Comprehensive Test
Bank for Pilbeam’s
Mechanical
Ventilation,
Physiological And
Clinical Applications
6th Edition By J.M.
Cairo, PhD, RRT, FAARC
, Pilbeam's Mechanical Ventilation: Physiological and Clinical
Applications, 6th Edition
J.M. Cairo, PhD, RRT, FAARC
Elsevier, 2016
Chapter 1: Oxygenation and Acid-Base Evaluation
PART A: MULTIPLE CHOICE QUESTIONS (35 Questions)
1. The structure responsible for returning oxygenated blood to the left atrium is the:
A) Pulmonary artery
B) Pulmonary vein
C) Superior vena cava
D) Inferior vena cava
Answer: B
Rationale: The pulmonary veins carry oxygenated blood from the lungs back to the left
atrium of the heart. The pulmonary artery carries deoxygenated blood from the right
ventricle to the lungs. The superior and inferior vena cava return deoxygenated blood to
the right atrium .
Difficulty: Easy
Learning Objective: 1.1
, 2. The primary chemical receptors that stimulate inspiration are located in the:
A) Brain (central chemoreceptors)
B) Lungs (pulmonary stretch receptors)
C) Aorta and carotid arteries (peripheral chemoreceptors)
D) Both A and C
Answer: D
Rationale: Inspiration is stimulated by both central chemoreceptors in the brain (which
respond to changes in CSF pH and CO2) and peripheral chemoreceptors located in the
carotid and aortic bodies (which respond primarily to changes in PaO2, pH, and PaCO2) .
Difficulty: Medium
Learning Objective: 1.2
3. A patient's arterial blood gas shows: pH 7.28, PaCO2 55 mmHg, HCO3- 24 mEq/L.
What is the primary acid-base disorder?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Answer: C
Rationale: The pH is low (acidemia) and the PaCO2 is elevated (55 mmHg). Since CO2 is
the primary respiratory acid, this indicates a respiratory acidosis. The normal bicarbonate
(HCO3-) suggests that this is an acute process without renal compensation .
Difficulty: Hard
Learning Objective: 1.3
4. The fraction of inspired oxygen (FiO2) delivered by a nasal cannula at 4 L/min is
approximately:
A) 0.24
B) 0.28
, C) 0.32
D) 0.36
Answer: D
Rationale: The approximate FiO2 delivered by a nasal cannula can be estimated using
the rule of thumb: FiO2 = 0.21 + (0.03 × L/min). At 4 L/min, this is 0.21 + (0.03 × 4) =
0.33, but more commonly accepted values are slightly higher. The correct answer is D)
0.36, which matches the standard approximations for 4 L/min. Each liter of oxygen
increases the FiO2 by approximately 3-4%.
Difficulty: Medium
Learning Objective: 1.4
5. A patient has a PaO2 of 60 mmHg while breathing room air (FiO2 = 0.21). The
PaO2/FiO2 (P/F) ratio is approximately:
A) 60
B) 143
C) 286
D) 300
Answer: C
Rationale: The P/F ratio is calculated by dividing the PaO2 by the FiO2. In this case, 60 /
0.21 = 285.7, which rounds to approximately 286. A P/F ratio less than 300 indicates
acute lung injury, while a P/F ratio less than 200 indicates ARDS .
Difficulty: Hard
Learning Objective: 1.5
6. During spontaneous inspiration, alveolar pressure (PA) is approximately:
A) -1 cm H2O
B) +1 cm H2O
C) 0 cm H2O
D) -5 cm H2O
Bank for Pilbeam’s
Mechanical
Ventilation,
Physiological And
Clinical Applications
6th Edition By J.M.
Cairo, PhD, RRT, FAARC
, Pilbeam's Mechanical Ventilation: Physiological and Clinical
Applications, 6th Edition
J.M. Cairo, PhD, RRT, FAARC
Elsevier, 2016
Chapter 1: Oxygenation and Acid-Base Evaluation
PART A: MULTIPLE CHOICE QUESTIONS (35 Questions)
1. The structure responsible for returning oxygenated blood to the left atrium is the:
A) Pulmonary artery
B) Pulmonary vein
C) Superior vena cava
D) Inferior vena cava
Answer: B
Rationale: The pulmonary veins carry oxygenated blood from the lungs back to the left
atrium of the heart. The pulmonary artery carries deoxygenated blood from the right
ventricle to the lungs. The superior and inferior vena cava return deoxygenated blood to
the right atrium .
Difficulty: Easy
Learning Objective: 1.1
, 2. The primary chemical receptors that stimulate inspiration are located in the:
A) Brain (central chemoreceptors)
B) Lungs (pulmonary stretch receptors)
C) Aorta and carotid arteries (peripheral chemoreceptors)
D) Both A and C
Answer: D
Rationale: Inspiration is stimulated by both central chemoreceptors in the brain (which
respond to changes in CSF pH and CO2) and peripheral chemoreceptors located in the
carotid and aortic bodies (which respond primarily to changes in PaO2, pH, and PaCO2) .
Difficulty: Medium
Learning Objective: 1.2
3. A patient's arterial blood gas shows: pH 7.28, PaCO2 55 mmHg, HCO3- 24 mEq/L.
What is the primary acid-base disorder?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Answer: C
Rationale: The pH is low (acidemia) and the PaCO2 is elevated (55 mmHg). Since CO2 is
the primary respiratory acid, this indicates a respiratory acidosis. The normal bicarbonate
(HCO3-) suggests that this is an acute process without renal compensation .
Difficulty: Hard
Learning Objective: 1.3
4. The fraction of inspired oxygen (FiO2) delivered by a nasal cannula at 4 L/min is
approximately:
A) 0.24
B) 0.28
, C) 0.32
D) 0.36
Answer: D
Rationale: The approximate FiO2 delivered by a nasal cannula can be estimated using
the rule of thumb: FiO2 = 0.21 + (0.03 × L/min). At 4 L/min, this is 0.21 + (0.03 × 4) =
0.33, but more commonly accepted values are slightly higher. The correct answer is D)
0.36, which matches the standard approximations for 4 L/min. Each liter of oxygen
increases the FiO2 by approximately 3-4%.
Difficulty: Medium
Learning Objective: 1.4
5. A patient has a PaO2 of 60 mmHg while breathing room air (FiO2 = 0.21). The
PaO2/FiO2 (P/F) ratio is approximately:
A) 60
B) 143
C) 286
D) 300
Answer: C
Rationale: The P/F ratio is calculated by dividing the PaO2 by the FiO2. In this case, 60 /
0.21 = 285.7, which rounds to approximately 286. A P/F ratio less than 300 indicates
acute lung injury, while a P/F ratio less than 200 indicates ARDS .
Difficulty: Hard
Learning Objective: 1.5
6. During spontaneous inspiration, alveolar pressure (PA) is approximately:
A) -1 cm H2O
B) +1 cm H2O
C) 0 cm H2O
D) -5 cm H2O
