Ch. 7 Test, Final Considerations in Vent Setup

Question 1

What fractional inspired oxygen (FIO2) setting should be set on the ventilator when the patient currently has a partial pressure of oxygen (PaO2) of 53 mm Hg while receiving 50% oxygen and the desired PaO2 is 90 mm Hg?

a. 64%
b. 74%
c. 85%
d. 95%

Answer 1

ANS: C
DIF: 2 REF: pg. 104

Question 2

A patient’s baseline arterial blood gas (ABG) reveals a partial pressure of oxygen (PaO2) of 78 mm Hg while receiving 35% supplemental oxygen. What should the ventilator fractional inspired oxygen (FIO2) be set at to obtain a target PaO2 of 95mm Hg?

a. 34%
b. 43%
c. 55%
d. 67%

Answer 2

ANS: B

Question 3

A patient receiving 60% oxygen from an air entrainment mask has a partial pressure of oxygen (PaO2) of 45 mm Hg. The patient is being intubated and the ventilator set up. What is the appropriate fractional inspired oxygen (FIO2) to achieve a PaO2 of 60 mm Hg?

a. 0.65
b. 0.75
c. 0.8
d. 0.95

Answer 3

ANS: C

Question 4

The goal of selecting a specific oxygen concentration is to try to achieve clinically acceptable arterial oxygen tensions within which of the following ranges?

a. 40 and 55 mm Hg
b. 50 and 60 mm Hg
c. 60 and 100 mm Hg
d. 100 and 120 mm Hg

Answer 4

ANS: C
The goal of selecting a specific fractional inspired oxygen (FIO2) for a patient is to achieve a clinically acceptable arterial oxygen tension (e.g., 60-100 mm Hg).

Question 5

Following successful cardiac resuscitation, a patient being placed on mechanical ventilation should have which of the following fractional inspired oxygen (FIO2) settings?

a. 0.5
b. 0.6
c. 0.8
d. 1

Answer 5

ANS: D
Using a high oxygen concentration following a cardiac arrest can provide a way of restoring normal oxygenation and replacing tissue oxygen storage when oxygen debt and lactic acid accumulations occur, as with this patient.

DIF: 3 REF: pg. 104

Question 6

What is the range for setting flow triggering?

a. 1 to 10 L/min
b. 10 to 15 L/min
c. 12 to 16 L/min
d. 20 to 30 L/min

Answer 6

ANS: A
Flow triggering is set in a range of 1 to 10 L/min below the base flow depending on the selected ventilator.

DIF: 1 REF: pg. 104

Question 7

A patient is intubated due to an acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD). The patient is now breathing with pressure support ventilation 5 cm H2O and continuous positive airway pressure (CPAP) 5 cm H2O. The patient is unable to flow trigger every inspiration. Unintended positive-end-expiratory pressure (auto-PEEP) is measured at 10 cm H2O. The most appropriate action is to take is which of the following?

a. Decrease the CPAP to 3 cm H2O.
b. Increase the CPAP to 8 cm H2O.
c. Increase pressure support to 10 cm H2O.
d. Change the flow trigger setting to 1 L/min.

Answer 7

ANS: B
Patients may have trouble triggering a breath when unintended positive-end-expiratory pressure (auto-PEEP) is present. When this occurs, adjusting the sensitivity may not alleviate the patient’s inability to trigger the ventilator. When auto-PEEP occurs in mechanically ventilated, spontaneously breathing patients with airflow obstruction, setting extrinsic PEEP to a level equal to about 80% of the patient’s auto-PEEP level may allow the ventilator to sense the patient’s inspiratory efforts. Decreasing the extrinsic PEEP level will not alleviate this problem. Altering the pressure support or the flow trigger will not alleviate this problem.

DIF: 3 REF: pg. 104

Question 8

How much patient effort is needed to trigger a ventilator breath when there is 8 cm H2O of unintended positive-end-expiratory pressure (auto-PEEP) and a pressure trigger setting of 2 cm H2O?

a. 2 cm H2O
b. 6 cm H2O
c. 8 cm H2O
d. 10 cm H2O

Answer 8

ANS: D
The effort required to trigger a breath equals the sum of the auto-PEEP and the pressure trigger setting.

DIF: 2 REF: pgs. 104-106

Question 9

A humidifier used with a mechanical ventilator should deliver a minimum of how much humidity?

a. 10 mg H2O/L at 35° C to 37° C
b. 20 mg H2O/L at 31° C to 35° C
c. 30 mg H2O/L at 31° C to 35° C
d. 47 mg H2O/L at 35° C to 37° C

Answer 9

ANS: C
The humidification system used during mechanical ventilation should provide at least 30 mg H2O/L of absolute humidity at a range of about 31° C to 35° C for all available flows up to 20 to 30 L/min.

DIF: 1 REF: pg. 106

Question 10

Calculate the humidity deficit when a heat moisture exchanger (HME) provided 14 mg/L of water to the set tidal volume.

a. 14 mg/L of water
b. 23 mg/L of water
c. 30 mg/L of water
d. 37 mg/L of water

Answer 10

ANS: C
Humidity deficit = 44 mg/L – absolute humidity

DIF: 2 REF: pgs. 106, 107 (Critical Care Concept 7-1)

Question 11

In which situation should the heat moisture exchanger (HME) be replaced with a heated humidification system?

a. With all tracheostomy tubes
b. After 3 days of ventilation
c. After 24 hours of ventilation
d. Thick secretions not cleared by suctioning

Answer 11

ANS: D
If secretions appear thick after two consecutive suctioning procedures, the heat moisture exchanger (HME) should be removed and the patient switched to a heated humidification system.

DIF: 2 REF: pg. 107

Question 12

Following intubation and placement on volume-controlled continuous mandatory ventilation (VC-CMV), a patient’s average peak inspiratory pressure (PIP) is 26 cm H2O following suctioning. The appropriate settings for the low and high pressure alarms are which of the following?

a. Low pressure = 6 cm H2O, high pressure = 46 cm H2O
b. Low pressure = 15 cm H2O, high pressure = 41 cm H2O
c. Low pressure = 20 cm H2O, high pressure = 36 cm H2O
d. Low pressure = 24 cm H2O, high pressure = 31 cm H2O

Answer 12

ANS: C
Low-pressure alarms are usually set about 5 to 10 cm H2O below peak inspiratory pressure (PIP). High-pressure alarms are set about 10 cm H2O above PIP. The only answer that fits both of these criteria is answer “C.”

DIF: 2 REF: pg. 110

Question 13

A patient is being ventilated with pressure controlled-synchronized intermittent mandatory ventilation (PC-SIMV) of 12 breaths/minute. The apnea alarm time setting should be which of the following?

a. 4 seconds
b. 10 seconds
c. 15 seconds
d. 20 seconds

Answer 13

ANS: B
Apnea alarms are usually set so the patient will not miss two consecutive machine breaths (apnea time > total cycle time [TCT] and

Question 14

The ventilator volume is set at 575 mL. The low exhaled tidal volume (VT) alarm should be set at which of the following?

a. 150 mL
b. 350 mL
c. 400 mL
d. 500 mL

Answer 14

ANS: D
The low exhaled tidal volume (VT) alarm should be set at 10% to 15% below the set VT.

DIF: 2 REF: pgs. 108, 109

Question 15

A patient set up on pressure support ventilation (PSV) has an average minute volume of 5.8 L. What should the low exhaled minute volume alarm be set at?

a. 5 L
b. 4 L
c. 3 L
d. 2 L

Answer 15

ANS: A
The low exhaled minute volume alarm should be set between 10% and 15% below the average minute volume.

DIF: 2 REF: pgs. 110, 111

Question 16

The mechanical ventilator event that is considered potentially life-threatening or a level 2 event is which of the following?

a. Intrinsic positive-end-expiratory pressure (PEEP)
b. High respiratory rate
c. Humidifier malfunction
d. Exhalation valve failure

Answer 16

ANS: C
Intrinsic PEEP = level 3; High respiratory rate = level 3; Humidification malfunction = level 2; Exhalation valve failure = level 1.

DIF: 1 REF: pg. 108

Question 17

The respiratory therapist in the intensive care unit (ICU) responds to a patient’s room because the ventilator is alarming. The most appropriate immediate action is which of the following?

a. Replace the ventilator immediately.
b. Silence the alarms and call for help.
c. Ensure the patient is being ventilated.
d. Troubleshoot the alarm settings.

Answer 17

ANS: C
When a ventilator alarm rings, the respiratory therapist must first ensure that the patient is being ventilated. If the RT doubts this, the patient should be disconnected from the ventilator and ventilated using a manual resuscitation bag. The RT should silence the alarms at that time and call for help.

DIF: 3 REF: pg. 109

Question 18

Identify the patient that could benefit from sigh breaths.

a. Patient on pressure-controlled continuous mandatory ventilation (PC-CMV) with peak inspiratory pressure (PIP) = 38 cm H2O
b. Patient on volume-controlled continuous mandatory ventilation (VC-CMV) with a plateau pressure (Pplateau) = 36 cm H2O
c. Spontaneously breathing patient receiving continuous positive airway pressure (CPAP)
d. 70 kg ideal body weight (IBW) patient on 400 mL with Pplateau = 25 cm H2O

Answer 18

ANS: D
Mechanical ventilator sigh breaths are not recommended with higher tidal volumes (VTs > 7 mL/kg IBW) or in the presence of plateau pressures Pplateau >30 cm H2O. Sigh breaths may be harmful to spontaneously breathing patients receiving continuous positive airway pressure (CPAP) for the treatment of hypoxemia. Therefore, only the 70 kg ideal body weight (IBW) patient on 400 mL (5.7 mL/kg) with the plateau pressure of 25 cm H2O could benefit from sigh breaths.

DIF: 2 REF: pgs. 109, 110

Question 19

All of the following are appropriate situations for the use of sigh or deep breaths except which?

a. During chest physiotherapy
b. During an extubation procedure
c. During continuous positive airway pressure (CPAP) with spontaneous breathing
d. Before and after endotracheal tube suctioning

Answer 19

ANS: C
Sigh breaths may be harmful to spontaneously breathing patients receiving continuous positive airway pressure (CPAP) for the treatment of hypoxemia. Sigh breaths are appropriate during chest physical therapy (CPT), extubation, and before and after suctioning

DIF: 1 REF: pg. 111

Question 20

How much pressure and time is necessary during a lung recruitment maneuver?

a. 20 to 35 cm H2O for 30 to 40 seconds
b. 30 to 40 cm H2O for 15 to 25 seconds
c. 35 to 45 cm H2O for 40 to 60 seconds
d. 40 to 50 cm H2O for 35 to 45 seconds

Answer 20

ANS: C
The recruitment maneuver used to expand collapsed areas of the lung involves using a sustained high pressure of 35 to 45 cm H2O for 40 to 60 seconds.

DIF: 1 REF: pg. 111

Question 21

Essential capabilities of an adult intensive care unit (ICU) ventilator include all of the following except:

a. Expiratory pause
b. Pressure control modes
c. Flow rates up to 250 L/min.
d. Respiratory rates up to 60 breaths/min.

Answer 21

ANS: C
Flow rates up to 180 L/min are suggested for adult ICU ventilators. Expiratory pause is used to measure intrinsic positive-end-expiratory pressure (PEEP). The pressure control modes are essential for the ventilation of patients with low lung compliance. Respiratory rates of between 1 and 6 breaths/minute are essential.

DIF: 1 REF: pg. 111

Question 22

A 70-year-old, 61-inch-tall, female patient was admitted with an acute exacerbation of chronic obstructive pulmonary disease (COPD). After 12 hours of oxygen therapy, bronchodilator therapy, and intravenous corticosteroids, the patient began to show signs of clinical deterioration. Her chest x-ray revealed an enlarged heart and bilateral infiltrates. Her arterial blood gas shows acute on chronic respiratory failure. It is decided that this patient requires intubation and mechanical ventilation. The most appropriate ventilator settings for this patient include which of the following?

a. Volume-controlled continuous mandatory ventilation (VC-CMV) rate 15, VT 200 mL, FIO2 100%, positive-end-expiratory pressure (PEEP) 5 cm H2O
b. VC-CMV rate 12, VT 400 mL, FIO2 40%, PEEP 3 cm H2O
c. Pressure-controlled synchronized intermittent mandatory ventilation (PC-SIMV) rate 10, peak inspiratory pressure (PIP) 30 cm H2O, FIO2 60%, PEEP 3cm H2O
d. PC-SIMV rate 12, PIP 35 cm H2O, FIO2 30%, PEEP 8 cm H2O

Answer 22

ANS: B
The tidal volume setting for patients with chronic obstructive pulmonary disease (COPD) should be 5 – 8 mL/kg with a rate of 8 – 16 breaths/min. Positive-end-expiratory pressure (PEEP) should be less than or equal to 5 cm H2O. The ideal body weight (IBW) for this patient is 50 kg. Therefore, her tidal volume (VT) setting should be between 250 and 400 mL. Fractional inspired oxygen (FIO2) should be less than 50% with a PEEP of 3 – 5 cm H2O. The only answer that fits these criteria is “B.”

DIF: 2 REF: pgs. 113, 114

Question 23

Methods to minimize air trapping in mechanically ventilated patients include which of the following?

a. Using a longer inspiratory time (TI)
b. Switching to pressure support ventilation (PSV)
c. Increasing inspiratory flow
d. Administering a mucolytic agent

Answer 23

ANS: C
To minimize air trapping, or intrinsic positive-end-expiratory pressure (PEEPI), the following steps may be taken: switch to pressure-controlled continuous mandatory ventilation (PC-CMV) with a short inspiratory time (TI), use a lower tidal volume (VT), maintain a clear airway, administer bronchodilators for bronchospasm, and increase inspiratory flow to lengthen expiratory time (TE).

DIF: 1 REF: pg. 114

Question 24

A chronic obstructive pulmonary disease (COPD) patient with an ideal body weight of 65 kg is brought to the emergency department. The patient is short of breath and using accessory muscles. Aerosolized bronchodilators are administered. The arterial blood gas reveals the following: pH 7.31, partial pressure of carbon dioxide (PaCO2) 72 mm Hg, partial pressure of oxygen (PaO2) 88 mm Hg, oxygen saturation (SaO2) 90%, bicarbonate (HCO3-) 32 mEq/L on nasal cannula 2 L/min. The respiratory therapist should recommend which of the following at this time?

a. Intubate, volume-controlled continuous mandatory ventilation (VC-CMV) rate 15 bpm, tidal volume (VT) 650 mL, fractional inspired oxygen (FIO2) 50%, positive-end-expiratory pressure (PEEP) 6 cm H2O
b. Noninvasive positive pressure ventilation (NPPV) with bilevel positive airway pressure (Bilevel PAP) rate 8 bpm, inspiratory positive airway pressure (IPAP) 10 cm H2O, expiratory positive airway pressure (EPAP) 2 cm H2O
c. Intubate, pressure-controlled synchronized intermittent mandatory ventilation (PC-SIMV) rate 10 bpm, peak inspiratory pressure (PIP) 30 cm H2O, FIO2 60%, PEEP 3cm H2O
d. Administer 30% oxygen via air entrainment mask and continuous bronchodilator therapy

Answer 24

ANS: B
Unless critical emergency, an initial attempt with noninvasive ventilation should be tried using inspiratory positive airway pressure (IPAP) 10 – 12 cm H2O and expiratory positive airway pressure (EPAP) 3 to 3 cm H2O.

DIF: 3 REF: pg. 112

Question 25

Sigh breaths could be beneficial during which of the following situations?

a. Continuous positive airway pressure (CPAP) used for the treatment of hypoxemia
b. Mechanical ventilation with VTS = 8-10 mL/kg
c. Ventilating acute respiratory distress syndrome (ARDS) patient with plateau pressure Pplateau > 30 cm H2O
d. Pressure-supported ventilation with tidal volume (VT) = 4-6 mL/kg

Answer 25

ANS: D
Sigh breaths are not indicated for patients on continuous positive airway pressure (CPAP) for hypoxemia because it may be harmful. Sighs are not recommended for patients being ventilated with tidal volumes > 7 mL/kg or in the presence of plateau pressures > 30 cm H2O. Sighs may be beneficial to patients who are receiving pressure-supported ventilation and who have low tidal volumes with mild hypoxemia.

DIF: 1 REF: pgs. 109, 110

Question 26

A 45-year-old, 73-inch-tall, 200 lb male patient is admitted to the emergency department with an exacerbation of myasthenia gravis. The respiratory therapist assesses the patient and finds the patient’s maximum inspiratory pressure is 15 cm H2O and his vital capacity is 1200 mL. It is decided that the patient requires ventilatory support. The most appropriate ventilator settings for this patient are which of the following?

a. Pressure support ventilation (PSV) 5 cm H2O, continuous positive airway pressure (CPAP) 10 cm H2O, FIO2 50%
b. Pressure-controlled continuous mandatory ventilation (PC-CMV), f = 16 breaths/min, peak inspiratory pressure (PIP) = 35 cm H2O, positive-end-expiratory pressure (PEEP) 3 cm H2O, fractional inspired oxygen (FIO2) 45%
c. Noninvasive positive pressure ventilation - bilevel positive airway pressure (NPPV – BiPAP), f = 14 breaths/min, inspiratory positive airway pressure (IPAP) = 28 cm H2O, expiratory positive airway pressure (EPAP) = 5 cm H2O, FIO2 30%
d. Volume-controlled synchronized intermittent mandatory ventilation (VC-SIMV), f = 12 breaths/min, tidal volume (VT) = 725 mL, PS 5 cm H2O, PEEP 5 cm H2O, FIO2 24%

Answer 26

ANS: D
The patient is 73 inches and weighs 200 pounds. So ideal body weight (IBW) = 106 + 6(13) = 194 lbs or 88 kg. The patient’s body surface area (BSA) is 2.16 m2. The estimated minute ventilation is 4 × 2.16 = 8.64 L. Using 7 – 10 mL/kg the set tidal volume should be between 617 mL and 880 mL. The positive-end-expiratory pressure (PEEP) should be 5 cm H2O and the fractional inspired oxygen (FIO2) should be 21% or close to it unless there is hypoxemia. A frequency of 12 with a tidal volume (VT) of 725 gives a minute volume of 8.7 L. This will give the patient full ventilatory support. Pressure support ventilation (PSV) is not appropriate because the patient appears too weak to breathe spontaneously. Noninvasive positive pressure ventilation (NPPV) is not appropriate because of the increased risk of aspiration.

DIF: 3 REF: pg. 116

Question 27

A 36-year-old female patient with a history of asthma is admitted to the ICU from the emergency department. Her respirations are 30, very labored, with accessory muscle use and bilateral inspiratory and expiratory wheezing. There is bilateral hyperresonance during chest percussion. A blood gas taken in the ICU after 1 hour of continuous aerosolized albuterol (15 mg) reveals: pH 7.38, partial pressure of carbon dioxide (PaCO2) 42mm Hg, partial pressure of oxygen (PaO2) 53 mm Hg, oxygen saturation (SaO2) 88%, bicarbonate (HCO3-) 25 mEq/L with nasal cannula 6 L/min. The patient is 5’5” and weighs 135 lbs. The most appropriate action at this time is which of the following?

a. Continue current therapy with 20 mg albuterol and reassess in 1 hour.
b. Noninvasive positive pressure ventilation (NPPV) with bilevel positive airway pressure (BiLevel PAP), f= 12, inspiratory positive airway pressure (IPAP) 28 cm H2O, expiratory positive airway pressure (EPAP) 3 cm H2O, fractional inspired oxygen (FIO2) 30%
c. Intubate, use pressure-controlled continuous mandatory ventilation (PC-CMV), f = 8, peak inspiratory pressure (PIP) 28 cm H2O, TI 0.75 sec, positive-end-expiratory pressure (PEEP) 3 cm H2O, FIO2 100%
d. Intubate, use volume-controlled continuous mandatory ventilation (VC-CMV), f = 12, tidal volume (VT) 600 mL, PF 40 L/min, PEEP 5 cm H2O, FIO2 60%

Answer 27

ANS: C
The assessment and arterial blood gases (ABG) for this patient reveals impending respiratory failure. This patient should be intubated and may possibly require sedation and paralysis, depending on the ability to ventilate with synchrony. Therefore, continuation of the current therapy is not appropriate. Noninvasive positive pressure ventilation (NPPV) is not appropriate with asthma patients who are in respiratory failure and may be unable to provide airway protection. The settings for the volume-controlled continuous mandatory ventilation (VC-CMV) are not appropriate because the tidal volume is set too high, the frequency too low, and the peak flow too low. This would not allow enough time for exhalation and may cause barotrauma. The pressure-controlled continuous mandatory ventilation (PC-CMV) mode will allow for more control over the pressures. The short expiratory time will allow time for exhalation that will decrease the likelihood of hyperexpansion of the lungs.

DIF: 3 REF: pg. 117

Question 28

Patients with acute severe asthma requiring mechanical ventilation are difficult to manage because of which of the following?

a. Diaphragmatic paralysis
b. Increased lung compliance
c. Decreased airway resistance
d. Uneven alveolar hyperexpansion

Answer 28

ANS: D
Increased airway resistance from bronchospasm, increased secretions, and mucosal edema cause air trapping, which can cause uneven hyperexpansion of various lung units. This can cause rupture or compress other areas of the lungs leading to pneumothorax, pneumomediastimum, subcutaneous emphysema, and other forms of barotrauma.

DIF: 1 REF: pg. 117

Question 29

During mechanical ventilation, a patient with a closed head injury develops the Cushing response. This may be immediately managed by using which of the following?

a. Pressure-controlled continuous mandatory ventilation (PC-CMV) with positive-end-expiratory pressure (PEEP)
b. Sedation and paralysis
c. Permissive hypercapnia
d. Iatrogenic hyperventilation

Answer 29

ANS: D
The Cushing response is the normal response to acute increases in intracranial pressure (ICP). This includes hypertension with bradycardia. Iatrogenic hyperventilation, although controversial, is recommended when there is acute uncontrolled increased ICP. The partial pressure of carbon dioxide in the arteries (PaCO2) should be maintained between 25 and 30 mm Hg or titrated to the ICP if it is being monitored. This is a temporary solution and should be gradually reversed within 24 to 48 hours, allowing acid-base balance to restore itself. The use of pressure-controlled continuous mandatory ventilation (PC-CMV) and positive-end-expiratory pressure (PEEP) can increase ICP further. Sedation and paralysis should only be used in extreme cases when the ventilator and patient are asynchronous (usually with severe asthma). Permissive hypercapnia may result in further increases in ICP.

DIF: 3 REF: pg. 116

Question 30

A male patient who is 5’10” and weighs 190 lbs arrives at the hospital having suffered a closed head injury in a motor vehicle accident. The patient is unconscious and a computer tomogram of the head reveals an intracranial bleed. The patient receives an intracranial pressure (ICP) monitor following neurosurgery. Initial ventilator settings should include which of the following?

a. Volume-controlled continuous mandatory ventilation (VC-CMV), respiratory frequency (f) 15 bpm, tidal volume (VT) 750 mL, positive-end-expiratory pressure (PEEP) 5 cm H2O, fractional inspired oxygen (FIO2) 100%
b. Pressure-controlled continuous mandatory ventilation (PC-CMV), f 15 bpm, peak inspiratory pressure (PIP) 35 cm H2O, PEEP 10 cm H2O, FIO2 100%
c. Volume-controlled synchronized intermittent mandatory ventilation (VC-SIMV), f 6 bpm, VT 300 mL, pressure support (PS) 10 cm H2O, PEEP 5 cm H2O, FIO2 50%
d. Pressure-controlled synchronized intermittent mandatory ventilation (PC-SIMV), f 12 bpm, PIP 20 cm H2O, PS 10 cm H2O, PEEP 5 cm H2O, FIO2 40%

Answer 30

ANS: A
The initial settings for a closed head injury patient include pressure-controlled (PC) or volume-controlled (VC) continuous mandatory ventilation (CMV), tidal volumes between 8 to 12 mL/kg, respiratory frequency (f) 15 to 20 bpm, positive-end-expiratory pressure (PEEP) 0 to 5 cm H2O with caution and higher only if there is severe hypoxemia, and fractional inspired oxygen (FIO2) 100% to start and titrate to keep partial pressure of oxygen (PaO2) between 70 and 100 mm Hg. This eliminates both synchronized intermittent mandatory ventilation (SIMV) choices. The PC-CMV choice has a peak inspiratory pressure (PIP) and PEEP that are too high for this type of patient because it would increase intracranial pressure (ICP). Choice “A” fits within the guideline for ventilation of the closed head injury patient.

DIF: 2 REF: pg. 116

Question 31

An 18-year-old, 5’6” and 125 lb female patient was admitted to the hospital 2 days ago for spinal meningitis. She developed sepsis and suffered hypercapnic respiratory failure. The patient was intubated and placed on volume-controlled continuous mandatory ventilation (VC-CMV), respiratory frequency (f) 12 bpm, tidal volume (VT) 600 mL, positive-end-expiratory pressure (PEEP) 5 cm H2O, fractional inspired oxygen (FIO2) 40%. Twenty-four hours later, the patient’s oxygen requirements have dramatically increased and her lung compliance has dramatically dropped, while her chest x-ray showed development of bilateral fluffy infiltrates. The most appropriate actions to take include which of the following?

a. Keep VT the same, increase f to 25 bpm, increase PEEP to 12 cm H2O.
b. Decrease VT to 250 mL, increase f to 15 bpm, increase PEEP to 15 cm H2O.
c. Increase VT to 550 mL, decrease f to 8 bpm, increase PEEP to 10 cm H2O.
d. Decrease VT to 400 mL, decrease f to 8 bpm, decrease PEEP to 3 cm H2O.

Answer 31

ANS: B
During the acute phase of the disease, adequate ventilation should be provided using a tidal volume (VT) in the range of 4 to 6 mL/kg while plateau pressure (Pplateau) is maintained at

Question 32

While initially ventilating a patient with acute respiratory distress syndrome (ARDS), the extrinsic positive-end-expiratory pressure (PEEPE) should be maintained using which of the following methods?

a. 50% of intrinsic positive-end-expiratory pressure (PEEP)
b. Open lung approach
c. Offset intrinsic PEEP
d. Minimize mean airway pressure

Answer 32

ANS: B
During the early phase of acute respiratory distress syndrome (ARDS), it is important to keep extrinsic positive-end-expiratory pressure (PEEPE) high enough to at least exceed the inflection point on a slow or static pressure-volume. It is generally accepted by clinicians that the deflation limb of a slow pressure-volume loop best approximates the end-expiratory pressure range required to prevent alveolar collapse. Maintaining PEEPE above this pressure range helps to prevent opening and closing of small airways and alveoli. This is referred to as the open lung approach to ventilatory management.

DIF: 1 REF: pgs. 117, 118

Question 33

The statement that is true concerning the use of permissive hypercapnia in the management of patients with acute respiratory distress syndrome (ARDS) includes which of the following?

a. The pH may be allowed to drop as low as 7.1.
b. Tromethamine (THAM) may be used to keep the pH above 7.2.
c. Partial pressure of carbon dioxide (PaCO2) needs to rise rapidly to achieve success.
d. PaCO2 should not be allowed to rise above 60 mm Hg.

Answer 33

ANS: B
Acceptable end points for the management of acute respiratory distress syndrome (ARDS) based on arterial blood gases (ABGs) are partial pressure of carbon dioxide (PaCO2) = 40 to 80 mm Hg; pH = 7.20 to 7.40; PaO2 = 60 to 100 mm Hg. Note that these values may vary between institutions. Some physicians prefer to use Tromethamine (THAM) or sodium bicarbonate when pH drops below 7.20.

DIF: 1 REF: pgs. 117, 118

Question 34

The application of positive pressure for patients with left ventricular failure is beneficial because of which of the following?

a. Increases venous return
b. Decreases preload to the heart
c. Increases afterload to the heart
d. Improves perfusion to the myocardium

Answer 34

ANS: B
The use of positive pressure in patients with left ventricular failure will reduce venous return and therefore reduce preload to the left ventricle.

DIF: 1 REF: pgs. 118, 119

Question 35

A 72-year-old male patient (height 6’2”, weight 95 kg) with a history of congestive heart failure (CHF) presents to the emergency department complaining of shortness of breath and inability to lie down to sleep. Physical assessment reveals a very anxious patient with a pulse of 140, respirations 32 and labored with diaphoresis. Breath sounds are decreased with bibasilar coarse crackles. The patient has a productive cough of pink frothy secretions. The patient is placed on a nonrebreather mask and the resulting arterial blood gases (ABG) shows: pH 7.25, partial pressure of carbon dioxide (PaCO2) 55 mm Hg, partial pressure of oxygen (PaO2) 54 mm Hg, oxygen saturation (SaO2) 86%, bicarbonate (HCO3-) 24 mEq/L. The most appropriate immediate action to take includes which of the following?

a. Face mask continuous positive airway pressure (CPAP) 10 cm H2O
b. Intubate, volume-controlled continuous mandatory ventilation (VC-CMV), respiratory frequency (f) 20, tidal volume (VT) 810 mL, positive-end-expiratory pressure (PEEP) 8 cm H2O, fractional inspired oxygen (FIO2) 100%
c. Intubate, volume-controlled synchronized intermittent mandatory ventilation (VC-SIMV), f 6, VT 425 mL, PEEP 10 cm H2O, FIO2 80%
d. Noninvasive positive pressure ventilation (NPPV) with bilevel positive airway pressure (BiLevel PAP), inspiratory positive airway pressure (IPAP) 15 cm H2O, expiratory positive airway pressure (EPAP) 5 cm H2O, FIO2 60%

Answer 35

ANS: D
The patient is suffering from cardiogenic pulmonary edema from congestive heart failure (CHF) and has both hypercapnic and hypoxemic respiratory failure. The use of noninvasive positive pressure ventilation (NPPV) with bilevel positive airway pressure (BiLevel PAP) while waiting for pharmacological treatment to take effect would be appropriate. Face mask continuous positive airway pressure (CPAP) may not provide enough support to allow the patient to reduce the partial pressure of carbon dioxide (PaCO2). Although intubation is a more aggressive alternative, the choices provided are not within the guidelines for ventilation of patients with CHF. These guidelines include a tidal volume (VT) between 8 and 12 mL/kg. That would be between 405 and 648 mL. This eliminates the answer with 810 mL tidal volume. The fractional inspired oxygen (FIO2) initially should be 100%; this eliminates the choice with 80%.

DIF: 3 REF: pg. 120