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Recognize auto-PEEP

Vent control

Recognize auto-PEEP

The best bedside clue is expiratory flow that has not returned to zero before the next breath starts.

HAMILTON-T1 measurementExact waveform and Monitoring paths.Now check BP/MAPDynamic hyperinflation can cause shock.Increase expiratory timeGive the patient more time to exhale.

Flow, volume, and expiratory-hold clues

Flow, volume, and expiratory-hold clues

The pressure-time trace usually returns to set PEEP; intrinsic PEEP measurement is ventilator-specific; pair the supported measurement method with the flow-time waveform.

Original Airway of the Month teaching diagrams redrawn from standard ventilator scalar and loop conventions. Interpretation is anchored to the AARC 2024 Patient–Ventilator Assessment guideline, the peer-reviewed Basics of Ventilator Waveforms review, the 2026 SYNAPsE asynchrony consensus, and the University of Pennsylvania Ventilator Overview and Troubleshooting tip sheet. Waveforms are pattern-recognition aids, not diagnoses; display colors, labels, and orientation vary by ventilator brand.

Look for

  • Expiratory flow remains below zero when the next inspiration begins.
  • Volume-time may not return to baseline.
  • Rising chest volume, increasing difficulty bagging, hypotension, or worsening hypercapnia may accompany severe dynamic hyperinflation.

Evidence and use limits

Last reviewed: 2026-07-17. 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
Website creator: Kyle Brown, MD Airway educational contributors: Andrew Pirotte, MD; Kyle Brown, MD; Reba Hodge, MD; Amanda Vanderwerf, PharmD, BCEMP; Morgan Kimball, PharmD, BCEMP; Joshua Mohess Clinical review: Emergency medicine faculty review completed. Medication content reviewed by Amanda Vanderwerf, PharmD, BCEMP, and Morgan Kimball, PharmD, BCEMP. 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: [email protected]