CARDIO: ABGs Overview

Question 1

ABGs Normal Values

This is the general way to approach an acid-base disturbance. They’re not really as bad as they seem at first. You just need to remember that **CO2 is acidic **and HCO3- is basic. So an increase in CO2 makes the body acidotic and an increase in HCO3- makes the body alkalotic.

It’s also good to remember to calculate the anion gap when doing these calculations.

AG = Na – (Cl- + HCO3-) it’s just the cations minus the anions. If this gap between the cations and anions is large, it means that the anions are stacking their team and have an extra anion helping out.

The classic mnemonic is MUDPILES

Methanol
Uremia
Diabetic ketoacidosis
Paraldehyde
Isopropyl alcohol
Lactic acidosis
Ethylene glycol
Salicylates

If the anion gap is big, it’s good to look at the ratio between the change in the gap and the change in the HCO3-.

Increase in AG < decrease in HCO3- = coexisting non-anion gap metabolic acidosis
Increase in AG > decrease in HCO3- = coexisting metabolic alkalosis

Answer 1

This is the general way to approach an acid-base disturbance. They’re not really as bad as they seem at first. You just need to remember that __?__ is acidic and __?__ is basic. So an increase in__?__makes the body acidotic and an increase __?__ makes the body alkalotic.

It’s also good to remember to calculate the anion gap when doing these calculations.

AG = Na – (Cl- + HCO3-) it’s just the cations minus the anions. If this gap between the cations and anions is large, it means that the anions are stacking their team and have an extra anion helping out.

The classic mnemonic is MUDPILES

Methanol
Uremia
Diabetic ketoacidosis
Paraldehyde
Isopropyl alcohol
Lactic acidosis
Ethylene glycol
Salicylates

If the anion gap is big, it’s good to look at the ratio between the change in the gap and the change in the HCO3-.

Increase in AG < decrease in HCO3- = coexisting non-anion gap metabolic acidosis
Increase in AG > decrease in HCO3- = coexisting metabolic alkalosis

Question 2

ABGs Normal Values

ABG Overview

Answer 2

Question 3

ABGs Normal Values

pH

Answer 3

7.35-7.45

Question 4

ABGs Normal Values

PaCO₂

Answer 4

35-45 mm Hg

Question 5

ABGs Normal Values

PaO₂

Answer 5

80-100 mm Hg

Question 6

ABGs Normal Values

PaO2

at altitudes of 3000 ft or higher oxygen values increase or decrease?

Answer 6

decrease

Question 7

ABGs Normal Values

HCO₃^-

Answer 7

22-26 mEq/L

Question 8

ABGs Normal Values

Determining

Respiratory and Metabolic Alkalosis and Acidosis Mnemonics

Answer 8

Remember ROME = Respiratory Opposite, Metabollic Equal.