Deck 17: Effects of Positive Pressure Ventilation on the Pulmonary System

Question 1

Shear stress injury and loss of surfactant from the resulting unstable lung units result in a loss of surfactant.This type of pulmonary trauma is known as _____________.

A) atelectrauma
B) barotrauma
C) biotrauma
D) volutrauma

Answer 1

A
Shear stress injury and loss of surfactant constitute atelectrauma.Lung injury caused by high levels of pressure and volume is referred to as barotrauma or volutrauma.The release of inflammatory mediators from the lungs that can lead to multiorgan failure is called biotrauma.

Question 2

Healthy areas of lung tissue in a patient with ARDS may be protected from lung injury caused by overdistention by which of the following?

A) Increasing FɪO₂
B) Decreasing PEEP
C) Using the prone position
D) Using a Vᴛ of 10-12 mL/kg

Answer 2

C
Placing a patient with ARDS in a prone position restricts chest wall movement,thereby preventing severe transpulmonary pressure from causing alveolar stretch and edema,or shear stress.Increasing the FɪO₂ may cause more atelectasis,which could worsen the situation.Decreasing PEEP would derecruit alveoli,shifting the volume to more compliant areas,which could increase the amount of lung injury.Using tidal volumes of 10-12 mL/kg would increase the risk of lung injury.

Question 3

The RT performs a patient-ventilator system check on a 24-year-old,5-foot,10-inch male patient who has been intubated because of a drug overdose.The RT notices what appears to be swelling around the patient's upper anterior chest and neck area.Palpation elicits a tissue paper feeling.The ventilator settings are: VC-CMV,rate 12/min with no patient assist,Vᴛ 900 mL,PEEP 5 cm H₂O,FɪO₂ 0.4,Tɪ 1.2 sec.The most appropriate action for the RT to take is which of the following?

A) Increase the set flow rate.
B) Decrease the set tidal volume.
C) Reduce the set respiratory rate.
D) Perform emergency needle decompression.

Answer 3

B
Assessment of this patient reveals that he has subcutaneous emphysema,as evidenced by the swelling around the upper anterior chest and neck area and the tissue paper feeling on palpation.This is a form of barotrauma caused by alveolar rupture as a result of too much volume.The PEEP setting is only 5 cm H₂O,which is physiologic.The Vᴛ setting,however,is too high.The IBW for this patient is 75 kg; 900 ÷ 75 = a set volume of 12 mL/kg.This needs to be adjusted to 8-10 mL/kg.The subcutaneous emphysema should subside on its own.

Question 4

Alveolar tissue and pulmonary capillary injury is caused by which of the following?

A) Barotrauma
B) Biotrauma
C) Shear stress
D) Overdistention

Question 5

In a mechanically ventilated patient who is receiving lorazepam and succinylcholine,the diaphragm moves in which of the following ways?

A) A
B) B
C) C
D) D

Question 6

The RT responds to the high pressure,high respiratory rate,low exhaled volume,and low exhaled minute volume alarms of a mechanically ventilated patient in the ICU.Upon entering the room,the RT notices that the patient,who is still attached to the ventilator,appears diaphoretic,tachypneic,tachycardic,and hypertensive.Breath sounds are absent on the left and distant on the right.The patient's trachea is deviated to the left,and jugular vein distention is present.The endotracheal tube is 24 cm at the teeth.Immediate action should include which of the following?

A) Order a chest radiograph in the upright position.
B) Administer intravenous etomidate and succinylcholine.
C) Pull back the endotracheal tube to 22 cm at the teeth.
D) Insert a 14-gauge needle into the second intercostal space right midclavicular line.

Question 7

Prolonged ventilator-induced hyperventilation can lead to which of the following?

A) Hypokalemia
B) Hyperkalemia
C) Increased ICP
D) Headaches

Question 8

Preservation of spontaneous breathing during mechanical ventilation favors the distribution of gas to which areas of the lung?

A) Peribronchial area
B) Upper airway
C) Lung periphery
D) Central airways

Question 9

In what areas of the lung are ventilation and perfusion best matched during spontaneous ventilation in the supine position?

A) Apices of the lungs
B) Nondependent anterior lung areas
C) Dependent posterior lung areas
D) Basilar segments of lower lobes

Question 10

Shear stress is most likely to affect a patient with which of the following?

A) PA = 35 cm H₂O; Pₚ₁ = 21 cm H₂O
B) PA = 35 cm H₂O; Pₚ₁ = 12 cm H₂O
C) PA = 45 cm H₂O; Pₚ₁ = 33 cm H₂O
D) PA = 50 cm H₂O; Pₚ₁ = 38 cm H₂O

Question 11

Inappropriate ventilator settings can cause the release of inflammatory mediators within _______.

A) 1-3 hours
B) 5-10 hours
C) 10-12 hours
D) 24 hours

Question 12

Biotrauma is caused directly by which of the following?

A) High oxygen levels
B) Overdistention of alveoli
C) Long expiratory times
D) Fast respiratory rates

Question 13

What is the minimum transpulmonary pressure that has been associated with lung injury in animals?

A) 30 cm H₂O
B) 40 cm H₂O
C) 50 cm H₂O
D) 60 cm H₂O

Question 14

The RT assesses the flow-time scalar from an apneic patient mechanically ventilated in the VC-CMV mode.The most appropriate action for this patient is to do which of the following?

A) Decrease the set flow rate.
B) Reduce the set ventilator rate.
C) Increase the inspiratory time.
D) Decrease the set tidal volume.

Question 15

Ventilator-induced lung injury (VILI)is associated with which of the following?

A) Air trapping
B) Biotrauma
C) Patient-ventilator asynchrony
D) Ventilator-associated pneumonia

Question 16

Which of the following mechanically ventilated patients shows clinical signs of hypoventilation?

A) A patient who is cool to the touch and has negative T waves on the ECG
B) A patient who has twitchy extremities and also atrial flutter on the ECG
C) A patient who is anxious and hypertensive and has elevated T waves on the ECG
D) A patient who has cool, twitchy extremities and also low, rounded T waves on the ECG

Question 17

What is the minimum range of time constants necessary for the lungs to empty 98% of the inspired volume?

A) 1-2
B) 2-3
C) 3-4
D) 4⁻⁵

Question 18

Which of the following mechanically ventilated patients shows clinical signs of hyperventilation?

A) A patient who has hot skin and also long P-R intervals on the ECG.
B) A patient who has cool skin and also shows paroxysmal tachycardia on the ECG.
C) A patient who is hypertensive and agitated and has S-T segment depression on the ECG.
D) A patient who is hypotensive and dyspneic and has widened QRS complexes on the ECG.

Question 19

Overdistention of the lungs causes the release of which inflammatory mediators?

A) Cytokines
B) Alpha-1 antitrypsin
C) Histamine
D) Macrophages

Question 20

Lung injury is more likely to occur with which of the following with normal lung tissue?

A) PA = 25 cm H₂O; Pₚ₁ = 18 cm H₂O
B) PA = 29 cm H₂O; Pₚ₁ = 10 cm H₂O
C) PA = 30 cm H₂O; Pₚ₁ = 21 cm H₂O
D) PA = 45 cm H₂O; Pₚ₁ = 34 cm H₂O

Question 21

A patient receiving pressure controlled-continuous mandatory ventilation (PC-CMV)has initial arterial blood gas (ABG)findings as follows: PₐO₂ of 101 mm Hg,partial pressure of carbon dioxide in the arteries (PₐCO₂)of 60 mm Hg,and pH of 7.30.The respiratory therapist should:

A) increase minute ventilation to this patient.
B) decrease pressure setting.
C) change the ventilation mode.
D) increase the minute ventilation to this patient very gradually over the next several days.

Question 22

The combination of __________________ and ____________________ increases the risk of absorption atelectasis.

A) High tidal volumes, FɪO₂ >0.4
B) High tidal volumes, FɪO₂ ³0.7
C) Low tidal volumes, FIOs >0.5
D) Low tidal volumes, FɪO₂ >0.7

Question 23

The acceptable lower limit of PₐO₂ for a mechanically ventilated patient with ARDS is which of the following?

A) 50 mm Hg
B) 60 mm Hg
C) 70 mm Hg
D) 80 mm Hg

Question 24

When setting up a patient on volume ventilation with constant flow,the initial flow setting should be ________.

A) 50 L/min
B) 60 L/min
C) 70 L/min
D) 80 L/min

Question 25

A patient with asthma is being ventilated in PSV,5 cm H₂O,with CPAP of 5 cm H₂O.The patient has chest wall retractions on most breaths and appears to have an increased WOB.The following graphic occurred the entire time the respiratory therapist was assessing the patient.What does this graphic demonstrate?

A) Trigger asynchrony
B) Mode asynchrony
C) PEEP asynchrony
D) Cycle asynchrony

Question 26

The pressure-time scalar of a patient with COPD who is receiving PSV shows positive deflection toward the end of inspiration.The most appropriate way to alleviate this is to do which of the following?

A) Increase the PSV level.
B) Decrease the PSV level.
C) Increase the flow cycle percentage.
D) Decrease the flow cycle percentage.

Question 27

Assessment of a mechanically ventilated patient reveals use of accessory muscles and a respiratory rate of 26 breaths/min.The mode is CPAP with 5 cm H₂O and an FɪO₂ of 0.4.The most appropriate action is which of the following?

A) Return the patient to full ventilatory support.
B) Add pressure support to the CPAP.
C) Increase the CPAP to 8 cm H₂O.
D) Deflate the cuff of the ET tube.