Author Question: A patient is being weaned from invasive mechanical ventilation using VC-IMV. The respiratory ... (Read 67 times)

kodithompson · **on:** Jul 16, 2018

A patient is being weaned from invasive mechanical ventilation using VC-IMV. The respiratory therapist reviews the following data from the past few hours.

Time Set VT (mL) Spontaneous VT (mL) Set Rate (per min) Spontaneous Rate (per min)
0630 650 410 8 6
1020 650 400 6 10
1600 650 320 4 20
2200 650 250 2 32
What should the respiratory therapist recommend for this patient?
a. Switch the mode to VC-CMV.
b. Add and titrate pressure support.
c. Extubate and place the patient on NPPV.
d. Increase the set rate to 8 breaths/min.

Question 2

At what pressure is pressure support not high enough to contribute significantly to ventilatory support but is sufficient to overcome the work imposed by the ventilator system?

a. 2 cm H2O
b. 5 cm H2O
c. 8 cm H2O
d. 10 cm H2O

choc0chan · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
The data demonstrate that as the set IMV was decreased, the patient's spontaneous respiratory rate increased and the spontaneous tidal volume decreased. This shows that the patient's work of breathing is excessive and most likely due to the resistance from the ventilator system, circuit, and artificial airway. Initiate pressure support and titrate the level to improve the spontaneous volume and decrease the spontaneous rate. Once the patient is stable, the pressure support may be weaned.

Answer to Question 2

ANS: B
When pressure support is reduced to about 5 cm H2O, the pressure level is not high enough to contribute significantly to ventilatory support. However, this level of support is usually sufficient to overcome the work imposed by the ventilator system (i.e., the resistance of the ET tube, trigger sensitivity, demand-flow capabilities, and the type of humidifier used).