What are advanced life support obstetric concepts?

Advanced Life Support Obstetric Concepts

Advanced life support in obstetrics encompasses specialized resuscitation protocols that address the unique physiological challenges of pregnancy, with core principles including immediate relief of aortocaval compression, prioritized airway management, and preparation for perimortem cesarean delivery within 4-5 minutes of maternal cardiac arrest. 1

Core Resuscitation Modifications for Pregnancy

Aortocaval Compression Relief

• Manual left lateral uterine displacement must be maintained throughout all resuscitation efforts in pregnant patients at ≥20 weeks gestation or when fundal height reaches the umbilicus 1
• The gravid uterus compresses the inferior vena cava in the supine position, reducing venous return, stroke volume, and cardiac output—making this intervention critical for successful maternal resuscitation 1
• This can be performed using either a two-handed pull technique (pulling the uterus upward and leftward toward the provider) or a one-handed push technique (pushing away from the provider) 1

Airway Management Priority

• Oxygenation and airway management take precedence over other interventions because pregnant patients have increased metabolic demands and decreased functional reserve capacity, making them profoundly susceptible to rapid hypoxia 1
• The most experienced provider available should manage the airway, as difficult airways are common in pregnancy 1
• Options include endotracheal intubation or supraglottic airway devices (laryngeal mask airway, Combitube, Intubating LMA) 1
• Waveform capnography or capnometry must be used to confirm and continuously monitor endotracheal tube placement 1
• Once an advanced airway is secured, deliver 1 breath every 6 seconds (10 breaths per minute) with continuous chest compressions 1

Failed Airway Protocol

• If intubation fails, immediately attempt mask ventilation with cricoid pressure 1
• If mask ventilation fails, use a laryngeal mask airway or other supraglottic device 1
• If ventilation remains impossible and the patient cannot be awakened, create a surgical airway immediately 1, 2

Perimortem Cesarean Delivery (PMCD)

Critical Timing

• If return of spontaneous circulation (ROSC) is not achieved within 4 minutes of maternal cardiac arrest, begin hysterotomy immediately 1, 2
• The goal is to complete delivery within 5 minutes of arrest onset to optimize both maternal and fetal outcomes 1
• Maternal survival has been reported up to 39 minutes after arrest, but median time to delivery in survivors is 9 minutes versus 20 minutes in non-survivors 1
• Neonatal survival is dramatically better when PMCD occurs within 5 minutes: 24/25 infants survived versus 7/10 when performed after 5 minutes 1

Indications for Immediate PMCD

• In cases of nonsurvivable maternal trauma or prolonged pulselessness where maternal resuscitation is futile, proceed directly to PMCD without delay 1
• PMCD should be prepared for any pregnant patient with fundus at or above the umbilicus who has not achieved ROSC with standard measures plus uterine displacement 1

Physiological Rationale

• Delivery relieves aortocaval compression, improving maternal cardiac output and the effectiveness of chest compressions 1
• The American Heart Association notes that 4-5 minutes is the maximum time to determine if Basic Life Support and Advanced Cardiac Life Support can reverse the arrest before proceeding to delivery 1

Equipment and Team Preparation

Immediate Availability Requirements

• Basic and advanced life-support equipment must be immediately available in the operative area of all labor and delivery units 1, 2
• Required basic equipment includes: pulse oximeter, qualitative carbon dioxide detector, and standard airway management tools 1, 2
• Portable difficult airway equipment must be readily accessible in the operative area 1

Multidisciplinary Team Planning

• Team planning for maternal cardiac arrest must involve obstetric, neonatal, emergency, anesthesiology, intensive care, and cardiac arrest services 1
• For out-of-hospital arrests, protocols should facilitate rapid transport to facilities capable of immediate PMCD and neonatal resuscitation, with early activation of all relevant teams 1

Additional Resuscitation Considerations

Fetal Monitoring

• Do not perform fetal monitoring during maternal cardiac arrest as it interferes with maternal resuscitation efforts 1

Post-Resuscitation Care

• Targeted temperature management is recommended for pregnant women who remain comatose after ROSC 1
• During targeted temperature management, continuously monitor the fetus for bradycardia and obtain obstetric and neonatal consultation 1

Standard ACLS Modifications

• Initiate standard ACLS protocols immediately upon cardiac arrest 1, 2
• Maintain left uterine displacement throughout all resuscitation efforts 1, 2
• All standard medications and defibrillation protocols apply without modification 1

Common Pitfalls to Avoid

• Never delay PMCD beyond 4 minutes of maternal cardiac arrest 2
• Do not underestimate the physiological changes of pregnancy that complicate airway management during emergencies 2
• Ensure a preformulated difficult airway strategy is in place before emergencies occur 1, 2
• Do not attempt to tilt the patient or use wedges for aortocaval decompression during CPR—manual left lateral uterine displacement is more effective and allows proper chest compressions 1