ABG

Question 1

What are the necessary data to gather for acid-base assessment?

Answer 1

Na’, CI, HCO3, pH, pCO2

Preferably, all obtained from the same blood sample.

Question 2

If pH > 7.4, what does it indicate?

Answer 2

The patient has a primary alkalosis

Proceed to Step 3a.

Question 3

If pH < 7.4, what does it indicate?

Answer 3

The patient has a primary acidosis

Proceed to Step 3b.

Question 4

What does pCO2 > 40 indicate in the context of alkalosis?

Answer 4

Patient’s alkalosis is metabolic

This is part of Step 3a.

Question 5

What does pCO2 < 40 indicate in the context of alkalosis?

Answer 5

Patient’s alkalosis is respiratory

This is part of Step 3a.

Question 6

What does pCO2 > 40 indicate in the context of acidosis?

Answer 6

Patient’s acidosis is respiratory

This is part of Step 3b.

Question 7

What does pCO2 < 40 indicate in the context of acidosis?

Answer 7

Patient’s acidosis is metabolic

This is part of Step 3b.

Question 8

What is the predicted pCO2 calculation for metabolic acidosis?

Answer 8

Calc. predicted pCO2 = (1.5 x HCO3) + 8 +/- 2

This is based on Step 5.

Question 9

What does it indicate if the actual pCO2 is too low?

Answer 9

There is additional respiratory alkalosis

This is part of Step 6.

Question 10

What does it indicate if the actual pCO2 is too high?

Answer 10

There is additional respiratory acidosis

This confirms findings from Steps 2 through 4.

Question 11

What indicates an anion gap metabolic acidosis?

Answer 11

AG is significantly elevated (>12-18)

AG = Na - Cl - HCO3.

Question 12

What mnemonic is used for causes of elevated anion gap metabolic acidosis?

Answer 12

MUDPILERS

Methanol, Uremia, DKA/Alcoholic KA, Isoniazid, Paraldehyde, Lactic acidosis, EtOH/Ethylene glycol, Rhabdo/Renal failure, Salicylates.

Question 13

What indicates an underlying metabolic alkalosis regarding corrected bicarb?

Answer 13

If corrected bicarb > 30

This is associated with anion gap metabolic acidosis.

Question 14

What indicates an underlying non-anion gap metabolic acidosis regarding corrected bicarb?

Answer 14

If corrected bicarb < 23

This signifies non-anion gap metabolic acidosis.

Question 15

What mnemonic is used for causes of non-anion gap metabolic acidosis?

Answer 15

HARDUF

Hyperalimentation, Acetazolamide, Renal tubular acidosis, Diarrhea, Uretero-Pelvic shunt, Post-hypocapnia, Spironolactone.

Question 16

What are some causes of chronic respiratory acidosis?

Answer 16

COPD and restrictive lung disease

Chronic respiratory acidosis is often related to these conditions.

Question 17

What mnemonic is used for causes of metabolic alkalosis?

Answer 17

CLEVER PD

Contraction, Licorice, Endo: Conn’s/Cushing’s/Bartter’s, Vomiting, NG suction, Excess alkali, Refeeding alkalosis, Post-hypercapnia, Diuretics.

Question 18

What indicates a primary respiratory acidosis?

Answer 18

Primary process is respiratory

This should be evaluated along with additional disorders.

Question 19

What indicates a primary metabolic acidosis?

Answer 19

Primary process is metabolic

This should be evaluated along with additional disorders.

Question 20

True or False: Anxiety can cause respiratory alkalosis.

Answer 20

True

This is one of the contributors to respiratory alkalosis.