Amniotic Fluid Embolism(AFE)羊水栓塞
Amniotic Fluid Embolism (AFE) 羊水栓塞
Definition of AFEAFE is a rare obstetric emergency in whichamnioticfluid,fetal cells,hair,or otherdebris enter the maternalcirculation,causing cardiorespiratorycollapse
Definition of AFE ◼ AFE is a rare obstetric emergency in which amniotic fluid, fetal cells, hair, or other debris enter the maternal circulation, causing cardiorespiratory collapse
epidemiologyThe incidence of clinically detectable AFE is lowestimatedtobe1in 20,000to 80,000live births.Maternal mortality approaches 80%.5%-10%of maternal mortality in theUnited StatesisduetoAFEOf patientswithAFE,50%die withinthefirsthourof onset of symptoms.Of survivors of the initial cardiorespiratory phase,50% develop a coagulopathyNeonatal survivalis70%
epidemiology ◼ The incidence of clinically detectable AFE is low ◼ estimated to be 1 in 20,000 to 80,000 live births. ◼ Maternal mortality approaches 80%. ◼ 5%- 10% of maternal mortality in the United States is due to AFE. ◼ Of patients with AFE, 50% die within the first hour of onset of symptoms. ◼ Of survivors of the initial cardiorespiratory phase, 50% develop a coagulopathy. ◼ Neonatal survival is 70%
Current data suggest that the process ismore similar to anaphylaxis than toembolismterm anaphylactoid syndrome of pregnancyhasbeensuggested
◼ Current data suggest that the process is more similar to anaphylaxis than to embolism ◼ term anaphylactoid syndrome of pregnancy has been suggested
Major causes and factorsoccurs in obstetric terms or during labormultiparous woman with a large babya short tumultuous laboruse of uterine stimulantsoccurred during abortionamnioinfusionAmniocentesiscaesarian sectionplacenta accretaruptured uterus
Major causes and factors ◼ occurs in obstetric terms or during labor ◼ multiparous woman with a large baby ◼ a short tumultuous labor ◼ use of uterine stimulants ◼ occurred during abortion ◼ amnioinfusion ◼ Amniocentesis ◼ caesarian section ◼ placenta accreta ◼ ruptured uterus
pathologyAmnioticfluidand fetal cellsenterthematernal circulation, possibly triggering ananaphylactic reaction to fetal antigens.(1)Clinical symptomsresultfrommast celldegranulation with the release of histamineandtryptase,(2) Clinical symptoms result from activationof the complement pathway
pathology ◼ Amniotic fluid and fetal cells enter the maternal circulation, possibly triggering an anaphylactic reaction to fetal antigens. ◼ (1) Clinical symptoms result from mast cell degranulation with the release of histamine and tryptase, ◼ (2) Clinical symptoms result from activation of the complement pathway
.Progression usuallyoccurs in2phasesphase I:pulmonary artery vasospasm withpulmonary hypertension and elevated rightventricular pressure cause hypoxia.Hypoxia causes myocardial capillarydamage and pulmonary capillary damage,leftheartfailure,and acuterespiratorydistresssyndrome
◼ . Progression usually occurs in 2 phases. ◼ phase I: ◼ pulmonary artery vasospasm with pulmonary hypertension and elevated right ventricular pressure cause hypoxia. ◼ Hypoxia causes myocardial capillary damage and pulmonary capillary damage, left heart failure, and acute respiratory distress syndrome. ◼
Women who survivethese events may enterphase II. This is a hemorrhagic phase characterizedby massive hemorrhage with uterine atonyandDIChowever,fatal consumptive coagulopathymay be the initial presentation
◼ Women who survive these events may enter phase II. ◼ This is a hemorrhagic phase characterized by massive hemorrhage with uterine atony and DIC ◼ however, fatal consumptive coagulopathy may be the initial presentation
PresentationThe clinicalpresentation of AFE isgenerallydramaticin the late stages , acutely dyspnea andhypotension with rapid progression tocardiopulmonaryarrestIn 40% of cases, followed by some degree ofconsumptive coagulopathy
Presentation ◼ The clinical presentation of AFE is generally dramatic ◼ in the late stages , acutely dyspnea and hypotension with rapid progression to cardiopulmonary arrest ◼ In 40% of cases, followed by some degree of consumptive coagulopathy
Hypotension: Blood pressure may dropsignificantly with loss of diastolic measurement.Dyspnea: Labored breathing and tachypnea mayoccur.Seizure: The patient may experience tonic-clonicseizures. Cough:This is usually a manifestation of dyspneaCyanosis:As hypoxia/hypoxemia progresses,circumoral and peripheral cyanosis and changes inmucous membranes may manifest
◼ Hypotension: Blood pressure may drop significantly with loss of diastolic measurement. ◼ Dyspnea: Labored breathing and tachypnea may occur. ◼ Seizure: The patient may experience tonic-clonic seizures. ◼ Cough: This is usually a manifestation of dyspnea. ◼ Cyanosis: As hypoxia/hypoxemia progresses, circumoral and peripheral cyanosis and changes in mucous membranes may manifest