Преэклампсия и эклампсия: диагностика, осложнения и лечение.

Pre eclampsia characterized by the presence of seizures
The diagnostic criterion for pre eclampsia is high blood pressure, occurring after 20 weeks gestation or during the second half of pregnancy. Other preventative recommendations include calcium supplementation in areas with low calcium intake and treatment of prior hypertension with anti hypertensive medications. Exercise during pregnancy may also be useful. Treatment options include blood pressure medications such as hydralazine and emergency delivery of the baby either vaginally or by cesarean section. In the developed world eclampsia rates are about 1 in 2,000 deliveries due to improved medical care whereas in developing countries it can impact 10 30 times as many women. They resulted in 46,900 deaths in 2015. Maternal mortality due to eclampsia occurs at a rate of approximately 0 1.8% of cases in high income countries and up to 15% of cases in low to middle income countries. The word eclampsia is from the Greek term for lightning.

There are risks to both the mother and the fetus when eclampsia occurs. The fetus may grow more slowly than normal within the womb (uterus) of a woman with eclampsia, which is termed intrauterine growth restriction and may result in the child appearing small for gestational age or being born with low birth weight. Eclampsia may also cause problems with the placenta. The placenta may bleed (hemorrhage) or begin to separate early from the wall of the uterus. It is normal for the placenta to separate from the uterine wall during delivery, but it is abnormal for it to separate prior to delivery; this condition is called placental abruption and can be dangerous for the fetus. Placental insufficiency may also occur, a state in which the placenta fails to support appropriate fetal development because it cannot deliver the necessary amount of oxygen or nutrients to the fetus. It may be safer to deliver the infant preterm than to wait for the full 40 weeks of fetal development to finish, and as a result prematurity is also a potential complication of eclampsia. In the mother, changes in vision may occur as a result of eclampsia, and these changes may include blurry vision, one sided blindness (either temporary due to amaurosis fugax or potentially permanent due to retinal detachment), or cortical blindness, which affects the vision from both eyes. There are also potential complications in the lungs. The woman may have fluid slowly collecting in the lungs in a process known as pulmonary edema. It is also possible that during a seizure breathing will stop temporarily or become inefficient, and the amount of oxygen reaching the woman's body and brain will be decreased (in a state known as hypoxia). If it becomes difficult for the woman to breathe, she may need to have her breathing temporarily supported by an assistive device in a process called mechanical ventilation. In some severe eclampsia cases, the mother may become weak and sluggish (lethargy) or even comatose. Women who have long term high blood pressure before becoming pregnant have a greater risk of pre eclampsia. Furthermore, women with other pre existing vascular diseases (diabetes or nephropathy) or thrombophilia disease such as the antiphospholipid syndrome are at higher risk to develop pre eclampsia and eclampsia. In addition, there is a genetic component: a woman whose mother or sister had the condition is at higher risk than otherwise. Patients who have experienced eclampsia are at increased risk for pre eclampsia/eclampsia in a later pregnancy.

The mechanisms of eclampsia and preeclampsia are not definitively understood, but following provides some insight. The presence of a placenta is required, and eclampsia resolves if it is removed. Also, activation of the coagulation cascade can lead to microthrombi formation, which may further impair blood flow. Thirdly, increased vascular permeability results in the shift of extracellular fluid from the blood to the interstitial space which reduces blood flow and causes edema. These events can lead to hypertension, renal dysfunction, pulmonary dysfunction, hepatic dysfunction, and cerebral edema with cerebral dysfunction and convulsions. In clinical context, increased platelet and endothelial activation may be detected before symptoms appear. Other vasodilators, including prostacyclin, thromboxane A2, nitric oxide, and endothelins, are reduced in eclampsia and may lead to vasoconstriction. An eclamptic convulsion usually does not cause chronic brain damage unless intracranial haemorrhage occurs.

If a pregnant woman has already been diagnosed with pre eclampsia during the current pregnancy and then develops a seizure, she may be assigned a 'clinical diagnosis' of eclampsia without further workup. While seizures are most common in the third trimester, they may occur any time from 20 weeks of pregnancy until 6 weeks after birth. Because pre eclampsia and eclampsia are common conditions in women, eclampsia can be assumed to be the correct diagnosis until proven otherwise in pregnant or postpartum women who experience seizures. However, if a woman has a seizure and it is unknown whether or not they have pre eclampsia, testing can help make the diagnosis clear. Pre eclampsia is diagnosed when repeated blood pressure measurements are greater or equal to 140/90mmHg, in addition to any signs of organ dysfunction, including: proteinuria, thrombocytopenia, renal insufficiency, impaired liver function, pulmonary edema, cerebral symptoms, or abdominal pain.

One of the core features of pre eclampsia is the new onset of high blood pressure. Blood pressure is a measurement of two numbers: systolic blood pressure and diastolic blood pressure. A systolic blood pressure (the top number) of greater than 140 mmHg and/or a diastolic blood pressure (the bottom number) of greater than 90 mmHg is higher than the normal range. If the blood pressure is high on at least two separate occasions after the first 20 weeks of pregnancy and the woman has signs of organ dysfunction (e. g. proteinuria), then they meet the criteria for a diagnosis of pre eclampsia. Appropriate management of a woman with pre eclampsia generally involves the use of magnesium sulfate to prevent eclamptic seizures. In some cases, low dose aspirin has been shown to decrease the risk of pre eclampsia in women, especially when taken in the late first trimester. The study demonstrating the effectiveness of magnesium sulfate for the management of eclampsia was first published in 1955. Effective anticonvulsant serum levels range from 2.5 to 7.5 mEq/L, however the ideal dosing regime (dose, route of administration, timing of dosing) to prevent and treat eclampsia is not clear. With intravenous administration, the onset of anticonvulsant action is fast and lasts about 30 minutes. Following intramuscular administration the onset of action is about one hour and lasts for three to four hours. Magnesium is excreted solely by the kidneys at a rate proportional to the plasma concentration (concentration in the blood) and glomerular filtration (rate at which the blood is filtered through the kidneys). Even with therapeutic serum magnesium concentrations, recurrent convulsions may occur, and additional magnesium may be needed, but with close monitoring for respiratory, cardiac, and neurological depression. If magnesium administration with resultant high serum concentrations fails to control convulsions, the addition of other intravenous anticonvulsants may be used and intubation and mechanical ventilation may be initiated. It is important to avoid magnesium toxicity, including thoracic muscle paralysis, which could cause respiratory failure and death. Magnesium sulfate results in better outcomes than diazepam, phenytoin or a combination of chlorpromazine, promethazine, and pethidine.

Blood pressure is controlled to prevent stroke, which accounts for 15 to 20 percent of deaths in women with eclampsia. Common drugs used for blood pressure control during eclampsia are hydralazine or labetalol, due to their effectiveness, lack of negative effects on the fetus, and mechanism of action. Blood pressure management is indicated with a diastolic blood pressure above 105–110 mm Hg.

If the baby has not yet been delivered, steps need to be taken to stabilize the woman and deliver her speedily. This needs to be done even if the baby is immature, as the eclamptic condition is unsafe for both baby and mother. As eclampsia is a manifestation of a type of non infectious multiorgan dysfunction or failure, other organs (liver, kidney, lungs, cardiovascular system, and coagulation system) need to be assessed in preparation for a delivery (often a caesarean section), unless the woman is already in advanced labor. Regional anesthesia for caesarean section is contraindicated when a coagulopathy has developed. There is limited to no evidence in favor of a particular delivery method for women with eclampsia. Therefore, the delivery method of choice is an individualized decision.

Invasive hemodynamic monitoring may be elected in an eclamptic woman at risk for or with heart disease, kidney disease, refractory hypertension, pulmonary edema, or poor urine output. The term 'toxemia of pregnancy' is no longer recommended: placental toxins are not the cause of eclampsia occurrences, as previously believed.

In Downton Abbey, a historical drama television series, the character Lady Sybil dies (in series 3, episode 5) of eclampsia shortly after child birth. In Call the Midwife, a medical drama television series set in London in the 1950s and 1960s, the character (in series 1, episode 4) named Margaret Jones is struck with pre eclampsia, ultimately proceeding from a comatose condition to death. The term "toxemia" was also used for the condition, in the dialogue. In House M. D., a medical drama television series set in the U. S., Dr. Cuddy, the hospital director, adopts a baby whose teenage mother dies from eclampsia and had no other parental figures available. In The Lemon Drop Kid, the main character's wife dies of eclampsia shortly after giving birth to a boy. In Fringe, a science fiction series, the character Olivia (in the parallel universe) is diagnosed with a fictionalized version of the disorder, called "viral propagated eclampsia", which threatens her and her unborn child (series 3, episode 18).