Think
- Cardiac arrest, severe shock, massive PE/RV failure, profound hyperventilation, or leak/disconnect.
- Use waveform shape, pulse/rhythm, perfusion, and clinical context.
Rescue pathway
EtCO₂: low-flow state
Low EtCO₂ can mean low pulmonary blood flow even when the tube is correct.
Clinical review / use limits
Authored by: Airway of the Month education team. Last reviewed: July 2026. Audience: EM learners, faculty, EMS, RT, simulation educators, and airway teams.
This is an educational cognitive-aid scaffold, not a bedside order set. Verify medications, ventilator changes, pediatric dosing, and procedures against local ED, ICU, anesthesia, pharmacy, RT, EMS, and pediatric policies.
Resources · Editorial policy · ACEP intubation policy · ARDS ventilation reference