Amniotic Fluid Embolism Xiong yu Obstetric & Gynecology Hospital, Fudan University.

Amniotic Fluid Embolism Xiong yu Obstetric & Gynecology Hospital, Fudan University

Case 1 Gravida 3 and Parturition 1, 41w, labor induced by propess, membrane ruptured naturally, at the same time, dyspnea and cyanosis occurred. What happened? If you are the doctor,what should you do? Trachea cannula was done immediately, and CS was prepared. The baby was survival with 9 apgar score. In the operation, sudden cardiac arrest occurred and autonomously heartbeat recovered after 50 minutes external chest compression. But DIC emerged, hysterectomy was done. Finally, the patients life was saved, but she became a vegetable. One year later, she died.

Serious intrapartum complication A complex disorder caused by amniotic fluid entering maternal circuration and classically characterized by the abrupt onset of hypotension, hypoxia, and consumptive coagulopathy Incidence: 1:20000 Mortality: 80%, in term pregnancy Amniotic Fluid Embolism(AFE)

Rupture of membrane Hypertonia of amnion cavity Open blood sinus Injury of cervical canal or uterine wall Placenta previa, placenta abruption, placenta marginal sinus rupture Adherence site of placenta Condition of AFE Onset

Premature rupture of membrane, artificial rupture or stripping of membrane, artificial expansion of cervix Too strong uterine contraction Rigidity contraction and precipitate labour caused by inappropriate using of oxytocin and operation in cavity Injury Cervical laceration, rupture of uterus, uterine incision in caesarean section, forcep curettage Predisposing factors

Some pathological pregnancy Twin, multiplets, macrosomia, polyhydramnions, prolonged labour, dystocia, placenta abruption, placenta previa, retention of dead fetus, infection of amnion cavity, fetal distress Press abdoman and uterus by brute force

Internal cervical vein Amniotic fluid volume entering maternal circulation related to : strength of contraction degree of injury Uterine placenta bed Broken venule in adherence site of placenta Fissure in adherence site of placenta Open decidua blood sinus placenta marginal vessel Amniotic permeation pressure of amniotic cavity intensity of amniotic membrane Pathway of amnion fluid entering maternal blood circulation

Pathyphysiology Pulmonary hypertension Allergic shork Disseminated intravascular coagulation(DIC) Acute renal failure

Amniotic fluid (Epithelial cell, mucus,meconium, vernix caseosa, lanugo) Maternal circulation allergic reaction Bleeding without coagulation chill pulmonary circulation Vessel embolism Acute pulmonary heart disease Vessel block stenosis Pulmonary hypertention returned blood volume to LA output Vessel spasm Right heart failure Peripheral circulatory failure, Bp drop shork reflectively bronchospasmbronchi secretio n increase d bronchiostenosi s ventilation obstruct Acute respiratory failure toxicosis and anoxia of the whole body Respirator y acidosis cerebral anoxia, Anxious, seizure, coma Histanoxia (cyanosis) renal anoxia Metaboli c acidosis Acute renal failure

Abrupt onset, critical oncoming force Three stages appear in sequence in typical cases Only mass vaginal bleeding and shork in atypical cases Degree of syptoms related to amount of particle matter in amniotic fluid, amount and velocity of amniotic fluid entering maternal circulatin Clinical manifestation

Premonitory symptom Short-period dysphoria, chill and shiver, cough and dyspnea, cyanosis, vomit at the time of rupture of membrane Symptoms disappear after treatment in mild AFE, severe AFE arise three stages : Respiratory and circulatory failure, shork Bleeding caused by DIC Acute renal failure

Acute respiratory and circulatory failure Obvious cyanosis Dyspnea Coughing frothy sputum, raised heart rate, moist rales in lung Fall of blood pressure Coma, seizure Severe cases: scream, respiratory arrest, cardiopulmonary arrest die Clinical manifestation the first stage

Coagulation disorders hypercoagulable statehypocoagulable stage Bleeding of skin, mucosa, needle eye, incision Hematuria, hematemesis Mass vaginal bleeding Typical symptom of DIC Clinical manifestation the second stage

Multiple organ failure (MOF) Acute renal failure Oliguria urine volume < 400ml/24h or 17ml/h Anuria

After rupture of membrane, after birth, or in operation Break out shiver, bucking, dyspnea, dysphoria, scream, cyanosis, seizure, bleeding, shork unkown reason, AFE should be considered Rescue immediately The key to improve rescue livability is correct and prompt dignosis, effective therapeutic measures Dignosis

Blood smear to find amniotic visible particle Bedside chest X-lay Bedside ECG or CDFI Right atrium enlargement, cardiac damage Laboratory examination related to DIC Assistant examination

Blood smear to find amniotic visible matter Left A (case1)shows pink and wedge-shaped fetal squamous epithelium, left B(case2) shows pink fetal squamous epithelium surrounded by platelet Right A(case1) right B(case2) showed fetal squamous epithelium from bronchic asearse fluid red arrow

Squamous epithelium in a peripheral pulmonary artery Fetal keratin in a peripheral pulmonary artery pulmonary artery

Bedside chest X-lay 70% of patients may have mild symptoms of lung edema Disseminated effusion in pulmonary alveolus Increased heart shadow

Dissipative hypocoagulability Progressive drop of platelet count 3 Kaolin active partial thromboplastin time( KPTT > 10 Fibrinogen < 1.5/L Coagulation examination

Secondary hyperfibrinolysis 1.Plasma Protamine para-coagulation test (3P test) 2.Others D-dimer Antithrombase AT ) Fibrinopeptide A FDA Fibrin degradation production (FDP Capillary hemolysis Broken RBC more than 10% in 20~30% blood smears of late stage DIC

To draw right ventricle blood for precipitation test to find visible particle of amniotic fluid Autopsy Notable right ventricle expansion Pulmonary edema, alveolar hemorrhage, embolus containing amniotic particle in kidney, heart, brain, uterine, or broad ligament, embolus containing Deciduous squamous epithelial cell from fetal skin Lanugo Fragment of fetal skin and amnion Mucin from fetal intestinal tract Bile from meconium Dignosis after death

Air embolism severe chest and back pain, sence of precordia pressure, occurred in rupture of uterus, placenta previa, operation in cavity Pulmonary embolism by thrombus varicose vein and thrombophlebitis of lower limb, occurred at 9-14 days after birth, acute chest pain, bloody sputum, chest fricative, pulmonary embolism in X-ray Eclampsia hypertention, proteinuria, shork appeared later Rupture of uterus cephalopelvic disproportion, signs of impending of rupture of uterus ( abdominal pain, hematuria) Differential diagnosis

Reasonable using of oxytocin, to master indication and controll dose, watched by special person Avoid inappropriate operation in uterine cavity and birth canal injury Notice in artificial rupture of membrane Avoid pressing abdomen and uterus strongly at the time of delivery of baby Master indication of CS strictly Using sedative to suppress excessive contraction Prevention

To rescue quickly and decisively To treat respiratory and circulatory failure firstly Appropriate obstetric management Principle of management

Steps of management

Improve hypoxemia Semireclining position Oxygen uptake High concentration oxygen(>50%) by mark flow velocity 5-10L/min Continious positive airway pressure by trachea cannula Antiallergic Dexamethasone 20mg iv, 20mg ivgtt p.r.n Hydrocortisone 1000- 2000mg/d ivgtt Step 1

Relieve pulmonary hypertension Paraverine Relax vascular smooth muscle 30-90mg+5%GS20ml ivgtt Amniophylline Dilate coronary artery and bronchi smooth muscle 250mg+5%GS 20ml ivgtt Atropine Relieve pulmonary vasospasm, bronchospasm, cardiac depression 1-2mg im or iv Phentolamine Relieve pulmonary vasospasm 5-10mg+5%GS100ml ivgtt adjust infusion rate according blood pressure

Correct shork Circulatory support with blood and component replacement central venous pressure(CVP): 8-10cmH 2 O Adjust vessel tensity dopamine 10-20mg+5%GS 250ml ivgtt Treat acidosis 5%NaHCO 3 100-200ml ivgtt Step 2

Treat DIC Hypercoagulability in early stageheparin 0.5mg-1mg/kg heparin 1mg to be equivalent to 125IU First 25mg+NS100ml ivgtt in 1h Then 25mg+5%GS500ml ivgtt Clotting time maintain at 15min Excessive heparin detoxified using 1% equivalent protamine solution To plan CS is a contraindication of using heparin Step 3

Hyperfibrinolysis Antifibrinolysis 6-aminoacetic acid (EACA ivgtt P-aminiomethyl beozonic acid(Pamba)200-300mg/d ivgtt Blood coagulation factors supply Fresh blood Fresh frozen blood plasma, condensation sediment Platelet suspension, fibrinogen VitK 20-40mg to promote liver to synthesis coagulation factors

Prevent heart failure Lanatoside 0.4mg+5%GS 20ml ivgtt slowly Energy mixture Prevent renal failure Furosemide 40mg iv repeated p.r.n Prevent infection To select broad-spectrum antibiotic with less renal toxicity Step 4

Obstetric management Onset in first stage of labor termination of pregnancy by CS Onset in second stage of labor termination of labor by vaginal midwifery PPH occurred and not stopping bleeding hysterectomy

Thanks for your attention

Amniotic Fluid Embolism Xiong yu Obstetric & Gynecology Hospital, Fudan University.

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