Question

A patient receiving continuous mandatory ventilation in the assist-control mode develops auto-PEEP. Which of the following changes in ventilatory patterns would you consider to minimize the effects of auto-PEEP in this patient?

I. decreasing the rate or increasing VT
II. using low-rate synchronized intermittent mandatory ventilation
III. decreasing the peak inspiratory flow
IV. lowering the VT and letting the PaCO2 rise


A) II and IV


B) III and IV


C)I, II, and III


D)I, II, and IV

Answer 1

To minimize the effects of auto-PEEP, options such as decreasing the rate/increasing tidal volume, using low-rate SIMV, and lowering tidal volume while accepting a higher PaCO2 are considered. The correct choices to minimize auto-PEEP are decreasing the rate/increasing VT, using low-rate SIMV, and lowering the VT allowing the rise of PaCO2.

Step-by-step explanation:

To minimize the effects of auto-PEEP in a patient receiving continuous mandatory ventilation in the assist-control mode, the following changes in ventilatory patterns would be considered:

• Decreasing the rate of mandatory breaths or increasing tidal volume (VT) could help reduce the buildup of pressure from auto-PEEP.
• Using low-rate synchronized intermittent mandatory ventilation (SIMV), which allows spontaneous breathing between mechanical breaths, thus reducing the risk of air trapping and auto-PEEP.
• Decreasing the peak inspiratory flow can also minimize breath stacking and the development of auto-PEEP by allowing more time for expiration.
• Lowering the VT to reduce the likelihood of generating high intrinsic PEEP and accepting a higher PaCO2, within limits, this approach is also referred to as 'permissive hypercapnia'.

Therefore, the correct answer to minimize the effects of auto-PEEP would be option D) I, II, and IV, which includes decreasing the rate/increasing VT, using low-rate SIMV, and lowering the VT while letting the PaCO2 rise.