RC 212 Midterm Exam Study Guide
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. Which of the following modes of ventilatory support would you recommend for a severely
hypoxemic patient with acute lung injury or acute respiratory distress syndrome (ARDS)?
a. Continuous positive airway pressure
b. High VT volume-cycled ventilation
c. Pressure-controlled ventilation
d. Bilevel pressure support by mask
____
2. A patient who just suffered severe closed-head injury and has a high intracranial pressure (ICP) is
about to be placed on ventilatory support. Which of the following strategies could help to lower the
ICP?
a. Maintain a PaCO2 from 25 to 30 mm Hg (deliberate hyperventilation).
b. Allow as much spontaneous breathing as possible (SIMV).
c. Maintain a high mean pressure using PEEP levels of 10 to 15 cm H2O.
d. Maintain a PaCO2 of 50 to 60 mm Hg (deliberate hypoventilation).
____
3. What are some causes of dynamic hyperinflation?
1. Increased expiratory time
2. Increased airway resistance
3. Decreased expiratory flow rate
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____
4. Which of the following are associated with hypercapnic respiratory failure due to decreased
ventilatory drive?
1. Brainstem lesions
2. Encephalitis
3. Hypothyroidism
4. Asthma
a. 1, 2, and 3 only
b. 2 and 4 only
c. 3 and 4 only
d. 2, 3, and 4 only
____
5. A patient with an opiate drug overdose is unconscious and exhibits the following blood gas results
breathing room air: pH = 7.19; PCO2 = 89; HCO3– = 27; PO2 = 48. Which of the following best
describes this patient’s condition?
a. Chronic hypoxemic respiratory failure
b. Chronic hypercapnic respiratory failure
c. Acute hypoxemic respiratory failure
d. Acute hypercapnic respiratory failure
____
6. Which of the following MIP measures taken on an adult patient indicates inadequate respiratory
muscle strength?
a. 90 cm H2O
b. 70 cm H2O
c. 40 cm H2O
d. 15 cm H2O
____
7. Which of the following patients are at greatest risk for developing auto-PEEP during mechanical
ventilation?
a. Those with acute lung injury
b. Those with COPD
c. Those with congestive heart failure
d. Those with bilateral pneumonia
____
8. Ventilatory support may be indicated when the VC falls below what level?
a. 45 ml/kg
b. 65 ml/kg
c. 10 ml/kg
d. 30 ml/kg
____
9. What is the normal range for PaO2/FiO2?
a. 350 to 450
b. 250 to 350
c. 150 to 250
d. 75 to 150
____ 10. What is the most common cause of low mixed venous oxygen?
a. Liver disease
b. Cardiac disease
c. Neuromuscular disease
d. Vascular disease
____ 11. What happens to the P(Aa)O2 with mismatch and shunt?
a. It increases with
mismatch and decreases with shunt.
b. It decreases with both
mismatch and shunt.
c. It increases with both
mismatch and shunt.
d. It does not change.
____ 12. In patients suffering from acute respiratory acidosis, below what pH level are intubation and
ventilatory support generally considered?
a. 7.2
b. 7.3
c. 7.1
d. 7.0
____ 13. You determine that an acutely ill patient can generate an MIP of 18 cm H2O. Based on this
information, what might you conclude?
a. The patient has inadequate respiratory muscle strength.
b. The patient has inadequate alveolar ventilation.
c. The patient has an excessive work of breathing.
d. The patient has an unstable or irregular ventilatory drive.
____ 14. Which of the following measures taken on adult patients indicate unacceptably high ventilatory
demands or work of breathing?
a. VE of 17 L/min
b. Breathing rate of 22/min
c. VD/VT of 0.45
d. MIP of 40 cm H2O
____ 15. Because an elevated PaCO2 increases ventilatory drive in normal subjects, the clinical presence of
hypercapnia indicates which of the following?
1. Inability of the stimulus to get to the muscles
2. Weak or missing central nervous system response to the elevated PCO2
3. Pulmonary muscle fatigue
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 16. A reversible impairment in the response of an overloaded muscle to neural stimulation best describes
which of the following?
a. Central respiratory muscle fatigue
b. Transmission respiratory muscle fatigue
c. Contractile respiratory muscle fatigue
d. Chronic respiratory muscle fatigue
____ 17. Which of the following is false about the “acute-on-chronic” form of respiratory failure?
a. It usually involves patients with hypoxemic respiratory failure.
b. It is most common in patients with chronic airway obstruction.
c. Bacterial or viral infections are common precipitating factors.
d. Mortality is associated with severity of acidosis.
____ 18. What is the optimal treatment of intrapulmonary shunt?
a. Increase the FiO2.
b. Decrease the FiO2.
c. Surgery.
d. Alveolar recruitment.
____ 19. Hypercapnic (type II) respiratory failure is a synonym for which one of the following terms?
a. Mismatching
b. Shunt
c. Diffusion impairment
d. Ventilatory failure
____ 20. Which of the following clinical signs suggest more severe hypoxemia?
a. Tachycardia
b. Cyanosis with polycythemia
c. Central nervous system dysfunction
d. Use of accessory muscles
____ 21. Which of the following are associated with hypercapnic respiratory failure due to respiratory muscle
weakness or fatigue?
1. Hyperthyroidism
2. Myasthenia gravis
3. Amyotrophic lateral sclerosis
4. Guillain-Barré syndrome
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 22. What type of disease is associated with perfusion/diffusion impairment?
a. Liver disease
b. Renal disease
c. Neuromuscular disease
d. Vascular disease
____ 23. What is the normal range of maximum inspiratory pressure, or MIP (also called negative inspiratory
force, or NIF), generated by adults?
a. 80 to 100 cm H2O
b. 50 to 80 cm H2O
c. 30 to 50 cm H2O
d. 20 to 30 cm H2O
____ 24. Which of the following measures are useful indicators in assessing the adequacy of a patient’s
oxygenation?
1. PaO2–PaO2
2. PaO2-to-FiO2 ratio
3. VD/VT
4. Pulmonary shunt
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3 only
____ 25. Mr. Adam is in the ICU on an FiO2 of 100%. An arterial blood gas reveals the following
information: pH of 7.18, PaCO2 of 59 mm Hg, PaO2 of 65 mm Hg, HCO3 of 24 mEq/L What action
would you recommend?
a. Provide ventilatory support.
b. Put patient on steroids.
c. Give patient chest PT.
d. Put patient on CPAP.
____ 26. Which of the following could cause hypercapnic respiratory failure?
1. Smoke inhalation
2. Opiate drug overdose
3. Chronic obstructive pulmonary disease
4. Hypothyroidism
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 27. Which of the following is the cardinal sign of increased work of breathing?
a. Hyperventilation
b. Retractions
c. Bradycardia
d. Tachypnea
____ 28. Which of the following are associated with hypercapnic respiratory failure due to increased work of
breathing?
1. Asthma
2. COPD
3. Obesity
4. Kyphoscoliosis
a. 1 and 2 only
b. 1, 2, and 4 only
c. 3 and 4 only
d. 1, 2, 3, and 4
____ 29. A diagnosis of respiratory failure can be made if which of the following are present?
1. PaO2 55 mm Hg, FiO2 0.21, PB 760 mm Hg
2. PaCO2 57 mm Hg, FiO2 0.21, PB 760 mm Hg
3. P(Aa)O2 45 mm Hg, FiO2 1.0, PB 760 mm Hg
4. PaO2/FiO2 400, PB 750 mm Hg
a. 1 and 2 only
b. 1, 3, and 4 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 30. Which of the following is a feature of Guillain-Barré?
a. Ascending muscle weakness
b. Descending muscle weakness
c. Limited to lower extremities
d. Limited to trunk
____ 31. A patient develops acute hypercapnic respiratory failure due to muscle fatigue. Which of the
following modes of ventilatory support would you consider for this patient?
1. Assist-control ventilation with adequate backup
2. Continuous positive airway pressure
3. Intermittent mandatory ventilation with adequate backup rate
4. Bilevel pressure support by mask
a. 2 and 4 only
b. 3 and 4 only
c. 1, 2, and 3 only
d. 1, 3, and 4 only
____ 32. Your patient is hypoventilating. Which of the following would be likely findings?
a. A normal P(A–a)O2 with a marked response to an increase in FiO2
b. An increases P(A–a)O2 with a marked response to an increase in FiO2
c. A normal P(A–a)O2 with no response to an increase in FiO2
d. A increased P(A–a)O2 with no response to an increase in FiO2
____ 33. Common bedside measures used to assess the adequacy of lung expansion include which of the
following?
1. VC
2. Respiratory rate
3. VT
4. VD/VT
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 34. If the pressure waveform of a ventilator remains the same when a patient’s lung mechanics change,
then what is the ventilator?
a. Volume controller
b. Pressure controller
c. Time controller
d. Flow controller
____ 35. A mode that allows spontaneously breathing patients to breathe at a positive-pressure level, but
drops briefly to a reduced pressure level for CO2 elimination during each breathing cycle is also
known as:
a. intermittent mandatory ventilation.
b. airway pressure release ventilation.
c. continuous mandatory ventilation (CMV).
d. continuous spontaneous ventilation.
____ 36. While observing a patient receiving ventilatory support, you notice that all delivered breaths are
initiated or terminated by the machine. Which of the following modes of ventilatory support is in
force?
a. Intermittent mandatory ventilation
b. Partial ventilatory support
c. Continuous mandatory ventilation
d. Continuous spontaneous ventilation
____ 37. During pressure-targeted ventilation, which of the following setting(s) determine(s) VT?
1. Pressure difference
2. Inspiratory time
3. Time constant
a.
b.
c.
d.
1 and 2 only
2 and 3 only
3 only
1, 2, and 3
____ 38. A physician requests that you switch from pressure-triggering a patient to flow-triggering. Which of
the following new settings would be appropriate?
a. Base flow = 0 L/min; trigger at 2 L/min
b. Base flow = 10 L/min; trigger at 2 cm H2O
c. Base flow = 10 L/min; trigger at 2 L/min
d. Base flow = 0 L/min; trigger at 10 cm H2O
____ 39. Mean airway pressure is highest with what waveform?
a. Rectangular flow
b. Rectangular pressure
c. Ascending ramp flow
d. Sinusoidal flow
____ 40. What is the application of pressure above atmospheric at the airway throughout expiration during
mechanical ventilation?
a. Positive end expiratory pressure (PEEP)
b. Pressure support ventilation
c. Continuous mandatory ventilation (CMV)
d. Continuous positive airway pressure (CPAP)
____ 41. During volume control ventilation, the clinician has control over which of the following?
1. Pressure waveform
2. Volume waveform
3. Flow waveform
a. 1 or 2 only
b. 2 or 3 only
c. 2 only
d. 1, 2, and 3
____ 42. Which of the following are true of the relationship between flow and volume?
1. Volume is the integral of flow.
2. Volume is the derivative of flow.
3. Flow is the derivative of volume.
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 43. The respiratory therapist has been called to transport a patient from the emergency department to
obtain a CT scan. Which of the following types of ventilator should the therapist chose to transport
the patient?
a. Electric
b. Apneuistic
c. Pneumatic
d. Electronic
____ 44. When you adjust the pressure drop necessary to trigger a breath on a ventilator, what are you
adjusting on the machine?
a. Sensitivity
b. Pressure limit
c. Mode setting
d. Positive end expiratory pressure (PEEP) level
____ 45. During volume-targeted ventilation, which of the following settings determine the expiratory time?
1. Volume
2. Flow
3. Rate
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 46. During volume-targeted ventilation, which of the following setting(s) determine(s) the total cycle
time?
1. Volume
2. Flow
3. Rate
a. 1 and 2 only
b. 2 and 3 only
c. 3 only
d. 1, 2, and 3
____ 47. A volume-cycled ventilator has a rate knob for setting the controlled frequency of breathing. If this
control is set to 12/min, which of the following other settings will determine the inspiratory and
expiratory times?
1. FiO2
2. Flow
3. Volume
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 48. A ventilator’s pressure waveform changes when a patient’s lung mechanics change, but its volume
waveform remains the same. The device does not directly control the delivered volume. What is this
ventilator?
a. Volume controller
b. Pressure controller
c. Time controller
d. Flow controller
____ 49. A complete ventilatory cycle or breath consists of which of the following phases?
1. Expiration
2. Initiation of inspiration
3. Inspiration
4. End of inspiration
a. 1 and 4 only
b. 2 and 3 only
c. 1, 2, and 4 only
d. 1, 2, 3, and 4
____ 50. Which of the following is the primary parameter used to alter the breath size in pressure controlled?
a. Positive inspiratory pressure (PIP)—positive end expiratory pressure (PEEP)
b. Continuous positive airway pressure (CPAP)
c. Tidal volume
d. Flow
____ 51. What ventilatory variable reaches and maintains a preset level before inspiration ends?
a. Limit
b. Cycle
c. Trigger
d. Baseline
____ 52. For which of the following uses might you consider the use of a purely pneumatically powered
ventilator?
1. As a backup to electrically powered ventilators
2. When electrical device cannot be used (e.g., magnetic resonance imaging)
3. During certain types of patient transport
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 53. A patient is receiving continuous mandatory ventilation in the control mode at a rate of 15/min. The
expiratory time is 2.9 sec. What is the inspiratory time?
a. 1.1 sec
b. 1.3 sec
c. 1.5 sec
d. 1.7 sec
____ 54. Which of the following equations best describes the pressure (P) necessary to drive gas into the
airway and inflate the lungs?
a. P = (Elastance  Volume) + (Resistance  Flow)
b. P = (Elastance – Volume) + (Resistance ÷ Flow)
c. P = (Volume + Compliance) + (Resistance ÷ Flow)
d. P = (Volume ÷ Compliance) – (Resistance  Flow)
____ 55. Pure time-triggered ventilation is the same as what type of ventilation?
a. Assist
b. Intermittent mandatory ventilation
c. Assist and control
d. Proportional assist
____ 56. During volume-targeted ventilation, which of the following settings determine I:E ratio?
1. Volume
2. Flow
3. Rate
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 57. A patient is receiving continuous mandatory ventilation in the control mode at a rate of 10/min. The
inspiratory time control is set at 25%. What is the I:E ratio?
a. 1:3
b. 1:2
c. 1:4
d. 1:1
____ 58. A ventilator can derive its input power from which of the following sources?
1. Alternating current (AC) electricity
2. Battery
3. Pneumatic
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 59. Which of the following major categories of ventilator function are useful in classifying ventilators?
1. Control system
2. Power transmission and conversion
3. Output
4. Input
a. 1 and 2 only
b. 3 and 4 only
c. 1, 3, and 4 only
d. 1, 2, 3, and 4
____ 60. Which of the following ventilators is controlled by fluidic logic systems?
a. Siemens Servo 300
b. Bio-Med MVP-10
c. Bird 8400ST
d. Bear 1000
____ 61. A patient is receiving continuous mandatory ventilation in the control mode at a rate of 20/min. The
inspiratory time is 0.75 sec. What is the percentage inspiratory time?
a. 20%
b. 25%
c. 30%
d. 33%
____ 62. In which of the following modes inspiration ends when flow decays to some preset value?
a. Intermittent mandatory ventilation
b. Pressure support ventilation
c. Continuous mandatory ventilation
d. Airway pressure release ventilation
____ 63. During mechanical ventilation, a spontaneous breath is defined as one that:
a. initiated and terminated by the machine.
b. begun by the patient and ended by the machine.
c. initiated and terminated by the patient.
d. begun by the machine and ended by the patient.
____ 64. Which of the following strategies are useful in the management of shunt?
1. Positive end expiratory pressure
2. Permissive hypercapnia
3. Control of membrane permeability
a. 2 and 3 only
b. 1 and 3 only
c. 1, 2, and 3
d. 1 only
____ 65. Which of the following conditions may require higher initial respiratory rates?
1. Metabolic alkalosis
2. ARDS
3. Increased intracranial pressure
4. Metabolic acidosis
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 66. Which of the following is the consequence of decreased resistance or compliance?
a. It takes more time to fill the alveoli.
b. It takes more time to empty the alveoli.
c. It takes less time to fill and more time to empty the alveoli.
d. It takes less time to fill and empty the alveoli.
____ 67. Mean airway pressures can be increased by which of the following factors?
1. Increasing the inspiratory time
2. Increasing compliance
3. Increasing level of PEEP
4. Changing from a square to a decelerating ramp waveform
a. 1, 2, and 3 only
b. 1, 3, and 4 only
c. 2 and 4 only
d. 1, 2, 3, and 4
____ 68. The volume delivered by a pressure-limited ventilator will decrease under which of the following
conditions?
1. The patient’s lung or thoracic (chest wall) compliance falls.
2. Airway resistance rises (inspiratory time <3 times the time constant).
3. The patient tenses the respiratory muscles during inspiration.
4. Airway resistance rises (inspiratory time >3 times the time constant).
a. 1 and 3 only
b. 1, 3, and 4 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 69. In which of the following modes of ventilatory support would the patient’s work of breathing be
least?
a. Continuous positive airway pressure (CPAP)
b. Pressure-supported ventilation (PSV)
c. Intermittent mandatory ventilation (IMV)
d. Continuous mandatory ventilation (CMV)
____ 70. When bedside work of breathing measures are unavailable, you should adjust the level of
pressure-supported ventilation (PSV) to which of the following breathing patterns?
Spontaneous Rate
VT
a. 20 breaths/min
6 ml/kg
b. 27 breaths/min
9 ml/kg
c. 22 breaths/min
4 ml/kg
d. 10 breaths/min
9 ml/kg
____ 71. To prevent muscle fatigue or atrophy, the level of PSV should be adjusted to achieve what work
load?
a. 0 J/L
b. 0.6 to 0.8 J/L
c. 0 to 0.5 J/L
d. Greater than 0.8 J/L
____ 72. All of the following factors would tend to increase mean airway pressure except:
a. short inspiratory times.
b. increased mandatory breaths.
c. increased levels of positive inspiratory pressure (PIP).
d. increased levels of positive end expiratory pressure (PEEP).
____ 73. Primary indications for using positive end expiratory pressure (PEEP) in conjunction with
mechanical ventilation include which of the following?
1. When dynamic hyperinflation occurs in chronic obstructive pulmonary disease (COPD) patients.
2. When the imposed work of breathing is excessive.
3. When acute lung injury causes refractory hypoxemia.
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 74. In which of the following patients is positive end expiratory pressure (PEEP) most indicated?
a.
b.
c.
d.
FiO2
0.3
0.5
0.3
0.5
PaO2
80 mm Hg
80 mm Hg
50 mm Hg
50 mm Hg
____ 75. Contraindications for using positive end expiratory pressure (PEEP) in conjunction with mechanical
ventilation include which of the following?
1. Untreated bronchopleural fistula
2. Chronic airway obstruction
3. Untreated pneumothorax
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 76. Compared with a square wave flow pattern, a decelerating flow waveform has which of the
following potential benefits?
1. Reduced peak pressure
2. Improved cardiac output
3. Less inspiratory work
4. Decreased volume of dead space-to-tidal volume ratio (VD/VT)
a. 1 and 3 only
b. 1, 3, and 4 only
c. 2 and 4 only
d. 2, 3, and 4 only
____ 77. Which of the following is a benefit of high inspiratory flows during positive-pressure ventilation?
a. Improved gas exchange
b. Higher peak pressures
c. Reduced air trapping
d. Higher work of breathing
____ 78. Volume-controlled (VC) modes of mechanical ventilation include which of the following?
1. VC continuous mandatory ventilation
2. VC intermittent mandatory ventilation
3. Volume-assured, pressure-controlled
4. Bilevel positive airway pressure
a. 2 and 4 only
b. 1, 2, 3, and 4
c. 1 and 2 only
d. 1, 3, and 4 only
____ 79. Which of the following modes of support provides all of the patient’s minute ventilation (VE) as
mandatory volume-controlled (VC) breaths?
a. VC continuous mandatory ventilation
b. VC intermittent mandatory ventilation
c. Pressure-supported ventilation
d. Continuous positive airway pressure
____ 80. Which of the following modes of ventilatory support would result in the highest mean airway
pressure?
a. Volume-controlled intermittent mandatory ventilation
b. (Volume-controlled intermittent mandatory ventilation) + pressure-supported
ventilation
c. Pressure-controlled intermittent mandatory ventilation
d. Volume-controlled continuous mandatory ventilation
____ 81. What are some key causes of patient-ventilator asynchrony and increased work of breathing during
pressure-triggered volume-controlled continuous mandatory ventilation?
1. Improper trigger setting
2. Insufficient inspiratory flow
3. High peak airway pressures
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 82. Which of the following modes of ventilatory support combines the advantages of pressure-controlled
and volume-controlled ventilation?
a. Volume-assured pressure-supported ventilation
b. Pressure-supported ventilation
c. Bilevel positive airway pressure
d. Airway pressure-release ventilation
____ 83. During volume-assured pressure-supported ventilation, the breath will be pressure-limited under
what conditions?
a. The delivered tidal volume (VT) is greater than the preset minimum VT.
b. The patient’s lung or thoracic compliance decreases from the baseline.
c. The delivered VT is less than the preset minimum VT.
d. The patient’s Raw increases from baseline.
____ 84. What are some physiological advantages of volume-assured pressure-supported ventilation?
1. Improved patient-ventilator synchrony
2. Increased pressure-time product
3. Decreased work of breathing
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 85. Which of the following are true about continuous positive airway pressure (CPAP)?
1. It maintains alveoli at greater inflation volumes.
2. It holds airway pressure essentially constant.
3. It provides the pressure gradient needed for ventilation.
4. It has side effects similar to those of positive pressure ventilation.
a. 1 and 3 only
b. 1, 2, and 4 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 86. Which of the following variables determine the level of support achieved with proportional assist
ventilation?
1. Patient effort
2. Elastance
3. Resistance
a. 1 and 3 only
b. 2 only
c. 1 only
d. 1, 2, and 3
____ 87. Moderate rises in pleural pressure during positive-pressure ventilation have a minimal effect on
cardiac output in normal subjects. What are some reasons for this lack of effect?
1. Compensatory dilation of the large arteries
2. Compensatory increase in venomotor tone
3. Compensatory increase in the cardiac rate
a. 2 and 3 only
b. 1 and 2 only
c. 1, 2, and 3
d. 1 and 3 only
____ 88. Assuming a constant rate of breathing, which of the following inspiratory-to-expiratory (I:E) ratio
would tend to most greatly impair a patient’s systemic diastolic pressure?
a. 1:4
b. 1:3
c. 1:2
d. 1:1
____ 89. Potential effects of hyperventilation on the central nervous system include which of the following?
1. Increased O2 consumption
2. Increased cerebral vascular resistance (CVR)
3. Increased intracranial pressure (ICP)
a. 1 and 2 only
b. 2 and 3 only
c. 1 and 3 only
d. 1, 2, and 3
____ 90. Hyperventilation should generally be avoided during mechanical ventilatory support. Exceptions to
this rule include:
1. Trying to calm an agitated patient.
2. Failure of other methods to reduce intracranial pressure.
3. Hypokalemia causing cardiac arrhythmias.
a. 2 and 3 only
b. 1 and 3 only
c. 2 only
d. 1 and 2 only
____ 91. A patient receiving long-term positive-pressure ventilation support exhibits a progressive weight
gain and a reduction in the hematocrit. Which of the following is the most likely cause of this
problem?
a. Pulmonary hemorrhage
b. Water retention
c. Hypovolemia
d. Hyponatremia
____ 92. Which of the following mechanisms explains the impaired renal function seen in patients receiving
ventilatory support with positive pressure?
1. Decreased secretion of aldosterone
2. Decreased intravascular volume
3. Increased secretion of vasopressin
a. 1 only
b. 2 only
c. 1 and 3 only
d. 1, 2, and 3
____ 93. Which of the following mechanisms explains the hepatic dysfunction in patients receiving
positive-pressure ventilation (PPV)?
a. Decreased hepatic blood flow
b. Increased portal venous pressure
c. Hepatic congestion
d. Increased bilirubin conjugation
____ 94. What is traumatic injury to lung tissue caused by excessive pressure called?
a. Pulmonary barotrauma
b. Pulmonary hemorrhage
c. Pulmonary infarction
d. Pulmonary embolism
____ 95. Types of damage associated with pulmonary barotrauma include which of the following?
1. Pneumoconiosis
2. Pneumomediastinum
3. Pneumothorax
4. Subcutaneous emphysema
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 96. What patients are at greatest risk for auto-PEEP?
1. Those supported by spontaneous breath modes
2. Those with high airway resistance
3. Those with high expiratory flow resistance
a. 1 and 2 only
b. 2 and 3 only
c. 1 and 3 only
d. 1, 2, and 3
____ 97. The increased work of breathing associated with auto-positive end expiratory pressure (PEEP)
during mechanical ventilation is due to:
1. Hyperinflation or impaired contractility of the diaphragm.
2. Large alveolar pressure drops required to trigger breaths.
3. Increased volume of the intrathoracic airways.
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 98. Which level of FiO2 and what time of exposure has been associated with oxygen toxicity?
1. FiO2 of 0.5
2. FiO2 of 0.7
3. FiO2 of 0.6
4. 24 to 48 hr
a. 1 and 2 only
b. 3 and 4 only
c. 2 and 3 only
d. 1 and 4 only
____ 99. Which of the following is the recommended tidal volume for mechanical ventilation in patients with
COPD?
a. 4 to 8 ml/kg
b. 3 to 5 ml/kg
c. 6 to 8 ml/kg
d. 10 to 12 ml/kg
____ 100. During ventilatory support, peak inspiratory pressure (PIP) is the pressure needed to overcome
which of the following?
1. Chest wall compliance
2. Lung compliance
3. Airway resistance
4. Systemic arterial pressure
a. 1 and 2 only
b. 2 and 3 only
c. 1, 2, and 3 only
d. 2, 3, and 4 only
____ 101. The respiratory therapist has been called to place a 70-kg male patient with ARDS on ventilatory
support. The physician has requested a respiratory rate of 20/min. Which of the following would be
an appropriate VT for this patient?
a. 140 ml
b. 200 ml
c. 350 ml
d. 700 ml
____ 102. Which of the following is considered a patient-related cause of poor patient-ventilator interaction?
a. Abnormal respiratory drive
b. Asynchrony
c. Inadequate ventilatory support
d. Inadequate FiO2
____ 103. Which of the following are variables controlled during pressure assist/control mechanical
ventilation?
1. Volume
2. Flow
3. Time
4. Pressure
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 1, 2, 3, and 4
____ 104. Which of the following is a technique for minimizing the effects of auto-PEEP?
a. Secretion management
b. Minimizing bronchodilator therapy
c. Increasing inspiratory time
d. Smaller sized endotracheal tubes
____ 105. Which of the following is the primary reason that patients poorly interact with the ventilator?
a. Mode of mechanical ventilation selected
b. Change in their clinical status
c. FiO2 setting
d. PEEP setting
____ 106. Which of the following can cause trigger delay?
1. Auto-PEEP
2. Poor sensitivity setting
3. Water in the circuit
4. Ventilator malfunction
a. 3 only
b. 1, 2, and 4 only
c. 2 and 3 only
d. 1, 2, 3, and 4
____ 107. Your patient who is orally intubated and receiving mechanical ventilation was just repositioned by
the nursing staff following their bedsheets being changed. Suddenly, airway pressures and tidal
volumes rapidly decrease. Which of the following explains this finding?
a. Pneumothorax.
b. A dislodged mucus plug is obstructing the endotracheal tube.
c. Acute bronchospasm.
d. Movement of the endotracheal tube.
____ 108. Your patient’s clinical status abruptly changed and the alarms on the ventilator are sounding. What
is/are the first step(s) you should take?
a. Silence the alarms and adjust the alarm parameters.
b. Perform a rapid physical examination.
c. Remove the patient from the ventilator and manually ventilate.
d. Check the patency of the airway.
____ 109. Which of the following modes of mechanical ventilation are least likely to cause asynchrony?
1. Proportional assist ventilation
2. Pressure support ventilation
3. Neurally adjusted ventilator assist
4. Volume control/assist ventilation
a. 1 and 3 only
b. 2, 3, and 4 only
c. 2 and 3 only
d. 1 and 4 only
____ 110. In which mode does flow asynchrony most commonly occur?
a. Volume ventilation.
b. Pressure ventilation.
c. CPAP.
d. No mode is more susceptible.
____ 111. In which mode does double triggering most commonly occur?
a. Volume ventilation.
b. Pressure ventilation.
c. CPAP.
d. No mode is more susceptible.
____ 112. Which of the following modes of ventilation can inappropriately set sensitivity cause asynchrony?
1. Volume A/C
2. Pressure A/C
3. PSV
4. NAVA
a. 1 and 3 only
b. 1, 2, and 3 only
c. 2 and 4 only
d. 1, 2, 3, and 4
____ 113. Your patient that is receiving mechanical ventilation has a high ventilatory demand. Which of the
following is the most appropriate inspiratory time?
a. 0.4 sec
b. 0.7 sec
c. 1.0 sec
d. 1.2 sec
____ 114. You have determined your patient receiving volume ventilation has flow asynchrony. How can this
be improved?
1. Increasing peak flow
2. Decreasing inspiratory time
3. Adjusting rise time
4. Adding an inspiratory pause
a. 1 and 2 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 1, 3, and 4 only
____ 115. The most important variable affecting trigger asynchrony is:
a. the mode of mechanical ventilation being used.
b. the tidal volume being delivered.
c. the presence of auto-PEEP.
d. the patient’s underlying disease process requiring mechanical ventilation.
____ 116. How are the effects of auto-PEEP on missed triggering improved in the presence of dynamic airway
obstruction?
a. Adjustment of the sensitivity setting
b. The application of PEEP
c. Mode change
d. Administration of a bronchodilator
____ 117. What is the normal trigger delay?
a. Less than 100 msec
b. Less than 150 msec
c. Less than 200 msec
d. Less than 250 msec
____ 118. Which of the following clinical findings is least likely to be seen in a patient with acute hypoxic
respiratory failure?
a. Confusion
b. Tachycardia
c. Hypotension
d. Dyspnea
____ 119. After starting volume-cycled mechanical ventilation on a patient in respiratory failure with a VT of
10 ml/kg, you measure and obtain a plateau pressure of 45 cm H2O. Which of the following actions
would you recommend to the patient’s physician?
a. Decrease the inspiratory flow.
b. Lower the delivered VT.
c. Administer a bronchodilator.
d. Add PEEP.
____ 120. Which the following are hazards associated with mechanical ventilation?
1. Reduced cardiac output
2. Liver failure
3. Increased work of breathing
4. Acute lung injury
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 1, 3, and 4 only
____ 121. Which of the following are advantages of Assist Control Volume ventilation?
1. Minimal safe level of ventilation achieved.
2. Patient can set breathing rate.
3. May reduce work of breathing.
4. Pressure is limited.
a. 1 and 3 only
b. 1, 2, and 3 only
c. 3 and 4 only
d. 2, 3, and 4 only
____ 122. Which of the following modes of ventilatory support would you recommend for a patient who can
breathe spontaneously and only requires assistance to overcome the work of breathing created by the
ET tube?
a. Pressure-targeted continuous mandatory ventilation
b. Pressure-supported ventilation
c. Volume-targeted CMV
d. Pressure-targeted intermittent mandatory ventilation
____ 123. If the patient is being ventilated via a mechanical ventilator via intermittent mandatory ventilation
with partial ventilatory support, what would probably happen to PaCO2 if the patient suddenly had
no spontaneous breathing?
a. Increase
b. Decrease
c. Stay the same
d. Change according to FiO2
____ 124. When a patient is initially started on mechanical ventilation common orders from the physician in
the patient’s chart include which of the following?
a. FiO2
b. Mode
c. Sensitivity
d. Tidal volume
a. 1 and 2 only
b. 1, 2, and 4 only
c. 3 and 4 only
d. 1, 2, 3, and 4
____ 125. Air trapping is a major concern in patients with what diagnosis when using the assist-control mode?
a. Pneumonia
b. Chronic obstructive pulmonary disease (COPD)
c. Chest trauma
d. Neuromuscular disease
____ 126. In what scenario is pressure-controlled ventilation (PCV) most often used?
a. When limiting plateau pressure is needed
b. When a pneumothorax is present
c. When the patient has chronic obstructive pulmonary disease
d. When bilateral pneumonia is present
____ 127. On a ventilator that has separate rate and minute ventilation (VE) controls, the rate is set at 13/min
and the VE at 11 L/min. Approximately what VT is the patient receiving?
a. 700 ml
b. 850 ml
c. 1000 ml
d. 1200 ml
____ 128. A physician orders intubation and mechanical ventilation in the continuous mandatory ventilation
assist-control mode for a 125-lb adult woman with normal lungs. Which of the following initial
settings would you recommend?
Rate
VT
a. 10 breaths/min
550 ml
b. 14 breaths/min
400 ml
c. 18 breaths/min
450 ml
d. 12 breaths/min
470 ml
____ 129. A physician orders intubation and mechanical ventilation in the synchronized intermittent mandatory
ventilation mode for a 160-lb adult man with a history of chronic obstructive pulmonary disease.
Which of the following settings would you recommend?
Rate
VT
a. 12 breaths/min
500 ml
b. 15 breaths/min
550 ml
c. 20 breaths/min
300 ml
d. 16 breaths/min
500 ml
____ 130. Which of the following is false about flow-triggered ventilatory support?
a. The work of breathing with flow triggering is less than with pressure triggering.
b. Flow-triggered systems respond to changes in flow rather than pressure.
c. Pressure triggering on new ventilators may be as sensitive as flow-triggering.
d. Flow triggering will decrease the work of breathing in patients with small
endotracheal tubes and auto-PEEP.
____ 131. For adults with otherwise normal lungs who are receiving ventilatory support in the continuous
mandatory ventilation control or assist-control mode, inspiratory flow should be set to provide what
1:E?
a. 2:1
b. 3:1
c. 1:1
d. 1:2
____ 132. A chronic obstructive pulmonary disease (COPD) patient receiving ventilatory support in the CMV
assist-control mode at a rate of 14 and a VT of 750 ml exhibits clinical signs of air trapping. Which
of the following would you recommend to correct this problem?
1. Decrease “E” time.
2. Increase the inspiratory flow rate.
3. Decrease the assist-control rate.
a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3
____ 133. When adjusting the FiO2 setting for a patient receiving mechanical ventilatory support, what should
your goal be?
a. Decrease the FiO2 to below 0.70 as soon as possible.
b. Maintain the highest possible FiO2 as long as needed.
c. Decrease the FiO2 to below 0.30 as soon as possible.
d. Decrease the FiO2 to below 0.50 as soon as possible.
____ 134. An adult patient in respiratory failure has the following blood gases on a nasal cannula at 5 L/min:
pH = 7.20; PaCO2 = 67 mm Hg; HCO3–= 27 mEq/L; PaO2 = 89 mm Hg. The attending physician
orders intubation and ventilatory support. What FiO2 would you recommend to start with?
a. 0.21
b. 0.30
c. 0.50
d. 0.90
____ 135. To prevent atelectasis and improve gas exchange, most thoracic surgery patients placed on
ventilatory support receive which of the following?
a. 0 cm H2O PEEP
b. 5 cm H2O PEEP
c. 8 cm H2O PEEP
d. 10 cm H2O PEEP
____ 136. When the therapist is initially setting the high-pressure alarm on the ventilator and the patient’s
plateau pressure is less than 30 cm H2O, what should the high-pressure alarm be set at?
a. 5 to 10 cm H2O above the peak pressure
b. 10 to 20 cm H2O above the peak pressure
c. 10 to 12 cm H2O above the plateau pressure
d. 10 to 15 cm H2O above the mean airway pressure
____ 137. If available, the FiO2 alarm should be set to what percentage?
a. ±3%
b. ±5%
c. ±8%
d. ±10%
____ 138. What limits should be initially set for high and low VT values and/or minute volume alarms on a
ventilatory support device?
a. ±5% to 10%
b. ±10% to 15%
c. ±15% to 20%
d. ±20% to 25%
____ 139. A heat-moisture exchanger (HME) should be avoided in which of the following circumstances?
1. Patients with excessive secretions
2. Patients with a high FiO2
3. Patients with low body temperature
a. 1 only
b. 1 and 2 only
c. 1 and 3 only
d. 1, 2, and 3
____ 140. Which of the following criteria should be met before considering use of a heat-moisture exchanger
(HME) for a patient being placed on ventilatory support?
1. There should be no problem with retained secretions.
2. The patient should not have fever (normothermic).
3. The patient should be adequately hydrated.
4. The support should be short term (24 to 48 hr).
a. 1, 2, and 3 only
b. 2 and 4 only
c. 1, 2, 3, and 4
d. 3 and 4 only
____ 141. A patient suffering from postoperative complications has been receiving mechanical ventilation for 6
days with a volume ventilator. A heat-moisture exchanger (HME) is providing control over
humidification and airway temperature. Over the past 24 hr, the patient’s secretions have decreased
in quantity but are thicker and more purulent. Which of the following actions would you suggest at
this time?
a. Replace the HME.
b. Switch over to a heated wick humidifier.
c. Administer acetylcysteine every 2 hr via the nebulizer.
d. Increase the frequency of suctioning.
____ 142. Indications for delivering sigh breaths during mechanical ventilation include which of the following?
1. Before and after suctioning
2. During chest physical therapy
3. In patients with stiff lungs
4. When small VT values are used
a.
b.
c.
d.
1 and 3 only
1, 2, and 4 only
2 and 4 only
2, 3, and 4 only
____ 143. When setting the tidal volume on a patient being mechanically ventilated, what criteria should be
kept in mind?
a. It should never cause the plateau pressure to exceed 28 mm Hg.
b. It should never cause the peak pressure to exceed 35 mm Hg.
c. It should result in the static pressure of less than 10 mm Hg.
d. It should result in a peak pressure of no more than 25 mm Hg.
____ 144. When adjusting a patient’s oxygenation during mechanical ventilatory support, what should your
goal be?
a. SaO2 of 80% to 90%
b. PaO2 of 100 to 150 mm Hg
c. SaO2 of 95% to 100%
d. PaO2 of 60 to 100 mm Hg
____ 145. A patient with ARDS receiving ventilatory support with PEEP through a volume-cycled ventilator
has a plateau pressure of 38 cm H2O. ABGs on 55% O2 are as follows: pH = 7.44; PCO2 = 37 mm
Hg; HCO3– = 25 mEq; PO2 = 55 mm Hg; SaO2 = 88%. Which of the following would you
recommend?
a. Increase the PEEP level.
b. Make no changes.
c. Reduce the VT.
d. Increase the FiO2.
____ 146. When the patient stabilizes on mechanical ventilation with a PEEP of 12 cm H2O and the FiO2 has
been reduced to 0.40, how should the PEEP level reduce?
a. In increments of 2 cm H2O every 6 hr
b. In increments of 3 to 5 cm H2O every 2 hr
c. In increments of 3 to 5 cm H2O every 1 hr
d. In increments of 5 cm H2O every 2 hr
____ 147. What is the recommended response to a drop in PaO2 when the PEEP level is reduced in a
mechanically ventilated patient?
a. Increase the FiO2.
b. Return the PEEP to the previous level.
c. Increase the rate of mechanical breaths.
d. Do nothing.
____ 148. Which of the following techniques can be used to improve oxygenation beyond increasing the FiO2
or PEEP level?
1. Proning the patient
2. Use of an expiratory pause
3. Use of inverse I:E ratio ventilation
a. 1 only
b. 1 and 2 only
c. 2 and 3 only
d. 1 and 3 only
____ 149. Your patient develops a fever while being mechanically ventilated in the control mode. As a result of
the fever, the patient’s CO2 production increases while alveolar ventilation is unchanged. What is the
probable change in ABGs?
a. Increase in PaCO2
b. Decrease in PaO2
c. Decrease in PaCO2
d. All of the above
____ 150. A patient receiving control-mode continuous mandatory ventilation has the following ABGs on an
FiO2 of 0.4: pH = 7.51; PCO2 = 30 mm Hg; HCO3– = 25 mm Hg. Her current minute ventilation
(VE) is 7.9 L/min. What new VE would you recommend?
a. 9.0 L/min
b. 6.7 L/min
c. 7.5 L/min
d. 5.9 L/min
RC 212 Midterm Exam
Answer Section
MULTIPLE CHOICE
1. ANS: C
Volume-cycled ventilation in patients with ARDS frequently leads to high-peak airway and plateau
pressures.
PTS: 1
2. ANS: A
DIF: Analysis
REF: p. 984
OBJ: 7
Hyperventilation applied acutely and for short periods of time may be used to reduce ICP. The goal
is to lower the PaCO2 to between 25 and 30 mm Hg, which causes alkalosis, which in combination
with hypocapnia helps reduce cerebral blood flow until the ICP can be controlled by other measures.
PTS: 1
3. ANS: C
DIF: Application
REF: p. 984
OBJ: 7
In such patients, lower tidal volumes (6 to 8 ml/kg), moderate respiratory rates, and high inspiratory
flow rates (70 to 100 L/min) are recommended to avoid dynamic hyperinflation.
PTS: 1
4. ANS: A
DIF: Recall
REF: p. 985
OBJ: 7
This ventilatory drive can be diminished by various factors such as drugs (overdose/sedation),
brainstem lesions, diseases of the central nervous system such as multiple sclerosis or Parkinson’s
disease, hypothyroidism, morbid obesity (e.g., obesity-hypoventilation), and sleep apnea.
PTS: 1
5. ANS: D
DIF: Recall
REF: p. 978
OBJ: 3
Hypercapnic respiratory failure (“pump failure,” “ventilatory failure”) is characterized by an
elevated PaCO2, creating an uncompensated respiratory acidosis (whether acute or
acute-on-chronic).
PTS: 1
6. ANS: D
DIF: Application
REF: p. 977
OBJ: 3
DIF: Recall
REF: p. 981
OBJ: 6
See Table 44-3.
PTS: 1
7. ANS: B
These patients frequently have problems with elevated airway pressure or dynamic hyperinflation
(auto-PEEP), which can cause barotrauma and increased dyssynchrony between the patient and the
ventilator.
PTS: 1
8. ANS: C
DIF: Application
REF: p. 985
OBJ: 7
DIF: Recall
REF: p. 981
OBJ: 6
See Table 44-3.
PTS: 1
9. ANS: A
See Table 44-3.
PTS: 1
10. ANS: B
DIF: Recall
REF: p. 981
OBJ: 7
Congestive heart failure with low cardiac output is the most common cause of low mixed venous
oxygen, due to increased peripheral extraction of oxygen.
PTS: 1
11. ANS: C
A
DIF: Recall
REF: pp. 975-976
OBJ: 3
mismatch and shunt both result in elevated P(Aa)O2 levels.
PTS: 1
12. ANS: A
DIF: Recall
REF: p. 976
OBJ: 3
DIF: Recall
REF: p. 981
OBJ: 6
DIF: Application
REF: p. 981
OBJ: 6
DIF: Application
REF: p. 981
OBJ: 6
See Table 44-3.
PTS: 1
13. ANS: A
See Table 44-3.
PTS: 1
14. ANS: A
See Table 44-3.
PTS: 1
15. ANS: D
Because an elevated PaCO2 increases ventilatory drive in healthy subjects, the very existence of
hypoventilation suggests other problems with the respiratory apparatus. Specifically, the presence of
acute respiratory acidosis indicates one of three major problems: (1) the respiratory center is not
responding normally to the elevated PaCO2, (2) the respiratory center is responding normally, but the
signal is not getting through to the respiratory muscles, or (3) despite normal neurologic response
mechanisms, the lungs and chest bellows are simply incapable of providing adequate ventilation due
to parenchymal lung disease or muscular weakness.
PTS: 1
16. ANS: C
DIF: Application
REF: p. 983
OBJ: 7
Contractile respiratory muscle fatigue is a reversible impairment in the contractile response to a
neural impulse in an overloaded muscle.
PTS: 1
17. ANS: A
DIF: Recall
REF: p. 983
OBJ: 6
Patients with chronic hypercapnic respiratory failure (chronic ventilatory failure) are at significant
risk for this, as indicated by the fact that COPD is now the fourth leading cause of death in the
United States. Acute-on-chronic respiratory failure can also be the presenting manifestation of
neuromuscular disease in the setting of a concurrent pulmonary infection. Most common
precipitating factors include bacterial or viral infections, congestive heart failure, pulmonary
embolus, chest wall dysfunction, and medical noncompliance.
PTS: 1
18. ANS: D
DIF: Recall
REF: p. 979
OBJ: 4
Treatment of intrapulmonary shunt must be directed toward opening collapsed alveoli or clearing
fluid or exudative material before oxygen can be beneficial at below toxic levels.
PTS: 1
19. ANS: D
DIF: Recall
REF: p. 976
OBJ: 3
Hypercapnic respiratory failure is also known as ventilatory failure.
PTS: 1
20. ANS: C
DIF: Recall
REF: p. 973
OBJ: 2
More severe hypoxemia can lead to significant central nervous system dysfunction, ranging from
irritability to confusion to coma.
PTS: 1
21. ANS: D
DIF: Recall
REF: p. 974
OBJ: 2
Examples include spinal trauma, motor neuron disease where lesions of the anterior horn cells may
gradually lead to progressive ventilatory failure (such as in amyotrophic lateral sclerosis, or
poliomyelitis), motor nerve disorders (including Guillain-Barré syndrome and Charcot-Marie-Tooth
disease), disorders of the neuromuscular junction (such myasthenia gravis and botulism), and
muscular diseases (including muscular dystrophy, myositis, critical care myopathy, and metabolic
disorders).
PTS: 1
22. ANS: D
DIF: Recall
REF: p. 978
OBJ: 3
Perfusion/diffusion impairment is a rare cause of hypoxemia found in individuals with liver disease
complicated by the hepatopulmonary syndrome.
PTS: 1
23. ANS: A
DIF: Recall
REF: p. 975
OBJ: 3
DIF: Recall
REF: p. 981
OBJ: 6
DIF: Recall
REF: p. 981
OBJ: 6
See Table 44-3.
PTS: 1
24. ANS: A
See Table 44-3.
PTS: 1
25. ANS: A
The patient is in hypoxic (type I) and hypercapnic (type II) acute respiratory failure. Providing full
mechanical ventilatory support will provide the ventilator support needed to normalize pH and
improve oxygenation.
PTS: 1
26. ANS: D
DIF: Analysis
REF: p. 981
OBJ: 7
This ventilatory drive can be diminished by various factors such as drugs (overdose/sedation),
brainstem lesions, diseases of the central nervous system such as multiple sclerosis or Parkinson’s
disease, hypothyroidism, morbid obesity (e.g., obesity-hypoventilation), and sleep apnea.
PTS: 1
27. ANS: D
DIF: Recall
REF: pp. 976-977
OBJ: 3
Tachypnea is the cardinal sign of increased work of breathing.
PTS: 1
28. ANS: D
DIF: Recall
REF: p. 978
OBJ: 5
Most commonly, this situation occurs when increased dead space accompanies COPD or elevated
airway resistance accompanies asthma. Both of these obstructive airway diseases may raise
respiratory work requirements excessively due to the presence of intrinsic positive end expiratory
pressure. Increased workload can also result from thoracic abnormalities such as pneumothorax, rib
fractures, pleural effusions, and other conditions creating a restrictive burden on the lungs. Finally,
requirements for increased minute ventilation can arise when increased CO2 production accompanies
hypermetabolic states, such as in extensive burns.
PTS: 1
29. ANS: A
DIF: Recall
REF: pp. 978-979
OBJ: 3
Criteria for respiratory failure based on arterial blood gases have been established by Campbell and
generally define failure as a PaO2 (arterial partial pressure of oxygen) less than 60 mm Hg and/or a
PaCO2 (alveolar partial pressure of carbon dioxide) greater than 50 mm Hg in otherwise healthy
individuals breathing room air at sea level.
PTS: 1
30. ANS: A
DIF: Application
REF: p. 973
OBJ: 1
Guillain-Barré syndrome can commonly show up with lower extremity weakness progressing to the
respiratory muscles in one-third of patients.
PTS: 1
31. ANS: D
DIF: Recall
REF: p. 978
OBJ: 3
Noninvasive positive-pressure ventilation can improve hypoxemia and hypercarbia by several
mechanisms including but not limited to (1) compensating for the inspiratory threshold load imposed
by intrinsic positive end-expiration pressure, (2) supplementing a reduced tidal volume, (3) partial or
complete unloading of the respiratory muscles, (4) reducing venous return and left ventricular
afterload, and (5) alveolar recruitment.
PTS: 1
32. ANS: A
DIF: Application
REF: p. 982
OBJ: 7
DIF: Analysis
REF: p. 976
OBJ: 3
DIF: Recall
REF: p. 981
OBJ: 6
See Table 44-1.
PTS: 1
33. ANS: B
See Table 44-3.
PTS: 1
34. ANS: B
If the ventilator controls pressure, the pressure waveform will remain consistent but volume and
flow will vary with changes in respiratory system mechanics.
PTS: 1
DIF: Application
REF: p. 988
OBJ: 2
35. ANS: B
At this level of description, we can avoid the cumbersome verbal ad hoc definition for airway
pressure release ventilation such as “a mode that allows spontaneously breathing patients to breathe
at a positive-pressure level, but drops briefly to a reduced pressure level for CO2 elimination during
each breathing cycle.”
PTS: 1
OBJ: 3
36. ANS: C
DIF: Recall
REF: pp. 1001-1002
In continuous mandatory ventilation, all breaths are mandatory.
PTS: 1
37. ANS: D
DIF: Application
REF: p. 1002
OBJ: 3
DIF: Recall
REF: p. 1000
OBJ: 3
See Table 45-1.
PTS: 1
38. ANS: C
For example, if you set the base continuous flow at 10 L/min and the trigger at 2 L/min, the
ventilator will trigger when the output flow falls to 8 L/min or less.
PTS: 1
39. ANS: B
DIF: Analysis
REF: p. 1002
OBJ: 2
DIF: Recall
REF: p. 992
OBJ: 3
See Figure 45-5.
PTS: 1
40. ANS: A
PEEP is the application of pressure above atmospheric pressure at the airway throughout expiration.
PTS: 1
41. ANS: B
DIF: Recall
REF: p. 995
OBJ: 3
Volume can be controlled directly by the displacement of a device such as a piston or bellows.
Volume can be controlled indirectly by controlling flow.
PTS: 1
42. ANS: B
DIF: Recall
REF: p. 988
OBJ: 2
This follows from the fact that volume and flow are inverse functions of time (i.e., volume is the
integral of flow and flow is the derivative of volume).
PTS: 1
43. ANS: C
DIF: Application
REF: p. 998
OBJ: 2
For patient transport you must use either a pneumatically powered ventilator or one that can run
solely on batteries. Always take along a manually powered bag-valve mask, and for long transports
be sure to have backup power available (extra cylinders or batteries).
PTS: 1
44. ANS: A
DIF: Application
REF: p. 988
OBJ: 2
Pressure triggering occurs when a patient’s inspiratory effort causes a drop in pressure within the
breathing circuit. When this pressure drop reaches the pressure sensing mechanism, the ventilator
triggers on and begins gas delivery. On most ventilators, you can adjust the pressure drop needed to
trigger a breath. The trigger level is often called the sensitivity.
PTS: 1
45. ANS: D
DIF: Recall
REF: p. 998
OBJ: 2
DIF: Recall
REF: p. 1000
OBJ: 3
DIF: Recall
REF: p. 1000
OBJ: 3
See Table 45-1.
PTS: 1
46. ANS: C
See Table 45-1.
PTS: 1
47. ANS: C
When a rate control is used, inspiratory and expiratory times will vary according to other control
settings, such as flow and volume.
PTS: 1
48. ANS: D
DIF: Application
REF: p. 1002
OBJ: 2
If the ventilator controls flow, the flow and volume waveforms will remain consistent, but pressure
will vary with changes in respiratory mechanics. Flow can be controlled directly using something as
simple as a flow meter or as complex as a proportional solenoid valve. Flow can be controlled
indirectly by controlling volume.
PTS: 1
49. ANS: D
DIF: Recall
REF: p. 999
OBJ: 2
A complete ventilatory cycle or breath consists of four phases: the initiation of inspiration,
inspiration itself, the end of inspiration, and expiration.
PTS: 1
50. ANS: A
DIF: Recall
PTS: 1
51. ANS: A
DIF: Recall
REF: p. 998
OBJ: 2
Because tidal volume is not directly controlled, the pressure gradient (PIP  PEEP) is the primary
parameter used to alter the breath size and hence carbon dioxide tensions.
REF: p. 1000
OBJ: 3
A limit variable is one that can reach and maintain a preset level before inspiration ends but does not
terminate inspiration.
PTS: 1
52. ANS: D
DIF: Recall
REF: p. 995
OBJ: 2
These devices are ideal in situations where electrical power is unavailable (e.g., during certain types
of patient transport) or as a backup to electrically powered ventilators in case of power failures. They
are also particularly useful where electrical power is undesirable, as near magnetic resonance
imaging equipment.
PTS: 1
DIF: Application
REF: p. 988
OBJ: 2
53. ANS: A
See Table 45-1.
PTS: 1
54. ANS: A
DIF: Application
REF: p. 1000
OBJ: 3
REF: pp. 996-997
OBJ: 2
Pvent + Pmus = (E  V) + (R  V).
PTS: 1
55. ANS: B
DIF: Application
Currently, time triggering is most commonly seen when using the IMV mode (intermittent
mandatory ventilation).
PTS: 1
56. ANS: D
DIF: Recall
REF: p. 1002
OBJ: 2
DIF: Application
REF: p. 1000
OBJ: 3
PTS: 1
58. ANS: D
DIF: Application
REF: p. 1000
OBJ: 3
PTS: 1
59. ANS: D
DIF: Recall
See Table 45-1.
PTS: 1
57. ANS: A
See Table 45-1.
The power source for a ventilator is either electrical energy (Energy = Volts  Amperes  Time) or
compressed gas (Energy = Pressure  Volume).
REF: p. 988
OBJ: 1
To understand mechanical ventilators, we must first understand their four basic functions:
 Input power
 Power transmission and conversion
 Control system
 Output (pressure, volume, and flow waveforms)
PTS: 1
60. ANS: B
DIF: Recall
REF: p. 988
OBJ: 1
Fluidic logic-controlled ventilators, such as the Bio-Med MVP-10 (Bio-Med Devices, Stanford, CT),
also use pressurized gas to regulate the parameters of ventilation.
PTS: 1
61. ANS: B
DIF: Recall
REF: p. 989
OBJ: 2
DIF: Application
REF: p. 1000
OBJ: 3
See Table 45-1.
PTS: 1
62. ANS: B
Another example of patient cycling is the pressure support mode. Here, inspiration ends when flow
decays to some preset value (i.e., flow cycling).
PTS: 1
DIF: Recall
REF: p. 1002
OBJ: 3
63. ANS: C
A spontaneous breath is a breath for which the patient decides the start time and the tidal volume.
That is, the patient both triggers and cycles the breath.
PTS: 1
64. ANS: B
DIF: Recall
REF: p. 1002
OBJ: 3
The use of PEEP and control of membrane permeability accompany the management of shunt.
PTS: 1
65. ANS: D
DIF: Recall
REF: p. 1025
OBJ: 2
Conditions that may necessitate a higher initial rate include ARDS, acutely increased intracranial
pressure (with caution), and metabolic acidosis.
PTS: 1
66. ANS: D
DIF: Application
REF: p. 1022
OBJ: 2
If compliance or resistance decreases, the time constant for a given lung unit decreases, and the lung
fills and empties faster.
PTS: 1
67. ANS: B
DIF: Recall
REF: p. 1026
OBJ: 2
DIF: Recall
REF: p. 1027
OBJ: 2
See Box 46-1.
PTS: 1
68. ANS: B
However, if insufficient time is available for pressure equilibration, delivered volume decreases as
airway resistance increases.
PTS: 1
OBJ: 3
69. ANS: D
DIF: Application
REF: pp. 1027-1028
As the mode is changed from CPAP to PSV to synchronized intermittent mandatory ventilation to
time-triggered CMV, the ventilator assumes more of the work.
PTS: 1
70. ANS: A
DIF: Application
REF: p. 1039
OBJ: 3
Most clinicians increase PSV until the breathing pattern approaches normal, that is, until the
spontaneous ventilatory rate is 15 to 25 breaths/min and the spontaneous tidal volume (VT) is normal
(5 to 8 ml/kg).
PTS: 1
71. ANS: B
DIF: Application
REF: p. 1039
OBJ: 3
Normal work of breathing is 0.6 to 0.8 J/L.
PTS: 1
72. ANS: A
DIF: Recall
REF: p. 1039
OBJ: 3
Mean airway pressure is decreased by decreasing inspiratory time, tidal volume, respiratory rate,
PEEP, or PIP.
PTS: 1
73. ANS: B
DIF: Recall
REF: p. 1027
OBJ: 3
PEEP is used primarily to improve oxygenation in patients with refractory hypoxemia. PEEP may be
indicated in the care of patients with COPD who have dynamic hyperinflation (auto-PEEP) during
mechanical ventilatory support after other efforts to decrease auto-PEEP fail.
PTS: 1
74. ANS: C
DIF: Recall
REF: p. 1025
OBJ: 4
As a rule, refractory hypoxemia exists when a patient’s PaO2 cannot be maintained above 50 to 60
mm Hg with an FiO2 of 0.40 to 0.50 or more.
PTS: 1
75. ANS: B
DIF: Analysis
REF: p. 1025
OBJ: 4
PEEP is contraindicated in the presence of an unmanaged bronchopleural fistula or pneumothorax.
PTS: 1
76. ANS: B
DIF: Recall
REF: p. 1031
OBJ: 4
Compared with a square flow waveform, decreasing flow has been shown to reduce peak pressure,
inspiratory work, VD/VT, and P(Aa)O2 without affecting hemodynamic values.
PTS: 1
77. ANS: C
DIF: Recall
REF: p. 1032
OBJ: 4
High ventilator inspiratory flow allows more time for exhalation and reduces the incidence of air
trapping.
PTS: 1
78. ANS: C
DIF: Application
REF: p. 1032
OBJ: 4
VC modes include VC continuous mandatory ventilation and VC synchronized intermittent
mandatory ventilation.
PTS: 1
OBJ: 3
79. ANS: A
DIF: Recall
REF: pp. 1032-1033 |p. 1035
VC continuous mandatory ventilation provides all of the patient’s minute ventilation as mandatory
breaths.
PTS: 1
80. ANS: D
DIF: Recall
REF: p. 1032
OBJ: 3
Because every breath is volume controlled, mean airway pressure tends to be greater compared with
the mean airway pressure with synchronized intermittent mandatory ventilation and
pressure-supported ventilation, and pulmonary arterial pressure and cardiac output may be lower.
PTS: 1
81. ANS: A
DIF: Recall
REF: p. 1027
OBJ: 3
If sensitivity is set too low, such that considerable effort is necessary to trigger the ventilator,
patient-ventilator asynchrony occurs. A pressure sensitivity of 0.5 to 1.5 cm H2O or flow
sensitivity of 1 to 2 L/min is regarded as optimal. Inspiratory flow must be set to meet the patient’s
inspiratory demand. An insufficient inspiratory flow can cause patient-ventilator asynchrony and
increased work of breathing.
PTS: 1
82. ANS: A
DIF: Application
REF: p. 1032
OBJ: 8
Pressure-supported ventilation with a volume guarantee is the goal of volume-assured
pressure-supported ventilation.
PTS: 1
OBJ: 3
83. ANS: A
DIF: Application
REF: pp. 1040-1041
If delivered tidal volume is greater than the preset minimum tidal volume, the breath becomes a
pressure-supported breath.
PTS: 1
84. ANS: B
DIF: Recall
REF: p. 1041
OBJ: 3
Physiological effects of volume-assured pressure-supported ventilation include improved
patient-ventilator synchrony and reduced pressure-time product, which is an indicator of decreased
work of breathing.
PTS: 1
85. ANS: B
DIF: Recall
REF: p. 1041
OBJ: 3
Because airway pressure does not change, CPAP does not provide ventilation.
PTS: 1
86. ANS: D
DIF: Recall
REF: p. 1039
OBJ: 4
Proportional assist ventilation is a mode of ventilation designed to vary inspiratory pressure in
proportion to patient effort, elastance, and resistance.
PTS: 1
87. ANS: A
DIF: Recall
REF: p. 1040
OBJ: 3
Compensatory mechanisms used to counter the decrease in stroke volume include an increased heart
rate, an increase in systemic vascular and peripheral venous resistance, and shunting of blood away
from the kidneys and lower extremities, which results in a consistent blood pressure.
PTS: 1
88. ANS: D
DIF: Recall
REF: p. 1044
OBJ: 5
The factors of positive-pressure ventilation that may decrease the systemic diastolic pressure are
high mean airway pressure, due to a high positive end expiratory pressure, high tidal volume, or long
inspiratory time.
PTS: 1
89. ANS: B
DIF: Application
REF: p. 1044
OBJ: 5
When mechanical hyperventilation is used, CVR increases, and the result is decreased ICP.
PTS: 1
90. ANS: C
DIF: Application
REF: p. 1046
OBJ: 5
Hyperventilation should be used temporarily after traumatic brain injury until other methods can be
used to decrease elevated intracranial pressure.
PTS: 1
91. ANS: B
DIF: Recall
REF: p. 1046
OBJ: 6
Among critically ill patients, water retention usually is evident when rapid weight gain occurs. In
addition, such patients may have a reduced hematocrit, which is also consistent with hypervolemia
due to water retention.
PTS: 1
92. ANS: B
DIF: Application
REF: p. 1046
OBJ: 6
Results of more recent analysis tend to refute this explanation, instead showing that impaired renal
function during positive-pressure ventilation is better associated with a decrease in intravascular
volume.
PTS: 1
93. ANS: A
DIF: Recall
REF: p. 1047
OBJ: 6
These effects appear to be directly related to the reduction in hepatic blood flow that occurs with
PPV.
PTS: 1
94. ANS: A
DIF: Recall
REF: p. 1047
OBJ: 6
High ventilation pressure has long been associated with barotrauma.
PTS: 1
95. ANS: D
DIF: Recall
REF: p. 1049
OBJ: 7
Barotrauma is categorized as pneumothorax, pneumomediastinum, pneumopericardium, and
subcutaneous emphysema (Figure 46-19).
PTS: 1
96. ANS: B
DIF: Recall
REF: p. 1049
OBJ: 7
Patients at greatest risk of development of auto-PEEP are those with high airway resistance who are
being supported by modes that limit expiratory time.
PTS: 1
97. ANS: A
DIF: Application
REF: p. 1052
OBJ: 7
First, hyperinflation caused by auto-PEEP stretches the lung, and the stretching impairs the
contractile action of the diaphragm. Second, in pressure- or flow-triggered breaths, the high alveolar
pressure caused by auto-PEEP must be overcome before any airway pressure change can occur.
PTS: 1
98. ANS: B
DIF: Application
REF: p. 1052
OBJ: 7
An FiO2 of 0.5 or more for longer than 24 to 48 hr is associated with the development of oxygen
toxicity.
PTS: 1
DIF: Recall
REF: p. 1052
OBJ: 7
99. ANS: C
The currently acceptable tidal volume for mechanically ventilated patients in acute respiratory
failure with normal lungs or with COPD is 6 to 8 ml/kg.
PTS: 1
100. ANS: C
DIF: Recall
REF: p. 1021
OBJ: 2
During positive pressure mechanical ventilation, peak inspiratory pressure (PIP) is the pressure
necessary to overcome airway resistance and lung and chest wall compliance.
PTS: 1
101. ANS: C
DIF: Recall
REF: p. 1052
OBJ: 1
The currently acceptable tidal volume for a mechanically ventilated patient with ARDS in acute
respiratory failure is 4 to 8 ml/kg. Therefore, the VT must be set between 280 (70 kg  4 ml/kg) and
560 ml (70 kg  8 ml/kg).
PTS: 1
102. ANS: A
DIF: Application
REF: p. 1022
OBJ: 2
DIF: Recall
REF: p. 1060
OBJ: 2
DIF: Recall
REF: p. 1064
OBJ: 4
DIF: Application
REF: p. 1065
OBJ: 5
See Table 47-1.
PTS: 1
103. ANS: C
See Table 47-2.
PTS: 1
104. ANS: A
See Box 47-4.
PTS: 1
105. ANS: B
One of the primary reasons that patients poorly interact with the mechanical ventilator is a change in
their clinical status. Excessive secretions, bronchospasm, and agitation are the most common and
regularly seen causes of poor patient-ventilator interaction and issues that should be assessed at
every patient-ventilator assessment.
PTS: 1
106. ANS: B
DIF: Recall
REF: p. 1060
OBJ: 2
DIF: Recall
REF: p. 1072
OBJ: 9
See Box 47-5.
PTS: 1
107. ANS: D
Another common problem with endotracheal tubes is movement of the airway into the oral pharynx
or movement into the right main stem bronchus. Both of which can be life threatening although
movement into the oral pharynx, essentially extubation, is the most life threatening. In some
situations the airway can be moved back into the trachea, in others reintubation is necessary. If this
occurs adequate ventilation is generally impossible. Airway pressures and tidal volumes rapidly
decrease and there is frequent gas leakage from the mouth and nose. It is thus important to determine
at each patient-ventilator assessment the location of the endotracheal tube.
PTS: 1
108. ANS: C
DIF: Analysis
REF: p. 1061
OBJ: 5
DIF: Recall
REF: p. 1062
OBJ: 5
See Box 47-1.
PTS: 1
109. ANS: A
In pressure support only the pressure is controlled, thus of all the classic modes of ventilation the
mode that is least likely if set properly to cause asynchrony is pressure support. However, as well
documented in the literature, proportional assist ventilation (PAV) and neurally adjusted ventilatory
assist (NAVA) are the modes of ventilation that are least likely to cause asynchrony because they do
not exert any control over the patient.
PTS: 1
110. ANS: A
DIF: Analysis
REF: p. 1065
OBJ: 13
Flow asynchrony occurs when the flow from the ventilator does not match the flow demand of the
patient. This can occur in any mode of ventilation but most commonly occurs in volume ventilation
because the clinician sets the tidal volume, peak flow, flow waveform, and inspiratory time.
PTS: 1
111. ANS: A
DIF: Analysis
REF: p. 1064
OBJ: 6
Double triggering is usually a result of the patients’ ventilatory center wanting a larger breath or a
longer inspiratory time than is set on the ventilator. This causes the patient to continue inspiration
when the ventilator transitions into the expiratory phase resulting in the ventilator triggering a
second time. The biggest problem with double triggering is that normally there is no exhalation after
the first breath, so that the actual delivered tidal volume may be up to double what is set on the
ventilator. Double triggering is most common with volume A/C because of the precise setting of the
tidal volume.
PTS: 1
112. ANS: B
DIF: Analysis
REF: p. 1065
OBJ: 7
Across all modes of ventilation, inappropriately set sensitivity, inappropriate selection of PEEP, and
the presence of auto-PEEP result in asynchrony. The one exception to this is NAVA, since NAVA is
controlled by the diaphragmatic EMG signal; the presence of auto-PEEP does not affect the function
of this mode.
PTS: 1
113. ANS: B
DIF: Analysis
REF: p. 1065
OBJ: 4
Many adults with moderate or high ventilatory demands desire an inspiratory time between 0.6 and
0.9 sec.
PTS: 1
114. ANS: A
DIF: Analysis
REF: p. 1067
OBJ: 9
Flow asynchrony can be greatly improved in volume ventilation by increasing peak flow and
decreasing inspiratory time. In pressure ventilation, flow asynchrony can be corrected by adjusting
rise time.
PTS: 1
115. ANS: C
DIF: Recall
REF: p. 1065
OBJ: 6
However, the single most important variable affecting trigger asynchrony is the presence of
auto-PEEP.
PTS: 1
116. ANS: B
DIF: Recall
REF: p. 1068
OBJ: 12
In the presence of dynamic airways obstruction, the application of PEEP offsets the effect of
auto-PEEP on missed triggering.
PTS: 1
117. ANS: A
DIF: Recall
REF: p. 1069
OBJ: 8
Normally the trigger delay should be minimal, less than 100 msec. When it exceeds 150 msec, the
cause should be determined. Adjusting the sensitivity, setting the tidal volume appropriately and/or
applying PEEP should correct delayed triggering unless there is a true malfunction of the ventilator.
PTS: 1
118. ANS: C
DIF: Recall
REF: p. 1065
OBJ: 9
Clinical manifestations of acute hypoxemia and acute ventilatory failure are listed in Table 48-6.
PTS: 1
119. ANS: B
DIF: Recall
REF: p. 1095
OBJ: 1
Plateau pressure (Pplat) during mechanical ventilation reflects alveolar pressure, the best bedside
clinical reflection of transalveolar pressure. Limiting Pplat reduces the likelihood of
ventilator-induced lung injury, although patients with decreased thoracic compliance may require
plateau pressures greater than 30 cm H2O without resulting overdistention.
PTS: 1
120. ANS: D
DIF: Application
REF: p. 1079
OBJ: 2
Hazards of mechanical ventilation include decreased venous return and cardiac output, increased
work of breathing and ventilatory muscle dysfunction due to inappropriate ventilator settings, and
ventilator-induced lung injury. Nosocomial pneumonia poses a significant risk for intubated patients.
PTS: 1
121. ANS: B
DIF: Recall
REF: p. 1080
OBJ: 2
Advantages of assist-control volume ventilation include the assurance that a minimum safe level of
ventilation is achieved, yet the patient can still set his or her own breathing rate. In the event of
sedation or apnea, a minimum safe level of ventilation is guaranteed by the selection of an
appropriate backup rate, usually approximately 4 to 6 breaths/min less than the patient’s assist rate
but not less than the rate necessary to provide a minimum safe level of ventilation (e.g., a backup
rate of at least 12 to 14 breaths/min). Because assist-control ventilation usually provides full
ventilatory support, it may result in less WOB. In volume control ventilation, pressure is variable
and not limited.
PTS: 1
122. ANS: B
DIF: Recall
REF: p. 1082
OBJ: 3
PSV can reduce work of breathing and may improve patient ventilator synchrony by placing more
control with the patient. Many clinicians use PSV simply to overcome WOB imposed by the
artificial airway.
PTS: 1
123. ANS: A
DIF: Application
REF: p. 1084
OBJ: 4
With partial ventilatory support, if spontaneous breathing ceases or becomes inadequate, as may be
the case with the development of rapid shallow breathing or apnea, alveolar ventilation may
decrease, and PaCO2 may increase above an acceptable level.
PTS: 1
124. ANS: B
DIF: Analysis
REF: p. 1084
OBJ: 5
Initial ventilator settings include choice of mode, tidal volume, rate, FiO2, and PEEP. The respiratory
therapist must set the trigger level, inspiratory flow or time, alarms and limits, backup ventilation,
and humidification.
PTS: 1
125. ANS: B
DIF: Recall
REF: p. 1081
OBJ: 5
Patients with COPD are at special risk of air trapping in the assist-control mode, especially if they
attempt to breathe at an increased rate.
PTS: 1
126. ANS: A
DIF: Recall
REF: p. 1109
OBJ: 6
PCV may be used immediately upon ventilator initiation when limiting the plateau pressure is a
concern and in the care of patients expected to need prolonged inspiration or an increased 1:E ratio
(1:1, 1.5:1, 2:1). These patients typically have acute lung injury or ARDS.
PTS: 1
127. ANS: B
DIF: Recall
REF: p. 1083
OBJ: 6
Tidal volume (VT) and rate (f) determine minute ventilation.
PTS: 1
128. ANS: B
DIF: Application
REF: p. 1085
OBJ: 6
DIF: Application
REF: p. 1088
OBJ: 6
DIF: Analysis
REF: p. 1088
OBJ: 6
See Table 48-4.
PTS: 1
129. ANS: A
See Table 48-4.
PTS: 1
130. ANS: D
Flow triggering may not be effective in reducing work of breathing because of the presence of a
small endotracheal tube or auto-PEEP.
PTS: 1
131. ANS: D
DIF: Recall
REF: p. 1086
OBJ: 6
For most adults, an initial inspiratory time of approximately 1 sec (0.8 to 1.2 sec) with a resultant
1:E ratio of 1:2 or lower is a good starting point.
PTS: 1
132. ANS: C
DIF: Recall
REF: p. 1087
OBJ: 6
Higher flow (up to 100 L/min) may improve gas exchange in COPD patients, probably because of
the resulting increase in expiratory time.
PTS: 1
133. ANS: D
DIF: Analysis
REF: p. 1087
OBJ: 6
After initiation of mechanical ventilation with an FiO2 of 1.0, the FiO2 should be reduced to 0.40 to
0.50 or less as soon as is practical to avoid O2 toxicity and absorption atelectasis.
PTS: 1
134. ANS: C
DIF: Recall
REF: p. 1092
OBJ: 6
Patients who have undergone previous blood gas measurement or oximetry who are doing well
clinically and patients with disease states or conditions that normally respond to low to moderate
concentrations of O2 may begin ventilation with 50% to 70% O2.
PTS: 1
135. ANS: B
DIF: Application
REF: p. 1096
OBJ: 6
In terms of ventilator initiation, initial PEEP/CPAP levels usually are 5 cm H2O.
PTS: 1
OBJ: 6
136. ANS: B
DIF: Recall
REF: pp. 1093-1104
If the plateau pressure is less than 30 cm H2O, the high pressure limit can be adjusted to 10 to 20 cm
H2O above the peak inspiratory pressure.
PTS: 1
137. ANS: B
DIF: Application
REF: p. 1093
OBJ: 6
Suggested initial settings for these alarms and backup ventilator settings are described in Table 48-5.
PTS: 1
138. ANS: B
DIF: Recall
REF: p. 1093
OBJ: 6
Suggested initial settings for these alarms and backup ventilator settings are described in Table 48-5.
PTS: 1
139. ANS: C
DIF: Recall
REF: p. 1093
OBJ: 6
Use of HMEs should be avoided in the care of patients with secretion problems and those with low
body temperature (<32° C), high spontaneous minute ventilation (>10 L/min), or air leaks in which
exhaled tidal volume is less than 70% of delivered tidal volume.
PTS: 1
140. ANS: C
DIF: Recall
REF: p. 1093
OBJ: 6
Use of HMEs should be avoided in the care of patients with secretion problems and those with low
body temperature (<32° C), high spontaneous minute ventilation (>10 L/min), or air leaks in which
exhaled tidal volume is less than 70% of delivered tidal volume.
PTS: 1
141. ANS: B
DIF: Recall
REF: p. 1093
OBJ: 6
We prefer an optimal humidity approach and use of a heated humidifier to deliver gas in the range of
35° to 37° C at the airway.
PTS: 1
142. ANS: B
DIF: Analysis
REF: p. 1093
OBJ: 6
Constant, monotonous tidal ventilation at a small volume (<7 ml/kg) may result in progressive
atelectasis. Sighs may be used to prevent atelectasis. Atelectasis may be caused before and after
suctioning and when using small tidal volumes. CPT is also used when attempting to correct
atelectasis.
PTS: 1
143. ANS: A
DIF: Recall
REF: p. 1093
OBJ: 6
Tidal volume usually is based on specific patient considerations but should ideally never result in a
plateau pressure of 28 cm H2O or greater.
PTS: 1
144. ANS: D
DIF: Recall
REF: p. 1085
OBJ: 9
The FiO2 is then titrated to achieve a PaO2 in the range of 60 to 80 mm Hg with an SaO2 of 90% or
greater or an SpO2 of 92% or greater.
PTS: 1
145. ANS: B
DIF: Recall
REF: p. 1096
OBJ: 9
An SaO2 of 88% to 90% may be acceptable for patients who need an FiO2 of 0.80 or more for an
extended time.
PTS: 1
146. ANS: A
DIF: Analysis
REF: p. 1094
OBJ: 7
After reduction of the FiO2 to 0.40, PEEP can be reduced gradually as the patient improves at a rate
of 2 cm H2O every 6 to 8 hr.
PTS: 1
147. ANS: B
DIF: Recall
REF: p. 1108
OBJ: 8
If the PaO2 decreases after PEEP is decreased the PEEP level should be returned to its prior setting.
PTS: 1
148. ANS: D
DIF: Recall
REF: p. 1101
OBJ: 8
Other techniques that may be helpful in improving arterial O2 levels include the use of PCV with a
prolonged inspiratory time, use of an inspiratory pause, inverse 1:E ratio ventilation, and prone
positioning.
PTS: 1
149. ANS: A
DIF: Recall
REF: p. 1102
OBJ: 8
Increases in A or decreases in CO2 result in a decrease in PaCO2, whereas increases in CO2 or
decreases in A result in an increase in PaCO2.
PTS: 1
150. ANS: D
DIF: Application
REF: p. 1110
OBJ: 7
Box 48-20 gives an example of the effect of a change in A on PaCO2.
PTS: 1
DIF: Analysis
REF: p. 1114
OBJ: 9