Chapter 23: Special Techniques in Ventilatory Support
Cairo: Evolve Resources for Pilbeam’s Mechanical Ventilation: Physiological and
Clinical Applications, 6th Edition .
MULTIPLE CHOICE
1. In the APRV mode, which of the following is considered baseline?
a. Plow
b. Phigh
c. Tlow
d. Thigh
ANS: B
In the APRV mode, the Phigh is considered the baseline pressure.
REF: pg. 487
2. Compared with pressure-controlled inverse ratio ventilation, APRV does which of the
following?
a. Decreases the cardiac index
b. Reduces the need for sedation
c. Increases the peak airway pressure
d. Increases the central venous pressure
ANS: B
Compared with pressure-controlled inverse ratio ventilation, APRV reduces peak and mean
airway pressures, increases cardiac index, decreases central venous pressure, increases urine
output, increases oxygen delivery, and reduces the need for sedation and paralysis.
REF: pg. 488 | pg. 489
3. The advantage of APRV over VC-CMV or PC-CMV is which of the following?
a. It enhances CO2 elimination.
b. Volume delivery is consistent.
c. Independent lung regions are better ventilated.
d. It reduces the risk of ventilator-induced lung injury.
ANS: D
APRV can reduce airway pressure in patients with ALI/ARDS; it therefore is also thought to
reduce the risk of ventilator-induced lung injury. In APRV, the volume delivery varies,
depending on lung compliance, airway resistance, and the patient’s spontaneous effort. APRV
helps ventilate the dependent regions of the lungs, which are better perfused, improving the
patient’s ventilation/perfusion matching. CO2 elimination is not completely supported by
APRV and relies more on the patient’s spontaneous breathing.
REF: pg. 488 | pg. 489
4. When Thigh is set at 5.5 seconds, and the Tlow is set at 0.5 second, what is the set ventilator rate?
a. 8
b. 10
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, c. 14
d. 16
ANS: B
Thigh + Tlow = TCT; 60/TCT = f.
REF: pg. 489
5. Which variable in APRV is responsible for the removal of CO2 from the body?
a. Tlow
b. Thigh
c. Plow
d. Phigh
ANS: A
During the release time, or Tlow, the patient exhales a volume of gas; this allows ventilation
and the removal of CO2 from the body.
REF: pg. 490
6. The variable that allows for an unimpeded expiratory gas flow is which of the following?
a. Tlow
b. Thigh
c. Plow
d. Phigh
ANS: C
Some practitioners recommend initially setting Plow at 0 cm H2O; this setting allows an
unimpeded expiratory gas flow and a rapid drop in pressure.
REF: pg. 490
7. What is the maximum pressure setting for Phigh?
a. 25 cm H2O
b. 30 cm H2O
c. 35 cm H2O
d. 40 cm H2O
ANS: C
Phigh should not exceed 30-35 cm H2O, to prevent overdistention injury to the lungs.
REF: pg. 490
8. A patient being ventilated with APRV has the following settings: Phigh = 24 cm H2O; Thigh = 5
sec; Plow = 4 cm H2O; Tlow = 1 second, FIO2 = 0.3. The patient’s spontaneous respiratory rate is
10 breaths/min. The current arterial blood gas values are: PaO2 = 91 mm Hg; PaCO2 = 62 mm
Hg. What should the respiratory therapist recommend for this patient?
a. Increase the Plow to 5.5 cm H2O.
b. Decrease the Tlow to 0.5 sec.
c. Increase the Phigh to 40 cm H2O.
d. Decrease the Plow to 0 cm H2O.
ANS: D
This study source was downloaded by 100000842568006 from CourseHero.com on 05-07-2022 13:39:22 GMT -05:00
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Cairo: Evolve Resources for Pilbeam’s Mechanical Ventilation: Physiological and
Clinical Applications, 6th Edition .
MULTIPLE CHOICE
1. In the APRV mode, which of the following is considered baseline?
a. Plow
b. Phigh
c. Tlow
d. Thigh
ANS: B
In the APRV mode, the Phigh is considered the baseline pressure.
REF: pg. 487
2. Compared with pressure-controlled inverse ratio ventilation, APRV does which of the
following?
a. Decreases the cardiac index
b. Reduces the need for sedation
c. Increases the peak airway pressure
d. Increases the central venous pressure
ANS: B
Compared with pressure-controlled inverse ratio ventilation, APRV reduces peak and mean
airway pressures, increases cardiac index, decreases central venous pressure, increases urine
output, increases oxygen delivery, and reduces the need for sedation and paralysis.
REF: pg. 488 | pg. 489
3. The advantage of APRV over VC-CMV or PC-CMV is which of the following?
a. It enhances CO2 elimination.
b. Volume delivery is consistent.
c. Independent lung regions are better ventilated.
d. It reduces the risk of ventilator-induced lung injury.
ANS: D
APRV can reduce airway pressure in patients with ALI/ARDS; it therefore is also thought to
reduce the risk of ventilator-induced lung injury. In APRV, the volume delivery varies,
depending on lung compliance, airway resistance, and the patient’s spontaneous effort. APRV
helps ventilate the dependent regions of the lungs, which are better perfused, improving the
patient’s ventilation/perfusion matching. CO2 elimination is not completely supported by
APRV and relies more on the patient’s spontaneous breathing.
REF: pg. 488 | pg. 489
4. When Thigh is set at 5.5 seconds, and the Tlow is set at 0.5 second, what is the set ventilator rate?
a. 8
b. 10
This study source was downloaded by 100000842568006 from CourseHero.com on 05-07-2022 13:39:22 GMT -05:00
https://www.coursehero.com/file/22207000/c23/
, c. 14
d. 16
ANS: B
Thigh + Tlow = TCT; 60/TCT = f.
REF: pg. 489
5. Which variable in APRV is responsible for the removal of CO2 from the body?
a. Tlow
b. Thigh
c. Plow
d. Phigh
ANS: A
During the release time, or Tlow, the patient exhales a volume of gas; this allows ventilation
and the removal of CO2 from the body.
REF: pg. 490
6. The variable that allows for an unimpeded expiratory gas flow is which of the following?
a. Tlow
b. Thigh
c. Plow
d. Phigh
ANS: C
Some practitioners recommend initially setting Plow at 0 cm H2O; this setting allows an
unimpeded expiratory gas flow and a rapid drop in pressure.
REF: pg. 490
7. What is the maximum pressure setting for Phigh?
a. 25 cm H2O
b. 30 cm H2O
c. 35 cm H2O
d. 40 cm H2O
ANS: C
Phigh should not exceed 30-35 cm H2O, to prevent overdistention injury to the lungs.
REF: pg. 490
8. A patient being ventilated with APRV has the following settings: Phigh = 24 cm H2O; Thigh = 5
sec; Plow = 4 cm H2O; Tlow = 1 second, FIO2 = 0.3. The patient’s spontaneous respiratory rate is
10 breaths/min. The current arterial blood gas values are: PaO2 = 91 mm Hg; PaCO2 = 62 mm
Hg. What should the respiratory therapist recommend for this patient?
a. Increase the Plow to 5.5 cm H2O.
b. Decrease the Tlow to 0.5 sec.
c. Increase the Phigh to 40 cm H2O.
d. Decrease the Plow to 0 cm H2O.
ANS: D
This study source was downloaded by 100000842568006 from CourseHero.com on 05-07-2022 13:39:22 GMT -05:00
https://www.coursehero.com/file/22207000/c23/
