Ambolia with amniotic fluid

Embolism with amniotic fluid (EOB) is a critical condition associated with the ingestion of the amniotic fluid and its components into the maternal bloodstream with the development of a severe anaphylactoid reaction with a symptomatic complex of shock of mixed genesis up to cardiac arrest, ODN and acute DIC syndrome.

Synonyms

Amniotic Fluid Embolism (AFE), anaphylactoid syndrome of pregnancy (anaphylactoid syndrome of pregnancy).

ICD-10 code

O88 Obstetrical embolism.

O88.1. Embolism with amniotic fluid.

Epidemiology

Epidemiology

According to various authors, the frequency of EOV is 3-5 per 100 thousand births. Mortality varies from 26.4% to 86%, depending on the diagnostic criteria used - only pathomorphological or clinical and pathomorphological. There was no racial or ethnic predisposition to EOV. The transferred EOB does not affect the likelihood and frequency of occurrence of this in subsequent pregnancies.

[1], [2], [3], [4], [5], [6], [7], [8], [9], [10]

Causes Ambolia with amniotic fluid

Causes of embolism with amniotic fluid

Embolism by amniotic fluid is the least predictable complication in obstetrics. To hit amniotic fluid in the maternal blood stream, certain prerequisites for premature detachment of the normal and pathologically located placenta, trauma, polyhydramnios, multiple birth, stimulation of labor by oxytocin, discoordination of labor, caesarean section are necessary. There are numerous reports of cases of EOV in abortions at late stages and with induced miscarriages in the II trimester of pregnancy. The above factors create the conditions for the occurrence of a situation in which the amniotic pressure can become significantly higher than the venous pressure in the vessels of the uterus. Possible ways of penetration of amniotic fluid into the mother's bloodstream are presented below:

• Through intervorsed space (with premature detachment of the normally located placenta).
• Transplacental (through the defects of the placenta and pathologically altered areas of the placenta).
• Through the vessels of any part of the uterus with a violation of their integrity (ruptures of the uterus, cesarean section operation).
• Transcervical (through the vessels of the neck when it ruptures).

[11], [12], [13], [14], [15], [16], [17]

Pathogenesis

How does embolism develop with amniotic fluid?

Normally, a pregnant woman in the uterus contains 0.5-1.5 liters of amniotic fluid - a suspension containing both the products of the fetus and the secretion products of the placental membranes. Of the particles that make up the suspension, the most significant are lanugo, birth fetus lubrication, epithelial flakes, meconium with bile pigments, intestinal mucin and trophoblasts. In the liquid part, amniotic fluid contains a huge amount of biologically active substances arachidonic acid, thromboplastin, tissue factor III, leukotrienes C4 and D4, interleukin-1, TNF, thromboxane A2, phospholipase A2, prostaglandins, profibrinolysin, endothelium, collagen and surfactant. In addition, proteins, fats, lipids, carbohydrates, potassium, calcium, sodium, microelements, urea, hormones (folliculin, gonadotropic hormone, etc.), lysozyme, lactic and other acids, enzymes, substances contributing to uterine contraction (oxytocin ), group antibodies corresponding to the fetal blood group.

Embolism with amniotic fluid can manifest itself even in the early postpartum period - it was reported about the development of the clinical picture of EOV in 10-20 and even 32 hours after birth and cesarean section. In addition, the severity of clinical manifestations often does not correspond to the degree of pulmonary vascular lesions. In connection with this, it is now common to link the clinical manifestations of EOV with the development of a severe systemic anaphylactoid reaction in response to the entry into the mother's bloodstream of biologically active substances of the amniotic fluid. With intrauterine fetal infection, amniotic fluid can be infected, and their entry into the mother's bloodstream causes an even more severe anaphylactoid reaction. Entry into the mother bloodstream with amniotic fluid a significant amount of biologically active substances listed above, causes degranulation of mast cells, the release of histamine and endothelin, leukotrienes and FIO. Such a powerful mediator explosion can lead to the development of bronchospasm, spasm of pulmonary vessels, right ventricular, and then left ventricular failure with the development of AL and shock of mixed genesis. In especially severe cases, cardiac arrest is described.

After 1-1.5 hours after the episode of EOV acute coagulopathy with massive bleeding occurs, which is associated with the receipt of tissue thromboplastin and the action of mediators. The clinical picture follows the scenario of lightning-fast ICE syndrome with poorly docked massive bleeding, accompanied by critical blood loss with the outcome of the PON syndrome.

As mentioned above, amniotic fluid embolism is characterized by massive profuse bleeding caused by severe DIC-syndrome with hypofibrinogenemia, thrombocytopenia, sharply activated fibrinolysis and exhaustion of all clotting factors. In the development of thrombohemorrhagic complications associated with EOV, the main role is played by the amount of amniotic fluid that has entered the maternal blood flow, as well as the degree of immune reactivity of the woman.

DIC-syndrome with embolism by amniotic fluid proceeds in two stages - a very short-term stage of hypercoagulation and the stage of hypocoagulation and deficiency of clotting factors. The phase of hypercoagulability is caused by the ingress of the tissue thromboplastin into the mother's bloodstream along with the amniotic fluid, which triggers an external coagulation mechanism. This phase is fast-paced and very rarely detected in the laboratory.

Along with thromboplastin, the amniotic fluid contains a factor that accelerates the retraction of the blood clot. As a result of consumption, coagulation factors and thrombocytopenia deplete. Activation of fibrinolysis occurs and the process passes to the stage of hypocoagulation, characterized by massive bleeding. According to different data, the fetal death in a severe clinical picture of EOV in childbirth is between 50 and 80% Of these, a large part (90%) is killed intranatally. The main cause of death is intrauterine asphyxia.

Often, the DIC syndrome may be the only manifestation of EOV. It should be noted that the basis of most unexplained hemorrhages in obstetrics, apparently, is the etiological factor of EOV.

Symptoms Ambolia with amniotic fluid

Symptoms of embolism with amniotic fluid

Symptoms of embolism by amniotic fluid are very variable and depend on the total number of amniotic fluid in the mother's bloodstream, the rate of their entry and the degree of reactivity of the woman's body

As a rule, the onset is sudden and acute. On the background of intensive labor activity, excitation, labored breathing, cyanosis of the face and limbs suddenly occur. Short-term chest pain and fear of death are possible. Often there is chills and fever to 38.5-39.0 ° C , which indicates a pyrogenic reaction to the parenteral intake of foreign protein

Breathing rapid (up to 20-25 per minute), shortness of breath is possible. Auscultatory breathing is hard, single scattered dry wheezes, which quickly disappear. Hemodynamics is characterized by rapidly increasing tachycardia, lowering blood pressure. In severe cases, shock can occur with loss of consciousness and coma.

The clinical picture described above is characteristic of massive, one-stage embolism with amniotic fluid in labor. If the picture of cardiopulmonary shock is persistent, hard-to-purchase, it is necessary to conduct differential diagnosis with thromboembolism of small branches of the pulmonary artery, which often occur in pregnant women with a pregnant pregnancy.

Differential diagnosis of embolism by amniotic fluid and thromboembolism of small branches of the pulmonary artery

Symptoms	Ambolia with amniotic fluid	Tela of small branches
Tachycardia	Short-term	Prolonged
Reduction of saturation	Short-term	Prolonged
Dyspnea	Short-term	Prolonged
Increased airway pressure	Short-term	Prolonged
Clotting time	Elongated	Shortened
Electrocardiographic signs of congestion of the right heart	Short-term	Prolonged
Increase CVP	Short-term	Prolonged

If amniotic fluid enters the mother's bloodstream in small fractions at the height of the fights, such a pronounced and sudden clinical picture does not arise, cardiopulmonary shock does not develop, and embolism with amniotic fluid manifests itself immediately with coagulopathic bleeding.

Embolism with amniotic fluid can also occur during cesarean delivery, at the time of fetal extraction. If operative delivery is performed under conditions of regional anesthesia, the clinical picture of EOV will be similar to that during labor. In addition, an indirect evidence of EOV can be a short-term reduction of saturation to 85-80%, and in severe cases - up to 70%. In the operation of cesarean section under endotracheal anesthesia, the manifestations of EOV will be expressed in the reduction of saturation, the appearance of dry wheezing in the lungs over the lesion and the increase in pressure in the respiratory circuit of the anesthesia apparatus by inhalation up to 30-35 mm. Water. Art. In the presence of central venous access, it is possible to fix the increase in CVP.

All these manifestations can be of a short-term nature and remain out of sight of the doctor. The more unexpected will be the emergence of lightning DVS-syndrome with massive profuse bleeding in the early postoperative period.

Diagnostics Ambolia with amniotic fluid

Diagnosis of embolism with amniotic fluid

Diagnosis is based mainly on the clinical picture and additional research methods:

• Study of the coagulating and anticoagulant system of blood determination of the time of activation of blood coagulation, degree and time of lysis of the clot. To obtain more accurate information on the state of primary hemostasis and fibrinolysis, a coagulogram study is needed.
• Electrocardiographic signs of an overload of the right heart (deviation of the electric axis of the heart to the right more than 90 °, an increase in the size of the P wave in I, III standard leads is more than 2 mm, a decrease in the amplitude of the T wave in standard and right thoracic leads).
• Radiography of the chest. In the lungs, signs of interstitial edema can be observed for a short time.

[18], [19], [20], [21]

Treatment Ambolia with amniotic fluid

Treatment of embolism with amniotic fluid

Specific treatment of embolism with amniotic fluid is not present. However, there are data on the successful use of large doses of glucocorticoids (prednisolone) after the clinical manifestation of EOV (before the development of DIC syndrome) in order to block anaphylactoid reaction according to the following scheme: intravenously, 360-420 mg of prednisolone is injected intravenously within 45-50 min after the episode of EOV. After 10-15 minutes 280-360 mg of prednisolone are recomputed from the total dose calculation - 700-800 mg for the manifestation of the immunosuppressive effect of prednisolone. In the next two days, a supporting course is carried out (30 mg 4 times on the first day and 30 mg 2 times on the second day intravenously).

Pregnant women need urgent operative delivery.

With prolonged non-recoverable respiratory disorders, ventilation with PEEP is indicated.

If treatment of embolism with amniotic fluid is not started at the time of acute onset of symptoms, it is reduced, mainly, to the reduction of the DIC syndrome and its consequences.

Given that in the puerperium in the presence of DIC syndrome bleeding from the placental site is possible even with a fully contracted uterus, surgical hemostasis, as a rule, involves ligation of the iliac arteries and, in the absence of effect, extirpation of the uterus.

Drug therapy of DIC-syndrome and massive bleeding with EOV does not differ from that in general practice.