Amniotic Fluid Embolism
(AFE)
羊水栓塞
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,
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 is
more similar to anaphylaxis than to
embolism
? term anaphylactoid syndrome of pregnancy
has been suggested
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
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 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 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,
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 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,
? Pulmonary edema,identified on chest
radiograph,
? Cardiac arrest
? Uterine atony,
? Fetal bradycardia,In response to the hypoxic
? Uterine atony usually results in excessive
bleeding after delivery,
Differentials
? Anaphylaxis
? Aortic Dissection(动脉瘤）
? Cholesterol Embolism
? Myocardial Infarction
? Pulmonary Embolism
? Septic Shock
Lab Studies
? Arterial blood gas (ABG) levels,Expect
changes consistent with ypoxia/hypoxemia
,
? Decreased pH levels
? Decreased PO2 levels
? Increased PCO2 levels
? Base excess increased
? Hemoglobin and hematocrit
/Thrombocytopenia is rare/ platelets /
? Prothrombin time (PT)
? Activated partial thromboplastin time (aPTT)
? fibrinogen (Fg)
? Blood type and screen
? Chest radiograph
? A 12-lead ECG
Treatment
? Administer oxygen to maintain normal
saturation,
? Initiate cardiopulmonary resuscitation (CPR)
if the patient arrests,
? Treat hypotension with crystalloid and blood
products,
? Consider pulmonary artery catheterization in
patients who are hemodynamically unstable,
? Treat coagulopathy with fresh frozen
plasma(FFP) for a prolonged aPTT,
cryoprecipitate for a fibrinogen level less
than 100 mg/dL,and transfuse platelets for
platelet counts less than 20,000/mL,
? Continuously monitor the fetus,
? Delivery quickly (forceps)
? Surgical Care,Perform emergent cesarean
delivery in arrested mothers who are
unresponsive to resuscitation,
? hemorrhage was controlled with bilateral
uterine artery embolization,
Uterine Rupture
? is one of the most feared complications of
pregnancy
? the fetus,placenta,and a lot of blood
extruding into the mother's abdomen
? from a weak spot in the uterine wall or
uterus scar
epidemiology
? the risk of uterine rupture was 1 per 625 women
who chose repeat cesarean without labor,
? 1 per 192 women who went into labor and tried for
VBAC,
? 1 per 129 for those who had their labor induced
without prostaglandins (usually with Pitocin)
? 1 per 41 when prostaglandin medications were
used for induction
? When the uterus did rupture,1 in 18 babies died,
and 1 in 23 of the women required a hysterectomy,
Causes and factors
? previous surgery on the uterus
? Prior classical cesareans,where the incision
is near the top of the uterus
? prior removal of fibroid tumors
? any other uterine surgery that went through
the full depth of the muscular portion of the
uterus,
? multiple (three or more) prior low transverse
cesareans
? having had more than five full-term
pregnancies
? having an overdistended uterus (as with
twins or other multiples),
? abnormal positions of the baby such as
transverse lie
? the use of Pitocin and other labor-inducing
medications like prostaglandins
presentation
? Most uterine ruptures occur without
symptoms and do not cause problems for
the mother or fetus,
? This mild type is only noticed when surgery
is required for other reasons,
? In the most severe form,the laceration is
large or cuts across the uterine blood vessels
? the mother may hemorrhage and require a
blood transfusion
? the uterus may not be repairable and must
be surgically removed (hysterectomy)
? Many women will be advised not to get
pregnant again,due to the risk of repeated
rupture
? the baby may not survive
? the mother's life cannot be saved
Signs of uterine rupture
? severe,localized pain
? abnormalities of the fetal heart rate
? vaginal bleeding
? the vaginal examination may show that the
baby is not as low in the birth canal as he
had been earlier,
Preventing and Treatment
? Some uterine ruptures occur before labor and are
considered unpreventable,
? Sudden severe abdominal pain in later pregnancy
should be reported
? Women with risk factors ( prior classical cesareans,
deep fibroid excisions,and other major uterine
surgeries )should not attempt labor
? should be scheduled for cesarean usually between
36 and 39 weeks' gestation,
? If trying for vaginal birth after low transverse
cesarean(VBAC),fetal monitoring is important
? When uterine rupture is diagnosed during
labor,an emergency cesarean is performed,
? Usually the baby's life can be saved,
(AFE)
羊水栓塞
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,
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 is
more similar to anaphylaxis than to
embolism
? term anaphylactoid syndrome of pregnancy
has been suggested
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
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 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 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,
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 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,
? Pulmonary edema,identified on chest
radiograph,
? Cardiac arrest
? Uterine atony,
? Fetal bradycardia,In response to the hypoxic
? Uterine atony usually results in excessive
bleeding after delivery,
Differentials
? Anaphylaxis
? Aortic Dissection(动脉瘤）
? Cholesterol Embolism
? Myocardial Infarction
? Pulmonary Embolism
? Septic Shock
Lab Studies
? Arterial blood gas (ABG) levels,Expect
changes consistent with ypoxia/hypoxemia
,
? Decreased pH levels
? Decreased PO2 levels
? Increased PCO2 levels
? Base excess increased
? Hemoglobin and hematocrit
/Thrombocytopenia is rare/ platelets /
? Prothrombin time (PT)
? Activated partial thromboplastin time (aPTT)
? fibrinogen (Fg)
? Blood type and screen
? Chest radiograph
? A 12-lead ECG
Treatment
? Administer oxygen to maintain normal
saturation,
? Initiate cardiopulmonary resuscitation (CPR)
if the patient arrests,
? Treat hypotension with crystalloid and blood
products,
? Consider pulmonary artery catheterization in
patients who are hemodynamically unstable,
? Treat coagulopathy with fresh frozen
plasma(FFP) for a prolonged aPTT,
cryoprecipitate for a fibrinogen level less
than 100 mg/dL,and transfuse platelets for
platelet counts less than 20,000/mL,
? Continuously monitor the fetus,
? Delivery quickly (forceps)
? Surgical Care,Perform emergent cesarean
delivery in arrested mothers who are
unresponsive to resuscitation,
? hemorrhage was controlled with bilateral
uterine artery embolization,
Uterine Rupture
? is one of the most feared complications of
pregnancy
? the fetus,placenta,and a lot of blood
extruding into the mother's abdomen
? from a weak spot in the uterine wall or
uterus scar
epidemiology
? the risk of uterine rupture was 1 per 625 women
who chose repeat cesarean without labor,
? 1 per 192 women who went into labor and tried for
VBAC,
? 1 per 129 for those who had their labor induced
without prostaglandins (usually with Pitocin)
? 1 per 41 when prostaglandin medications were
used for induction
? When the uterus did rupture,1 in 18 babies died,
and 1 in 23 of the women required a hysterectomy,
Causes and factors
? previous surgery on the uterus
? Prior classical cesareans,where the incision
is near the top of the uterus
? prior removal of fibroid tumors
? any other uterine surgery that went through
the full depth of the muscular portion of the
uterus,
? multiple (three or more) prior low transverse
cesareans
? having had more than five full-term
pregnancies
? having an overdistended uterus (as with
twins or other multiples),
? abnormal positions of the baby such as
transverse lie
? the use of Pitocin and other labor-inducing
medications like prostaglandins
presentation
? Most uterine ruptures occur without
symptoms and do not cause problems for
the mother or fetus,
? This mild type is only noticed when surgery
is required for other reasons,
? In the most severe form,the laceration is
large or cuts across the uterine blood vessels
? the mother may hemorrhage and require a
blood transfusion
? the uterus may not be repairable and must
be surgically removed (hysterectomy)
? Many women will be advised not to get
pregnant again,due to the risk of repeated
rupture
? the baby may not survive
? the mother's life cannot be saved
Signs of uterine rupture
? severe,localized pain
? abnormalities of the fetal heart rate
? vaginal bleeding
? the vaginal examination may show that the
baby is not as low in the birth canal as he
had been earlier,
Preventing and Treatment
? Some uterine ruptures occur before labor and are
considered unpreventable,
? Sudden severe abdominal pain in later pregnancy
should be reported
? Women with risk factors ( prior classical cesareans,
deep fibroid excisions,and other major uterine
surgeries )should not attempt labor
? should be scheduled for cesarean usually between
36 and 39 weeks' gestation,
? If trying for vaginal birth after low transverse
cesarean(VBAC),fetal monitoring is important
? When uterine rupture is diagnosed during
labor,an emergency cesarean is performed,
? Usually the baby's life can be saved,
