Chapter 9 pb Flashcards
How do you calculate flow?
F=Vt/TI
How do you determine the given VT?
VT= Flow x TI
If the lungs are very compliant and easy to inflate, how much pressure is required?
not much pressure is required.
If the lungs are very stiff (low compliance), how much pressure is required?
more pressure is required to inflate them
What law pertains to RAW?
Poiseuille’s law. The larger the diameter of the airway, the lower the resistance and the greater the flow
the smaller the diameter of the airway, How much RAW, and how much flow?
the higher the resistance and the lower the flow
term used to specify the waveforms for pressure, flow, and volume that are graphed relative to time
scalar
The pressure at the mouth at any point in time is the sum of the
transairway pressure (Pta) and the alveolar pressure (Palv).
1 psig = how much cm h20?
70 cm h20
50 psig is how much cm h20
3500 cm h20
50 x 70= 3500
If you wanted to check for auto peep and couldn’t use the exhalation hold maneuver, what would you use?
respirometer in line between the ET and the Y-connector (see Fig. 9-2). (If the respirometer’s needle is still rotating when the next breath occurs, air trapping is present
When flow drops to zero at the end of inspiration,
an inspiratory pause is present.
. When flow is zero, the pressure gradient between the ventilator and the patient’s lungs
is the same.
What can cause a pressure overshoot?
with turbulent airflow, which is created when the delivered pressure encounters a small ET or an obstructed airway
What can eliminate a pressure over shoot?
Decreasing the inspiratory rise time (slope) can eliminate this artifact by limiting the maximum available flow.
