Acid Base Equations

Question 1

Metabolic Acidosis compensation equation

Answer 1

∆pCO2 = 1.2 * ∆HCO3

pCO2 = 1.5 x HCO3 +8 +/- 2 (winter’s equation)

Question 2

Metabolic Alkalosis Compensation equation

Answer 2

∆pCO2 = 0.7 * ∆HCO3

Question 3

Acute respiratory acidosis equation

Answer 3

∆HCO3 = (0.1 * ∆pCO2) * 1

Question 4

Chronic respiratory acidosis equation

Answer 4

∆HCO3 = (0.1 * ∆pCO2) * 3

Question 5

Acute respiratory alkalosis equation

Answer 5

∆HCO3 = (0.1 * ∆pCO2) * 2

Question 6

Chronic respiratory alkalosis equation

Answer 6

∆HCO3 = (0.1 * ∆pCO2) * 5

Question 7

pH change for each 10 of pCO2

Answer 7

0.08

Question 8

Anion Gap equation

Answer 8

Na - (HCO3 + CL)

Question 9

Albumin correction of anion gap

Answer 9

4 - (measured albumin) x 2.5

Add result to measured anion gap

Question 10

Delta ratio equation

Answer 10

∆Anion gap/∆HCO3

Question 11

Delta ratio < 0.4 indication

Answer 11

Hyperchloremic NAGMA

Question 12

Delta ratio 0.5 - 1.0 indication

Answer 12

HAGMA +/- NAGMA (usually ketoacids)

Question 13

Delta ratio 1 - 2 indication

Answer 13

HAGMA only (usually lactic acid)

Question 14

Delta ratio > 2 indication

Answer 14

HAGMA + metabolic alkalosis or compensated respiratory acidosis

Question 15

Osmolar gap formula

Answer 15

(2 x Na) + (glu/18) + BUN/2.8 + (ethanol/4.6)