Plateau pressure (Pplat) in a mechanically ventilated patient can be accurately measured only if:
- A An end-expiratory hold manoeuvre of 0.5 seconds is performed
- B The peak airway pressure is recorded at maximum inspiratory flow
- C An end-inspiratory hold manoeuvre of 0.5 to 1 second is performed ✓
- D PEEP is temporarily reduced to zero
Correct answer: C. An end-inspiratory hold manoeuvre of 0.5 to 1 second is performed
Explanation
Plateau pressure reflects alveolar pressure and is measured by applying an end-inspiratory hold of 0.5 to 1 second, allowing airflow throughout the lung to cease so that pressure equilibrates across all alveoli. Peak airway pressure includes resistive forces and always exceeds Pplat. An expiratory hold measures total PEEP, and removing PEEP alters lung volume and gives a misleading value.
Reference: Morgan and Mikhail's Clinical Anesthesiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.