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?

Accepted Answer

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?

Accepted Answer

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?

Accepted Answer

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:

Accepted Answer

As pressure increases, the affected side's lung collapses and begins to compress the unaffected side. In severe cases, the mediastinum and trachea are shifted away from the side with the pneumothorax.

Question 5

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

Accepted Answer

In men, the tube should be positioned approximately 23 cm at the teeth (incisors) and 21 cm in women.

Question 6

Which of the following are variables controlled during pressure assist/control mechanical ventilation?
1) Volume
2) Flow
3) Time
4) Pressure

Accepted Answer

In pressure assist/control mechanical ventilation, the variables controlled are time and pressure. The ventilator adjusts the flow to achieve the set pressure within the set time.

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

Accepted Answer

Auto-PEEP, poor sensitivity setting, and ventilator malfunction can all cause trigger delay. Water in the circuit is unlikely to cause trigger delay.

Question 8

Which of the following is considered a patient-related cause of poor patient-ventilator interaction?

Accepted Answer

Abnormal respiratory drive, such as anxiety or pain, can affect a patient's ability to coordinate with the ventilator and lead to poor patient-ventilator interaction. Asynchrony and inadequate ventilatory support are ventilator-related causes of poor patient-ventilator interaction. Inadequate FiO2 (fraction of inspired oxygen) can also affect gas exchange, but it is not directly related to patient-ventilator interaction.

Question 9

Your patient that is receiving mechanical ventilation has a high ventilatory demand. Which of the following is the most appropriate inspiratory time?

Accepted Answer

Many adults with moderate or high ventilatory demands desire an inspiratory time between 0.6 and 0.9 sec.

Question 10

The most important variable affecting trigger asynchrony is:

Accepted Answer

However, the single most important variable affecting trigger asynchrony is the presence of auto-PEEP.

Question 11

In which mode does double triggering most commonly occur?

Accepted Answer

Double triggering is usually a result of the patients' ventilatory center wanting a larger breath or a longer inspiratory time than is set on the ventilator. This causes the patient to continue inspiration when the ventilator transitions into the expiratory phase resulting in the ventilator triggering a second time. The biggest problem with double triggering is that normally there is no exhalation after the first breath, so that the actual delivered tidal volume may be up to double what is set on the ventilator. Double triggering is most common with volume A/C because of the precise setting of the tidal volume.

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

Accepted Answer

Poor patient-ventilator interaction can adversely affect gas exchange, ventilatory patterns, hemodynamics, and the length of mechanical ventilation. This is because synchronization issues or inappropriate settings can lead to inefficient breathing efforts, altered blood gas levels, compromised cardiac function, and potentially prolonged need for mechanical support.

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

Accepted Answer

The answer of You have determined your patient receiving volume...

Question 14

Which of the following is the primary reason that patients poorly interact with the ventilator?

Accepted Answer

One of the primary reasons that patients poorly interact with the mechanical ventilator is a change in their clinical status. Excessive secretions, bronchospasm, and agitation are the most common and regularly seen causes of poor patient-ventilator interaction and issues that should be assessed at every patient-ventilator assessment.

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.

Accepted Answer

Correcting flow asynchrony in volume ventilation can be achieved by changing to a decelerating flow pattern, increasing peak flow to meet the patient's demand, and matching the ventilator's inspiratory time to the patient's inspiratory time.

Question 16

In which mode does cycle asynchrony most commonly occur?

Accepted Answer

Cycle asynchrony occurs when the ventilator ends the breath at a time different from when the patients' respiratory center wants to end the breath. It is more common in pressure than volume-targeted ventilation, but it can occur in all modes of ventilation.

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

Accepted Answer

Proportional assist ventilation (PAV) and neurally adjusted ventilator assist (NAVA) are both modes of mechanical ventilation that are designed to reduce asynchrony between the patient's breathing efforts and the ventilator's delivery of support. PAV adjusts the level of support provided by the ventilator in proportion to the patient's effort, while NAVA uses a signal from the patient's diaphragm muscle to trigger and cycle ventilator support. Pressure support ventilation (PSV) and volume control/assist ventilation (VC/AC) can both potentially contribute to asynchrony if the level of support is not appropriately matched to the patient's needs.

Question 18

Which of the following is a technique for minimizing the effects of auto-PEEP?

Accepted Answer

Secretion management helps reduce airway resistance and improves expiratory flow, thereby minimizing the effects of auto-PEEP.

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

Accepted Answer

The answer of Which of the following modes of ventilation...

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?

Accepted Answer

In an emergency situation where the ventilator alarms are sounding and the patient's status has changed, the priority is to ensure adequate ventilation. Manually ventilating the patient allows for immediate assessment and intervention.

Quiz 47: Patient Ventilator Interaction

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?

How are the effects of auto-PEEP on missed triggering improved in the presence of dynamic airway obstruction?

In which mode does flow asynchrony most commonly occur?

In severe cases of pneumothorax, the mediastinum and trachea:

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

Which of the following are variables controlled during pressure assist/control mechanical ventilation? 1) Volume 2) Flow 3) Time 4) Pressure

Which of the following can cause trigger delay? 1) Auto-PEEP 2) Poor sensitivity setting 3) Water in the circuit 4) Ventilator malfunction

Which of the following is considered a patient-related cause of poor patient-ventilator interaction?

Your patient that is receiving mechanical ventilation has a high ventilatory demand. Which of the following is the most appropriate inspiratory time?

The most important variable affecting trigger asynchrony is:

In which mode does double triggering most commonly occur?

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

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

Which of the following is the primary reason that patients poorly interact with the ventilator?

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.

In which mode does cycle asynchrony most commonly occur?

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

Which of the following is a technique for minimizing the effects of auto-PEEP?

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

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?