A patient with an IBW of 68 kg is intubated and being mechanically ventilated with VC-CMV, f = 12/min, and VT = 470 mL

Question

The patient has a combined respiratory rate of 25/min. The ABG results are: pH 7.56, PaCO2 26 mm Hg, and HCO3? 22 mEq/L. The most appropriate action is to do which of the following?
a. Decrease the set f to 8/min.
b. Decrease the set VT to 300 mL.
c. Sedate and paralyze the patient.
d. Change the mode to VC-IMV.

Answer 1

ANS: D
The patient has ventilator-induced respiratory alkalosis, because the patient is triggering the ma-chine breaths each time there is a spontaneous effort. Decreasing the set f will not alter the rate at which the patient is assisting. Decreasing the set VT to 300 mL will most likely result in the pa-tient's breathing at a faster rate because of the low volume. The patient could be sedated and paralyzed. However, the patient is not demonstrating a need for this option (i.e., extreme agita-tion, increased WOB, and patient-ventilator asynchrony). Changing to the VC-SIMV mode will allow the patient to breathe spontaneously and not trigger a machine breath each time.