Eclampsia
Encyclopedia
Eclampsia an acute and life-threatening complication of pregnancy
, is characterized by the appearance of tonic-clonic seizure
s, usually in a patient who had developed pre-eclampsia
. (Preeclampsia and eclampsia are collectively called Hypertensive disorder of pregnancy and toxemia of pregnancy.)
Eclampsia includes seizures and coma that happen during pregnancy but are not due to preexisting or organic brain disorders.
and proteinuria
prior to the onset of the hallmark of eclampsia, the eclamptic convulsion. Other cerebral signs may precede the convulsion such as nausea, vomiting, headaches, and cortical blindness. In addition, with the advancement of the pathophysiological process, other organ symptoms may be present including abdominal pain, liver failure, signs of the HELLP syndrome
, pulmonary edema
, and oliguria
. The fetus may already have been compromised by intrauterine growth retardation, and with the toxemic changes during eclampsia may suffer fetal distress
. Placental bleeding and placental abruption
may occur.
; this stage lasts about one minute. The final stage is a more or less prolonged coma
. When the patient awakens, she is unlikely to remember the event. In some rare cases there are no convulsions and the patient falls directly into a coma. Some patients may experience temporary blindness upon waking from the coma .
During a seizure, the fetus may experience bradycardia
.
s is involved. Further, women with preexisting vascular diseases (hypertension
, diabetes, and nephropathy
) or thrombophilic diseases such as the antiphospholipid syndrome
are at higher risk to develop preeclampsia and eclampsia. Having a large placenta (multiple gestation, hydatiform mole) also predisposes women to toxemia. Further, there is a genetic component; patients whose mother or sister had the condition are at higher risk. Patients who've experienced eclampsia are at increased risk for preeclampsia/eclampsia in a later pregnancy.
and is resolved by its removal. Dr.Mayank suggested that placental hypoperfusion is a key feature of the process. It is accompanied by increased sensitivity of the maternal vasculature to pressor agents leading to vasospasm and hypoperfusion of multiple organs. Further, an activation of the coagulation
cascade leads to microthrombi
formation and aggravates the perfusion problem. Loss of plasma from the vascular tree with the resulting edema
additionally compromises the situation. These events lead to signs and symptoms of toxemia including hypertension, renal, pulmonary, and hepatic dysfunction, and - in eclampsia specifically - cerebral dysfunction. Preclinical markers of the disease process are signs of increased platelet and endothelial activation
Placental hypoperfusion is linked to abnormal modeling of the fetal-maternal interface that may be immunologically mediated The invasion of the trophoblast appears to be incomplete.
Adrenomedullin
, a potent vasodilator, is produced in diminished quantities by the placenta in preeclampsia (and thus eclampsia). Other vasoactive agents are at play including prostacyclin
, thromboxane
A2, nitric oxide
, and endothelin
s leading to vasoconstriction. Many studies have suggested the importance of a woman's immunological tolerance to her baby's father, whose genes are present in the young fetus and its placenta and which may pose a challenge to her immune system.
Eclampsia is seen as a form of hypertensive encephalopathy
in the context of those pathological events that lead to preeclampsia. It is thought that cerebral vascular resistance
is reduced, leading to increased blood flow to the brain. In addition to abnormal function of the endothelium
, this leads to cerebral edema
. Typically an eclamptic seizure will not lead to lasting brain damage; however, intracranial hemorrhage may occur.
Investigations
CBC,
RFT (Renal Function test),
LFT (Liver Function test),
coagulation profile,
plasma rate concentration,
24 hour urine analysis,
ultrasound
convulsion
is usually done using magnesium sulfate
. The idea to use Mg2+ for the management of eclamptogenic toxemia
dates from before 1955 when it was tested and published—the serum Mg2+ therapeutic range for the prevention of the eclampsic uterine contractions is still considered: 4.0-7.0 mEq/L. As per Lu and Nightingale, serum Mg2+ concentrations associated with maternal toxicity (also neonate depression or hypotonia and low Apgar scores) are:
Even with therapeutic serum Mg2+ concentrations, recurrent convulsions and seizures may occur—patients would receive additional MgSO4 but under close monitoring for respiratory, cardiac and neurological depression: 4–6 g loading dose in 100 mL IV fluid over 15–20 min., then 2 g/hr as a continuous infusion. If high Mg2+ concentrations fail to take effect, IV anticonvulsants will ease patient intubation and mechanical ventilation as adjuvants against the eclamptic convulsions (plus the hypermagnesemic thoracic muscle paralysis
).
Recently the long-term implications of the magnesium sulfate
therapies were evaluated by the international MAGPIE study.
has developed.
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
, is characterized by the appearance of tonic-clonic seizure
Tonic-clonic seizure
Tonic–clonic seizures are a type of generalized seizure that affects the entire brain...
s, usually in a patient who had developed pre-eclampsia
Pre-eclampsia
Pre-eclampsia or preeclampsia is a medical condition in which hypertension arises in pregnancy in association with significant amounts of protein in the urine....
. (Preeclampsia and eclampsia are collectively called Hypertensive disorder of pregnancy and toxemia of pregnancy.)
Eclampsia includes seizures and coma that happen during pregnancy but are not due to preexisting or organic brain disorders.
Signs and symptoms
Typically patients show signs of pregnancy-induced hypertensionPregnancy-induced hypertension
Gestational hypertension or pregnancy-induced hypertension is defined as the development of new arterial hypertension in a pregnant woman after 20 weeks gestation without the presence of protein in the urine.-Conditions:...
and proteinuria
Proteinuria
Proteinuria means the presence of anexcess of serum proteins in the urine. The protein in the urine often causes the urine to become foamy, although foamy urine may also be caused by bilirubin in the urine , retrograde ejaculation, pneumaturia due to a fistula, or drugs such as pyridium.- Causes...
prior to the onset of the hallmark of eclampsia, the eclamptic convulsion. Other cerebral signs may precede the convulsion such as nausea, vomiting, headaches, and cortical blindness. In addition, with the advancement of the pathophysiological process, other organ symptoms may be present including abdominal pain, liver failure, signs of the HELLP syndrome
HELLP syndrome
HELLP syndrome is a life-threatening obstetric complication usually considered to be a variant of pre-eclampsia. Both conditions usually occur during the later stages of pregnancy, or sometimes after childbirth.HELLP is an abbreviation of the main findings:...
, pulmonary edema
Pulmonary edema
Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
, and oliguria
Oliguria
Oliguria is the low output of urine, It is clinically classified as an output below 300-500ml/day. The decreased output of urine may be a sign of dehydration, renal failure, hypovolemic shock, HHNS Hyperosmolar Hyperglycemic Nonketotic Syndrome, multiple organ dysfunction syndrome, urinary...
. The fetus may already have been compromised by intrauterine growth retardation, and with the toxemic changes during eclampsia may suffer fetal distress
Fetal distress
In medicine , the term fetal distress refers to the presence of signs in a pregnant woman—before or during childbirth—that suggest that the fetus may not be well...
. Placental bleeding and placental abruption
Placental abruption
Placental abruption is a complication of pregnancy, wherein the placental lining has separated from the uterus of the mother. It is the most common pathological cause of late pregnancy bleeding. In humans, it refers to the abnormal separation after 20 weeks of gestation and prior to birth...
may occur.
The eclamptic seizure
Chesley distinguishes these four stages of an eclamptic event: In the stage of invasion facial twitching can be observed around the mouth. In the stage of contraction tonic contractions render the body rigid; this stage may last about 15 to 20 seconds. The next stage is the stage of convulsion when involuntary and forceful muscular movements occur, the tongue may be bitten, foam appears at the mouth. The patient stops breathing and becomes cyanoticCyanosis
Cyanosis is the appearance of a blue or purple coloration of the skin or mucous membranes due to the tissues near the skin surface being low on oxygen. The onset of cyanosis is 2.5 g/dL of deoxyhemoglobin. The bluish color is more readily apparent in those with high hemoglobin counts than it is...
; this stage lasts about one minute. The final stage is a more or less prolonged coma
Coma
In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
. When the patient awakens, she is unlikely to remember the event. In some rare cases there are no convulsions and the patient falls directly into a coma. Some patients may experience temporary blindness upon waking from the coma .
During a seizure, the fetus may experience bradycardia
Bradycardia
Bradycardia , in the context of adult medicine, is the resting heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min. It may cause cardiac arrest in some patients, because those with bradycardia may not be pumping enough oxygen to their heart...
.
Risk factors
Eclampsia, like preeclampsia, tends to occur more commonly in first pregnancies and young mothers where it is thought that novel exposure to paternal antigenAntigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
s is involved. Further, women with preexisting vascular diseases (hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, diabetes, and nephropathy
Nephropathy
Nephropathy refers to damage to or disease of the kidney. An older term for this is nephrosis.-Causes:Causes of nephropathy include administration of analgesics, xanthine oxidase deficiency, and long-term exposure to lead or its salts...
) or thrombophilic diseases such as the antiphospholipid syndrome
Antiphospholipid syndrome
Antiphospholipid syndrome or antiphospholipid antibody syndrome , often also Hughes syndrome, is an autoimmune, hypercoagulable state caused by antibodies against cell-membrane phospholipids that provokes blood clots in both arteries and veins as well as pregnancy-related complications such as...
are at higher risk to develop preeclampsia and eclampsia. Having a large placenta (multiple gestation, hydatiform mole) also predisposes women to toxemia. Further, there is a genetic component; patients whose mother or sister had the condition are at higher risk. Patients who've experienced eclampsia are at increased risk for preeclampsia/eclampsia in a later pregnancy.
Pathophysiology
While multiple theories have been proposed to explain preeclampsia and eclampsia, it occurs only in the presence of a placentaPlacenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
and is resolved by its removal. Dr.Mayank suggested that placental hypoperfusion is a key feature of the process. It is accompanied by increased sensitivity of the maternal vasculature to pressor agents leading to vasospasm and hypoperfusion of multiple organs. Further, an activation of the coagulation
Coagulation
Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...
cascade leads to microthrombi
Thrombus
A thrombus , or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system...
formation and aggravates the perfusion problem. Loss of plasma from the vascular tree with the resulting edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
additionally compromises the situation. These events lead to signs and symptoms of toxemia including hypertension, renal, pulmonary, and hepatic dysfunction, and - in eclampsia specifically - cerebral dysfunction. Preclinical markers of the disease process are signs of increased platelet and endothelial activation
Placental hypoperfusion is linked to abnormal modeling of the fetal-maternal interface that may be immunologically mediated The invasion of the trophoblast appears to be incomplete.
Adrenomedullin
Adrenomedullin
Adrenomedullin is a peptide associated with pheochromocytoma- a tumour arising from adrenal medulla. It was discovered in 1993.Adrenomedullin is a ubiquitously expressed peptide initially isolated from phaechromyctoma in 1993...
, a potent vasodilator, is produced in diminished quantities by the placenta in preeclampsia (and thus eclampsia). Other vasoactive agents are at play including prostacyclin
Prostacyclin
Prostacyclin is a member of the family of lipid molecules known as eicosanoids.As a drug, it is also known as "epoprostenol". The terms are sometimes used interchangeably.-History:...
, thromboxane
Thromboxane
Thromboxane is a member of the family of lipids known as eicosanoids. The two major thromboxanes are thromboxane A2 and thromboxane B2. The distinguishing feature of thromboxanes is a 6-membered ether-containing ring....
A2, nitric oxide
Nitric oxide
Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...
, and endothelin
Endothelin
Endothelins are proteins that constrict blood vessels and raise blood pressure. They are normally kept in balance by other mechanisms, but when they are over-expressed, they contribute to high blood pressure and heart disease....
s leading to vasoconstriction. Many studies have suggested the importance of a woman's immunological tolerance to her baby's father, whose genes are present in the young fetus and its placenta and which may pose a challenge to her immune system.
Eclampsia is seen as a form of hypertensive encephalopathy
Hypertensive encephalopathy
Hypertensive encephalopathy is a neurological dysfunction induced by malignant hypertension. The term "hypertensive encephalopathy" was introduced to describe this type of encephalopathy by Oppenheimer and Fishberg in 1928. It describes cerebral conditions, typically reversible, caused by sudden...
in the context of those pathological events that lead to preeclampsia. It is thought that cerebral vascular resistance
Vascular resistance
Vascular resistance is a term used to define the resistance to flow that must be overcome to push blood through the circulatory system. The resistance offered by the peripheral circulation is known as the systemic vascular resistance , while the resistance offered by the vasculature of the lungs...
is reduced, leading to increased blood flow to the brain. In addition to abnormal function of the endothelium
Endothelium
The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells. Endothelial cells line the entire circulatory system, from the heart...
, this leads to cerebral edema
Cerebral edema
Cerebral edema or cerebral œdema is an excess accumulation of water in the intracellular or extracellular spaces of the brain.-Vasogenic:Due to a breakdown of tight endothelial junctions which make up the blood-brain barrier...
. Typically an eclamptic seizure will not lead to lasting brain damage; however, intracranial hemorrhage may occur.
Diagnosis
Seizures during pregnancy that are unrelated to preeclampsia need to be distinguished from eclampsia. Such disorders include seizure disorders as well as brain tumor, aneurysm of the brain, medication- or drug-related seizures. Usually the presence of the signs of severe preeclampsia that precede and accompany eclampsia facilitate the diagnosis.Investigations
CBC,
RFT (Renal Function test),
LFT (Liver Function test),
coagulation profile,
plasma rate concentration,
24 hour urine analysis,
ultrasound
Prevention
Detection and management of preeclampsia is critical to reduce the risk of eclampsia. Appropriate management of patients with preeclampsia generally involves the use of magnesium sulfate as an agent to prevent convulsions, and thus preventing eclampsia.Treatment
The treatment of eclampsia requires prompt intervention and aims to prevent further convulsions, control the elevated blood pressure and deliver the fetus.Prevention of convulsions
Prevention of seizureSeizure
An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
convulsion
Convulsion
A convulsion is a medical condition where body muscles contract and relax rapidly and repeatedly, resulting in an uncontrolled shaking of the body. Because a convulsion is often a symptom of an epileptic seizure, the term convulsion is sometimes used as a synonym for seizure...
is usually done using magnesium sulfate
Magnesium sulfate
Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...
. The idea to use Mg2+ for the management of eclamptogenic toxemia
Toxemia
Toxemia may refer to:* A generic term for the presence of toxins in the blood, see Bacteremia* An outdated medical term for Pre-eclampsia...
dates from before 1955 when it was tested and published—the serum Mg2+ therapeutic range for the prevention of the eclampsic uterine contractions is still considered: 4.0-7.0 mEq/L. As per Lu and Nightingale, serum Mg2+ concentrations associated with maternal toxicity (also neonate depression or hypotonia and low Apgar scores) are:
- 7.0–10.0 mEq/L - loss of patellar reflex
- 10.0–13.0 mEq/L - respiratory depression
- 15.0–25.0 mEq/L - altered atrioventricular conduction and (further) complete heart blockHeart blockA heart block can be a blockage at any level of the electrical conduction system of the heart .* Blocks that occur within the sinoatrial node are described as SA nodal blocks....
- >25.0 mEq/L - cardiac arrestCardiac arrestCardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
Even with therapeutic serum Mg2+ concentrations, recurrent convulsions and seizures may occur—patients would receive additional MgSO4 but under close monitoring for respiratory, cardiac and neurological depression: 4–6 g loading dose in 100 mL IV fluid over 15–20 min., then 2 g/hr as a continuous infusion. If high Mg2+ concentrations fail to take effect, IV anticonvulsants will ease patient intubation and mechanical ventilation as adjuvants against the eclamptic convulsions (plus the hypermagnesemic thoracic muscle paralysis
Paralysis
Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...
).
Recently the long-term implications of the magnesium sulfate
Magnesium sulfate
Magnesium sulfate is a chemical compound containing magnesium, sulfur and oxygen, with the formula MgSO4. It is often encountered as the heptahydrate epsomite , commonly called Epsom salt, from the town of Epsom in Surrey, England, where the salt was distilled from the springs that arise where the...
therapies were evaluated by the international MAGPIE study.
Antihypertensive management
Antihypertensive management at this stage in pregnancy may consist of hydralazine (5–10 mg IV every 15-20 min until desired response is achieved) or labetalol (20 mg bolus iv followed by 40 mg if necessary in 10 minutes; then 80 mg every 10 up to maximum of 220 mg).Delivery
If the baby has not yet been delivered, steps need to be taken to stabilize the patient and deliver her speedily. This needs to be done even if the fetus is immature as the eclamptic condition is unsafe for fetus and mother. As eclampsia is a manifestation of a multiorgan failure, other organs (liver, kidney, clotting, lungs, and cardiovascular system) need to be assessed in preparation for a delivery, often a cesarean section, unless the patient is already in advanced labor. Regional anesthesia for cesarean section is contraindicated when a coagulopathyCoagulopathy
Coagulopathy is a condition in which the blood’s ability to clot is impaired. This condition can cause prolonged or excessive bleeding, which may occur spontaneously or following an injury or medical and dental procedures.The normal clotting process depends on the interplay of various proteins in...
has developed.