7.1 Acid-Base Balance Equations

Question 1

What is the equation for calculating whether or not a patient is compensated adequately for metabolic acidosis?

Answer 1

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

Question 2

What is the equation for calculating whether or not a patient is compensated adequately for metabolic alkalosis?

Answer 2

Expected change in PaCO2 = (.5 to 1.0) change in HCO3

Question 3

What are the equations for calculating whether or not respiratory acidosis is acute or not?

Answer 3

Acute:

HCO3 = 24 + (PaCO2 - 40)/10

Chronic:

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

Question 4

What is the equation for calculating anion gap?

Answer 4

Anion gap = [Na] - ([Cl] + [HCO3])

Question 5

What are the equations for calculating whether or not respiratory alkalosis is acute or not?

Answer 5

Acute

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

Chronic:

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