Identify the V/Q mismatch

Alveolar ventilation 4

Alveolar perfusion 5

4/5 ratio = 0.8

Explain why a high V/Q would happen?

Mismatch between perfusion and ventilation.

A PE would cause a high V/Q

4/4 ratio example =1

Low V/Q would result in what?

Something obstructing ventilation

3/5 V/Q mismatch =0.6

example would be a mucous plug

What is shunting?

Mismatch between the alveoli, ventilation

and blood flow

What shunting can be a septal defect?

Venous Admixture Shunting

Which kind of shunting can be helped if PaO2 is decreased and given O2 to increase PaO2?

Shunt-like effect-decreased but not completely absent ventilation.  Different areas of the lungs could be exhibiting different kinds of shunting.

What is the number we want to see a

  PIP (peak inspiratory pressure) at to reduce the incident of baotrauma?

less than 40

25-30 cm H2O plateau pressure

On a ventilator, why would we want to increase

PEEP?

If the person has

atelectasis and/or pulmonary edema

also in refractory hypoxemia

What ventilator delivery system set pressure that is held during the entire inspiration (each spontaneous breath) while decreasing the work of breathing.

The tidal volume is determined by the patients efforts?

PSV mode

(Pressure Support Ventilation)

What does MIP/MIF or muscle strength have to be at in

order to extubate a patient?

at least -20 to be able to effectively clear their own

secretions

As a nurse how can we help with MIP or MIF?

Starting the patient on a incentive spirometer in the morning and asking them to do it 10 X an hour

Or ask patient to hold a pillow against chest and cough

What is the A-a gradient mean?

(basically like the V/Q mismatch)

ratio of ventilation and perfusion

What would cause decreased surface area in a patient?

atelectasis, or scar tissue

This can lead to hypoxia

Why do we worry about scar tissue and fibrosis which causes Membrane thickness in the lungs?

the alveolus oxygen and CO2 hav a hard time diffusing appropriately

Why do we worry about tachypnea breathing and shallow respirations?

Inadequate time fo rdiffusion of exchages of gas

(compare to tachycardia-high output heart failure-difficult time diffusing because it isn't in contact with the alveolus for a long enought period of time)