Author Question: For a given minute ventilation, partial pressure of end-tidal carbon dioxide (PetCO2) is a function ... (Read 69 times)

armygirl · **on:** Jul 16, 2018

For a given minute ventilation, partial pressure of end-tidal carbon dioxide (PetCO2) is a function of which of the following? 1. Metabolic rate 2. Cardiac output 3. Alveolar dead space 4. Physiologic shunt

a. 1 and 3 only
b. 1, 2, and 3 only
c. 2, 3, and 4 only
d. 1, 2, 3, and 4

Question 2

During shift report, the day shift respiratory therapist informs the night shift respiratory therapist about a freshly postoperative patient who is receiving full support via mechanical ventilation.

At the time of the last patient-ventilator system check the patient had not awaken from anesthe-sia. During first round on the day shift the respiratory therapist notes the capnography shown in the figure. The most appropriate action to take would be to do which of the following?

a. Administer a bronchodilator.
b. Begin the weaning process.
c. Fix the leak in the sampling line.
d. Reinflate the ET tube cuff.

Sassygurl126 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
Changes in metabolic rate cause changes in partial pressure of end-tidal carbon dioxide (PetCO2). For instance, fever and shivering increase the metabolism and increase the PetCO2. A change in cardiac output will change PetCO2 because the heart transports the blood that carries the carbon dioxide (CO2) to the lungs for elimination. Increases in cardiac output will increase PetCO2. A change in dead space ventilation will also cause changes in the PetCO2. Increasing dead space will decrease the PetCO2.

Answer to Question 2

ANS: B
The figure shows a patient whose capnography is demonstrating spontaneous respiratory efforts during mechanical ventilation. This corresponds to the patient's waking up from anesthesia. With all else stable, the next step would be to begin the weaning process.