Acid-Base Disorders

Question 1

Equation for delta-gap ratios & interpreation?

Answer 1

DeltaAG/DeltaBicarb
-Lactic acidosis: 1.6:1
-Ketoacids: 1:1
(Determined by renal excretion)

Question 2

Equation for calculated osmolarity? Normal values?

Answer 2

Osm = 2*Na + Gluc/18 + BUN/2.8

-Normal gap <10

Question 3

Causes of NAGMA? (Hint: mnemonic)

Answer 3

• Hyperchloremia
• Acetazolamide, Addison’s
• RTA
• Diarrhea, ileostomies, fistulae
• Ureteroenterostomies
• Pancreatoenterostomies

Question 4

Compensation for acute metabolic acidosis?

Answer 4

Winter’s Forumla:

PaCO2 = HCO3*1.5 +8 +/- 2

Question 5

Compensation for acute respiratory acidosis?

Answer 5

Increase in HCO3 = 1* change in PaCO2 / 10

Question 6

Compensation for chronic respiratory acidosis?

Answer 6

Increase in HCO3 = 4* (change in PaCO2 / 10)

Question 7

Compensation for metabolic alkalosis?

Answer 7

Increase in PaCO2 = 0.6 * HCO3
-or-
pCO2 = 0.7 * HCO3 +20 +/- 5

Question 8

Compensation for acute respiratory alkalosis?

Answer 8

Decrease in HCO3 = 2* (change in PaCO2 / 10)

Question 9

Comepnsation for chronic respiratory alkalosis?

Answer 9

Decrease in HCO3 = 5* (change in PaCO2 / 10)