The nurse is caring for a client receiving assist-control (AC) via mechanical ventilation. The nurse understands that this setting is used to do which of the following?
The nurse is caring for a client receiving assist-control (AC) via mechanical ventilation. The nurse understands that this setting is used to do which of the following?
A. Allow spontaneous breaths at the client’s tidal volume.
[30%]
B. Deliver additional pressure at the end of exhalation.
[11%]
C. Deliver a preset tidal volume during spontaneous breaths.
[40%]
D. Provide inspiratory pressure during ventilations.
[19%]
Statistics
Subject/Lesson
Subject
Critical Care
Lesson
Critical Care Concepts
Client Need
Test Plan
Reduction of Risk Potential
Related Topic
Potential for Complications of Diagnostic Tests/Treatments/Procedures
Item Type
Item Type
Knowledge/Comprehension
Explanation
Choice C is correct. Assist-control (AC) is a volume mode on a mechanical ventilator that senses a client’s ability for a spontaneous breath. When the client takes a spontaneous breath, it will deliver the tidal volume preset on the ventilator. This is in addition to the client receiving the ventilated breaths preset in the rate. For example, if the client is at a preset rate of 12 and taking 4 spontaneous breaths, each breath of the 16 will receive 515 mL of gas (the tidal volume preset).
Choices A, B, and D are incorrect. AC differs from SIMV (synchronized intermittent mandatory ventilation); in SIMV, the client may trigger a spontaneous breath and their own tidal volume. Pressure added at the end of exhalation to prevent alveoli collapse would be a description of PEEP (positive end-expiratory pressure). Inspiratory pressure during ventilation would be a description appropriate for pressure support ventilation.
Related Videos
3 Key Topics
Ventilators- Critical Care
27.1 Critical Care Respiratory System
Additional Info
When caring for a client on a ventilator, you should be familiar with the following settings:
- Mode (Volume [SIMV, A/C] or Pressure [PSV])
- Rate (Number of breaths per minute)
- Tidal volume (the amount of gas delivered to the client)
- Fraction of inspired oxygen (FiO2 - the percentage of oxygen given per breath)
- PEEP (pressure added at exhalation to keep the small airways open and mitigate atelectasis)
- Pressure support (PS - provides added pressure when the client takes a spontaneous breath)
