V/Q & Acid/Base Compensation

Question 1

Define V/Q

Answer 1

Alv. Vent/cardiac output

Question 2

What is the avg. V/Q

Answer 2

0.8

Question 3

With a low V/Q, what is happening

Answer 3

Decreased vent/increased perfusion - blood is moving too fast or not enough air to meet demands

PaO2 goes down
PaCO2 goes up
Ph goes down

Pulmonary A Will equilibrate to Pulmonary V.

Seen in the base of the lung
Seen in hypoventilation

Question 4

Define what happens in increased V/Q

Answer 4

Results from increased vent with decreased blood flow

Seen in hypervent or PE

Increase in PaO2
decrease in PCO2

Increase in pH

Seen in apex of lung

Question 5

Define physiological shunt

Answer 5

Blockage of alv.

Question 6

Define anatomical shunt

Answer 6

Blood physically not getting to lungs

Like a patent foramen ovale

Question 7

Define hypoxic hypoxia

Answer 7

RBC do not cross alv. Cap to

Seen in COPD

Question 8

Define anemic hypoxia

Answer 8

Too few RBC

Co poisoning

Question 9

Define circulatory hypoxia

Answer 9

RBC at 100 mmHg but blockage of circulation

Seen in SSA and PE

Question 10

How will the body correct decreased V/Q

Answer 10

Hypoxic vascoconstriction

Causes blood to be shunted to other areas, raises V/Q

Question 11

How will body fix increased V/Q

Answer 11

Bronchoconstriction

Decreases inspiration

Question 12

Equation for metabolic acidosis check

Equation for metabolic alkalosis check

Equation for anion gap

Answer 12

PaCO2 = 1.5(HCO3) + 8 +/-2

Change in PaCO2 = (0.5 - 1) x change in HCO3

Na - (Cl+HCO3)

Question 13

What is equation for resp acidosis acute and chronic

Answer 13

Acute:
Expected HCO3 = 24+((PaCO2-40)/10))

Chronic:
Expected HCO3 = 24 +4((PaCO2 - 40)/10))

Question 14

What is the equation for acute and chronic resp. Alkalosis

Answer 14

Acute:
Expected HCO3 = 24-2((40-PaCO2)/10))

Chronic:
Expected HCO3 = 24-5((40-PaCO2)/10))