Acid-Base Disorders and Treatments

Question 1

Which buffer system is the principle regulator of blood pH?

Answer 1

Carbonic acid/ bicarbonate

Question 2

What regulates HCO3- and CO2? Which one is the acid? Base?

Answer 2

HCO3- =base regulated by the kidneys

CO2 = acid regulated by the lungs

Question 3

What is the reaction of CO2 buffer system?

Answer 3

CO2 + H2O H2CO3 H+ + HCO3-

Question 4

If pH balance is off, how can you tell if it is a respiratory disorder or metabolic disorder?

Answer 4

Respiratory -> kidneys slowly respond by increasing HCO3- if in respiratory acidosis and decreasing if in respiratory alkalosis

Metabolic -> lungs quickly respond by increasing pCO2 if in metabolic alkalosis and decreasing if in metabolic acidosis

Question 5

What are normal arterial blood ranges for these parameters?

pH   
pCO2
pO2
HCO3-
SaO2

Answer 5

pH = 7.4
pCO2 = 35-45 mm Hg
pO2 = 80 - 100 mmHg
HCO3- = 22-26 mEq/L
SaO2 = 95%

Question 6

If pH and pCO2 decrease or increase in the same direction, what type of disorder is this?

What about they changed in opposite directions?

Answer 6

Same direction = metabolic

Opposite direction = respiratory

Question 7

Describe the four disorders in acidemia and alkalemia

Answer 7

Acidemia - increase in pCO2 is respiratory acidosis
- decrease in HCO3- is metabolic acidosis

Alkalosis - decrease in pCO2 is respiratory alkalosis
- increase in HCO3- is metabolic alkalosis

Question 8

How do you assess for organic or mineral acidosis?

Answer 8

Calculate anion gap (AG)

[Na+] - [Cl-] - [HCO3-]

[Na+] + [unmeasured cations] = ([Cl-] + [HCO3-] + [unmeasured anions])

Normal range is ~10 mEq/L

Question 9

What accounts for about half of the cases of anion gap acidosis? What are the normal ranges?

What should therapy focus on?

Answer 9

Lactic acid levels

Normal: 0.5 to 2.2 mmol/L

Therapy should focus on oxygenation of tissues and treating underlying cause

Question 10

When you are acidotic, are you hyperkalemic or hypokalemic?

Answer 10

Acidotic - hyperkalemic
Alkalotic - hypokalemic

Exchange of H+ to the inside and K+ to the outside of the cell is altered

Question 11

Treatment for respiratory acidosis and metabolic acidosis?

Answer 11

Respiratory acidosis - oxygenation

Metabolic acidosis - sodium bicarbonate

Question 12

Treatment for metabolic alkalosis?

Answer 12

Chloride- rich fluids (for chloride responsive pts)

K+ repletion (for chloride resistant pts)