Eclampsia is a condition caused by pregnancy. The initial manifestations of this illness are called pre-eclampsia. Pre-eclampsia arises at about the 20th week of pregnancy and is characterized by hypertension (high blood pressure), edema (tissue swelling due to the movement of fluid out of blood vessels), and proteinuria (an excessive accumulation of protein in the urine). When a pre-eclamptic patient develops neurologic symptoms, the condition is referred to as eclampsia. Eclampsia is usually characterized by seizures, but can also present as blindness, visual hallucinations, or even coma. The main cause of these symptoms is hypertensive encephalopathy and cerebral edema.
Who is afflicted with eclampsia?
Eclampsia is a rare condition. About 6-8% of pregnancies are complicated by pre-eclampsia. This number rises up to 30% in twin pregnancies. Woman who are most at risk are those who are malnourished and who have never borne children. Eclampsia is one of the major causes of death and disability in pregnant women.
How is eclampsia treated in a neuro-ICU?
Treatment of eclampsia has three objectives:
Control of hypertension. Anti-hypertensive agents are administered for this purpose. The most commonly used drugs are labetalol, nicardipine, and nitroprusside.
Management of seizures. Magnesium sulfate is highly effective for the treatment of seizures which arise as a result of eclampsia. Thus magnesium sulfate remains a standard therapy for the treatment of eclampsia. Seizures can also be controlled by anticonvulsant drugs such as diazepam and phenytoin.
Treatment of cerebral edema. It is common for the increased blood pressure associated with pre-eclampsia to cause leakage of fluid from the blood vessels supplying the brain. Under these circumstances the brain can become swollen with fluid, a condition known as cerebral edema. Cerebral edema can give rise to a dangerous increase in the pressure within the skull (intracranial pressure or ICP). Cerebral edema is treated with: (a) hyperventilation, which causes the blood to become overly alkaline and results in the constriction of blood vessels supplying the brain. Since less blood is perfusing the brain cerebral edema, and thus ICP, is reduced; and (b) mannitol treatment, which osmotically draws fluid out of brain tissue and back into blood vessels, thus reducing cerebral edema and lowering ICP.