Ch. 7 Test, Final Considerations in Vent Setup Flashcards
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%
ANS: C
DIF: 2 REF: pg. 104
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%
ANS: B
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
ANS: C
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
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).
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
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
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
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
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.
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
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
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
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
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
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
ANS: C
Humidity deficit = 44 mg/L – absolute humidity
DIF: 2 REF: pgs. 106, 107 (Critical Care Concept 7-1)
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
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
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
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
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
ANS: B
Apnea alarms are usually set so the patient will not miss two consecutive machine breaths (apnea time > total cycle time [TCT] and
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
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
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
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
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
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
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.
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
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
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
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
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
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
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
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.
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
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
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
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
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
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
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
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
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
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
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
