Author Question: The therapist is measuring a patient's tidal volume as the patient receives mechanical ventilation. ... (Read 61 times)

storky111 · **on:** Jul 16, 2018

The therapist is measuring a patient's tidal volume as the patient receives mechanical ventilation. The pneumotachometer being used is a differential pressure flowmeter type incorporated in the system of the mechanical ventilator, which is currently administering 100 O2 to the patient. By what percent will the measurement be in error because of the 100 O2?

A. 5
B. 12
C. 16
D. 21

Question 2

Which of the following components comprise airway or ventilator circuit pressures? I. pressure generated to overcome airway resistance II. transpulmonary pressure III. pressure caused by dynamic compression IV. pressure from respiratory system compliance

A. I, IV only
B. II, III only
C. I, III, IV only
D. II, III, IV only

abro1885 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: B
A. Incorrect response: See explanation B.
B. Correct response: Gas viscosity affects the calibration of the Fleisch pneumotachometer when 100 O2 is used. An error of 12 occurs if 100 O2 is used on a differential pressure flowmeter calibrated on room air.
C. Incorrect response: See explanation B.
D. Incorrect response: See explanation B.

Answer to Question 2

ANS: A
A. Correct response: Airway or ventilator circuit pressures reflect the pressures to overcome airway resistance and respiratory system compliance. When an inspiratory pause is activated, the pressure related to respiratory system compliance is measured. The pressure is the static pressure or the plateau pressure.
B. Incorrect response: Transpulmonary pressure gradient is the pressure difference between alveolar pressure and the plateau (static) pressure.
C. Incorrect response: The pressure is not measured during mechanical ventilation.
D. Incorrect response: See explanation A.