial bolus, decrease the maintenance dose
- PHENYTOIN
- DIAZEPAM
2. ANTIHYPERTENSIVE : Hypertension associated with eclampsia often is controlled adequately by stopping the seizure.
Antihypertensive medications are used for diastolic blood pressures >110 mm Hg. The goal of therapy is to maintain diastolic blood pressure in the range of 90-100 mm Hg.
Antihypertensive therapy has 2 main goals: (1) reducing maternal morbidity and mortality associated with seizures, strokes, and pulmonary embolism and (2) reducing fetal morbidity and mortality secondary to intrauterine growth restriction, placental abruption, and infarcts.
Uterine hypoperfusion may result if blood pressure is lowered too quickly. Uterine vasculature always is maximally vasodilated, and a decrease in maternal blood pressure tends to decrease uteroplacental perfusion.
Although total body water in patients with eclampsia is excessive, intravascular volume is contracted and women with eclampsia are very sensitive to further volume changes. Hypovolemia results in decreased uterine perfusion. Therefore, diuretics and hyperosmotic agents should be avoided in eclampsia without prior assessment of intravascular volume.
Drugs used most commonly for hypertension in pregnancy are hydralazine and labetalol. Nifedipine has been used as well to control hypertension, but it is less accepted.
- HYDRALAZINE
- LABETALOL
- NIFEDIPINE
ALTERNATIVE DRUGS :
β’ Benzodiazepines, eg, diazepam 2 mg/min until resolution or 20 mg given, or lorazepam 1-2 mg/min up to
total of 10 mg, or phenytoin 18-20 mg/kg at a rate of 20-40 mg/min, or phenobarbital 100 mg/min to a total of
20 mg/kg given
PATIENT MONITORING : Blood pressure, neurological examination, condition of fetus
PREVENTION/AVOIDANCE :
β’ Adequate prenatal care
β’ Good control of preexisting hypertension
β’ Recognition and treatment of preeclampsia
β’ Aspirin has been suggested to lower fetal death; recent evidence in a large RCT showed no benefit
β’ Calcium supplementation has been shown to reduce the risk of preeclampsia by 30% (9 RCTs)
β’ There is some evidence for vitamin C (1000/mg/d) plus E (400U/d) in reducing risk for preeclampsia
POSSIBLE COMPLICATIONS :
β’ 56% have transient defi cits including cortical blindness
β’ Most women do not have long-term sequelae from eclampsia
β’ Death from toxemia or its complications
β’ Death of fetus
EXPECTED COURSE/PROGNOSIS :
β’ 25% of eclamptic women will have hypertension in subsequent pregnancies, but only 5% of these will be
severe, and only 2% will be eclamptic again
β’ Eclamptic, multiparous women may be at higher risk for subsequent essential hypertension
β’ Multiparous women with eclampsia have higher mortality in subsequent pregnancies than primiparous women
β’ Racial factors are unclear, since the higher incidence of essential hypertension in blacks may predispose them to higher rates of hypertension postpartum, rather than a history of eclampsia