During CPR with a supraglottic airway, does the Australian Resuscitation Council recommend a 30:2 compression‑to‑ventilation ratio or continuous chest compressions with asynchronous breaths?

CPR Ventilation Strategy with Supraglottic Airway

Once a supraglottic airway is placed during CPR, switch to continuous chest compressions with asynchronous ventilation at 10 breaths per minute (1 breath every 6 seconds), rather than continuing the 30:2 ratio. This approach maximizes chest compression fraction and maintains adequate ventilation without interrupting compressions.

Before Supraglottic Airway Placement

• Use 30:2 compression-to-ventilation ratio until the advanced airway (supraglottic airway or endotracheal tube) is successfully inserted 1
• Pause compressions briefly (less than 5 seconds) to deliver 2 breaths after every 30 compressions 1
• This recommendation applies to all EMS providers and healthcare professionals performing CPR 1

After Supraglottic Airway Placement

• Immediately transition to continuous chest compressions at 100-120 per minute without pauses 1, 2
• Deliver asynchronous ventilations at 10 breaths per minute (1 breath every 6 seconds) 1, 2
• Do not synchronize breaths with compressions—ventilate independently while compressions continue uninterrupted 1, 2

Rationale for the Strategy Change

The American Heart Association guidelines explicitly state this two-phase approach based on large randomized controlled trial evidence 1:

• A Resuscitation Outcomes Consortium trial of 23,711 cardiac arrest patients found no significant difference in survival to discharge between continuous compressions with asynchronous ventilation (9.0%) versus 30:2 ratio (9.7%) before advanced airway placement 1
• However, the key advantage of the supraglottic airway is that it allows continuous compressions, which maximizes chest compression fraction—a critical determinant of survival 3
• Studies demonstrate that supraglottic airway use increases chest compression fraction from 59% to 75% when continuous compressions are employed 3

Critical Implementation Details

Ventilation parameters with supraglottic airway in place:

• Rate: Exactly 10 breaths per minute (1 breath every 6 seconds) 1, 2, 4
• Tidal volume: 500-600 mL (just enough to produce visible chest rise) 2
• Oxygen: 100% during CPR 2
• Monitor with continuous waveform capnography targeting ETCO₂ of 35-40 mmHg 2, 5

Compression parameters:

• Rate: 100-120 compressions per minute 2
• Depth: 5-6 cm in adults
• Never pause compressions for ventilation once the supraglottic airway is placed 1, 2

Common Pitfalls to Avoid

• Do not continue 30:2 ratio after supraglottic airway placement—this negates the primary benefit of the advanced airway and reduces chest compression fraction 3
• Avoid hyperventilation (more than 10 breaths per minute), which decreases venous return, reduces cardiac output, and worsens outcomes 2, 4
• If supraglottic airway insertion fails (occurs in approximately 23% of attempts), immediately return to 30:2 ratio with bag-valve-mask ventilation 3
• Ensure proper supraglottic airway placement with capnography before transitioning to continuous compressions 2

Evidence Quality Considerations

While the American Heart Association guidelines provide Class IIa (reasonable) and Class IIb (may be reasonable) recommendations for both strategies 1, the practical advantage of continuous compressions with a supraglottic airway is clear: it maximizes chest compression fraction without compromising ventilation adequacy 3. The large RCT showed equivalent outcomes, but this was comparing strategies before advanced airway placement 1. Once the airway is secured, the rationale for pausing compressions disappears entirely.