Mechanical Ventilation Flashcards
From Figure 5.1, which of the following is true?
A A indicates inspiratory time.
B D indicates tidal volume.
C E indicates expiratory time. D All of the above.
E None of the above.
A A indicates inspiratory time.
SPSE 1
To increase CO2 clearance for a baby ventilated using pressure-limited time-cycled ventilation:
A increase the positive end-expiratory pressure (PEEP)
B increase the inspiratory time
C increase the positive inspiratory pressure (PIP)
D increase the fraction of inspired oxygen (FiO2)
E decrease the respiratory rate.
C
CO2 is controlled by the minute ventilation, which is a product of tidal volume (the size of breath) and the ventilatory rate.
In these examples, to increase CO2 clearance, the tidal volume needs to be increased. This can be done by increasing the PIP, or reducing the PEEP.
To reduce the CO2 the opposite is needed. Note, a reduction of PEEP will also result in a reduction in the mean airway pressure and therefore oxygenation.
SPSE 1
To improve oxygenation for a patient ventilated using pressure-limited time-cycled ventilation:
A increase the PEEP
B decrease the tidal volume
C decrease the PIP
D decrease the inspiratory time
E decrease the respiratory rate.
A increase the PEEP
Oxygenation is controlled by the mean airway pressure.
This is a function of the inspiratory time, PIP and PEEP.
To improve oxygenation, the PIP or PEEP can be increased.
Note, increasing the PEEP will reduce the tidal volume and therefore reduce CO2 clearance.
SPSE 1
