Acid-Base

Question 0

What is normal pH?

Answer 0

7.40

Question 1

What four steps should be taken to assess a patient with a pH disorder?

Answer 1

1. Determine acidosis or alkalosis
2. Determine anion gap
3. Determine osmol gap
4. Determine delta gap
5. Look at history and physical

Question 2

What is the equation used to calculate anion gap?

Answer 2

[Na] - ([HCO3] + [Cl])

Question 3

What anion gap level is abnormal?

Answer 3

AG > 15

Question 4

What equation is used to calculate serum osmolarity?

Answer 4

[Na]x2 + [Glucose]/18 + [BUN]/2.8

Question 5

What is a normal osmolar gap?

Answer 5

Osm gap </= 10

Question 6

How do you calculate the delta gap?

Answer 6

Add the osmolar gap to the measured bicarb. It should equal the amount of normal bicarb (24-26)

Question 7

What does it mean if the delta gap is low?

Answer 7

Non-anion gap acidosis

Question 8

What does it mean if there is an elevated delta gap?

Answer 8

Metabolic alkalosis

Question 9

What are the potential causes of elevated anion gap acidosis?

Answer 9

MUDPILES
M: Methanol
U: Uremia
D: Diabetic/Alcoholic ketoacidosis
P: Paraldehyde
I: Iron or INH
L: Lactic acidemia
E: Ethylene glycol
S: Salicylate overdose

Question 10

What are the most common causes of an elevated Osm gap with metabolic acidosis and increased anion gap?

Answer 10

Methanol, ethylene glycol, alcoholic ketoacidosis

Question 11

What levels would you expect creatinine and BUN to be in uremia?

Answer 11

Creatinine: >5
BUN: >60
Anion gap rarely over 20

Question 12

What are some causes of lactic acidosis?

Answer 12

Sepsis, CO or CN poisoning

Question 13

How do you treat ethylene glycol poisoning?

Answer 13

medications, alcohol, dialysis

Question 14

What are some causes of metabolic acidosis with a normal anion gap?

Answer 14

HARDASS
Hyperalimentation
Addison's disease
Renal tubular acidosis
Diarrhea
Acetazolamide
Spironolactone
Saline infusions

Question 15

What do you give to someone with chloride responsive metabolic alkalosis?

Answer 15

Saline infusion

Question 16

What are some causes of chloride responsive alkalosis?

Answer 16

Vomiting
Diuretics
NG suctioning
Cl wasting diarrhea (most diarrhea causes acidosis)
Villous adenoma

Question 17

What is chloride unresponsive metabolic alkalosis usually due to?

Answer 17

Inappropriately high aldosterone levels

Question 18

What can cause chloride unresponsive metabolic alkalosis?

Answer 18

Cushings
Hyperaldo including Barter’s
CHF, CRF
Bicarb ingestion

Question 19

What is the primary disturbance in respiratory acidosis?

Answer 19

Increased arterial CO2

Question 20

What does acute compensation of respiratory acidosis look like?

Answer 20

Increase HCO3 by 1 mEq per increase of 10 mEq CO2

Question 21

What does chronic compensation of respiratory acidosis look like?

Answer 21

Increase of 3 mEq HCO3 per increase of 10 mEq CO2

Question 22

What are common causes of respiratory acidosis?

Answer 22

Airway obstruction
Lung - COPD (by far most common), Asthma, Pneumothorax, infection
CNS depression - sedatives, hypnotics, tumor
Neuromuscular weakness

Question 23

What is the primary disturbance during respiratory alkalosis?

Answer 23

Decreased CO2

Question 24

What does acute compensation of respiratory alkalosis look like?

Answer 24

HCO3 falls 2 mEq per decrease of 10 mEq CO2

Question 25

What does chronic compensation of respiratory alkalosis look like?

Answer 25

HCO3 falls by 4 mEq per fall of 10 mEq of CO2

Question 26

What are causes of respiratory alkalosis?

Answer 26

Anxiety Aspirin, drugs, progesterone Any cause of tachypnea (sepsis, fever, hypoxia) Alcohol or narcotic withdrawal