Author Question: A patient is receiving ventilation with volume-controlled continuous mandatory ventilation (VC-CMV). ... (Read 95 times)

james0929 · **on:** Jul 16, 2018

A patient is receiving ventilation with volume-controlled continuous mandatory ventilation (VC-CMV). During a patient-ventilator system check the respiratory therapist sees the flow-volume loop below.

The most appropriate action is to do which of the following?

a. Add positive end-expiratory pressure (PEEP).
b. Switch to pressure-controlled continuous mandatory ventilation (PC-CMV).
c. Administer a bronchodilator.
d. Check the endotracheal (ET) tube cuff pressure.

Question 2

During a patient-ventilator system check the respiratory therapist notices that the pressure-volume loop begins at zero on the x-axis but does not return to zero during expiration. The cause of this is which of the following?

a. Active exhalation
b. Inadequate sensitivity
c. Ventilator circuit leak
d. Decreased compliance

yifu223 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: C
The flow-volume loop shown in this question reflects increasing airway resistance. The expiratory flow part of the loop shows the scooped-out appearance. This is typical of a patient with airway obstruction. Administration of a bronchodilator will help to relieve some of the airway obstruc-tion due to bronchospasm. Since the problem is obstructive and not restrictive, adding positive end-expiratory pressure (PEEP) or switching to pressure-controlled continuous mandatory venti-lation (PC-CMV) will not address the issue. The flow-volume loop shows no leak in the system.

Answer to Question 2

ANS: C
When the loop on a pressure-volume loop does not return to zero during exhalation, there is a leak in the ventilator circuit.