Deck 47: Patient Ventilator Interaction

Question 1

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.

Answer 1

D
Explanation: 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.

Question 2

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

Answer 2

B
Explanation: In the presence of dynamic airways obstruction, the application of PEEP offsets the effect of auto-PEEP on missed triggering.

Question 3

In which mode does flow asynchrony most commonly occur?

A) Volume ventilation.
B) Pressure ventilation.
C) CPAP.
D) No mode is more susceptible.

Answer 3

A
Explanation: 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.

Question 4

In severe cases of pneumothorax, the mediastinum and trachea:

A) remain midline.
B) sink posteriorly into the chest cavity.
C) are shifted toward from the side with the pneumothorax.
D) are shifted away from the side with the pneumothorax.

Question 5

Approximately how deep should an endotracheal tube be placed on an adult male?

A) 23 cm at the teeth
B) 21 cm at the teeth
C) 19 cm at the teeth
D) 17 cm at the teeth

Question 6

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

Question 7

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

Question 8

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

Question 9

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

Question 10

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.

Question 11

In which mode does double triggering most commonly occur?

A) Volume ventilation.
B) Pressure ventilation.
C) CPAP.
D) No mode is more susceptible.

Question 12

Which of the following can be adversely affected by poor patient-ventilator interaction?
1) Gas exchange
2) Ventilatory patterns
3) Hemodynamics
4) Length of mechanical ventilation

A)1 and 3 only
B)1, 2, and 3 only
C)2 and 4 only
D)1, 2, 3, and 4

Question 13

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

Question 14

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

Question 15

Possible ways to correct flow asynchrony in volume ventilation include which of the following?
1) Change to decelerating flow.
2) Increase peak flow to be greater than 60 L/min.
3) Match ventilator's inspiratory time to the patient's inspiratory time.
4) Decrease peak flow to be less than 60 L/min.

A)1 and 3 only
B)1, 2, and 3 only
C)3 and 4 only
D)1, 3, and 4 only

Question 16

In which mode does cycle asynchrony most commonly occur?

A) Volume ventilation.
B) Pressure ventilation.
C) CPAP.
D) No mode is more susceptible.

Question 17

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

Question 18

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

Question 19

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

Question 20

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.

Question 21

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

Question 22

Your patient has relatively normal lungs and is receiving mechanical ventilation following surgery. You observe double triggering. What is the most likely cause?

A) The termination criteria is set too low.
B) The flow rate is too slow.
C) Auto-PEEP.
D) The inspiratory time is too short.