Workbook + Answer Keys for Egan's Fundamentals of
Respiratory Care - 13th Edition by Kacmarek
1. A patient with acute respiratory distress syndrome (ARDS) is on volume-controlled ventilation
with a tidal volume of 6 mL/kg predicted body weight. Plateau pressure is 30 cm H2O, and PEEP
is 12 cm H2O. The driving pressure is calculated as 18 cm H2O. Which of the following
interventions is most likely to improve driving pressure without compromising alveolar
recruitment?
A. Increase PEEP to 15 cm H2O and reassess plateau pressure
B. Reduce tidal volume to 4 mL/kg and increase respiratory rate
C. Switch to pressure-controlled ventilation with same mean airway pressure
D. Administer a neuromuscular blocking agent to improve chest wall compliance
Answer: B
Rationale: Driving pressure (plateau pressure minus PEEP) is a key predictor of mortality in ARDS.
Reducing tidal volume to 4 mL/kg decreases plateau pressure and driving pressure, but permissive
hypercapnia may require increased respiratory rate. Increasing PEEP may increase plateau pressure
and driving pressure if compliance worsens. Switching modes does not directly reduce driving pressure.
Neuromuscular blockers improve oxygenation but not driving pressure.
2. A patient with chronic obstructive pulmonary disease (COPD) is receiving noninvasive
ventilation (NIV) for acute hypercapnic respiratory failure. Initial settings: IPAP 12 cm H2O,
EPAP 4 cm H2O, backup rate 12/min. Arterial blood gas after 1 hour: pH 7.28, PaCO2 68 mm Hg,
PaO2 55 mm Hg on 40% oxygen. Which adjustment is most appropriate?
A. Increase IPAP to 16 cm H2O and keep EPAP at 4 cm H2O
B. Increase EPAP to 6 cm H2O and keep IPAP at 12 cm H2O
C. Increase IPAP to 14 cm H2O and EPAP to 6 cm H2O
D. Switch to pressure support ventilation with a backup rate of 15/min
Answer: C
Rationale: The patient has persistent hypercapnia and hypoxemia. Increasing IPAP improves alveolar
ventilation and reduces PaCO2, while increasing EPAP improves oxygenation by recruiting alveoli and
counteracting intrinsic PEEP. Option C addresses both issues. Option A may worsen hyperinflation if
EPAP is too low. Option B does not improve ventilation. Option D is not a distinct mode change; NIV
already provides pressure support.
3. Which of the following best explains why the oxygen-hemoglobin dissociation curve shifts to the
right during exercise?
A. Increased pH and decreased PaCO2 enhance hemoglobin's affinity for oxygen
B. Increased temperature and 2,3-bisphosphoglycerate (2,3-BPG) reduce hemoglobin's affinity for oxygen
C. Decreased temperature and increased pH stabilize the R state of hemoglobin
Page 1
,D. Increased PaO2 and decreased 2,3-BPG promote oxygen unloading
Answer: B
Rationale: During exercise, increased temperature and 2,3-BPG (from anaerobic metabolism) shift the
curve right, facilitating oxygen unloading to tissues. Increased pH (alkalosis) shifts left, not right.
Decreased temperature shifts left. Increased PaO2 does not shift the curve; it moves along the curve.
4. A patient with a pulmonary embolism has a measured dead space to tidal volume ratio (VD/VT)
of 0.7. Which of the following is the most likely contributing factor?
A. Increased alveolar dead space due to ventilation-perfusion mismatch
B. Increased anatomical dead space from bronchoconstriction
C. Decreased tidal volume due to restrictive lung disease
D. Increased physiological dead space from hypoventilation
Answer: A
Rationale: Pulmonary embolism increases alveolar dead space by ventilating alveoli that are not
perfused, raising VD/VT. Anatomical dead space is not significantly affected. Decreased tidal volume
would increase the ratio but is not the primary cause in PE. Hypoventilation increases PaCO2 but does
not primarily increase dead space.
5. During a ventilator waveform analysis, you observe a pressure-time curve with a concave
upward shape during inspiration in volume-controlled ventilation. Which of the following is the
most likely cause?
A. Patient inspiratory effort during mandatory breaths
B. Airway obstruction from secretions
C. Chest wall rigidity
D. Leak in the ventilator circuit
Answer: A
Rationale: In volume-controlled ventilation, a concave upward pressure rise indicates the patient is
actively inspiring, reducing airway resistance and causing a slower pressure rise initially. Airway
obstruction would produce a convex upward shape (rapid pressure rise). Chest wall rigidity increases
resistance and also convex shape. Leaks cause low pressure and may not show a clear pattern.
6. A patient with severe sepsis develops acute respiratory distress syndrome (ARDS). The
respiratory therapist recommends a lung-protective ventilation strategy. Which of the following
ventilator settings is most consistent with the ARDS Network protocol for a patient with a
predicted body weight of 70 kg?
A. Tidal volume 500 mL, rate 20/min, plateau pressure 32 cm H2O
B. Tidal volume 420 mL, rate 16/min, plateau pressure 28 cm H2O
C. Tidal volume 350 mL, rate 24/min, plateau pressure 25 cm H2O
D. Tidal volume 600 mL, rate 18/min, plateau pressure 30 cm H2O
Answer: B
Rationale: ARDSNet protocol recommends tidal volume 6 mL/kg PBW (420 mL for 70 kg) and plateau
pressure 30 cm H2O. Option B meets both. Option A has tidal volume 7.1 mL/kg and plateau >30.
Option C has low tidal volume but rate may be too high leading to auto-PEEP; plateau is acceptable.
Page 2
,Option D uses 8.6 mL/kg and plateau 30, but tidal volume is too high.
7. Which of the following statements about heliox therapy is correct?
A. Heliox (70% helium/30% oxygen) reduces airway resistance by decreasing gas density, improving laminar
flow
B. Heliox is contraindicated in patients with upper airway obstruction because it increases work of breathing
C. Heliox is most effective in conditions where turbulent flow predominates, such as distal small airways
D. Heliox should be administered with a non-rebreather mask to maintain high oxygen concentration
Answer: A
Rationale: Helium's low density reduces resistance in large airways where flow is turbulent, promoting
laminar flow. It is effective in upper airway obstruction, not contraindicated. Turbulent flow occurs in
large airways, not small airways where flow is laminar. Heliox is typically given via a tight-fitting mask
or ventilator circuit, not a non-rebreather mask which dilutes the mixture.
8. A patient with left ventricular failure has a pulmonary artery catheter in place. Which of the
following hemodynamic profiles is most consistent with cardiogenic pulmonary edema?
A. Pulmonary artery wedge pressure (PAWP) 22 mm Hg, cardiac index 2.0 L/min/m², systemic vascular
resistance 1500 dyn-s-cm
B. PAWP 8 mm Hg, cardiac index 4.5 L/min/m², systemic vascular resistance 800 dyn-s-cm
C. PAWP 18 mm Hg, cardiac index 3.5 L/min/m², systemic vascular resistance 1200 dyn-s-cm
D. PAWP 30 mm Hg, cardiac index 1.8 L/min/m², systemic vascular resistance 2000 dyn-s-cm
Answer: A
Rationale: Cardiogenic pulmonary edema is characterized by elevated PAWP (>18 mm Hg) due to left
heart failure, reduced cardiac index (<2.2 L/min/m²), and high SVR from compensatory
vasoconstriction. Option A matches. Option B shows low PAWP and high CI, consistent with sepsis.
Option C has borderline PAWP and normal CI. Option D has very high PAWP and low CI but extremely
high SVR, more consistent with severe decompensated heart failure or cardiogenic shock, but option A is
more typical of pulmonary edema without shock.
9. A respiratory therapist is assessing a patient receiving mechanical ventilation who has a
high-pressure alarm. Upon inspection, the patient is biting the endotracheal tube. Which of the
following actions should the therapist take first?
A. Insert a bite block and assess for relief of the alarm
B. Suction the endotracheal tube to clear possible obstruction
C. Decrease the tidal volume setting to lower peak pressure
D. Administer a sedative to reduce patient agitation
Answer: A
Rationale: Biting the tube causes obstruction and high pressure. Inserting a bite block is the immediate,
non-invasive solution. Suctioning is appropriate if secretions are suspected but not the first step for
biting. Decreasing tidal volume does not address the cause. Sedation may be needed but is not the first
action; a bite block is quicker and safer.
Page 3
, 10. Which of the following is the most accurate method to measure functional residual capacity
(FRC) in a mechanically ventilated patient with acute respiratory failure?
A. Helium dilution technique
B. Nitrogen washout technique
C. Body plethysmography
D. Computed tomography (CT) scan
Answer: B
Rationale: Nitrogen washout is the preferred bedside method for ventilated patients; it uses a known
oxygen concentration and measures exhaled nitrogen. Helium dilution is less accurate in patients with
air trapping or leaks. Body plethysmography is not feasible for ventilated patients. CT scan measures
lung volume but is not a bedside method and involves radiation.
11. A patient presents with acute hypoxemic respiratory failure. Arterial blood gas on room air
shows pH 7.48, PaCO2 32 mm Hg, PaO2 55 mm Hg, HCO3- 24 mEq/L. The clinician initiates
noninvasive ventilation (NIV) with a fraction of inspired oxygen (FiO2) of 0.5. After 30 minutes,
repeat ABG shows pH 7.42, PaCO2 38 mm Hg, PaO2 70 mm Hg. Which of the following best
explains the improvement in PaO2?
A. Increased alveolar ventilation reduced PaCO2, thereby increasing alveolar oxygen partial pressure.
B. NIV improved cardiac output, increasing mixed venous oxygen content.
C. Positive end-expiratory pressure (PEEP) recruited atelectatic alveoli, reducing shunt fraction.
D. The FiO2 increase alone accounted for the rise in PaO2, as the alveolar gas equation predicts.
Answer: C
Rationale: The improvement in PaO2 in acute hypoxemic respiratory failure with NIV is primarily due to
PEEP recruiting collapsed alveoli, decreasing shunt. While increased FiO2 and reduced PaCO2
contribute, the magnitude suggests shunt reduction. Option C is correct because PEEP is the key
mechanism in NIV for hypoxemia. Option A is less significant; Option B is not a primary effect; Option
D ignores shunt physiology.
12. A clinician is evaluating a patient with suspected pulmonary embolism. The ECG shows sinus
tachycardia, right axis deviation, and an S1Q3T3 pattern. D-dimer is elevated. Which of the
following diagnostic findings would most strongly support the diagnosis of a massive pulmonary
embolism with right ventricular dysfunction?
A. Transthoracic echocardiogram showing a tricuspid annular plane systolic excursion (TAPSE) of 22 mm.
B. CT pulmonary angiography showing a clot in the main pulmonary artery and right ventricular-to-left
ventricular diameter ratio >1.0.
C. Right heart catheterization revealing pulmonary artery pressure of 30/12 mm Hg.
D. Arterial blood gas showing PaO2 75 mm Hg on room air and an alveolar-arterial gradient of 50 mm Hg.
Answer: B
Rationale: A right ventricular-to-left ventricular diameter ratio >1.0 on CT indicates RV dysfunction, a
criterion for massive PE. TAPSE >20 mm is normal (A). Pulmonary artery pressure of 30/12 is only
mild pulmonary hypertension (C). An A-a gradient of 50 is abnormal but not specific for massive PE
(D). Thus, B is the strongest evidence.
Page 4
Respiratory Care - 13th Edition by Kacmarek
1. A patient with acute respiratory distress syndrome (ARDS) is on volume-controlled ventilation
with a tidal volume of 6 mL/kg predicted body weight. Plateau pressure is 30 cm H2O, and PEEP
is 12 cm H2O. The driving pressure is calculated as 18 cm H2O. Which of the following
interventions is most likely to improve driving pressure without compromising alveolar
recruitment?
A. Increase PEEP to 15 cm H2O and reassess plateau pressure
B. Reduce tidal volume to 4 mL/kg and increase respiratory rate
C. Switch to pressure-controlled ventilation with same mean airway pressure
D. Administer a neuromuscular blocking agent to improve chest wall compliance
Answer: B
Rationale: Driving pressure (plateau pressure minus PEEP) is a key predictor of mortality in ARDS.
Reducing tidal volume to 4 mL/kg decreases plateau pressure and driving pressure, but permissive
hypercapnia may require increased respiratory rate. Increasing PEEP may increase plateau pressure
and driving pressure if compliance worsens. Switching modes does not directly reduce driving pressure.
Neuromuscular blockers improve oxygenation but not driving pressure.
2. A patient with chronic obstructive pulmonary disease (COPD) is receiving noninvasive
ventilation (NIV) for acute hypercapnic respiratory failure. Initial settings: IPAP 12 cm H2O,
EPAP 4 cm H2O, backup rate 12/min. Arterial blood gas after 1 hour: pH 7.28, PaCO2 68 mm Hg,
PaO2 55 mm Hg on 40% oxygen. Which adjustment is most appropriate?
A. Increase IPAP to 16 cm H2O and keep EPAP at 4 cm H2O
B. Increase EPAP to 6 cm H2O and keep IPAP at 12 cm H2O
C. Increase IPAP to 14 cm H2O and EPAP to 6 cm H2O
D. Switch to pressure support ventilation with a backup rate of 15/min
Answer: C
Rationale: The patient has persistent hypercapnia and hypoxemia. Increasing IPAP improves alveolar
ventilation and reduces PaCO2, while increasing EPAP improves oxygenation by recruiting alveoli and
counteracting intrinsic PEEP. Option C addresses both issues. Option A may worsen hyperinflation if
EPAP is too low. Option B does not improve ventilation. Option D is not a distinct mode change; NIV
already provides pressure support.
3. Which of the following best explains why the oxygen-hemoglobin dissociation curve shifts to the
right during exercise?
A. Increased pH and decreased PaCO2 enhance hemoglobin's affinity for oxygen
B. Increased temperature and 2,3-bisphosphoglycerate (2,3-BPG) reduce hemoglobin's affinity for oxygen
C. Decreased temperature and increased pH stabilize the R state of hemoglobin
Page 1
,D. Increased PaO2 and decreased 2,3-BPG promote oxygen unloading
Answer: B
Rationale: During exercise, increased temperature and 2,3-BPG (from anaerobic metabolism) shift the
curve right, facilitating oxygen unloading to tissues. Increased pH (alkalosis) shifts left, not right.
Decreased temperature shifts left. Increased PaO2 does not shift the curve; it moves along the curve.
4. A patient with a pulmonary embolism has a measured dead space to tidal volume ratio (VD/VT)
of 0.7. Which of the following is the most likely contributing factor?
A. Increased alveolar dead space due to ventilation-perfusion mismatch
B. Increased anatomical dead space from bronchoconstriction
C. Decreased tidal volume due to restrictive lung disease
D. Increased physiological dead space from hypoventilation
Answer: A
Rationale: Pulmonary embolism increases alveolar dead space by ventilating alveoli that are not
perfused, raising VD/VT. Anatomical dead space is not significantly affected. Decreased tidal volume
would increase the ratio but is not the primary cause in PE. Hypoventilation increases PaCO2 but does
not primarily increase dead space.
5. During a ventilator waveform analysis, you observe a pressure-time curve with a concave
upward shape during inspiration in volume-controlled ventilation. Which of the following is the
most likely cause?
A. Patient inspiratory effort during mandatory breaths
B. Airway obstruction from secretions
C. Chest wall rigidity
D. Leak in the ventilator circuit
Answer: A
Rationale: In volume-controlled ventilation, a concave upward pressure rise indicates the patient is
actively inspiring, reducing airway resistance and causing a slower pressure rise initially. Airway
obstruction would produce a convex upward shape (rapid pressure rise). Chest wall rigidity increases
resistance and also convex shape. Leaks cause low pressure and may not show a clear pattern.
6. A patient with severe sepsis develops acute respiratory distress syndrome (ARDS). The
respiratory therapist recommends a lung-protective ventilation strategy. Which of the following
ventilator settings is most consistent with the ARDS Network protocol for a patient with a
predicted body weight of 70 kg?
A. Tidal volume 500 mL, rate 20/min, plateau pressure 32 cm H2O
B. Tidal volume 420 mL, rate 16/min, plateau pressure 28 cm H2O
C. Tidal volume 350 mL, rate 24/min, plateau pressure 25 cm H2O
D. Tidal volume 600 mL, rate 18/min, plateau pressure 30 cm H2O
Answer: B
Rationale: ARDSNet protocol recommends tidal volume 6 mL/kg PBW (420 mL for 70 kg) and plateau
pressure 30 cm H2O. Option B meets both. Option A has tidal volume 7.1 mL/kg and plateau >30.
Option C has low tidal volume but rate may be too high leading to auto-PEEP; plateau is acceptable.
Page 2
,Option D uses 8.6 mL/kg and plateau 30, but tidal volume is too high.
7. Which of the following statements about heliox therapy is correct?
A. Heliox (70% helium/30% oxygen) reduces airway resistance by decreasing gas density, improving laminar
flow
B. Heliox is contraindicated in patients with upper airway obstruction because it increases work of breathing
C. Heliox is most effective in conditions where turbulent flow predominates, such as distal small airways
D. Heliox should be administered with a non-rebreather mask to maintain high oxygen concentration
Answer: A
Rationale: Helium's low density reduces resistance in large airways where flow is turbulent, promoting
laminar flow. It is effective in upper airway obstruction, not contraindicated. Turbulent flow occurs in
large airways, not small airways where flow is laminar. Heliox is typically given via a tight-fitting mask
or ventilator circuit, not a non-rebreather mask which dilutes the mixture.
8. A patient with left ventricular failure has a pulmonary artery catheter in place. Which of the
following hemodynamic profiles is most consistent with cardiogenic pulmonary edema?
A. Pulmonary artery wedge pressure (PAWP) 22 mm Hg, cardiac index 2.0 L/min/m², systemic vascular
resistance 1500 dyn-s-cm
B. PAWP 8 mm Hg, cardiac index 4.5 L/min/m², systemic vascular resistance 800 dyn-s-cm
C. PAWP 18 mm Hg, cardiac index 3.5 L/min/m², systemic vascular resistance 1200 dyn-s-cm
D. PAWP 30 mm Hg, cardiac index 1.8 L/min/m², systemic vascular resistance 2000 dyn-s-cm
Answer: A
Rationale: Cardiogenic pulmonary edema is characterized by elevated PAWP (>18 mm Hg) due to left
heart failure, reduced cardiac index (<2.2 L/min/m²), and high SVR from compensatory
vasoconstriction. Option A matches. Option B shows low PAWP and high CI, consistent with sepsis.
Option C has borderline PAWP and normal CI. Option D has very high PAWP and low CI but extremely
high SVR, more consistent with severe decompensated heart failure or cardiogenic shock, but option A is
more typical of pulmonary edema without shock.
9. A respiratory therapist is assessing a patient receiving mechanical ventilation who has a
high-pressure alarm. Upon inspection, the patient is biting the endotracheal tube. Which of the
following actions should the therapist take first?
A. Insert a bite block and assess for relief of the alarm
B. Suction the endotracheal tube to clear possible obstruction
C. Decrease the tidal volume setting to lower peak pressure
D. Administer a sedative to reduce patient agitation
Answer: A
Rationale: Biting the tube causes obstruction and high pressure. Inserting a bite block is the immediate,
non-invasive solution. Suctioning is appropriate if secretions are suspected but not the first step for
biting. Decreasing tidal volume does not address the cause. Sedation may be needed but is not the first
action; a bite block is quicker and safer.
Page 3
, 10. Which of the following is the most accurate method to measure functional residual capacity
(FRC) in a mechanically ventilated patient with acute respiratory failure?
A. Helium dilution technique
B. Nitrogen washout technique
C. Body plethysmography
D. Computed tomography (CT) scan
Answer: B
Rationale: Nitrogen washout is the preferred bedside method for ventilated patients; it uses a known
oxygen concentration and measures exhaled nitrogen. Helium dilution is less accurate in patients with
air trapping or leaks. Body plethysmography is not feasible for ventilated patients. CT scan measures
lung volume but is not a bedside method and involves radiation.
11. A patient presents with acute hypoxemic respiratory failure. Arterial blood gas on room air
shows pH 7.48, PaCO2 32 mm Hg, PaO2 55 mm Hg, HCO3- 24 mEq/L. The clinician initiates
noninvasive ventilation (NIV) with a fraction of inspired oxygen (FiO2) of 0.5. After 30 minutes,
repeat ABG shows pH 7.42, PaCO2 38 mm Hg, PaO2 70 mm Hg. Which of the following best
explains the improvement in PaO2?
A. Increased alveolar ventilation reduced PaCO2, thereby increasing alveolar oxygen partial pressure.
B. NIV improved cardiac output, increasing mixed venous oxygen content.
C. Positive end-expiratory pressure (PEEP) recruited atelectatic alveoli, reducing shunt fraction.
D. The FiO2 increase alone accounted for the rise in PaO2, as the alveolar gas equation predicts.
Answer: C
Rationale: The improvement in PaO2 in acute hypoxemic respiratory failure with NIV is primarily due to
PEEP recruiting collapsed alveoli, decreasing shunt. While increased FiO2 and reduced PaCO2
contribute, the magnitude suggests shunt reduction. Option C is correct because PEEP is the key
mechanism in NIV for hypoxemia. Option A is less significant; Option B is not a primary effect; Option
D ignores shunt physiology.
12. A clinician is evaluating a patient with suspected pulmonary embolism. The ECG shows sinus
tachycardia, right axis deviation, and an S1Q3T3 pattern. D-dimer is elevated. Which of the
following diagnostic findings would most strongly support the diagnosis of a massive pulmonary
embolism with right ventricular dysfunction?
A. Transthoracic echocardiogram showing a tricuspid annular plane systolic excursion (TAPSE) of 22 mm.
B. CT pulmonary angiography showing a clot in the main pulmonary artery and right ventricular-to-left
ventricular diameter ratio >1.0.
C. Right heart catheterization revealing pulmonary artery pressure of 30/12 mm Hg.
D. Arterial blood gas showing PaO2 75 mm Hg on room air and an alveolar-arterial gradient of 50 mm Hg.
Answer: B
Rationale: A right ventricular-to-left ventricular diameter ratio >1.0 on CT indicates RV dysfunction, a
criterion for massive PE. TAPSE >20 mm is normal (A). Pulmonary artery pressure of 30/12 is only
mild pulmonary hypertension (C). An A-a gradient of 50 is abnormal but not specific for massive PE
(D). Thus, B is the strongest evidence.
Page 4
