Is an endotracheal tube (ETT) or a supraglottic airway (SGA) better for airway management in an out-of-hospital cardiac arrest?

Airway Management in Out-of-Hospital Cardiac Arrest: SGA vs ETT

Direct Recommendation

For out-of-hospital cardiac arrest, supraglottic airways (SGAs) are preferred over endotracheal intubation (ETT) in settings with low intubation success rates, while either approach is acceptable in settings with high intubation success rates—but neither has been shown to improve survival compared to bag-mask ventilation. 1

Evidence-Based Decision Framework

Primary Outcome Evidence (Survival & Neurological Function)

The most recent and highest quality evidence comes from the AIRWAYS-2 trial (2022), a large cluster randomized controlled trial of 9,296 patients, which found:

• No difference in neurological outcomes: 6.4% good outcomes with SGA vs 6.8% with ETT (adjusted difference -0.6%, 95% CI -1.6% to 0.4%) 2
• No difference in survival at 3 or 6 months 2
• No difference in aspiration rates: 15.1% with SGA vs 14.9% with ETT 2

A 2024 systematic review and meta-analysis of randomized controlled trials confirmed these findings, showing SGA use may have no effect on survival at longest follow-up (RR 1.06; 95% CI 0.84-1.34) and has uncertain effects on survival with good functional outcome (RR 1.11; 95% CI 0.82-1.50) 3.

Practical Performance Advantages of SGAs

SGAs demonstrate clear operational superiority:

• Higher initial ventilation success rate: 87.4% with SGA vs 79.0% with ETT (adjusted difference 8.3%, 95% CI 6.3% to 10.2%) 2
• Faster time to airway placement: 2.5 minutes faster with SGA (95% CI 1.6-3.4 minutes less) 3
• Increased ROSC: SGA probably increases return of spontaneous circulation (RR 1.09; 95% CI 1.02-1.15) 3
• Can be inserted without interrupting chest compressions, unlike ETT which requires direct visualization 1, 4

Current Guideline Recommendations

The 2020 International Consensus on CPR provides the most recent guidance:

• Weak recommendation for bag-mask ventilation OR advanced airway strategy during CPR (low to moderate certainty evidence) 1
• In settings with LOW intubation success rates: SGAs are suggested over ETT for out-of-hospital cardiac arrest 1
• In settings with HIGH intubation success rates: Either SGA or ETT is acceptable 1

The 2015 AHA Guidelines similarly state that either bag-mask device or advanced airway may be used, and if an advanced airway is chosen, either SGA or ETT may be used as the initial device (Class IIb, LOE C-LD) 1.

Critical Nuance: No Survival Benefit from Advanced Airways

A crucial finding across all guidelines: there is no evidence that advanced airway measures improve survival rates compared to bag-mask ventilation in out-of-hospital cardiac arrest 1. The 2010 AHA Guidelines explicitly state that supraglottic airways are a reasonable alternative to both bag-mask ventilation (Class IIa, LOE B) AND endotracheal intubation (Class IIa, LOE A) 1.

Algorithm for Clinical Decision-Making

Step 1: Assess Provider Experience

• If providers lack frequent ETT experience or training: Choose SGA 1, 4
• SGAs require less training and skill maintenance than ETT 1, 4

Step 2: Consider System-Level Success Rates

• If your EMS system has documented low ETT success rates: Choose SGA 1
• If your system has high ETT success rates with quality improvement tracking: Either SGA or ETT acceptable 1, 5

Step 3: Prioritize Minimal Interruption in Compressions

• SGAs can be inserted without stopping chest compressions 1, 4
• ETT requires interruption for direct laryngoscopy 4
• Earlier airway placement (regardless of type) is associated with better outcomes 6

Step 4: Post-Placement Management

• Once advanced airway placed: deliver continuous chest compressions at ≥100/minute 4
• Ventilate at 1 breath every 6-8 seconds (8-10 breaths/minute) 1, 4
• Avoid excessive ventilation which compromises venous return 1, 4

Confirmation of Placement

Regardless of device chosen:

• Waveform capnography is mandatory for ETT confirmation (strong recommendation) 1
• If waveform capnography unavailable: use nonwaveform CO2 detector or esophageal detector device 1
• SGAs also benefit from capnography monitoring 1

Common Pitfalls to Avoid

With ETT:

• Prolonged intubation attempts causing excessive interruption in compressions 1
• Unrecognized esophageal intubation 4, 5
• Attempting ETT without adequate training/experience 1, 4

With SGA:

• Assuming complete protection against aspiration (SGAs do NOT provide absolute protection) 4, 5
• Failure to confirm placement with capnography 1
• Cuff rupture causing ventilation failure 1

With Both:

• Excessive ventilation rates compromising cardiac output 1, 4
• Delaying compressions for airway placement 1

Cost-Effectiveness

The AIRWAYS-2 trial found no meaningful difference in costs or cost-effectiveness between SGA and ETT strategies, with total costs £157 lower in the ETT group but with huge uncertainty (95% CI -£270 to £583) 2.

Bottom Line for Practice

Given equivalent survival outcomes, choose the airway device that:

1. Your providers can place most quickly and reliably
2. Minimizes interruptions in chest compressions
3. Matches your system's documented success rates

In most out-of-hospital settings, this favors SGAs due to faster placement, higher success rates, and ability to insert without stopping compressions 1, 2, 3. However, the most important factor is maintaining high-quality CPR with minimal interruptions, regardless of airway choice 1.