What are the causes and management of maternal collapse in obstetrics and gynaecology?

Maternal Collapse in Obstetrics: Causes and Management

Maternal collapse is a life-threatening emergency characterized by sudden cardiorespiratory failure during pregnancy or up to 6 weeks postpartum, with amniotic fluid embolism (AFE), hemorrhage, sepsis, and cardiovascular events being the primary causes requiring immediate multidisciplinary resuscitation and consideration of perimortem cesarean delivery within 4 minutes of cardiac arrest. 1, 2

Primary Causes of Maternal Collapse

Amniotic Fluid Embolism (AFE)

• Incidence: 1.9-6.1 per 100,000 births with case fatality rates exceeding 50% in classic presentations 1
• Timing: 70% occur during labor, 11% after vaginal delivery, 19% during cesarean delivery 1
• Classic presentation: Period of anxiety, agitation, sensation of doom preceding sudden cardiovascular collapse with cardiac arrest (pulseless electrical activity, asystole, ventricular fibrillation) 1
• Key feature: Rapid development of disseminated intravascular coagulation (DIC) following cardiopulmonary collapse distinguishes AFE from other causes 1
• Fetal signs: Electronic fetal monitoring shows decelerations, loss of variability, terminal bradycardia—notably, fetal bradycardia may precede maternal symptoms 1, 3

Obstetric Hemorrhage

• Postpartum hemorrhage is a leading cause of maternal collapse, particularly when associated with uterine atony, placental abnormalities (accreta, percreta, previa), or coagulopathy 1, 4
• Inadequate or prolonged resuscitation following major hemorrhage can lead to myocardial damage 4
• Active management of third stage of labor decreases incidence 4

Sepsis and Infection

• Maternal sepsis occurs in up to 6.8% of cases with preterm prelabor rupture of membranes (PPROM), with higher rates in expectant management 5
• Critical timing: Once infection is identified, median time to death is only 18 hours (IQR 12-120 hours), demonstrating rapid clinical deterioration 1, 5
• HELLP syndrome (hemolysis, elevated liver enzymes, low platelets) represents severe end of pre-eclampsia spectrum with maternal mortality of 3.4% 1
• Clinical signs include epigastric pain, upper abdominal tenderness, proteinuria, hypertension, jaundice 1

Cardiovascular Events

• Pulmonary embolism and venous thromboembolism are significant causes requiring immediate anticoagulation 4, 6
• Peripartum cardiomyopathy can present as acute decompensation 6
• Myocardial infarction must be considered in differential diagnosis 1

Hypertensive Emergencies

• Eclampsia with seizures and cardiovascular collapse 6
• Severe pre-eclampsia with cerebral symptoms, pulmonary edema 1

Immediate Management Algorithm

First 4 Minutes: ABCs and Cardiac Arrest Protocol

• Airway, breathing, circulation support with 100% oxygen 1, 2
• Manual uterine displacement or lateral tilt to relieve aortocaval compression 1, 2
• High-quality CPR with backboard if no pulse 1
• Designate timekeeper to call out times at 1-minute intervals 1
• START perimortem cesarean delivery (resuscitative hysterotomy) at 4 minutes if no pulse and gestational age >20 weeks 1, 2
• Consider move to operating room only if accomplished in 2 minutes or less; otherwise perform in delivery suite 1

Circulatory Management

• Avoid excessive fluid resuscitation to prevent pulmonary edema 1
• Norepinephrine 0.05-3.3 mcg/kg/min to maintain blood pressure 1
• Consider intraosseous line if large-bore IV access difficult 1
• Fluid boluses of 500 mL with reassessment (not aggressive volume loading) 1

Hemorrhage and Coagulopathy Management

• Activate massive transfusion protocol immediately 1
• Cryoprecipitate preferred over FFP to reduce volume overload 1
• Tranexamic acid 1 g IV over 10 minutes if DIC or hemorrhage occurs 1
• Oxytocin prophylaxis plus other uterotonics for anticipated uterine atony 1
• Aggressive treatment of uterine atony and search for anatomic bleeding sources 1
• Consider thromboelastometry if available 1

Right Ventricular Failure Management (AFE-specific)

• Echocardiography (transthoracic or transesophageal) to confirm right ventricular failure 1
• Inotropes: Dobutamine 2.5-5.0 mcg/kg/min OR Milrinone 0.25-0.75 mcg/kg/min 1
• Pulmonary vasodilators to unload right ventricle 1:
  • Inhaled nitric oxide 5-40 ppm, OR
  • Inhaled epoprostenol 10-50 ng/kg/min, OR
  • IV epoprostenol 1-2 ng/kg/min via central line, OR
  • Sildenafil 20 mg orally if awake/alert
• Consider ECMO for prolonged CPR or refractory right heart failure 1
• Wean FiO2 to maintain oxygen saturation 94-98% 1

Sepsis-Specific Management

• Immediate broad-spectrum antibiotics for suspected chorioamnionitis or sepsis 1, 5
• Early recognition critical as deterioration occurs within hours 1, 5

Critical Pitfalls to Avoid

Timing Errors

• Delaying perimortem cesarean beyond 4 minutes significantly worsens maternal survival—the procedure improves maternal resuscitation by relieving aortocaval compression and reducing oxygen consumption 1, 2
• Attempting to transport patient to operating room when delivery suite delivery would be faster 1

Fluid Management Errors

• Excessive fluid resuscitation worsens pulmonary edema, particularly in AFE with left ventricular failure 1
• Failure to recognize biphasic cardiac dysfunction in AFE (early right ventricular failure followed by left ventricular failure with cardiogenic pulmonary edema) 1

Diagnostic Delays

• Missing early signs of AFE when fetal bradycardia precedes maternal symptoms 3
• Misdiagnosing AFE as pulmonary embolism, myocardial infarction, high spinal block, or sepsis—all share similar initial presentations 1
• Failing to recognize HELLP syndrome as non-obstetric condition (acute cholecystitis, drug reaction) 1

Resource Allocation

• Inadequate staffing during critical moments increases maternal and neonatal morbidity and mortality 7
• Lack of immediate availability of multidisciplinary team (obstetrician, anesthesiologist, neonatology, critical care) 1, 2

Facility Preparedness Requirements

Level III and IV Facilities

• Onsite ICU accepting pregnant women with critical care providers available 24/7 1
• Maternal-fetal medicine team with critical care expertise for comanagement 1
• Equipment and personnel for ventilation and monitoring in labor and delivery unit 1

Essential Protocols

• Cognitive aids and checklists for AFE management reduce panic and improve outcomes 1
• Annual multidisciplinary simulation training for all maternity care professionals improves teamwork and emergency preparedness 2
• Massive transfusion protocols readily accessible 1

Differential Diagnosis Considerations

The initial management focuses on the same ABC principles regardless of specific etiology, but rapid appearance of DIC confirms AFE diagnosis 1. Other conditions to consider include:

• Pulmonary embolism 1, 4
• Myocardial infarction 1
• Air embolism 1
• High spinal block 1
• Septic shock 1, 6
• Eclampsia 6