Deck 14: Physiological Basis for Oxygenation and Lung Protection Strategies

Question 1

On which of the following conditions is oxygen therapy effective?
I.Anatomical shunting
II.V/Q mismatch
III.Diffusion defects
IV.Hypoventilation

A) I, II, III
B) III, IV
C) I, II, III, IV
D) II, III, IV

Answer 1

II, III, IV

Question 2

How should patients with unilateral lung disease be positioned to optimize oxygenation?

A) Supine
B) With the healthy lung down
C) With the healthy lung up
D) Prone

Answer 2

With the healthy lung down

Question 3

In which of the following types of patients is plateau pressure not a reliable surrogate for assessing alveolar overdistension ?

A) Patients with ARDS
B) Patients with pneumonia
C) Patients with restricted chest wall and diaphragmatic movement
D) Patients with ALI

Answer 3

Patients with restricted chest wall and diaphragmatic movement

Question 4

When should CPAP or PEEP be considered?

A) If a PaO₂ of at least 60 mm Hg with an FIO₂ of 0.5 or less cannot be achieved
B) If a PaO₂ of at least 50 mm Hg with an FIO₂ of 0.5 or less cannot be achieved
C) If a PaO₂ of at least 80 mm Hg with an FIO₂ of 0.5 or less cannot be achieved
D) If a PaO₂ of at least 60 mm Hg with an FIO₂ of 0.6 or less cannot be achieved

Question 5

What is the best correlate of alveolar pressure in mechanically ventilated patients?

A) Plateau pressure
B) Peak pressure
C) PEEP
D) Trans-airway pressure

Question 6

What is the most common target level of hemoglobin saturation when oxygen is administered?

A) At least 85%
B) At least 90%
C) At least 95%
D) At least 98%

Question 7

What is the most commonly recommended position for a patient in the immediate post-surgical period to improve the PaO₂?

A) Supine
B) Upright
C) With the healthy lung up
D) Prone

Question 8

Which of the following substances are examples of inflammatory mediators?
I.Cytokines
II.Endotoxins
III.Prostaglandins
IV.Oxygen radicals

A) I, II, III
B) III, IV
C) I, II, III, IV
D) II, III

Question 9

Which of the following are characteristics of ALI?
I.PaO₂/FIO₂ < 200 mm Hg
II.Alveolar-capillary membrane injury
III.Widespread atelectasis
IV.Low compliance

A) I, II, III
B) II, III, IV
C) I, II, III, IV
D) II, III

Question 10

What is the generally accepted plateau pressure below which lung injury is minimized?

A) 40 cm H₂O
B) 35 cm H₂O
C) 30 cm H₂O
D) 25 cm H₂O

Question 11

Which of the following statements are true of ROP?
I.A higher than normal PaO₂ may cause ROP.
II.The PaO₂ is the critical factor in ROP, not the FIO₂ per se.
III.ROP may cause permanent blindness.
IV.The FIO₂ is the critical factor in ROP, not the PaO₂ per se.

A) I, II, III
B) III, IV
C) I, II, III, IV
D) II, III

Question 12

What is the minimum level of FIO₂ that, when used for a prolonged period of time, has been associated with damage to alveolar cells?

A)0.30-0.39
B)0.40-0.49
C)0.50-0.59
D)0.60-0.69

Question 13

What type of oxygen device should be recommended for a patient with hypercapnic COPD?

A) High flow
B) Low flow
C) Non-rebreathing mask
D) Nasal cannula

Question 14

Which of the following levels of FIO₂ has been considered safe for preventing significant lung impairment?

A)0.50 or less for 7 to 10 days
B)0.50 or less for 2 to 7 days
C)0.40 or less for 7 to 10 days
D)0.60 or less for 7 to 10 days

Question 15

Which of the following is an absolute contraindication for CPAP?

A) ARDS
B) Patients who cannot sustain adequate spontaneous ventilation
C) Patients with unilateral lung disease
D) Patients with increased intracranial pressures

Question 16

Which of the following are considered mechanisms of ventilator-induced lung injury?
I.Barotrauma
II.Volutrauma
III.Biotrauma
IV.Atelectrauma

A) I, II, III
B) III, IV
C) I, II, III, IV
D) II, III

Question 17

Which of the following are considered poor candidates for PEEP and CPAP?
I.Unilateral or localized lung disease
II.Normally compliant lungs
III.Highly compliant lungs
IV.Bilateral lung disease

A) I, II, III
B) III, IV
C) I, II, III, IV
D) II, III

Question 18

What is the level of PaO₂ set as a goal for oxygen therapy in the healthy adult?

A) At least 50 mm Hg
B) At least 60 mm Hg
C) At least 70 mm Hg
D) At least 80 mm Hg

Question 19

What is the major difference between CPAP and PEEP?

A) Airway pressure does not rise during inspiration with CPAP.
B) Airway pressure does not rise during inspiration with PEEP.
C) Airway pressure does not rise during expiration with CPAP.
D) Airway pressure does not rise during expiration with PEEP.

Question 20

Which of the following parameters should be periodically evaluated in patients with COPD who are receiving oxygen therapy?

A) SpO2
B) PAO2
C) HCO3-
D) PaCO2

Question 21

Which of the following strategies is considered the standard of care in preventing alveolar collapse?

A) Low tidal volume
B) High PEEP
C) Open lung approach
D) Permissive hypercapnia

Question 22

Which of the following levels of tidal volume is associated with a 22% reduction in mortality of patients with ARDS?

A) 5 mL/kg
B) 6 mL/kg
C) 7 mL/kg
D) 10 mL/kg

Question 23

Which of the following strategies have been promoted for the management of patients with ARDS?
I.Inverse ratio ventilation
II.Liquid ventilation
III.High-frequency oscillatory ventilation
IV.Heliox therapy

A) I, III, IV
B) I, II, III
C) I, II, III, IV
D) II, IV

Question 24

What is the best explanation for the increased incidence of MODS in mechanically ventilated patients with ARDS?

A) Inflammatory mediators cause injury to other organs.
B) Mechanical ventilation disrupts other cellular membranes.
C) Patients with ARDS are more susceptible to renal failure.
D) Renal and liver failure may cause ARDS.