Skip to airway content Airway of the MonthReview the case. Understand the airway. Build the skill.

Troubleshooting review

No or low EtCO₂ waveform

No waveform is a crisis until proven otherwise.

Tube problemEsophageal, mainstem, dislodged, obstructed.Equipment problemCapnography, sampling line, circuit, monitor.Low-flow stateArrest, severe shock, very low perfusion.

Management considerations

  • Assume tube/circulation/equipment problem until proven otherwise.
  • Reconfirm tube with direct visualization if needed.
  • Check capnography connection, circuit, and monitor.
  • If in arrest/low-flow state, interpret EtCO₂ in resuscitation context.

Evidence and use limits

Last reviewed: 2026-07-23. Designed for: emergency medicine learners, clinicians, EMS, RT, and airway educators.

This is an educational clinical reference, not a bedside order set. Confirm medications, ventilator changes, pediatric dosing, procedures, and escalation decisions against the patient’s physiology, the ventilator in use, and local ED/ICU/anesthesia/pharmacy/RT/EMS/pediatric policy.

Full references · Editorial policy · AARC 2024 ventilator assessment · ATS/ESICM/SCCM lung-protective ventilation · ATS 2024 ARDS update

About this resource
Created by: Kyle Brown MD; Andrew Pirotte, MD; Reba Hodge, MD; Amanda Vanderwerf, PharmD, BCEMP; Morgan Kimball, PharmD, BCEMP; Joshua Mohess Clinical review: EM faculty Reviewed: local ED, ICU, EMS, anesthesia, pharmacy, and pediatric protocol review recommended before bedside teaching rollout. Last reviewed: 2026-07-23 Next scheduled review: 2027-01-23 Designed for: EM residents, emergency physicians, EMS clinicians, airway educators, and simulation faculty Important: Educational resource and clinical-reference guide only; not a bedside order set or substitute for local protocol, medical direction, or clinical judgment. Website contact: kybrown@kumc.edu