Which of the following occur in pressure-limited modes of ventilation?
1) The volume delivered at a given pressure must decrease as compliance falls.
2) The inspiratory flow varies with patient effort and lung mechanics.
3) Active effort by the patient against inspiration will decrease delivered volume.
4) The volume delivered at a given pressure must increase as Raw rises.

Question

Quizplus · Accepted Answer

In pressure-limited modes of ventilation, the ventilator delivers breaths up to a preset pressure limit, rather than a specific volume. This means that the actual volume delivered can vary based on changes in lung compliance and resistance. Specifically, as lung compliance decreases, the volume delivered for a given pressure will decrease (1), and inspiratory flow can indeed vary with patient effort and lung mechanics (2). If a patient actively resists inspiration, this can also decrease the volume delivered (3). The statement about volume increasing as airway resistance (Raw) rises is incorrect in the context of pressure-limited ventilation, as the volume delivered is primarily influenced by the preset pressure and the patient's lung compliance and resistance, not directly by changes in airway resistance in the manner described.

Which of the Following Occur in Pressure-Limited Modes of Ventilation