To identify auto-PEEP in a mechanically ventilated patient, which measurement is most appropriate?

• A. Measure unintended auto-PEEP
• B. Increase tidal volume
• C. Decrease PEEP
• D. Suction airway secretions

Answer: (A)

Auto-PEEP is intrinsic PEEP created by air trapping when expiration is incomplete. To identify it, you need to quantify how much pressure is present at end expiration that isn’t coming from the ventilator’s set PEEP. The most reliable method is to perform an expiratory hold (end-expiratory pause) to measure total PEEP, then subtract the set PEEP to obtain auto-PEEP. This direct measurement tells you how much of the PEEP is intrinsic and needs management.

Increasing tidal volume would worsen air trapping and doesn’t identify auto-PEEP. Decreasing PEEP might change patient support and isn’t a measurement of auto-PEEP. Suctioning targets secretions, not the intrinsic pressure amount.