What are the modifications to cardiopulmonary resuscitation (CPR) and advanced cardiac life support (ACLS) for a pregnant woman (≥20 weeks gestation) in cardiac arrest?

CPR Modifications for Pregnant Women

For pregnant women ≥20 weeks gestation in cardiac arrest, perform continuous manual left lateral uterine displacement while maintaining the patient supine, prioritize aggressive airway management with 100% oxygen, and if no return of spontaneous circulation occurs within 4 minutes, immediately begin perimortem cesarean delivery with the goal of completing delivery by 5 minutes. 1, 2

Critical Positioning Modification

Manual Left Lateral Uterine Displacement (LUD) - Not Tilt

• Perform continuous manual LUD for all pregnant women with uterus at or above the umbilicus (approximately ≥20 weeks gestation) throughout the entire resuscitation 1, 2
• Keep the patient supine on a firm backboard - do NOT use left lateral tilt positioning 1
• Manual LUD can be performed two ways: 1
  • From the patient's left side: cup and lift the uterus upward and leftward off the maternal vessels
  • From the patient's right side: push the uterus upward and leftward off the maternal vessels
• Avoid pushing downward, which worsens inferior vena cava compression 1
• Manual LUD produces significantly higher coronary perfusion pressures (20 mmHg) compared to left lateral tilt (5 mmHg, P<0.05) 1
• Left lateral tilt >30° causes the patient to slide off the incline and shifts the heart laterally, making chest compressions significantly less effective 1

Chest Compression Technique

Standard hand placement in the center of the chest - same as non-pregnant patients 1

• Use a firm backboard with patient supine 1
• Compress at rate of at least 100/minute 1
• Compress at depth of at least 2 inches (5 cm) 1
• Allow complete chest recoil after each compression 1
• Minimize interruptions and keep peri-shock pause <10 seconds 1
• Continue compressions while maintaining manual LUD simultaneously 1, 2

Airway and Oxygenation - HIGHEST PRIORITY

Airway management takes precedence over other interventions because pregnant patients have increased metabolic demands and decreased functional reserve capacity, making them profoundly susceptible to rapid hypoxia 1, 2, 3

• Assign the most experienced provider available - difficult airways are common in pregnancy due to obesity, sleep apnea, and airway edema 1, 2, 3
• Administer 100% oxygen at ≥15 L/min immediately 2, 3
• Use 2-handed bag-mask technique with proper seal to ensure no leak 1
• Deliver each rescue breath over 1 second with sufficient tidal volume to produce visible chest rise 1
• Give 2 breaths for every 30 compressions (before advanced airway) 1
• Avoid excessive ventilation 1

Advanced Airway Management:

• Perform endotracheal intubation (6.0-7.0 mm inner diameter tube) or supraglottic airway device 2, 3
• Use waveform capnography or capnometry to confirm and monitor ET tube placement 1
• Once advanced airway is placed, give 1 breath every 6 seconds (10 breaths per minute) with continuous chest compressions 1

The Critical 4-Minute Decision Point for Perimortem Cesarean Delivery (PMCD)

If ROSC is not achieved within 4 minutes of cardiac arrest onset, immediately begin hysterotomy with the goal of completing delivery by 5 minutes 1, 2, 3

Rationale:

• Relieving aortocaval compression by emptying the uterus significantly improves maternal cardiac output and coronary perfusion pressure 2
• Fetal survival: 24/25 infants (96%) survived when PMCD occurred within 5 minutes versus 7/10 (70%) when performed after 5 minutes 1, 2, 3
• Maternal survival has been reported up to 39 minutes after cardiac arrest onset 1, 3
• Median time from arrest to delivery was 9 minutes in surviving mothers versus 20 minutes in non-surviving mothers 1
• The 2024 International Consensus recommends PMCD for women in cardiac arrest in the second half of pregnancy, though insufficient evidence exists to define a specific time interval 1

Team Activation and Coordination

Immediately activate the maternal cardiac arrest team using a bundled emergency code to simultaneously alert: 1, 2, 3

• Obstetric services
• Neonatal services
• Emergency services
• Anesthesiology
• Intensive care
• Cardiac arrest team

Minimum 3 additional staff for basic life support response, plus code cart and AED 1

Standard ACLS Medications - No Modifications

• Administer standard ACLS medications including epinephrine 1 mg IV/IO every 3-5 minutes 2
• Follow standard defibrillation protocols - no dose adjustments needed 1
• Provide fluid resuscitation if pulseless electrical activity (PEA) is present 1

What NOT to Do During Active Resuscitation

Do NOT perform fetal monitoring during active maternal cardiac arrest - it interferes with maternal resuscitation efforts and risks delaying critical interventions 2, 3

Post-Resuscitation Care

For pregnant women who remain comatose after ROSC: 2, 3

• Implement targeted temperature management
• Continuously monitor the fetus for bradycardia as a potential complication
• Obtain immediate obstetric and neonatal consultation

Common Pitfalls to Avoid

• Using left lateral tilt instead of manual LUD - tilt reduces chest compression effectiveness and still allows inferior vena cava compression at >30° 1
• Delaying PMCD beyond 5 minutes - dramatically worsens both maternal and fetal outcomes 1, 2
• Underestimating airway difficulty - pregnancy causes airway edema and reduced functional reserve capacity 1, 2
• Changing hand position for chest compressions - use standard center-chest placement 1
• Performing fetal monitoring during active arrest - wastes critical time 2, 3