Deck 14: Respiratory Monitoring in Critical Care

Question 1

In mechanically ventilated patients, the addition of positive end-expiratory pressure (PEEP) to normal tidal volumes is associated with the following effects except a(n):

A)decrease in intrapulmonary shunting.
B)increase in functional residual capacity.
C)increase in partial pressure of arterial oxygen (PaO₂).
D)increase in residual volume.

Answer 1

increase in residual volume.

Question 2

Ventilatory measurements routinely monitored at the bedside include all of the following except:

A)airway pressures.
B)lung volumes and flows.
C)fractional gas concentrations.
D)oxygen consumption and carbon dioxide production.

Answer 2

oxygen consumption and carbon dioxide production.

Question 3

Which of the following ventilator changes will have to be made if the problem of "breath stacking" is to be resolved?

A)Increase in tidal volume
B)Increase in respiratory rate
C)Increase in inspiratory flow
D)Increase in both respiratory rate and inspiratory flow

Answer 3

Increase in inspiratory flow

Question 4

An important advantage of monitoring mechanical tidal volumes proximally is that:

A)it decreases circuit resistance and dead space.
B)it decreases the respiratory work for the patient.
C)the measuring device is less susceptible to condensation.
D)it eliminates the compressible volume factor of tubing circuits.

Question 5

All of the following changes can decrease "breath stacking" in a mechanically ventilated patient except:

A)a decreased ventilator rate.
B)an increased inspiratory flow.
C)a decreased expiratory time.
D)a decreased mechanical tidal volume.

Question 6

Patients who are ventilated with excessively large tidal volumes are at risk for:

A)air trapping.
B)volutrauma.
C)emphysema.
D)hyperventilation.

Question 7

In a sedated, mechanically ventilated patient, inspiratory tidal volumes are consistently larger than expiratory tidal volumes.If it is assumed that there is no leak in the circuit, which of the following provides the best explanation for this discrepancy?

A)Ventilator malfunction
B)The compressibility factor of the ventilator circuit
C)An increase in airway resistance that causes air trapping
D)Different pressure profiles

Question 8

Which of the following conditions explains why lung damage persists after recovery from a severe protracted episode of acute respiratory distress syndrome (ARDS)?

A)Volutrauma
B)Severity of the episode of ARDS
C)Use of excessive amounts of PEEP during the episode
D)Condition of the lungs before the onset of disease

Question 9

It is important to monitor ventilatory parameters in addition to arterial blood gases because:

A)it is easier and more cost-effective to monitor ventilatory parameters.
B)changes in ventilatory parameters will occur before they are seen in arterial blood gases.
C)monitoring of ventilatory parameters does not require specialized equipment and can be done more quickly.
D)monitoring of ventilatory parameters can be done without a physician's order, whereas arterial blood gas monitoring requires a physician's order.

Question 10

The "stacking" of breaths, which often is seen in mechanically ventilated patients with severe airway obstruction, can be caused by:

A)ventilator malfunction.
B)a low-measured tidal volume.
C)insufficient expiratory time.
D)a respiratory rate that is too low.

Question 11

If intubated and mechanically ventilated patients are given shallow tidal volumes without sighs, which of the following is most likely to occur?

A)Coughing
B)Atelectasis
C)Respiratory arrest
D)Increase in secretion production

Question 12

Volutrauma is most likely to develop in:

A)the larger airways.
B)dependent lung regions.
C)nondependent lung regions.
D)small airways.

Question 13

In healthy, spontaneously breathing patients, an occasional increase in tidal volume to three or four times the normal level, which normally occurs about six to ten times each hour, is the definition of a:

A)sigh.
B)cough.
C)sneeze.
D)forced vital capacity.

Question 14

A nonintubated patient should be monitored for lung volumes in the presence of the following clinical conditions except:

A)deteriorating blood gases.
B)receipt of noninvasive positive-pressure ventilation.
C)respiratory rate less than 30 breaths/min.
D)central nervous system depression.

Question 15

It is important to monitor lung volumes in ICU patients because changes in lung volumes reflect all of the following changes except:

A)changes in gas exchange in the lung.
B)changes in the patient's clinical status.
C)a response to therapy and any problems that may arise.
D)they influence the selection of antibiotic therapy in the ICU.

Question 16

All of the following are likely to cause a decrease in a patient's tidal volume except:

A)pulmonary edema.
B)metabolic acidosis.
C)acute respiratory distress syndrome.
D)the postoperative period after coronary artery bypass surgery.

Question 17

Which of the following is least likely to cause an increase in a patient's tidal volume?

A)Metabolic acidosis
B)Sepsis
C)Metabolic alkalosis
D)Severe neurologic injury

Question 18

Weaning failure during a spontaneous breathing trial may be predicted when the spontaneous respiratory rate is greater than:

A)20 breaths/min.
B)25 breaths/min.
C)30 breaths/min.
D)35 breaths/min.

Question 19

All the following activities are included in respiratory monitoring except:

A)alarm setting.
B)pulmonary consults.
C)physical examinations.
D)measurements and calculations.

Question 20

Which of the following statements about the tidal volume is true?

A)It usually is 10 to 15 mL/kg of ideal body weight.
B)It usually is about 25% to 30% of total lung capacity.
C)It is made up of two components: alveolar volume and dead space volume.
D)It has an inversely proportional relationship with minute ventilation.

Question 21

Carbon dioxide production is increased by approximately what percentage per 1° C of body temperature in patients with fever?

A)1%
B)10%
C)25%
D)50%

Question 22

Which of the following is normally used when PEEP levels are titrated to determine optimal PEEP?

A)Flow-time curve
B)Volume-time curve
C)Pressure-time curve
D)Pressure-volume curve

Question 23

When a patient's mechanical ventilator has a graphic display screen, which of the following waveforms could be used to determine whether there is any leak in the system and the amount of the leak?

A)Flow-time
B)Volume-time
C)Pressure-time
D)Pressure-flow

Question 24

All of the following are likely to increase the mean airway pressure (MAP) except an increase in:

A)flow rate.
B)PEEP levels.
C)peak pressure.
D)expiratory time.

Question 25

Which of the following values of VC is more consistent with impending respiratory failure?

A)10 mL/kg
B)30 mL/kg
C)50 mL/kg
D)70 mL/kg

Question 26

If auto-PEEP is present, it is most likely to be detected if the expiratory limb of the patient circuit is occluded at what point in the cycle?

A)At the end of exhalation
B)In the middle of inhalation
C)In maximal inhalation
D)At the middle of exhalation

Question 27

Which of the following ventilator changes is most likely to increase the functional reserve capacity (FRC) and reduce the extent of acute lung injury?

A)Increased FIO₂
B)Increased flow
C)Increased PEEP
D)Decreased inspiratory time

Question 28

For weaning to be successful, the patient's spontaneous minute ventilation needs to be less than _____ L/min.

A)10
B)20
C)30
D)40

Question 29

The amount of force needed to maintain a mechanical tidal volume breath in the patient's lungs is known as _____ pressure.

A)peak
B)static
C)positive end-expiratory
D)continuous positive airway

Question 30

Acute respiratory distress syndrome (ARDS), pneumonia, and pulmonary edema are likely to cause a decrease in lung compliance.This is evidenced in a mechanically ventilated patient by an increase in:

A)static pressure.
B)expiratory time.
C)inspiratory time.
D)dynamic pressure.

Question 31

Which of the following values for the ratio of respiratory frequency to tidal volume would predict that the patient will be successfully weaned off the ventilator?

A)50
B)100
C)150
D)200

Question 32

When carbon dioxide elimination is monitored, the highest levels are obtained at the:

A)end of inhalation.
B)end of exhalation.
C)middle of inhalation.
D)middle of exhalation.

Question 33

The ratio of respiratory frequency to tidal volume that is used to predict the likelihood of success in weaning the patient from mechanical ventilation is also known as:

A)a spontaneous breathing test.
B)the successful weaning test.
C)the spontaneous ventilation index.
D)the rapid-shallow breathing index.

Question 34

Which of the following RSBI values would predict that the patient is least likely to be successfully weaned from mechanical ventilation?

A)25
B)50
C)75
D)100

Question 35

Compliance is defined as:

A)elasticity.
B)pressure change per unit of volume.
C)volume change per unit of pressure change.
D)volume change per unit of flow.

Question 36

In adult patients, spontaneous tidal volumes should be at least what value if weaning is to be successful?

A)200 mL
B)300 mL
C)400 mL
D)500 mL

Question 37

In the intensive care unit (ICU), the airway resistance (Raw) of a mechanically ventilated patient can be estimated easily by using which of the following formulas?

A)(Flow - Inspiratory time)/60
B)(Peak pressure - Static pressure)/2
C)(Peak pressure - Static pressure)/Flow
D)(ET tube diameter - Static pressure)/Peak airway pressure

Question 38

Which of the following waveforms most accurately allows the clinician the recognition of auto-PEEP?

A)Pressure-volume
B)Pressure-time
C)Flow-time
D)Flow-volume

Question 39

The amount of force needed to overcome opposition to air flow in the lungs during mechanical ventilation is known as:

A)peak pressure.
B)airway pressure.
C)maximal airway resistance.
D)positive end-expiratory pressure.

Question 40

The highest incidence of postoperative morbidity is associated with which of the following surgery sites?

A)Transsternal
B)Upper abdominal
C)Lower abdominal
D)Thoracoabdominal

Question 41

Which of the following conditions is the most common cause of inadequate oxygenation of pulmonary capillary blood?

A)Hypovolemia
B) mismatch
C)Hypoventilation
D)Diffusion defect

Question 42

When the dead space-to-tidal volume ratio (Vᴅ/Vᴛ) is calculated, Vᴅ refers to the _____ dead space.

A)alveolar
B)anatomic
C)ventilatory
D)physiologic

Question 43

The portion of delivered oxygen actually consumed and an index of the efficiency of circulation is the definition for the:

A)oxygenation index (OI).
B)oxygen extraction ratio (C[a - v]O₂/CaO₂).
C)arterial-mixed venous oxygen content difference (C[a - v]O₂).
D)arterial-mixed venous oxygen saturation difference (S[a - v]O₂).

Question 44

All of the following will cause an increase in intrapulmonary shunting except:

A)ARDS.
B)atelectasis.
C)pneumonia.
D)cystic fibrosis.

Question 45

Under most clinical conditions, the PaO₂ should be kept within the range of _____ mm Hg.

A)60 to 80
B)80 to 100
C)100 to 120
D)120 to 150

Question 46

The parameter that indicates oxygen usage throughout the whole body is:

A)CaO₂.
B)
C)PaCO₂.
D)P(A - a)O₂.

Question 47

On the oxygen dissociation curve (ODC), the P-50 refers to the:

A)partial pressure of oxygen when the hemoglobin is 50% saturated.
B)hemoglobin saturation when the fraction of inspired oxygen is 50%.
C)partial pressure of oxygen when the fraction of inspired oxygen is 50%.
D)hemoglobin saturation when the partial pressure of oxygen is 50 mm Hg.

Question 48

The normal compensatory mechanism for a left shift in the oxygen dissociation curve is a(n):

A)increase in tidal volume.
B)increase in cardiac output.
C)increase in respiratory rate.
D)decrease in body temperature.

Question 49

Which level of a PaO₂/FIO₂ ratio is consistent with a definition of acute lung injury (ALI)?

A)50
B)100 to 200
C)150
D)200 to 300

Question 50

Under normal conditions, the hemoglobin is responsible for carrying approximately what percentage of the oxygen carried in the blood?

A)66%
B)75%
C)88%
D)99%

Question 51

The cardiac output will increase to compensate for a decrease in oxygen tension when the PaO₂ falls to below _____ mm Hg.

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