Mechanical Ventilation Flashcards

Which ventilator mode delivers a set tidal volume regardless of airway resistance or compliance changes?

Answer: Volume control ventilation (VCV)

Volume control ventilation guarantees delivery of a preset tidal volume by adjusting peak inspiratory pressure as lung mechanics change.

Plateau pressure should ideally be kept below which threshold to reduce ventilator-induced lung injury (VILI)?

Answer: 30 cmH2O

Current lung-protective ventilation guidelines recommend keeping plateau pressure below 30 cmH2O to minimize barotrauma and VILI.

PEEP (positive end-expiratory pressure) is used primarily to:

Answer: Prevent alveolar collapse and improve oxygenation

PEEP maintains alveolar patency at end-expiration, recruits collapsed lung units, and improves V/Q matching and oxygenation.

Auto-PEEP (intrinsic PEEP) occurs when:

Answer: Insufficient expiratory time prevents full exhalation before the next breath

Auto-PEEP develops when air trapping occurs because the next breath is delivered before the previous breath is fully exhaled, leading to gas stacking.

In pressure support ventilation (PSV), the ventilator:

Answer: Provides a fixed pressure boost to patient-initiated breaths

PSV augments each spontaneous patient-initiated breath with a clinician-set pressure boost, reducing work of breathing while maintaining patient control of rate and timing.

Which parameter is used to calculate static compliance on a mechanically ventilated patient?

Answer: Plateau pressure minus PEEP divided by tidal volume

Static compliance = Tidal Volume / (Plateau Pressure – PEEP), reflecting the compliance of the respiratory system without the influence of airway resistance.