Question 1

An increase in airway resistance during pressure ventilation will result in which of the following?

Accepted Answer

With increased airway resistance the flow-time scalar will show a curve that is flatter in appearance.Flow will not drop to zero by the time the set inspiratory time is reached.Consequently,the ventilator and lung pressures do not equilibrate and this can affect the overall volume delivered to the patient.

Question 2

During a patient-ventilator system check the respiratory therapist notices that the pressure-volume loop begins at zero on the x-axis but does not return to zero during expiration.The cause of this is which of the following?

Accepted Answer

When the loop on a pressure-volume loop does not return to zero during exhalation,there is a leak in the ventilator circuit.

Question 3

What is the flow-cycle setting for the pressure support ventilation (PSV)breaths shown in the scalars below?

Accepted Answer

The peak inspiratory flow is 40 L/min.Inspiration ends at 20 L/min.The flow-cycle is therefore set at 50%.

Question 4

A reduction in compliance during pressure ventilation will cause which of the following?

Accepted Answer

When compliance is reduced during pressure ventilation the volume delivered will be reduced proportionally.The volume curve ending under the zero line is indicative of active exhalation.Inspiration ending prior to the flow tapering to zero is consistent with an increase in airway resistance.The pressure curve becoming concave on inspiration is consistent with inadequate flow.

Question 5

The type of breath shown in the flow-volume loop below is which of the following?

Accepted Answer

Part of the flow-volume curve occurs to the left of the y-axis;this reflects a drop in pressure during inspiration (pressure value becomes negative)and an increase in pressure with exhalation (pressure becomes positive).

Question 6

A patient is receiving ventilation with volume-controlled continuous mandatory ventilation (VC-CMV).During a patient-ventilator system check the respiratory therapist sees the flow-volume loop below.The most appropriate action is to do which of the following?

Accepted Answer

The flow-volume loop shown in this question reflects increasing airway resistance.The expiratory flow part of the loop shows the scooped-out appearance.This is typical of a patient with airway obstruction.Administration of a bronchodilator will help to relieve some of the airway obstruction due to bronchospasm.Since the problem is obstructive and not restrictive,adding positive-end-expiratory pressure (PEEP)or switching to pressure-controlled continuous mandatory ventilation (PC-CMV)will not address the issue.The flow-volume loop shows no leak in the system.

Question 7

Calculate the static compliance using the information from the pressure-volume loop below.

Accepted Answer

The alveolar pressure is between 21 and 22 cm H₂O and the set positive-end-expiratory ventilation (PEEP)is 5 cm H₂O.The tidal volume is 500 mL.C_S = V_T/P_A- PIP

Question 8

Delayed termination during pressure support ventilation (PSV)can be avoided with patients who have chronic obstructive pulmonary disease (COPD)by doing which of the following?

Accepted Answer

The presence of active exhalation during pressure support ventilation (PSV)indicates that the patient is trying to end the breath early.This is referred to as delayed termination and is associated with patient-ventilator asynchrony.This phenomenon is often seen with patients who have increased airway resistance,as in chronic obstructive pulmonary disease (COPD).Since inspiratory time is determined by flow cycling in PSV,increasing the flow-cycle setting will shorten inspiration,allowing more time for exhalation.

Question 9

Which of the following conditions causes a pressure-volume loop during volume-controlled continuous mandatory ventilation (VC-CMV)to extend farther to the right and flatten out?

Accepted Answer

The extension to the right and flattening out of the pressure-volume loop during VC-CMV is indicative of decreasing compliance.This could be caused by pneumonia.Asthma,bronchitis,and emphysema all have increased airway obstruction.

Question 10

Identify the type of flow waveform the ventilator is delivering from the flow-volume loop below.

Accepted Answer

The inspiration is above the baseline and expiration is below the baseline in the flow-volume loop.The inspiratory flow pattern is rectangular.

Question 11

What is the cause of the change from pressure-volume loop A to pressure-volume loop B during volume-controlled continuous mandatory ventilation (VC-CMV)?

Accepted Answer

The volume delivered remains the same for both loops.However,the pressure has increased from approximately 20 cm H₂O to 35 cm H₂O.The alveolar pressure (P_A)has increased also.This is indicative of a decrease in compliance.

Quiz 9: Ventilator Graphics

An increase in airway resistance during pressure ventilation will result in which of the following?

During a patient-ventilator system check the respiratory therapist notices that the pressure-volume loop begins at zero on the x-axis but does not return to zero during expiration.The cause of this is which of the following?

What is the flow-cycle setting for the pressure support ventilation (PSV) breaths shown in the scalars below?

A reduction in compliance during pressure ventilation will cause which of the following?

The type of breath shown in the flow-volume loop below is which of the following?

A patient is receiving ventilation with volume-controlled continuous mandatory ventilation (VC-CMV) .During a patient-ventilator system check the respiratory therapist sees the flow-volume loop below.The most appropriate action is to do which of the following?

Calculate the static compliance using the information from the pressure-volume loop below.

Delayed termination during pressure support ventilation (PSV) can be avoided with patients who have chronic obstructive pulmonary disease (COPD) by doing which of the following?

Which of the following conditions causes a pressure-volume loop during volume-controlled continuous mandatory ventilation (VC-CMV) to extend farther to the right and flatten out?

Identify the type of flow waveform the ventilator is delivering from the flow-volume loop below.

What is the cause of the change from pressure-volume loop A to pressure-volume loop B during volume-controlled continuous mandatory ventilation (VC-CMV) ?