What is the recommended approach for using a laryngeal mask airway (LMA) during cardiopulmonary resuscitation (CPR) in a woman undergoing a lower‑segment cesarean section (LSCS)?

LMA Use During CPR in Cesarean Section

The laryngeal mask airway (LMA) is a reasonable alternative to endotracheal intubation during CPR in cesarean section, but only if the patient can be adequately ventilated and the LMA can be inserted without interrupting chest compressions. However, endotracheal intubation remains the preferred definitive airway when feasible, particularly given the increased aspiration risk in pregnant patients.

Key Principles for Airway Management During Maternal Cardiac Arrest

Prioritize Uninterrupted Chest Compressions

The primary goal during CPR is to minimize interruptions to chest compressions, as compression fraction >80% is critical for survival. 1

• Supraglottic airways like the LMA can be inserted without interrupting chest compressions, making them advantageous over endotracheal intubation which typically requires pausing compressions 1
• If endotracheal intubation is attempted, the pause should be kept to <10 seconds ideally 1
• Any airway intervention that can be performed during ongoing compressions should be done without introducing a pause 1

LMA as a Reasonable Alternative During CPR

For providers trained in its use, the supraglottic airway is a reasonable alternative to both bag-mask ventilation (Class IIa, LOE B) and endotracheal intubation (Class IIa, LOE A) during CPR. 1

• The LMA does not require visualization of the glottis, making both initial training and skill maintenance easier than endotracheal intubation 1
• Insertion can be accomplished without interrupting chest compressions, unlike endotracheal intubation 1
• Once the LMA is in place, continuous chest compressions at ≥100/minute should be provided without pauses, with ventilations delivered at 1 breath every 6-8 seconds (8-10 breaths/minute) 1

Special Obstetric Considerations

Pregnant patients present unique challenges that must be addressed during cardiac arrest:

• Airway management is more difficult during pregnancy due to physiologic changes 1
• The pregnant patient has increased aspiration risk due to decreased lower esophageal sphincter tone and delayed gastric emptying 1
• Left uterine displacement should be maintained during all resuscitative efforts to relieve aortocaval compression 1
• If maternal circulation is not restored within 4 minutes, perimortem cesarean delivery should be performed to improve maternal resuscitation outcomes 1

Clinical Algorithm for Airway Management During Maternal Cardiac Arrest

Step 1: Initial Airway Approach

• Begin with bag-mask ventilation while chest compressions are initiated 1
• Ensure left uterine displacement is maintained throughout 1
• Apply cricoid pressure cautiously (may impede ventilation but can reduce aspiration risk) 1

Step 2: Advanced Airway Decision

If bag-mask ventilation is adequate:

• An advanced airway may not be immediately necessary 1
• Continue bag-mask ventilation with high-quality chest compressions 1

If bag-mask ventilation is inadequate:

• Consider LMA insertion first if the provider is experienced and it can be placed without interrupting compressions 1
• The LMA should be a second-generation device (e.g., LMA Supreme, LMA ProSeal) which provides better seal pressures and some protection against aspiration 2, 3

Step 3: When to Choose Endotracheal Intubation Over LMA

Endotracheal intubation should be prioritized if:

• The provider is highly experienced and can intubate during ongoing compressions 1
• There is active regurgitation or high aspiration risk 1
• The LMA fails to provide adequate ventilation 1
• A pause of <10 seconds can be coordinated with other necessary interventions 1

Step 4: Ventilation Strategy After Advanced Airway Placement

• Deliver continuous chest compressions at ≥100/minute without pauses 1
• Provide 1 breath every 6-8 seconds (8-10 breaths/minute) 1
• Use 100% oxygen 1
• Avoid excessive ventilation as it compromises venous return and cardiac output 1
• Confirm placement with continuous waveform capnography 1

Critical Pitfalls to Avoid

Common Errors in Obstetric CPR Airway Management

Prolonged interruptions for intubation attempts:

• Endotracheal intubation frequently causes long pauses in chest compressions 1
• Each second without compressions reduces survival - prioritize compression continuity over securing a definitive airway 1

Inadequate LMA seal leading to aspiration:

• Correct positioning to achieve a good seal is essential to prevent reflux and aspiration 3
• Second-generation LMAs (Supreme, ProSeal) provide better seal pressures than classic LMA 2, 4
• If seal is inadequate or ventilation is compromised, proceed to endotracheal intubation 1

Excessive ventilation:

• Hyperventilation increases intrathoracic pressure, reducing venous return and cardiac output during CPR 1
• Stick to 8-10 breaths/minute once advanced airway is placed 1

Failure to maintain left uterine displacement:

• The gravid uterus compresses the inferior vena cava, reducing venous return 1
• Maintain left lateral tilt or manual uterine displacement throughout resuscitation 1

Delaying perimortem cesarean delivery:

• If ROSC is not achieved within 4 minutes, begin hysterotomy to improve maternal resuscitation outcomes 1
• Continue all maternal resuscitative interventions during and after cesarean section 1

Evidence Quality Considerations

The recommendations for LMA use during general CPR are based on Class IIa evidence from American Heart Association guidelines 1. However, there is limited specific evidence for LMA use during maternal cardiac arrest in cesarean section. The obstetric literature supports LMA use for elective cesarean section under general anesthesia in carefully selected patients 2, 3, 5, but these are not cardiac arrest scenarios.

The key tension: While the LMA minimizes compression interruptions (favoring its use), pregnant patients have increased aspiration risk (favoring endotracheal intubation). The 2013 AHA consensus statement notes that "a recent large study showed worse outcomes when supraglottic airways were compared with endotracheal intubation" 1, though this was not specific to obstetric patients.

In practice: The LMA should be viewed as an acceptable temporizing measure or alternative when endotracheal intubation would require prolonged compression interruption, but the team should be prepared to convert to endotracheal intubation if ventilation is inadequate or aspiration occurs.